As many of you may know, my transmission has a bad 2nd gear synchronizer. I've found a donor transmission and am going thru the learning process to rebuild. I'd assume do this once, so am going to replace as much as I can while it's apart. Both of the videos I watched of disassembly do not remove the front/clutch bearing. Page 203, figure 6 shows a special tool to remove the retaining nut. The retaining nut is very soft, not sure how to remove that without damage. I guess related....it's staked into place. How do I "unstake" it?
I have just the tool... I made it out of a 3 in pvc drain cap. The kind with the screw top. Drill a hole through the top square nut the size of the input shaft. Screw the cap parts together Slide it over the input shaft. Lock the input shaft against the cap. Turn the nut and the shaft and bearing will come right out.
I bought a Kent Moore wrench for these. It's basically a 1/8" thick, flat open end wrench. The nut should be replaced so order a new nut and use the size to find a wrench that fits. If you do some searches o here, Gene provides a part# for the nut and quick online searches find it as it was used many years. You may be able to buy an open end wrench and simply grind the sides of the business end to give you a flat wrench to fit in there. found a picture online of the wrench so attached it.
I can measure my wrench if you need but I'm just not close right now...
see this link. Mike has some good info and the nut part# is in the initial post.
Thanks Tim. That was a huge help. Muncie was a huge help in searching. There are affordable wrenches on ebay too. Seems like varying qualities. Some note that they are for assembly only (not removal). Guess those are on the low end of the quality spectrum. I bet I could've gotten one of these Muncie wrenches at Hershey yesterday. Dangit!!!
I'm needing to do this to my own transmission sometime once I get past the bodywork stage and can work on my chassis. I've been collecting pieces and none of it looks hard, just some weird things like this nut that are bound to come up. Please post lots of progress, questions and pictures as many of us will need the info...
1938 Canadian Pontiac Business Coupe (aka a 1938 Chevy Coupe with Pontiac shaped front sheet metal - almost all Chevy!) 1975 4-speed L82 Vette
I got my 2nd and 3rd gear cones out. I cleaned both sides and have a little rocking on the 2nd gear side depending on how I rotate the cone. Going to check again in the morning. In the photo, you can see where the original brass ring is staked in place. There are four stake points, each with an opening behind it. I presume I drive from behind to de-stake it and eventually it will come loose. Replacements on ebay note "Each ring must be pressed into the original synchronizer ring housing after removing the original ring". I presume a nice shop somewhere could do this for me. Marvin (a VCCA member in Canada) mentioned he had done it and used red loctite. He also mentioned staking them in place. I don't get how you can stake them in place unless already firmly attached and still have some assurance that things are centered and level. Also...how is staking not a recipe for messing up the nice smooth surface?
While we’re on the rebuild subject, does anybody know how this occurred? Its the gear that works with the Speedo gear. If you will look closely you can see the raised edge on the inside edge. Could I just cut this down? What would cause this?
While we’re on the rebuild subject, does anybody know how this occurred? Its the gear that works with the Speedo gear. If you will look closely you can see the raised edge on the inside edge. Could I just cut this down? What would cause this?
Thanks,
Mike
Please start a fresh post with your model/year info as this post is about Scott's 41 transmission rebuild. It will make it easier to focus on each separate item.
1938 Canadian Pontiac Business Coupe (aka a 1938 Chevy Coupe with Pontiac shaped front sheet metal - almost all Chevy!) 1975 4-speed L82 Vette
I've got everything taken all apart and cleaned. One thing I noticed about my donor transmission was that it mount seems a little different. I don't have the transmission out of my car...but the video I linked earlier and what I have is different. My donor had a double ended bolt (one side coarse threads going into transmission casting and the other side finer threads). There is a metal (I think) collar in the middle. The collar seems to be an offset for the mounting plate. i figure worst case, I can remove the mounting hardware from my original transmission at swapout time.
I'm waiting for Monday to visit my local transmission shop to see if they'll be helpful in removing the bearing on the input shaft (once I get that nut off). Not much space for anything.
A FYI for others that do this. If/when you take apart the shift fork mechanism (that slides the gears around), make sure you do this carefully. There are two ball bearings and a spring under pressure. They launch a long way if you aren’t careful. Am happy I had a second trans to borrow from while I track that ball bearing down somewhere in my basment
The bushing on the right gear on the top In photo has some play. I don’t have a way to measure to see if in spec. I see they are avail on Co40s. How does one go about removing them?
