SC38DLS

Brake/clutch spring 38 State Commander

62 posts in this topic

4 hours ago, fh4ever said:

 I would like to see which end is positive or negative, and see the ground cable routing.  I have no cables and need to see where they normally go (assuming your are correct).  I do have one small cable/strap from the battery hold down to the fender but I feel the main battery ground does not go there.  That strap is not very heavy and I feel it might be just to connect the fenders to the frame to service the headlights and horn.  

 

In a 1939 Commander the original battery ground is to the battery containing box clamping bolt at the top. The ground then goes through the box hold-down bolts to the chassis. The 1939 parts book says p.n. 195120, STRAP, battery ground, 4-3/4" (group D75) and that is it! This a useless earth so it was changed.

 

In the '34-46 parts book it shows it as  P.N. 511323 and 10-1/2" long (group 0630) with an engine ground 5-3/4" long. My guess is there is a service bulletin that gives a change to that battery ground strap. I don't know where the engine ground goes; mine is at the front engine mount. Both of these straps are shown as flat in the picture on p.239. My battery ground (non-original, non-flat cable) goes to an oil filter mounting bolt (installed by a P.O.). No doubt dealers did the upgrade but did they always follow the instructions?

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Posted (edited)

Thanks Spinney, I was wondering if there was a cable from the battery to that bolt at the top of the battery box and I figured it had to ground through the box to the frame....that small braided cable from the bolt on the box to the fender must only service the headlights being its size is small.  There is a ground strap on the front motor mount too.  so it looks like all I am missing is the battery cable to that bolt on the bat box.    With all that said, I would assume the ground post of the battery is closest to the bolt on the battery box?   

In addition, I am thinking of running a ground to a starter bolt as many folks recommend,...just wanted to know how the factory routing was first before I do anything.  thanks all

Edited by fh4ever (see edit history)

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Maybe this will help - out of my 37-38 shop and parts manuals. I'll get actual pic asap - family stuff too do this AM then garage time. 

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8 hours ago, fh4ever said:

that small braided cable from the bolt on the box to the fender must only service the headlights being its size is small.  There is a ground strap on the front motor mount too.  so it looks like all I am missing is the battery cable to that bolt on the bat box.    With all that said, I would assume the ground post of the battery is closest to the bolt on the battery box?   

In addition, I am thinking of running a ground to a starter bolt as many folks recommend,...

 

I think you have an extra strap from the battery box to the fender. The headlights struggle in these cars because of poor earthing so your extra strap would be useful. So it sounds like the wee strap at the front engine mount might be the original way.

 

Yes, if the original strap was 4.75" long, it would need the + terminal at the front of the box. If you measure 10.5" from the + terminal, you might get the idea of where the upgraded strap went. An oil filter bolt might just about be it. is your battery on the left as in RHD cars... if so, will it look messy running a cable round the steering stuff over to a starter bolt? Remember they are 6 V so a big cable is needed.

 

The 1937-8 part number is different to the 1939 part number too. But the upgraded strap was fitted to A to 12A.

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You're right about going to the starter bolt...to keep it clean looking, its 40" to go around the behind the battery back to the starter... that's why I wanted to see where did the factory put it.  I think going to the oil filter bolt could be the best route.  

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Got the spring installed and went with a bracket as it fit without it but spring was rubbing cross member. The spring had a longer hook on one end but still rubbed. 

As far as the battery hookup- the positive ground snakes all the way up to a bolt for starter. There is also a short wire that bolts to the bracket near the battery and a very small wire that goes to the electric fuel pump. Non of this is stock. The positive has a bracket holding it to the frame mean the pedals.  The negative snacked around and hooks up to starter soilinoid. Hard to get a decent pic in the limited space I have under it. I would guess your estimate of 40 inches is not far off. As mention somewhere above 6 volt is heavier wire than 12 so get the correct size if ordering new. Good luck. 

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Posted (edited)

Well the spring did not stop the vibration. I just hope it is not the universal joint as mine are the rubber type and I don't think they are available anywhere. Does anyone know if these are available or can be rebuilt? 

 

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Edited by SC38DLS (see edit history)

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glad you got the spring ...so your spring hit the crossmember like mine did.   regarding your first pic with the battery in it ...looks like you took the pic from underneath looking upwards.......is your battery under the floor ? I see what looks like a panel to remove to access the battery.  Mine is in the engine bay.  

Describe the vibration you are referring to.....did you hear it before the discovery of the spring on the floor? 

 

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Posted (edited)

My battery is under the floor under the seat.  It is a pain to do anything with it but leaves a lot of room in the engine bay. 

The vibration had started on the drive I found the spring in the driveway.  So I don't know if the spring broke because of the vibration or it started because the spring broke.  The test drive after replacing it was the same as with no spring.  It starts at about 30 mph and gets worse the faster you go.  I have not taken it over 40 as I do not want to break anything and only driven it about a mile or so to test it. The noise increases as the speed increases also.  It is smooth up until about 30 and disappears as you slow back down but does not go away until you are at about 20 or so.  

I was thinking of putting it up on jack stands and testing but I am just not comfortable that it is really safe. I have good stands but still that is still scary. 

Any ideas? 

Edited by SC38DLS (see edit history)

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You thought it was right front? What if you swap the right front wheel with left rear? This will check the wheel.

