Let me start by warning this is going to be a bit long and convoluted but I have a serious issue with my 53 Transmission that we cant sort out. Hoping someone has some ideas before we just pull her and rebuild for the second time. It was rebuilt 8 years ago but the car was hardly driven not more than 500 miles in all those years. no long trips so no idea if this issue was from the rebuild back then or developed since.
I am experiencing a reverse shudder and lock up issue only in reverse and only when the car is warm, drive a couple of miles no issues drive 10 miles have issues. It felt like the rear brakes locked up but that is not it. We then determined that a rear axle bearing was bad and the pinion seas leaking and a bit more play in the pinion than should be (thinking the preload was wrong). I replaced the rear end with another one from a 52 that was nice and tight and leak free hoping that the pinion pre-load and axle seals bearings were causing lock up on the old one. BTW I opened the pumpkin on the old one and there was no damage to any of the ring or spider gears.
Once we replaced the rear end and tookit for a test drive no issues. Revers worked backing up for 100 feet cold smooth as silk. Foward has neveer had issues except the typical 2-3 shift have to let off the gas for second to upshift 2-3. THat said after driving about 20 minutes I put it in reverse and once again same problem. will engage but shudder and lock up. tt will move with gas but that is forcing it and we dont want to do more damage. Feels like breaks are locking up but tha tis not it.
We then put it in reverse and one of us looked underneath as we tried to back up and the entire rear end tilted downward a good 4 inches or more, never seen anything like that before. So when the reverese is enaged after driving a bit it shudders in reverese and locks up to the poing that the rear axle and driveshaft torque downward severely, which makes no logical sense if the transmission is locked up, but we don't think anything is locking up the rear diff. We jacked the rearend up and with no load, wheels off ground putting in revese works fine, lower it back and boom there is an issue. We put her on the lift and the rear diff was warmer than expected almost hot and the transmission tailshaft was so hit you could not hold your hand on it more than to feel it. Agan no issues with the brakes so this is really cofusing since everything works fine cold and for short drives. I believe this is what ruined the bearings and pinion on the old rearend. Cannot see how the transmission locking up would torque the shaft and diff downward so hard. Also when it did that there was no movement in the transmission tail shaft so it seesm to pont to the rear locking up but that isnt it either (cant say that for 100% but it doesnt make sense either) Any ideas?
This sounds like the brakes rather than the transmission. Have you tried driving in the forward gears using the brakes a lot? Then see if the brake drums are hot an binding up. If this is the case I would suspect an over adjusted master cylinder pushrod and/or incorrectly adjusted shoes.
Brakes are messed up. Probably insufficient bevel on the leading edges of the shoes. Because the brakes are normally used in the forward direction, the shoes have developed a bit of wear in that direction and not in the reverse direction. Yeah, the brake shoes are locking up the drums in reverse (perhaps just the rear drums). The reason the front of the rear end (differential) is pointing down in reverse is that the wheels are totally locked in reverse and the transmission is trying to turn the driveshaft and the rear axles, but the rear axles are locked, so the diff is rotating relative to the axles, instead of the axles rotating relative to the diff. Pull the drums and look for issues (leaky wheel cylinders, odd wear patterns on the shoes, weak or broken brake springs, lack of good bevels at the leading and trailing edges of the shoes, funny marks on the drum friction surface, etc.). Adjust the parking brake cable (make it a tad looser). Check the master cylinder push rod adjustment -- there needs to be a little bit of play. Check the brake pedal linkage return spring.
If the diff is rotating up and down, it might not be secured to the leaf springs correctly any longer. Check the torque on the big U-bolts.
Yeah, I am betting this is a brake problem...
To add to what Art wrote, it would be useful to also do what Cadillac calls a "major" brake adjustment. This goes beyond merely adjusting the star wheel. Follow the instructions in the '53 shop manual, since the procedures vary somewhat from year to year.
I 3rd the brakes.
When we woke our 55 up after sitting for years I had a brake issue after it was warm. The pedal was a tad too long and the brakes had a little drag. When they warmed up, the fluid expanded and made the brakes tighter. It may be that 1 or both of your back brakes are just on the verge. When you are done driving it, get out and feel the hubcaps to see if any one is hotter than others. Our right front hubcap was really hot. A major brake adjustment did it.
