1925 Buick starter motor-generator

[KEK]

Hello everyone -

 

I have a 1925 Buck standard roadster and I want to replace the ‘plain bearing’ at the rear of the MG. There is a little slop in the armature shaft so I thought I would replace the ‘plain bearing’ with a new sealed bearing. Does anyone have a procedure to do this? There is virtually no details in the shop manual that I have. I am hoping I can replace it without removing the armature from the housing. I can move the shaft about 1/16” or more back and forth. I believe this may have lead to the failure of my sliding gear assembly so I want to replace the bearing before I put another sliding gear assembly in. Has anyone used the sealed New Departure bearing #1203 as a replacement for the ‘plain bearing’.

 

The number on my MG is 283. Hugh I believe you also have a 283 MG. Do you have any guidance or procedure how to remove and replace the bearing?

 

Thanks - Ken

 

 

[Hubert_25-25]

Ken, 

   Just to clarify,  The ball bearing is on the front and a bushing is used on the rear.  The ball bearing is pushed into the housing.   I have an SKF ball bearing in mine.  Looks like an SKF 6203.  The bushing is in the rear bearing holder which can be removed from the starter generator.  There is a wear sleeve to protect the armature.  I stayed with the bushing on mine but I did not have a lot of play either.  There are likely a lot more bearing options available now.  Attached is a link to a copy of my starter generator rebuilding procedure.    I do have a rebuilt spare 283 SG unit for my car, and a very rusty one that I am trying to pull apart for additional parts.

 

Edited February 3, 2020 by Hubert_25-25 (see edit history)

[KEK]

Hi Hugh - I think the bushing is what the manual calls the ‘plain bearing’. Thats the one that is worn and I want to replace with a sealed bearing. Can I remove the rear bearing holder and bushing without removing the starter MG from the car? Probably not but I thought I would ask since I have never had one of these off before. Thank you for the link to your rebuilding procedure. It references a ‘starter generator removal procedure”. Can you tell me how I can find the starter generator removal procedure?

 

Thanks - Ken

[Hubert_25-25]

Ken, 

    This is the starter generator removal procedure from the shop manual.  I would suggest setting the engine on TDC #1 first.  Watch the rotor.  It should be pointing at #1 on the distributor cap when you are on the 0-6 line on the flywheel.  Actually your car may be on the 7 degree line  when pointing to the #1 spot on the cap.  Do you think you will be able to remove the tapered pin and do you think the drive coupling will slide forward?  The side of the taper pin with the slot is the narrow end, and that is the end that you need to tap on to drive the pin out.  You will need to remove the SG unit to replace the rear bushing.  Hugh    

Edited February 3, 2020 by Hubert_25-25 (see edit history)

[Oregon Desert model 45]

Ken

The bushing is completely trapped until S-G unit has been removed from the car and end cover removed.  Old bushings will have to be pushed out and new bushings pressed in.

In front of the pictured end cover is a new bushing, and visible down inside the hole are the old bushings (there are 2).

To replace this bushing (should cost under $20) with a bearing would require a new re-engineered casting with more material to support a larger bearing OD, and could cost thousands after casting and machining.   The old bushings worked well for 90 years.

Kevin

[KEK]

Hugh - thanks for the procedures. I hope I can drive the pin out. I am going to tackle it later this week. I am a little intimidated by having to remove the armature. I’ll take my time and carefully follow the procedure but sure hope I don’t damage the 95 year old girl.

Kevin - thanks for the pics. Sounds like I need to find new bushings. Do you have any idea where I can find these?

 

Ken

[Hubert_25-25]

Ken, 

    In the long run, you will want to be able to drive the taper pin out and slide the generator coupling forward so that you can remove the SG unit without removing the water pump.  Even to remove the water pump in the future and not have to remove the SG unit first, the coupling needs to be able to slide.    Since your motor turns over, I would start with rotating the water pump shaft where the split in the pin is on the top side.  See if the taper pin will drive down.  You could consider using a center punch on the pin and drilling it out first to 3/16" or just under 1/4" to help with removal of the pin.  It will likely take a near 1/4" punch and a hand mallet.    