Took a few parts into my local transmission shop and they felt the bushing in question was good enough and that my bearings were good as well. They have recently replaced synchronizer rings in someone else's transmission and are willing to do mine. Will report back later this week once I get parts and can run the gear over there. He also suggested to smooth out the cones that ride in the brass ring with a scotchbrite pad. That helped a lot. I'm going to try to find a way to chuck one into a drill and take it a little further. Thinking of a rubber stopper with a bolt thru it.
Had some delays in getting my synchronizer rings shipped. Co40s and FS were a few weeks out. Sourced from another place on the Internet. Those came today and I dropped my 2nd/3rd gear drum at an independent transmission shop to be removed/pressed in. My rubber stopper idea worked.
I have everything reinstalled that I can. Hopefully will get it back in a day or so.
I need to read more about the gaskets back in the torque tube and also need to watch some clutch videos, in hopes of being able to see what I'm going to find when I get down in there.
Sealing the ball on the torque tube bell is a "trial & error" process. I recommend you do this before you put the transmission back into the vehicle. It is a lot easier.
The last transmission I rebuilt was a '49 1/2 ton truck. The only real problem I had was the typical issue that today's parts do not always fit like the originals. In my case the cork gasket that goes inside the bell was way too thick and the ball would noy fit in far enough.
I spent about a half hour gently sanding the gasket thinner on maybe 100 grit sandpaper. I also know that some people have fit an O-ring into that application.
The trial and error part is to determine the number of gaskets (which also act like shims) between the bell housing and the back of the transmission. You do not want the bell so tight that you cannot move it. It needs to move as the rear axle travels up and down. On the other hand, too loose and it leaks.
Thanks Rusty. I think the few articles I've looked at and then going to look at my transmission, bell housing, and the gaskets I have helped. I don't have the benefit of taking my transmission out and being able to see how the different pieces connect.
Sorry for my confusion. I thought you were rebuilding a transmission to install. If that is correct then you should be able to fit everything and get a good seal before you reinstall it.
Just a guess on my part but I bet you have not pulled the rear part of the u-joint and then the bell and retainer from the front end of the drive shaft. Just loosen the slip seal coupling on the back of the bell and it should slide backwards and forward easily. The rear half of the u-joint slides on the splines of the driveshaft. You should be able to simple pull it forward and off the driveshaft.
I recommend that you mark the rear u-joint half in relation to the drive shaft before you pull it. A couple of center punch marks should take care of that. I assume you marked the u-joint halves before you separated them.
Once you have the bell and retainer ring off clean them very well and polish the mating surfaces with 400 paper. That will help ensure a good seal.
A question about the bell housing. This is a pretty good description
There is a special procedure to adjust the U-joint ball housing. Using a new gasket set for the U-joint housing, take all of the 4-bolt gaskets (shims) and bolt the retaining collar and ball housing onto the back of the transmission. For this adjustment, do not use the gasket in the back of the collar. With a rubber mallet, strike the back of the ball housing to see if it moves easily. If it moves without much effort, take one of the shims out and tighten the collar. Test again until the housing can just barely be moved. If it is too tight, it will cause the U-joint to bind, causing damage to the U-joint or driveshaft bushings. If it is too loose, it will cause leaking.
Confirming that I do this without the larger cork gasket in there. I shouldn't be able to move it much (at all) with my hand...but it should move when I hit if from the the rear. The way it is now, is it's grabby in one direction and then I really have to force it in another. Presuming that's right...I then remove it and insert that large cork gasket.
Thanks Mike. That helped a lot. I'm approaching the reassembly process soon.
Yesterday I got the 2nd/3rd drum back with new synchronizer brass (had a local trans shop do it). On one side, the cone sits in the new synchronizer great. The other side it rocks a little bit. It's not the cone, as the same side does it regardless of which cone I try. Should I go back? Or should I assume that the brass will wear to the cone and remove any high spots?
Well, speaking in general terms, rather than about this specific transmission, it sounds to me like it wont work.
When overhauling a transmission using brass synchronizers, once everything is clean, a common trick is to rotate the synchronizer on to the cone and see if it grabs. In order to work, once in the transmission, the synchronizer will have to displace any oil present and grab the cone.