Also, how is your rear rubber line? Has the fluid been flushed recently?
Good luck,
Jeff R
Was my post invisible?
Thank You all for responding, Art you were spot on. We never would have looked at the bevel. This really confounded us for months. Such as simple fix. Even the transmission shop was at a loss they wanted to remove the tranny and break it down. Lesson learned had the shoes relined and did not think to check the bevels on the leading edges.
Thanks
Craig
Quote from: CRAIG LEWIS on October 05, 2023, 12:41:56 PMThank You all for responding, Art you were spot on. We never would have looked at the bevel. This really confounded us for months. Such as simple fix. Even the transmission shop was at a loss they wanted to remove the tranny and break it down. Lesson learned had the shoes relined and did not think to check the bevels on the leading edges.
Thanks
Craig
So have you added a bevel and tested the car again? Is it all working correctly now?
Art
Wow, I am invisible!🤣
Another thing that may not apply in this case it is correctly installing the brake shoes. Drum brake have a primary and a secondary shoe. Usually the shorter of the two shoes is the primary shoe which is on the front and the secondary on the rear of the backing plate. Originally the shoes were made of different materials. Oldsmobile had some applications where on the rear axle, the primary shoe was the long shoe and they would get installed incorrectly and cause braking issues.
Yes, "fat girl rides on the back", as a reminder as to where the shoes are normally installed. Clay/Lexi
Thank You everyone. Sorry we have been dealing with some other issues unrelated but did get back to it and have beveled the brakes. they were not beveled at all other than what wore in. Having done that we have taken it for a test run replicating a run that created the issue and it seems to be clear. We will be on a long run next week and know for sure if it resolved.
Thanks
Craig
I wish Phil Whyte would chime in....;)
Cheers,Pat MacPhail
@Eldovert I've sent you a PM. If you haven't seen my earlier PM you can ignore that. Thanks for the reply on my other (now deleted) post.
Not the most versed in inteernet things how do I get a PM?
The problem is still not resolved. Drove great for a 5 mile run, which it would lock up after before, so we got some progress. I drove about 30 miles and it locked up in reverse again. Thinking it is the heat still expanding the shoes out and they are not releasing back. However it doesnt appear to be springs or shoes themselves so thinking it is the fluid itself. All I can come up with now is to test the theory by driving long enough till locks up in reverse and then popping the bleeders open for a second and seeing if they release. I am also wondering if it is due to my changing out the single master cylinder to dual master cylinder somehow causing the pressure after it heats and expands to not fully relase back into the master (yes the master seems adjusted correctly for the pedal) I have already checked the parking brake and it is not the issue as we have loosend it to the point it doesnt engage right now. Mystery continues open to ideas.
Update from today's experiments,
Ran 5 miles no issues took it on freeway for 2 miles more and around the residential streets another 2 miles and they locked up in reverse. put it on the lift while still hot and locking and pulled drums off easy, not hung up at all. Put back on spun wheels while in the air and both sides turn with no indication of rubbing on the drum. Set it down and put in reverse locks up only on reverse. Checked pedal to be sure no hanging up keeping master cyl. rod from fully retracting, no issue there. Pulled hubs adjusted star adjuster to full retraction, put down on ground still locking up in reverse. Raised wheeels off ground and can go in reverse with no binding. Seems like the shoes are moving out of position and binding in reverse only but cant find it. Am now taking drums in to make sure they are not out of round or warped.
Quote from: CRAIG LEWIS on October 26, 2023, 05:55:26 PMUpdate from today's experiments,
Ran 5 miles no issues took it on freeway for 2 miles more and around the residential streets another 2 miles and they locked up in reverse. put it on the lift while still hot and locking and pulled drums off easy, not hung up at all. Put back on spun wheels while in the air and both sides turn with no indication of rubbing on the drum. Set it down and put in reverse locks up only on reverse. Checked pedal to be sure no hanging up keeping master cyl. rod from fully retracting, no issue there. Pulled hubs adjusted star adjuster to full retraction, put down on ground still locking up in reverse. Raised wheeels off ground and can go in reverse with no binding. Seems like the shoes are moving out of position and binding in reverse only but cant find it. Am now taking drums in to make sure they are not out of round or warped.