Once the pin is out, the next step is to see if the coupling will spin on the shaft.   If you can not get it to spin, you will not get it to slide forward.  To get it to spin, you will need to use something like vise grips or a pipewrench on the water pump shaft while you try to spin only the coupling.  The point is that you have to prevent any torque to the gear on the front of the shaft so the shaft has to be held steady.  If the coupling will not spin, we should discuss another plan.   

On the 1925 Standard, I think you have to remove the rear bearing support to allow room for the coupling to slide forward.  You will do this after you know that it spins.  When this coupling goes back on, the shaft and coupling hub need to be cleaned with sandpaper and both lubed with neverseize on reassembly.

 

It is possible that if you remove the starter pedal assembly (held on with 4 bolts on the top of the bell housing), that this will allow enough room for the SG unit to be removed without getting the coupling to free up.    

 

McMaster Carr sells bushings.  I would suggest Oilite for this application.   They also sell #4 taper pins.  I bought mine in stainless.  

 

By the way, I do create punch mark parts or use an engraver on the parts, and when I put these back together I do not have to retime the engine.  Not the end of the world but it does save time.  

 

Hugh

[Oregon Desert model 45]

Ken

removing the armature is not the tricky part, in fact it does not even need to be pulled out at all.  While the rear housing is removed, carefully pay close attention to these items:

1.  there is a jumper wire or 2 that need to be disconnected;

2.  first photo, red arrow- this spring loaded fork sits in a slotted insulating wheel. THIS MUST BE LIFTED OUT OF THE SLOT or else it gets bent.

3.  the copper brush (second photo red arrow) could get caught if the commutator is deeply worn, lift this up and put a piece of plastic or something under it so it does not catch. if it does get caught, the arm it is attached to will get bent. (I made this mistake)

If either part gets bent, its not that difficult to bend them back so that brushes line up with their respective commutator.

There are 2 insulated roller wheels that are often cracked and brittle or already broken.  I had to make new rollers using a metal lathe for my S-G.

Kevin

[KEK]

Hugh -  Do you know the specs for the bearings? ID, OD, length? Do you know if both bearings are the same dimensions. McMasters is a Business to Business so I cant buy from them but there are other places I found on the internet that sell bearings.

 

Kevin - those photos and instructions are terrific. I came to that conclusion that I didn’t have to remove the armature after re-reading the posts. I think I can do this without damaging anything with the help of you ‘lessons learned’. I have a good set of bearing drivers which should make the task easier.

 

Ken

[Hubert_25-25]

Ken, 

   I order little stuff from McMaster Carr all the time.  I don't know if I made up a company name or not.  I will have to break down my rusty SG unit to get bearing dimensions.  I have been meaning to pull it apart.  

 

Kevin makes a good point about the insulators needing replacement.  It's a 90 year old unit and worth going thru to clean and use new grease in it and inspect the insulators and the insulation.  Also a good time to clean up the commutator when it is out.    

 

Keep in mind that many of the screws have special threads.

[Oregon Desert model 45]

When I bought bushings, they came in a pack of 3. That leftover bushing measures 7/8 ID x  1-1/16 OD x 1 length. OD is +.003 oversize so it measures 1.0655.

It has been around 5 years since I replaced these bushings, and I don't recollect if I had to turn down the OD or if it fit the housing bore without modification.

Remove your bushings and get actual measurement  before ordering.  

Atlasbronze.com has 7/8 x 1-1/16x 1 bushings

Hugh is right about the screws. check screws with a thread gauge before replacing or chasing threads with tap or die. They are non-standard sizes.

Kevin

 

Edited February 4, 2020 by Oregon Desert model 45
edit (see edit history)

[KEK]

All good advice. I will check the insulators and clean everything up and grease while I have the M/G out.  Now that you mention it I do remember hearing that some of the screws used different threads. I think the thickness of the thread is greater than the modern threads, but that’s just from what I remember, I really don’t know how to tell the difference. Anyway thanks for the reminder. So many things to keep track of and to be careful about... I am going to pull the M/G out tomorrow and I am sure it is going to go well thanks to all your help.

 

Ken

[KEK]

I got the the pins out, the Oldham coupler and even took off the water pump but I can’t get the starter MG out because the operating pin that raises the brushes is connected to a shaft in the bell housing. The shaft in the bell housing has the fork for the sliding gear assembling. I can’t get the two shafts to disengage. 

