How to remove totque tube?

[70sWagoneers]

1937 Buick Special 40

 

How do i seperate the torque tube from the diff carrier? I believe i need to change my pinion bearings. Also, what is the chance that the drive shaft itself could be bent. The shaft that sticks out the front of the torque tube wobbles in it's hole when I spin it.

Thanks

James C

 

[DonMicheletti]

The outer tube cannot be removed from the pumpkin. They are pressed and riveted togethetr.

To get the torque tube assembly out of the dif housing you have to pull the axles first. To do that you have to remove the spider hear pin and block. Push the axles toward the center and remove a "C" clip on the axles.

Once out to get the pinion and drive shaft out, you have to remove the ring gear carrier. Then remove the 3 bolys with nuts you see and then the driveshaft / pinion assembly will come out. You can then check the bearings. Watch out for the shims between the front pinion bearing outer race and housing bore - they are important to maintain pinion position.

 

A little wobble at the end of the driveshaft at the trans is permissible. An actual bent driveshaft is unlikely.

[kgreen]

"A little wobble at the end of the driveshaft at the trans is permissible. An actual bent driveshaft is unlikely."

 

That is correct.  The front of the drive shaft is supported by a bushing at the end of the torque tube.  The configuration is thus: the drive shaft inserts into the universal joint which is supported by a bushing at the tail end of the torque ball.  It is not supported within the torque tube.  The photo below is of that bushing:

Edited September 7, 2018 by kgreen (see edit history)

[DonMicheletti]

The wobble is supposed to be measured at 1-1/2" behind the weld on the actual driveshaft tube. Max runout is .010". That cant be measured with the driveshaft and pinion in the housing of the torque tube.

A fairly worthless specification since the only way to measure it is when everything is totally apart..

 

[kgreen]

The other way to measure it is to allow a max of 0.006" clearance  between the bushing and the u-joint, then hope

[70sWagoneers]

Okay. So the pinion bearings are pressed in from the back?? Whats the best tool you would you use to pull them out (without destroying them)? One of those slide hammer bearing puller kits or what? 

The plot thickens....

 

Thanks

James C

 

 

[Terry Wiegand]

YEP!?

Terry Wiegand

 

[DonMicheletti]

The pinion bearings are not pressed in. There is a cage between the front double row bearing and the back roller bearing. Once you have the carrier out of the differential, take those 3 screws with lock nuts out - they hold the cage  and front bearing in place. Once the screws are out the driveshaft and pinion assembly will slide out. It mak take a  couple of blows on the trans end of the driveshaft to break it loose - protedt the end with something.

This is how it looks, those screws go into those holes you see.

 

I got a surprise to find that my pinion shaft had been welded to the driveshaft!  I was converting it to 3.9-1 gear ration.

[DonMicheletti]

Actually, the double row bearing is toward the FRONT and roller  toward the BACK. Note the shims behind the double row bearing at the front - critical.

[70sWagoneers]

Thanks Don. You've explained it better than the manual and in much fewer words. I'm sure I'll have more questions as I dig deeper.

Thanks

James C

[DonMicheletti]

Have Fun !!

 

I really need to check my spelling better.

[Mark Shaw]

Don,

     I'll bet that cork gasket made a difference in the pinion engagement too.

[DonMicheletti]

???  The cork gasket was for the rear cover.  Am I missing something?

[Mark Shaw]

10 hours ago, DonMicheletti said:

???  The cork gasket was for the rear cover.  Am I missing something?

No, just me...

[70sWagoneers]

So, there is no pinion preload setting, but only a pinion depth setting. Does anyone have any spec range for side bearing preload?

Thanks James C.

[Bob Engle]

I've always adjusted for zero clearance.  Put a dial indicator on the ring gear and gently pry in each direction.  When it doesn't move  the pointer, you're set right.  The bearing caps must be torqued to check this.  

 

Bob Engle

[Bloo]

For what it's worth, the 42 shop manual is online and often goes into more detail than 1937. The axle is very similar to 37.

 

http://oldcarblog.com/manuals/1942/Buick shop manual/05-Rear Axle/page1.html

 

Side bearing preload and backlash is on image 9 and 10.

 

The reason there is no pinion bearing preload setting is that the fore/aft movement of the pinion is controlled by the front (ball) bearing. It does have preload, but it is internal to the front bearing. Both preloaded bearings are in the ball bearing assembly. If worn, the front bearing assembly must be replaced.

 

[DonMicheletti]

The pinion location is determined by the shims between the bottom mof the bearing bore and the bearing. The bearing is forced against the shims via the 3 bolkts that hade tapered ends, pushing against the 3 holes that are in the spacer sleeve between the 2 pinion bearings.

I felt that it was a royal PITA to set up with the shims.

 

[70sWagoneers]

How does one seperate the driveshaft from the pinion shaft, after i pumched out the pin of course? I dont have the factory tool but i do work in a fabrication shop. So I need some ideas.

Edited September 11, 2018 by 70sWagoneers (see edit history)

[DonMicheletti]

Getting the pinion out of the driveshaft can be difficult.