I'm not sure I understand what you found out from your tests - were the wheels locked up or not? It seems to me that they weren't?
We had problems with our 1937 Series 60....not quite what you are running into I don't think..
It turns out that the brake shoes were a bit too wide. At some point the wrong shoes were installed'
At any rate....have you doubled checked to see that the brake shoes are the right ones ?
Jack Worstell
From what I translate, the brakes/wheels rotate freely but it only locks when the car is on the ground. Once the rear wheels are raised off the ground, the rear wheels will rotate in reverse with the transmission. When it is locking up, the torque from the transmission trying to go in reverse causes the differential to tilt downwards. Only happens when the car is "warmed up" and doesn't happen when it is cold. Did you use the 1953 axles in the 1952 carrier? When it is warmed up and locking up, are you able to roll the car rearward by hand with the transmission in neutral?
Thanks all for replies this has really got us stumped and i have talked to some folks with 40 yeas experience in brakes and stumped them too. I will clarify some things:
Phil it is still locking up but only when extended driving; first 7 miles give or take produces no issues.
This is a 51 seies 62 with a 53 engine and transmission . We pulled the 51 rearend entirely after first working on this problem and determining the pinion and bearings were shot. Which I now believe is a byproduct of what is happening since it is torquing the rear downward severly in reverse.We replaced it with a 52 rear end but used the wheel cylinders and pads from the 51 after changing the top ecentric bolt sine 51 has a larger diameter than 52 so everything fits like it should. The exact same problem persists.
Have beveled the shoes and just had the drums checked did not need turning.
Secondary shoes measured by the lining/pad is 11.75 x 2.5 inches and the primary pads are indeed shorter same width.
We noted the star djustment has the spring riding on top instead of underneath which the 50 manual shows while we think there is an issue in adjusting when in reverse we do not feel that is the issue since we replicated the issue with the star adjusted all the way in.
That is where we are now.
Thanks All for your input, suggestion are welcome. Once we put it back together we will try nuetral and push backwards by hand after we drive it and get it to lock up again. We have not tried that.
Well I checked the specs for 1951 should be 11 inch pad. I will double check the front pads as they are supposed to be the same. If so then this may be the issue. When relined should have checked the work closer they may have made the pads too big. If that is the case we will slice them down to size to match the front pads. Hope it is that simple a fix.
Sooo it isnt the shoes I measured wrong they are indeed 11 inch shoes. No modification needed there. will see what happens in neutral pushing back by hand later in the week to come.
Craig, I'm still not clear whether the wheels are locked up after the 7 miles of driving or not. Also are the front wheels locking up as well. If the wheels aren't locked up then it isn't the brakes. You have to use a clear process of elimination. Phil
Phil they locked up in reverse only after the 7 mile drive but at 5 miles they were not locking up. Today I spent more time pondering and testing. What I have now determined is that the primary shoe is catching on the passenger side at the bottom 2 inches of the shoe. The drum rotates freely but as i used my feeler gauge it caught at the leading edge of the primary only when spining the drum backwards. I could not get a .015 guage in between the shoe and drum in this one spot. I even went to .025 and had free movement in and out of the drum through the slot with the feeler gauge all the way around except the spot I identified. I am thinking the heat expansion is enough to cause full lock up due to the disparity in the gap between the shoe and drum in this spot. Since the primary is responsible for the braking in reverse and pushes the bottom of the primary shoe against the drum (I think I am correct in this action?) and the last two inches is already rubbing the heat expansion adds to that and locks it up.
After many attempts to correct it I took a dial indicator and determined the drum is out of round. I have not checked the driver side yet but it is likely the same issue. Warped or out of round. I dont feel any issues like a chatter or braking symptoms in foward from them being out of round which is a little confusing but... this whole issue has been a head scratcher.
When you installed the shoes did you do the major brake adjustment as specified in the shop manual?