 

I found a spare operating shaft in some of my Dads parts and provided a photo for you to see what I am talking about. However, I don’t know if this is an operating shaft for a 1925 standard. The pointed end goes into the MG and lifts the brushes when you step on the starter pedal. The other end is just a little bit smaller diameter than the rest of the shaft. That smaller diameter fits into the bell housing. The second photo shows the end of the operating shaft in the bell housing and if you look close you can see a little bit of the other shaft. Does anyone know how to disengaged these two shafts? What is the purpose of the 1/2 inch or so grove at the end of the operating shaft in the MG that you can see in the first photo? Does this grove have something to do with how it is connected to the other shaft in the bell housing?

 

Ken

[Hubert_25-25]

Ken, 

    The shaft with the pointer does not need to be removed to get out the starter generator.  I can see that you have removed the starter pedal cover.  You should be able to slide the pointer to the rear of the car.    Someone made that short pointer.    Hugh

[KEK]

Hugh -

 

That is a relieve to know the shaft doesn’t need to come out to remove the starter MG. I haven’t removed the bottom 3 bolts yet on the MG because it looked to me there wasn’t enough clearance to get it out and I didn’t want to get it out part way and have the weight of the starter put leverage on the shaft and crack the bell housing. I will have more confidence to try to remove it on Friday now that I know it should come out. 

 

If the shaft is one piece then if I ever need to replace the fork I will have to remove the starter again. Correct? Thanks for the photos that helps a lot.

 

Ken

[Hubert_25-25]

Ken, 

   You should never have to replace the fork.  If you did, the SG unit would need to come out.  See the lubrication photo as this is all you need to do with it.  Easy to pull it out now and clean the shaft and the hole and put fresh grease or oil on the slide.  Those 3 lower SG bolts are all that is holding the SG in.  Note that 2 of the bolts have a removeable cone on them (under the bolt head) for centering.  The SG unit is 60 lbs and clumsy.  I have hooked up a means to use a lifting handle as well as others.  The attachment could be low, so just make sure it is stable when you lift it out as it is top heavy on my attachment points but I have something to grab.     Hugh

 

Edited February 6, 2020 by Hubert_25-25 (see edit history)

[KEK]

Hugh - That handle is a great idea. I am going to rig something like that up. I will have a friend with me and he can steady the MG while I lift on it. I noticed in one of your pictures that the distributor is off. Do you think I should remove my distributor do give me more room to move the MG forward? I already have the water pump off.

 

Ken

[Hubert_25-25]

Ken,  You should not need to remove it, but this is your opportunity to remove all the old grease in all the parts and reapply.  Also, is your distributor housing pot metal or steel.  Use a magnet to check.  If it is pot metal, you will want to replace it.  I do have an extra steel one.  These pot metal ones freeze in the housing bore and then you are not able to adjust the timing.      Hugh

[KEK]

Hugh - I really don’t know if the distributor is steel or pot metal. I’ll check it on Friday, I think I’ll remove the distributor so I can clean and grease the clutch.

 

Ken

[KEK]

Hi Hugh -

 

I got the starter out with no issues. It looks good with new wiring and rollers. I cleaned it up a bit and put on the new sliding gear assembly, a new pinion gear and then back in the car. The fork looked good. All that is left is to make a few gaskets and replace the water pump and retime.

 

I also removed the distributor and cleaned and greased it before replacing. It also looked good. I used a magnet to test the metal and it looks like the upper is pot metal and the lower is steel. I remember the when it was running I could change the rpm by moving the spark lever up or down. How can I tell if the distributor is mechanically advancing and retarding the timing when it is running?

 

Ken

[Hubert_25-25]

Ken, 

     That is good to know that you located a replacement sliding gear assembly.  I am still trying to locate a pinion gear for my spare starter motor myself.    

 

You have both mechanical advance (the distributor body rotates by movement of the spark advance lever on the steering column), and centrifugal advance (there are 3 weights under the breaker plate that rotate out as the rpm increases).  If you hold the distributor gear and turn the rotor clockwise, you should feel spring tension pulling the rotor back.  If you have the distributor out, it would be a good time to lubricate the pivot points of the spring bases and the weight rivets.  These never get oiled and they could likely use a few drops.    You should feel the rotor spring back if it is working properly.    Hugh

  

[dibarlaw]

Ken:

Comparison of the 2 distributors

 On the left is my rebuilt cast iron unit. On the right is the cobbled up die cast unit that was in my car when I bought it.