I just grabbed the end of the driveshaft where it is welded and strong in a big vise and just drove the pinion out using a brass drift and a BIG hammer.

I was careful not to damage anything and was successful. It wasnt pretty.

[70sWagoneers]

So you hammered on the bearings toward the pinion? I grabbed the pinion nut in the vise and "tapped" on the driveshaft while i pulled on it and nothing. Im thinking mine also need some heat. Don, yours may have been welded on there because someone thought it was loose. Did yours have a pin re-installed?

Thanks

James C

[DonMicheletti]

There was a pin - doing nothing.

The rerason it was welded is that after I ground the weld out, I could pull that pinion out by hand. Somehow the splines had become wallowed out and were very loose. That is why the welding.

 

I didnt hammer on the bearings but on the back of the piion gear with a brass drift. That was with my spare.

 

Heat wouldnt hurt anything I dont think if you dont go crazt.

 

Why are you taking it apart? Bad bearings?

 

I might mention. When I had the torque tube assembly out, there was quite a bit of wobble at the end of the driveshaft, However there was no vibration when the car was driven.

[DonMicheletti]

If you look closely at the spiline on this, you can see the spline wear.

 

I wondered how it might have happened since the spilnes are supposed to be tight

[70sWagoneers]

Mine was put together real well! After a couple of sessions of propane and a brass drift i switched to oxy acetylene. I hung the assembly from a forklift with the pinion up and a brearing seperator against the shoulder on the nut. Eventually I started to manually slam the driveshaft downward after i heated the driveshaft splines almost dull red. I went ape on it. The nut is toast so if anyone can recommend a good replacement or the correct search terms please let me now. And perhaps torque specs. But Ive got the bearings off!

Thanks everyone

James C

Edited September 14, 2018 by 70sWagoneers (see edit history)

[DonMicheletti]

Good you got it apart, sorry you had such a topugh time.

 

 

[Krugie36]

Hello James,

I purchased a Pinion Bearing Nut a few years ago for my 1936 Special from The Buick Farm.  They may have one for your car.  You should make measurements and take descriptive photos of your original, because the first one they sent me was incorrect.  After giving them a good description of mine, they sent me the correct one.  Good luck.

 

Les

[Jim Nelson]

The pinion bearings are set by the nut at the front of the pinion assembly.  I’ve been down this road before.   The main thing is to see if the bearings are bad.   The ‘37’ has a roller bearing next to the pinion gear. (Not ball bearing as in earlier rear’s). If you find its noisy and its not the outboard axel bearings.  Those are never looked at after leaving Buick.  Nuff said on those.   Relativly eary to change when youtake the rear apart.  First,  you need to remove the axels by opening the pumpkin.   If you have never done this, its not rocket science.   Obtain a newer service manual and study the proceedure.   I personally have a ‘35’, ‘36’, 38’ 47’ and ‘54’ service manuals.   Ya, I read alot to find out what it takes to keep them running.   After pulling the axels,  you loosen one side of the ring & arrier.   This is to let you return it when reassembly.   After removing the ring gear unit you are looking at the pinion gear.   In one of my newer manuals it tell’s you how to check the rear pinionbearing for unacceptable wear.  I remember it only allows .0005 to 0015” vertical movement of the pinion gear.   If more than that,  the front bearing is also worn and both need tobe replaced.   Then you remove the screws up front that will allow you to pull the coomplete assembly / drive shaft back to the pinion gear out the back of the pumpkin.   More details but you get the picture.   If you need any info, I will help as best I can.  Oldbuickjim@gmail.com.      1938-46s and 1935-58 Vickey insanity—-

[Jim Nelson]

The old timers had a method to fix the worn spline.  As I remember,  they would clean the spline realwell.   Then with solder cleaning acid. Heat the spline enough to melt the solder.  Apply a coat of solder on the spline and then press the spline into the female fitting.  Resulting spline was tight again.  Their comments were that many years later, they were able to check the tighten of the repair.   All were like new.   So, having a small coating of solder on the spline works.  

[70sWagoneers]

Ive almost got everything ready to reassemble. Any advice on the 3 set screws that lock the pinion collar in place? Im guessing the tapered part of the screws pushes the pinion collar forward and i just tighten all 3 evenly until "snug".

Thanks

[DonMicheletti]

You have the right idea with the screws. NBo adjustment there, just tighten.

Be sure to clean the threads and apply some sealant, otherwise you will most likely have a lleak

[Jim Nelson]