Also if the fronts are also locking up at the same time it could well be the master cylinder pushrod is over adjusted - this would cause the brakes to pump up over a few applications as there is not enough movement to clear the relief passage in the master cylinder.
i have done the master adjustment. the front brakes are not loking up. I have an old rusty drum lying around that is in spec and used that this morning to see how it moves on the drum. the more I thought about it the more the drum does not seem the answer or it should rub on the shoe as it travels all the way across to be just one area of the shoe has to be the shoe. I am posting some pics if anyone sees something I am missing. the tape marks the spot the feeler gauge moves in and out freely and where it seemed the hub attachment was out of round but further checking indicates not an axle issue just the casting is off on the outer side but the inner part that the inserts into the wheel itself is not out of round. Hope that makes sense. 1st picture clearly shows where the primary is reubbing hard on the drum but past that point I have an easy .025 clearance so if I adjust to .015 it will only make it worse. Shoe does seem arched correctly but perhaps the lining should be thinner at this point on the shoe?
Are you using the 1951 brake drums or 1952 drums?
I am seeing that 1952 takes 12" shoes but I read you used the 51 bolt. I'd put the 52 bolt back in with proper 52 shoes and see what happens. You're mixing parts from two different years with differences between the two. I would suggest making it all 1952 brake parts.
Last but not least, I would also pull the wheel cylinder to make sure there are no issues with that somehow not retracting after you're braking once things warm up. If that shoe is dragging on the drum, things will get hot fast.
After all that, I would then do the major brake adjustment and see what happens.
Thanks Dan to clarify, this issue first appeared while using a 1951 rear end complete but it basically ruined the axle bearings and pinion seal from torquing the rear so hard downward in reverse ( we did not know it wa doing that for a bit) We had a 52 lying around for parts and took the rear out of it which had good seals and bearings and popped it in. We used the 51 drums, wheel cylinders, shoes and anchor pin from the 51 so basically all we had was 52 axles and backing plate which are the same. We also comparted the 512 drums to the 51 and they are the same size. The only difference really was the anchor pin which for the 51 was a larger pin and the shoes wont work with a 52. we set it all up and it drive and stops fine up until it heats up after about 7 miles or so of driving. Thne in reverse only we get lock up. Long story short if you read the whole thread we have chased this for a while.
Today we learned one of our mistakes was thinking the anchor pin wa eccentrical like the manual and all other drum setup I have seen calls for. But indeed this is not the case, theis one has a slot and only moves up and down in the slot once you lossen the nut and relieve tension on the backing spring. so whith much time and tedious checking on and off we think we have centered the shoes properly. We also lenghtned the bevel on the lower leading edge of the primary shoes since that was the hangup which allowed us to better adjust the shoes to center. we also adjusted the assembly back instead of foward since we had at least .035 clearance in the secondary and were closer to .010 in the primary. Not there yet but getting closer.Tomorrow we will test drive and see if it helped. then we will perform fine tunning adjustments and cross our fingers. There seems to be no issues with the front brakes. Seems
Craig,
The major brake adjustment involves loosening the anchor pin to centre the shoes. If you don't have the manual I do have a 51 manual somewhere and can scan it. From memory it is the same on other 50s Cadillacs.
Phil
Thanks for the information. Everything I've seen told me most 1952-1959 brake parts were interchangeable but not backwards to 1951. I don't know what exactly the differences are but I assumed there must be a reason they don't list it 1950-1959 interchangeable. Maybe someone else knows the differences?
Anyway, if you need the shop manual, multiple years can be found at the link below.
https://cadillac.oldcarmanualproject.com/
The 1952 rear (only the rear are 11x2.5 front are 12) brakes are indeed the same as the 50-51 except the eccentric anchor bolt for 51 was different so the shoes are like the 1950 set up. Since we had the same issue with the 51 rear when it was installed I dont see how the change over would impact that. Everything isis 51 except the rear end which is interchangeable but may have a gear ratio difference. After test driving today we know for sure the rear primary is stilllocking up but still dont see why. on the road we adjusted the brakes all the way in so we essentially had no rear braking contact and the problem is gone. Does anyone know if the 52 wheel cylinders are pressurized in such a way that they must go in specific to right and left sides. I am looking at that possibility as we sse more prssure applying to the secondary than the primary and perhaps the primary is hanging up under expansion and not retracting in enough. we are going to give the whell cylinders a goover and then swap them around and see whats what. Again front brakes are no issue. just double checking here but the rear are the primary stopping brakes not the front as is found in newer cars? with this issue we are relying mostly on the front right now.