Notice how the cast center bearing section was replaced with this turned solid piece. NO access for grease as there was in the original design. The shaft had a large amount of play. The final fit spacing was handled with a stack of copper crush washers. The spark adjustment plate was held on with peined over 1/4-20 screws

If I had the engine running I could just put a bit of finger pressure on the side of the housing and stall the engine. Also the mechanical governor had one spring missing and one disconnected. 

For the life of me I have no idea how the engine ran at all!

[Brian_Heil]

Rev engine with a timing light hooked up to see if advance mechanism is working 

 

 

[KEK]

Hugh -

 

That is quite the difference between your distributors. Someone spent a lot of time and effort trying to get that die cast back to original specs. I find it amazing how much ingenuity went into keeping these cars going with limited resources back in the day. I restored an original 1929 Ford Model A that had about 80,000 miles on the odometer. I bought it from a ranching family who purchased it new in 29. Some of the things I found that they must have done during the late 30s when life was so hard then to keep the car running. For example I found a bushing in the steering column they made with a beer can. The front tie rods were held together with bailing wire! Just unbelievable.

 

I pulled my distributor out of the car and posted a few photographs. The centrifugal advance appears to be working. I could feel the spring tension when I rotated the rotor. The shaft feels tight with very little play. I haven’t checked to see if all 3 springs are present. Do I need to drive the pin in the lower shaft off to remove the gear to pull the shaft out of the housing to check the springs. Can you tell from the photos what type off points are installed. I dont know what to look for if I need replacements. Do you think it would be wise to upgrade to the steel distributor.

 

That sounds like a good idea to hook up a timing light. I can see the 7 degree mark on the flywheel and there is a reference mark on the bell housing. Seems like I could hook up my light using a 12v battery to check the timing and centrifugal advance. Have you used a light to time your 25?

 

Ken

 

[Hubert_25-25]

Ken, 

   The good thing is that someone upgraded your points to inexpensive readily available points.  Hopefully you can find out what they match and get a spare to keep with the tool kit.  I am going to post some distributor rebuilding information for you.  Your distributor is pot metal, but it looks like it has not self destructed yet.  While they are still around, If it were my car, I would look for a replacement steel distributor housing.   

 

Undo the bottom bolt that holds the gear.  Do not hold the shaft from turning using the rotor.  Remove the 2 screws that locate the distributor cap and all the internals will come out the top.  

Hugh

 

 

Edited February 10, 2020 by Hubert_25-25 (see edit history)

[KEK]

Hugh -

 

Thank you for posting the distributor rebuilding information. I am going to get to that in a couple weeks after I return from an out of town trip.

 

On setting the timing the procedure says to raise the spark advance lever all the way up. On my car raising the lever will advance the timing and lowering the lever will retard the timing. I thought you fully retarded the timing on these old cars not advance the timing? That is how I time my model A by retarding the timing. However on a model A you raise the lever to retard and lower to advance. Just the opposite of the Buick...

 

Did you set your timing at the 7 degree mark?

 

Ken

[Hubert_25-25]

Ken, 

    Thanks for pointing that out.  The person that owned my car before me was a Model A person, and he flipped the lever arm that is over the starter geberator so that the spark lever worked in reverse (Like a model A).  I have corrected the text.  

 

Regarding setting my timing, I went between the 7 degree after mark, and the 1-6 line.   It advanced it a few degrees, and I feel I could still hand crank it when necessary.  I tried my car at the 7 degree before spot for full retard setting, but I could not tell any performance difference.  Others say they can tell a difference.  

 

Hugh

Edited February 10, 2020 by Hubert_25-25 (see edit history)

[Hubert_25-25]

Ken, 

    This is some timing and tune up information that you may find useful.  They did not have dwell meters and timing lights back in the day, and I have not seen any early work using vacuum gauges and compression testers either.  This is how I set my timing and I did use a vacuum gauge to improve the performance as well.  It is interesting how carburetor setting and timing will effect the vacuum.   Hugh

 

 

Edited November 6, 2023 by Hubert_25-25 (see edit history)

[KEK]

Hi Hugh -
 

I removed the distributor shaft from the body and the 3 centrifugal springs on the bottom of the plate look new. I noticed that the inside of the distributor body had been repaired with what looks like epoxy. I don’t know why it needed to be repaired but the pot metal probably was cracked or something like that. You mentioned that you have an extra steel distributor. I am interested if you are willing to sell it. Please let me know.