 

Is the castor set correctly?

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Spinneyhill the vibration came on suddenly-- I've put 1200 - 1500 miles on the car this last year or so and it was very smooth. I checked to see if I lost a balance weigh on one or more wheels but can not see any marks where one may be missing. I have thought of pulling all 4 and having them rebalanced. Talked with a tire guy and he did not think it would be that if I could not see a missing weight. If you think switching the wheels around I'll give it a try. Should I do all 4 or just 2? 

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Check the tightness of all the wheel nuts on all four wheels.

 

Jack up each front wheel, one at a time with the other on the ground and shake each wheel at 12 and 6 o'clock, then at 9 and 3.  Compare results.

 

Does the vibration occur while the clutch is disengaged?  That is, at say, 35 mph, disengage the clutch and coast.  Vibration still there?

 

Check the tightness of front suspension components and rear springs.

 

I'd be inclined to replace the driveshaft and old u-joints with available-anywhere, greaseable ones, just on General Principles--stand the old one with u-joints in a corner until you find replacements, if ever.  Unless you're shooting for absolute max points at a Stude meet or at Pebble Beach, the more modern driveshaft and u-joints, easily done at a driveline shop near you, will serve you infinitely better than the originals.  Did that with my Jeepster to replace the Rzeppa joints.

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SC38DLS...  I hope this makes sense ...this might help clue you in if its a wheel or driveshaft....  a driveshaft vibration will be at a higher or faster frequency...than a wheel vibration which is at a slower rate... I picture in my mind whether or not the wheel is spinning as fast as the vibration.   A bent rim can cause it too. but I assume you did not hit anything.  good luck   

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Thanks guys. The whole front end was rebuilt about 2-3 years ago.  I did check wheels for bearing play and did not feel any but remember I'm an old guy with a major back problem (old football injuries from using my head as a battering ram from 3rd grade thru college) and no longer have the strength to do what I did even 10 years ago. Interesting you brought up the drive shaft as that is what I was hoping to avoid. 

I think I'll put it up on jack stands pull the shaft and see if the universal has round or oval bolt holes. My thinking is if that is the vibration cause the metal (brass?) that the bolt passes thru will be out of round. Does that sound reasonable? 

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Before you pull the driveshaft, shake it to check for major looseness and check the tightness of all bolts.

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I know your a little hesitant to put it on jack stands and run it,  but that could clue you in too.  I do it,  but me or someone else is in the car in case we need to hit the brakes.    

I would imagine the u-joint bolts sandwich things tight so the holes would not be out of round unless you had a loose bolt.   If its the drive line vibrating and not a wheel, my bet is the hundred year old rubber has failed in the joint.  But let's hope it's a wheel instead!!

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I will get it up on stands and check wheels, bolts and shaft and then maybe try to run it if I can get someone other than my wife to sit in it. She does not like the mechanical part of old cars.  I'll. Let you all know what I find. 

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4 hours ago, SC38DLS said:

Spinneyhill the vibration came on suddenly-- I've put 1200 - 1500 miles on the car this last year or so and it was very smooth. I checked to see if I lost a balance weigh on one or more wheels but can not see any marks where one may be missing. I have thought of pulling all 4 and having them rebalanced. Talked with a tire guy and he did not think it would be that if I could not see a missing weight. If you think switching the wheels around I'll give it a try. Should I do all 4 or just 2? 

 

Something changed suddenly. A balance weight could have come off. Could a bolt have finally come loose enough somewhere? If it were drive train u-joint failing I would expect that to come on gradually, unless a bolt has come loose. I think change one thing at a time else you won't know what the problem was. Can you put the spare on one corner at a time?

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I'll try the one tire at a time. I don't see any unusual wear on any of the tires but maybe it is because I have not driven it much with this problem. 

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Bummer it's the rear universal!!! Switch tires around Took it for a test drive and same thing. Put it up on jack stands and got under it. Could not wiggle the drive shaft. I pulled it back a little and it moves side to side about a half inch each direction. What could I expect from 78 year old rubber! Now the parts hunt starts. 

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Here's what it looks like pulled back. 

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Posted (edited)

Has anyone switched this rubber universal to a standard needle type universal? If so do you know the parts used? I would assume you had to have a new drive shaft made up?  Any help will be appreciated.  Dave S 

Edited by SC38DLS (see edit history)

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Ahh  what bad luck.   I hope someone has a conversion kit for this.  I am still new to this site and dont know all the suppliers and their capabilities, but Dave Thibeault helped me locate some parts, give him a try.  Also RBK might can help.   Maybe someone can rebuild them?   

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My Pontiac had "Mechanics U joints".  Totally unavailable and un repairable.  I cut the yokes off the driveshaft and the ears off the transmission and differential yokes.  Installed regular spicer  u joints like many Ford and Chevs used.  The local transmission and driveshaft shop cut two old yokes they had and in two days I had a vibration free driveshaft.  Fifty years later still excellent.  Just have been repacking the joints every 30,000 miles or so.  I should have hunted for crosses with grease nipples I guess.

Good luck and vibrationless driving.

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Took the whole thing out and going to a drive shaft repair shop tomorrow to see what they can do. Will let you know outcome. 

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