If you have a '38' or later service manual, they tell you how.   Other  later service manuals work.   The first thing is to put the double row ball bearing on the front of the pinion shaft.  You then screw on the front nut and torque it to  -  I believe about 130#' to 140#'   That sets the bearing.   Then clean up the shims so they are clean.   Those shims set the position of the pinion gear against the ring gear.   Install the shims back into the  housing with a bit of oil to keep them from moving.   Then you slip on the pinion collar and follow it with the rear roller bearing.   Now this is important - you NEED to have the assembly spacer ring that keeps the roller bearing forward as you push the assembly forward into the carrier housing.   Also, twist the pinion collar to ALIGN the holes on the collar with the three screws in the carrier housing as you push it together.   If you don't get them aligned as you get it together, the holes in the spacer won't align with the holes where the screws are inserted.   If you are close, you can move the pinion collar by sticking a small screw driver in the hole to make sure they are aligned.    As you put the three screw in, they will provide the final alignment.  The service manual tell you how to sequence the three screws  -  tighten them correctly.   You will not be able to move the collar (rotation wise to align with the three screws)) once you start pushing it together.  Been there / done that, redone that again - - duh !    You need to use the spacer (C-shapped) to keep the roller bearing forward as you push it all in place.   After you have pushed it in place, you remove the instillation spacer and its sone.   NOW I remember - there may be a spacer ring between the pinion gear and the roller bearing to keep the roller bearing from moving rearward and touching the gear.   So sorry if my memory is not all there,  I am suffering from 'old timers' so I use my service manuals.   This should give you a good run at it.     Then you need to put the drive shaft back on the front of the pinion shaft.   I used teflon paste to lubricate the male spline for assembly.   Do it slowly to get the cross pin hole aligned.   I went to my favorite machine shop and played it on their metal bench.  Fixed the transmission end to a non moveable block ? and then used a screw jack on the pinion gear (with an aluminum block to protect the gear.   Slowly pressed / moved the two parts together until the cross pin holes aligned and then put in the cross pin.   Now yo can use any (?) 1/4" bolt for this function.   I used a grade 5 NF bolt and a lock washer to keep it together.   Being a nut about balance,  I matched the head of the bolt with a regular washer to try to keep the same weight at both ends of the bolt.   Works.  If you have a drive shaft shop close by, you can then take the complete assembly there and have them balance it perfectly.    A great way to finish up a part that you will not be able to do easily in the future.    Read you service manual to see if I forgot anything.   By the way,  "Dr Earl"  the moderator on these forums,  has the spacer assembly ring and the very important  forked tool to tighten the carrier bearing on final assembly.     It is not rocket science, just proper procedure with the proper tools.     JMHO

[DonMicheletti]

I used a roll pin to hold the driveshaft and pinion in place.

As tough as the press fit is between the driveshaft and pinion, the  pin seems innecessary - but I did it.

[Jim Nelson]

Yes, the pin is mostly redundant.   The possibility of the drive shaft needing the pin is a lawyer / engineer solution for a non existant problem.   The shafts I’ve worked on would never needed the pin.  The bolt I used is there JIC .   BY using a bolt, it becomes easier IF you need to seperate the pinion / drive shaft again.......

[DonMicheletti]

I did the rearend on m,y car when I converted to 3.9's

On disassembly, I found the pinion shaft welded to the driveshaft (nutso). When I cut the weld and took it apart, I found out why the weld. The pinion and driveshaft splines had been wallowed out and were really sloppy. I wondered how the heck that happened as tough as it usually is to get these 2 things apart.

I do not know the history of this car, but it had about 75K miles on it - showing on a broken speedometer.

[70sWagoneers]

[gdmn852]

Hello good luck on your rear end project I am currently doing this on my 1949 ,torque tube on it bolts to carrier .I am going to change out the complete carrier assembly with one from a Buick that is street rodded Was looking for new ring and pinion gears , but with no luck so far .I have a post looking for parts on the post war forum going to update it once I get it changed over.It has a howl like being chased by a pack of wolves. Pinion gear will have numbers stamped on it to show how much it is from standard for shimming , unfortunately you would need the dealer tooling to set it up that way, shims in pinion housing adjust it for gear mesh you may have to blue up the gear set to check mesh,trial and error .Again Good Luck.Gary

[gdmn852]

Shop manual will show how correct mesh pattern on gear teeth at least the 1948 49 does,

[gdmn852]

If mr. Earl will let you borrow the Special tool set that would be the way to go save a lot of time .once again shop manual shows how to use it .

[70sWagoneers]

Well, its back together, it spins, and it doesnt make noise... so I'm alright for now. Seperating the driveshaft from the pinion shaft was the hardest thing. I hung the assembly from a forklift with a bearing splitter and used a oxy-acetylene. When it had some heat, i picked the whole thing up and slammed it down on the bearing splitter. Brutal; I know. I replaced the pin with mild steel I turned down a couple of thou less than the hole. Replaced all the bearings which I found one of each of all four from different vendors (Bob's wants about $100 per bearing, I found em about $25 each). I made my own carrier bearing wrench. I set it up with the original set of pinion shims and about 0.006" backlash and hoped for the best. There was plenty more I WANTED to do but I tend to overdo things. Thanks to everyone that helped. If I can answer any questions, let me know

Thanks

James C

[Jim Nelson]

Just replacing with New bearings and set up with the proper clerances will give you a nice relatively quiet rear assembly.    I found Olcar to have a nice selection of bearing at a reasonable cost.   Several bearings are ‘standard’ size so you could buy them from a local bearing shop.   I owned a bearing shop for 18 years so I got familiar with them.    A good machinist can make some sleeves to change the OD  to match some of the “factory” only bearings.   When things get unavilable,  things become more fun to repair.  Junk to gold.