 

Great information on timing you posted above. That’s my next step later this week.  I plan to time my 25 the same as you did yours. That is a few degrees advanced. Before I pulled out the distributor I checked the timing and it was also set a few degrees advanced so I am going to return it to the same timing. I live in Colorado at 4500 ft and a few degrees advanced on my other cars works good.

 

My compression for 5 out of the 6 cylinders range from about 65 to 68 psi. One cylinder is at 60 psi but this engine is new and the rings have probably not seated completely yet. 

 

My manifold vacuum is around 15 to 16 in Hg. My vacuum gage indicates a healthy engine should pull about 20 in Hg at sea level. Since atmospheric pressure is about 30 in Hg at sea level and about 25 in Hg at 5000 ft I need to adjust my gage readings by about 1 in Hg per 1000 feet of elevation. At 4500 ft in elevation where I live a healthy engine should be about 15.5 in Hg (20 - 4.5). 

 

I found that adjusting my fuel mixture screw about 3/4 of the way open and my air adjusting valve flush with the end of the housing provided the best tune. This is exactly how you have yours set also. That gives me a lot of confidence I am on the right track. 

 

How important do you think it is to check the dwell? I dont see any obvious way to adjust the dwell if I need to.

 

Edited February 23, 2020 by KEK
Corrected atmospheric pressure at 5000 ft to 25 in Hg (see edit history)

[Hubert_25-25]

Ken, 

   Adjust your points with a feeler gauge.  If it looks good, put a dwell meter on it for reference only.  Then it is an easy check if you just want to see how the points are doing in the future.  Sounds like the motor is pretty healthy.   I will PM you regarding the distributor body.   Hugh

[KEK]

Hugh - When I tighten the special bolt with the spring that holds the distributor down I can rotate the distributor 20 degrees but it hangs up and is hard to rotate in one place. If I back the bolt out 1/2 turn then the distributor rotates freely. It seems to me this bolt should be tight so it doesn’t loosen up and fall out. Do you tighten this bolt down tight or is it designed to be backed out a little?

 

PS- I meant to say that atmospheric pressure is 25 in HG at 5000 ft (not 20 in HG). The calculation is correct that you need to adjust your vacuum gage reading approximately 1 in HG per 1000 ft of elevation. I don’t know how to revise my post above so I thought I would mention this so as not confuse anyone.

 

Ken

[Hubert_25-25]

Ken, 

       You can revise your postings.  I do it all the time.  Lots of knowledgeable folks on this forum and I find a need to correct what I say so that it does not get etched into history.  There is an Edit and a save button for each posting.  

 

The bolt is designed to be tight.  If you remove the spring, there should be .145 distance between the end of the threads and the bottom of the outer barrel.  

- Make sure the spring is not hanging up on the bottom shoulder of the bolt and preventing the barrel from moving.  

- Once assembled, you should be able to move the barrel "up" just a little and you should hear it spring back.  If the barrel will not move up, maybe you need to remove a small amount off the top of the barrel.

- I am wondering if someone drove the screw in so far that the shoulder is rounded and the screw is sitting lower than it should be.

 

By the way, if anyone has an extra one of these hold down bolts with the barrel , I could use a  better one.   This came off a spare rusty Starter Gen.  I could give you this old one too if you needed it for an exchange.   It still works, it just won't win any beauty contests.      Hugh

[KEK]

Hugh - I see my problem. My screw doesn’t have the barrel. I will take a photo of mine tomorrow when I go out to the shop.

[KEK]

Hugh - Here is a pic of my special screw that holds down the distributor. Apparently it does not have a barrel like yours. If I put the washer below the spring then I can tighten the screw all the way down and the distributor rotates freely. Problem solved!

 

I have a question about your stop light. Mine is mounted on the rear by the spare tire. See photo. I cant find a brake switch. Does your car have a brake switch somewhere that closes the circuit to illuminate the brake light or is this just a running light.

 

Ken

 

 

 

 

[Hubert_25-25]

The brake light is only a running light in 1925.  I will send you my turn signal and brake light stuff when I get back to my computer.  