It shouldn't turn round and round, it should grab the cone like it means it. If it will not, it usually means the synchroniser is worn out. This is how you figure out which ones to replace.
If your new one is warped so it is tipping around like a washing machine that needs it's feet adjusted, I'll bet it wont grab the cone, and thus wont work.
You could look to see if some little burr left over from machining the brass is causing the tipping. If so it might wear down, or could be scraped off. The taper must be round and fit the cone though. It must grab. IMHO don't put it in until it does.
I went back to the shop and he pressed it a little with the cone in. That helped a little bit. We also found a few burrs. That makes it sit a lot better. Reassembled. I have the right # of shims....I have the large cork washer installed...is there really that much compression of the cork when I tighten the ball housing down? Do I grease the cork?
Oh...and I should spring for the MT-90 fluid that Rusty mentioned for my newly rebuilt trans??
Glad it fits better and the shop had another look at it. Exciting to be at this point.
Do some searches on fluids as there have been some good discussions. GL-4 is recommended as GL-5 can cause problems with syncros I recall but may be more of a very long term/higher mileage problem that may not be an issue with an occasional use vehicle.
MT-90 is a GL-4 but I recall Gene and others preferring something heavier like a 75w140. I also seem to recall that people were having trouble finding the thicker synthetic fluids in a GL-4 as many were GL-5. Going from memory here.
If everything is tight and well sealed in your trans, I personally would try the MT-90 as thinner might help with break-in and it is indeed a good fluid but again, read some of the past discussions. You could always change it to something thicker after break-in as I imagine you want to try this out...
1938 Canadian Pontiac Business Coupe (aka a 1938 Chevy Coupe with Pontiac shaped front sheet metal - almost all Chevy!) 1975 4-speed L82 Vette
A trick for getting the rings back on the cone, to hold them into the synchronizer. I took a small screwdriver and placed it thru the slot I then took the ring and set it down on top of the screwdriver (pushing the ring towards the slot). One side of the opening in the ring needs to be on the screwdriver. Next, I pushed the cone down. The screwdriver now pushes the ring up onto the cone. Now you can rotate the cone and encourage the ring up towards/into the groove. Keep rotating until it finally clicks in place all the way around.
I just bought a 2 gallon jug of straight 90 GL4 at Theison’s our local farm store.
Dens Chevys 1927 Speedster 1928 coupe 1941street rod 1947Fleetline 4 door 1949 1/2 ton Pickup (sold) 1954 210 4 door 1972 Monte Carlo 2003 Corvette convt..
Let's talk about ball housings. So...I did the shim thing, I ended up with two shims giving me some movement...but effort was involved (this was without the cork gasket installed). So now (assuming I'm up under the car)...I'm supposed to grease the larger cork gasket and put it inside the backing plate and then put the ball housing/tube thru that and bolt that to the back of the transmission. And magically, the compression of the cork gasket, the grease, the two shims are going to give me a leak-free seal that also allows movement towards the rear end?
I got my trans out and the new one back in today. Ran out of time and energy, so still need to hook the shift linkage, brakes, etc back up. The yoke on my old transmission was different than expected. Dennis??. (the vcca tech expert for 41 autos) thinks it might be a Pontiac part (see photo) I struggled with a few things. Getting the trans out with the mount attached was difficult. Not sure if I read the instructions wrong, but it went in a lot easier without it, then mounted the mount to the frame and the trans to the mount. I also had a hard time keeping the torque tube supported while I was bolting the two halves of the yoke together. I slid a 2 ft long 1x2 that rested on a frame support under the ball housing. This kept the yoke at a perfect height.
For posterity....jack stands on the frame and jack up the axle....this allows the torque tube room to swing down. I used a milk crate to support the torque tube while it was disconnected. Crossing fingers for tomorrow. Thanks everyone for their help
If it were Pontiac, I think it would have to be 1934-36 or so, because from 37 on Pontiacs had open drivelines (except some Canadian ones that had whole Chevrolet drivetrains). That picture sure reminds me of my Pontiac u-joint, but I had been under the impression that the Chevrolet u-joint was the same.
The 1941 U joint was new for 1940 and up and did not use the stamped ring pictured. That was used for 1939 and prior. The previous U joints were different and had the stamped ring that the bolts went thru.
Success. Thanks for everyone’s help. I welcome any questions from anyone tackling this project
funny story.   I stared the car up while still on jack stands to make sure I could hit all the gears.   Pushed the clutch in, threw it in first and let the clutch out.    All good.   Pushed the clutch in and threw it into second.   Looked back tires weren’t spinning.   Threw it into third, tires not moving.  Tried all three gears again…nothing.   heart sunk.     Thought for a min.   Did you realize I never released the clutch after my first shift out of first? ????
Transmission was in gear but your mind wasn't. You were too interested in looking for spinning tires that you didn't think to pull your foot up! All of us have done something like that in the past. The male trait of looking straight at something and not seeing it is similar. I do it way too much. The Earth will still rotate!
I would like to know how the new brass rings were secured. I can't imagine duplicating the original method that involved some kind of small circular deformations.
My 1951 1 Ton is now on the road! My 38 Master 4 Door is also now on the road .
Test drives have gone well. Probably put about 50 miles on it since the install. I'm actually having to reteach my hands and feet a different shifting technique. Without the ability to downshift, I had to leave it in gear with the clutch in thru a turn, then wait til I'd slowed down enough and downshift after the turn. Now I can downshift before the turn and let the clutch out mid turn. Very happy I tackled the project.
Yes...I followed the shop manual, as it read like greek to me. I read it 20x sitting inside my house over a few weeks, still didn't really get it. Once I was under the car with a copy of the instructions it made perfect sense.
So Scott, It is good to see that those tranny's you picked up from me worked out
John
1954 Belair Sport Coupe 1960 2 door Impala Hardtop 348/340HP 4spd 1962 2 door Impala Hardtop 409/409 4spd 1962 2 Door Biscayne Sedan 327/250 Auto 1977 Monza Mirage 305 4 Speed 1988 Celebrity Wagon 2018 GMC Sierra 2500 HD Diesel
Yes. Very happy. Funny story. Last week I took my Chevy to Home Depot and met a guy that had a similar ”˜41 with grinding problems. Trying to convince him to tackle the same project with the second one you sold me
Just a note to say that I was successful in staking in a new synchro ring into the clutch drum of my 1940 Chevy truck transmission. After removing the ring, I pressed in the new ring and simply staked it in with a narrow punch.
did you drill a small hole in the brass ring and then stake it i can see how you might do it to one side does the side where the ring is staked come out of the housing this is my first try at this and just have to ask questions thank for any help
One side of the clutch drum you can see the holes where it is staked. I removed the ring by drilling out the stake through these holes. The other end of the drum you can’t see the holes so I drilled out the stakes from the inside using the staking dents as a guide. I each case I used a thin punch (I actually bent it a little) to catch the rim edge of the synchro ring from the inside the drum and drove the ring out. The drilling process doesn’t completely remove the staking metal so there is some drag on the ring. The brass ring is softer than the steel drum so that’s not a problem.
Putting them back in is not hard. I marked a line With a Majic marker, inside the synchro ring all the way around about 1/2 way down. I then marked on the drum where the staking holes were. Remember, one end you can see the holes from the outside and the other you can’t. Pressing in the ring will cover the holes from the inside. Don’t cover up the holes until you mark their location on the edge of the drum. After you press the rings in, Line up the mark you placed on the drum edge (marking the hole) and mark the staking place based on the line you put on the ring. I just use a punch to stake the rings in place. There is a picture a few comments up on this thread.
well after posting went to pals garage he is a hair sharper than i am he figured out what staking was all about to me it looked like small pin after he cleaned part and knocked out 1 of the synchros it was palin to see what was meant by staking got new ones in no problem good to go just waiting on the 4-lug part to get here hopefully can find i more NOS group 4.383 #591886 thanks for your reply
I drilled out the stakes to remove the synchro ring. One you can do from the outside the other you need to do from the inside. There was no drilling when I installed them. On inside of the new ring, I Marked how far down the hole was. Then , ON THE EDGE OF THE DRUM I marked where the hole was. (On one end you can see the holes from the outside, but on the other end you can’t. The only way you can see the staking holes for both ends is from the inside which gets covered up when you put the ring in. So make sure you mark it correctly.) After the ring is in place, I put a mark where the ring line and drum mark meet and use a pointed punch to stake it.