[KEK]

Hugh -

 

That’s what I thought- just a running light. Look forward to seeing what you did.

 

Do you know if there is a way to align the pinion gear on the starter with the sliding starter gear? I don’t know why my sliding starter gear teeth were damaged and if I can’t figure out why the same thing will happen with my new gear. All the bushings seem tight. I need to do a few more tests but it seems like the starter gear and pinion gear may be binding a little bit when it first engages. So the only thing I can think of is try and align the gears but it doesn’t.t look like there is a way..

[Hubert_25-25]

Ken, 

     Someone put the wrong gear on my starter generator and I could not get mine to mesh.  Start with verifying this gear.   OD  and teeth.   The Master has 1 less tooth and it fits the same size shaft.  There really is no adjustment.    Also here are the two links to the brake light installation and the turn signal addition.      Hugh

 

https://forums.aaca.org/topic/337485-brake-light-installation-mid-20s-buick/?tab=comments#comment-1968834

 

https://forums.aaca.org/topic/337486-turn-signal-addition/?tab=comments#comment-1969695

 

 

 

Edited February 23, 2020 by Hubert_25-25 (see edit history)

[KEK]

Hi Hugh -

 

Thanks for the tail light installation instructions. I have a Model A brake switch that I think I can make work like you did yours. I appreciate your help.

 

I didn’t think there was anyway to align the motor generator but I thought I would ask you just in case. The pinion gear that was installed on my 283 motor generator was the smaller 13 tooth when the sliding gear assembly broke.  I also have a larger 12 tooth master pinion gear that I was able to compare against. When I found a replacement sliding starter gear assembly I also got another 13 tooth pinion gear for the 283. It looks the same as the other one I have. I will check next week to see if the gear matches the dimensions in your drawing but I am fairly confident it is the correct pinion gear.

 

I just can’t figure out why the larger starter gear on the sliding assembly was damaged. I checked all the bushings on the bell housing and starter and they all appear fairly tight.  Although I don’t know what the tolerance should be. Not a lot of movement. Some clearance as you would expect but not a whole lot.

 

The pinion gear on the starter looks good with little sign of wear as does the smaller flywheel gear on the sliding gear assembly. The only gear damage is to the larger starter gear on the sliding assembly.  The damage to this gear is at the front where it engages with the pinion gear. I attached a photo so you can see where the damage is. The height of the gear is not changed. The damage is on the front edge of the gear and looks like a “C” shape. This is the location  where it first engages with the pinion gear and the damaged area is the same cross-sectional shape as the pinion teeth. So it looks like it is was not properly engaging at the beginning of the process but after the gear is engaged approximately 1/4 ithen all works good.

 

I replaced the damage sliding assembly with my replacement. I turned on the ignition and the starter was ‘motoring’ properly but when I depressed the starter pedal the assembly engaged but did not turn over the motor. I immediately released the pedal. I then put the damaged sliding assembly back on and the motor turned over. So why would an undamaged assmbly not work but the damaged assembly work.... I was thinking that the clutch may have something to do with it even though both assemblies had been disassembled and the clutches cleaned and lightly greased. So I replaced the clutch in the undamaged assembly with the clutch in the damaged assembly.  Tried to start the car but it still would not turn over the engine over with the undamaged gear. I don’t know what else to do. Any ideas?

 

Thanks- Ken

 

 

[Hubert_25-25]

Ken,    

   Wondering if perhaps you have a Master sliding gear.  We need to make sure on the teeth count and the diameter.   Also wondering if you can assemble the sliding gear one way clutch in the wrong direction.  I would keep the battery disconnected from the starter generator until you get the mesh issue worked out, otherwise you may grind off more teeth.  Remove the starter pedal assembly so that you can work the starter slide by hand.  It should line up easily and you should be able to engage it easily by hand.  Here is a photo of my sliding gear.   It could also be that someone used the Master pinion gear and messed up the sliding gear and now you have to fix everything.   Hugh

  

 

Edited February 23, 2020 by Hubert_25-25 (see edit history)

[Hubert_25-25]

Ken,   This is note number 2.  Do you have the 2 cones that hold the starter generator?  Are they concentric and not some oddball something that someone put in there.  The photo with the bolts has them in the right places.  Is the ground between the SG unit and the block clean.   Hugh