Three Speed Trans Rear Seal . . .

[grey beard]

My rear trans seal leaks. Anyone on this forum have actual hands-on experience changing these things? I have the shop manual and understand basically what's involved. Just thought it might be smart to listen to any experienced words of wisdom before I roll up my sleeves and try to do the deed, as it were.

Thanks for your time

[Flatie46]

I changed mine two years ago and I've slept since then. Best I can remember I worked it out with a screwdriver untill it was distorted then pulled it on out with visegrips. I cleaned the the hole out where it was and took a big sockett, laid it against the new seal and pecked it in place with a small hammer. I lubed the rubber part so it didn't tear it going on the shaft. It's not a bad job at all.

[Dodgeb4ya]

I changed mine two years ago and I've slept since then. Best I can remember I worked it out with a screwdriver untill it was distorted then pulled it on out with visegrips. I cleaned the the hole out where it was and took a big sockett, laid it against the new seal and pecked it in place with a small hammer. I lubed the rubber part so it didn't tear it going on the shaft. It's not a bad job at all.

Sounds like the correct way to me! Just pull the drive shaft yoke and remove the drum.

Here is some pics of a dodge truck 5 speed-procedure is all the same. Just check the brake drum hub seal wear area for a worn groove-if there is wear a speedi-sleeve should be installed on hub for new seal to seal against. Yes use a socket that matches the OD of the seal so you don't cave it in and carefully tap the seal into place after 1st lubing seal rubber lip. Sealant can also be applied to the od of seal to seal and help seal go into place.

Bob

[MBF]

Anyone have the p/n for a 3 spd trans (floor shifted) in a B1C? Thanks-Mike

[Young Ed]

Mike when I changed the seal in mine I couldn't find one at any of the parts places. I had to order one from I believe roberts. Came in a plain baggy so no part # either.

[austinsailor]

If you have decent NAPA or bearing supply house they can use the old one to identify one that will work. They've found every seal I needed on my 47 3 ton and my 48 pilothouse.

[pflaming]

My seal is on order from Vintagepowerwagons. My 3speed tranny looks very nearly the same as the photos in the above post.

[pflaming]

Seal from Vintage was INCORRECT. When contacted they did NOT have one for me. Went to MOTION INDUSTRIES this morning to get one, they couldn't find a match. Going to NAPA tomorrow, can't install the tranny til this is fixed.

[grey beard]

Changing Transmission Rear Seals

My Pilothouse is like an old dog, and marks its territory with oil leaks. The main leak is from the rear of the transmission. The seal had to be replaced.

This is not a fun job. Please do not attempt to do this unless you are an experienced wrench-type person. I have a shop manual and a parts book, none of which were much help for this job. It is almost impossible to change this seal with the transmission in the truck. I have no experience with MoPar automobiles, so I cannot speak to whether or not they are the same in this respect. The transmission on which I changed this seal was sitting on my bench, or I would not have been able to do the job.

First, the drive shaft must be removed. The rear U-joint comes off of the differential in the conventional manner. It’s up front that things get interesting. Pilothouse drive shafts have a splined slip joint in the drive shaft. On some units this spline just pulls apart. On others it is necessary to remove a threaded lock ring from the rear end of the female spline.

Once the main drive shaft is off, you still have the shorter female splined slip coupler, which is also a part of the front universal joint. This front U-joint must be pressed apart. I’m sure there is a special service tool for this job, but I do not have one. The usual way to get these joints apart is to beat on the cross area with a BFH – big fat hemmer. However, almost half of the U-joint is hidden inside the emergency brake drum. So the drum must be removed.

First you must remove the emergency brake band. This involves five bolts, four springs and some linkage. Watch out for the small coil spring between the band and the case on the left (driver’s) side.

The bolts that hold the drum to the transmission are screwed into the U-joint yoke from front to the rear. There is only one spot on the transmission where you can see these bolt heads, and this is at about one o’clock, looking at the brake drum from the rear. You look into the drum from the front side, so that you can get a wrench in the drum from the top to remove four 3/8-inch bolts. You must first turn the drum to the proper spot where you can get access to them from the front top side. This is why I say the job is nearly impossible to do in the vehicle. The shop manual simply tells you to remove the U-joint and the brake drum. Good luck!

Once the brake band and drum are out of the way, you now have access to the front U-joint. The drum is still held by the U-joint, although it is free to turn and move back and forth about a half inch. This is far enough to get access to the U-joint caps to remove them.

Had this joint been replaced somewhere in the past sixty years, it might have come apart more easily, but this one was a bear. I had to use a four-pound cross pien hammer and all my considerable lard on it to get this joint to come apart. I had full access to all this, lying on my work bench. In the truck, it would have been impossible to do.

Now remove the 1¼-inch castellated bolt that holds the front half of the U-joint to the output shaft. You pull a largish cotter pin and use an impact gun to get the bolt off. Then the front half of the U-joint yoke slides off. Next you remove the speedometer drive gear and pull four 3/8-inch bolts that hold the bearing retainer to the main transmission case. Once this retainer plate is off, it is then possible to hammer the old seal out from the inside and to install the new one.

My front yoke has a groove worn into the surface from the old seal lip. Putting a new seal onto this arrangement would guarantee another leak, so my next job will be to hunt down a speedy sleeve to fit the old yoke.

When the parts are put back together, the rear bearing retainer goes on with the new seal and gasket installed, and then the rear yoke and nut go on, with the drum on loose, in front of it. Then the U-joint goes back together before the drum can be bolted in place. You can put the bolts back into each hole with a needle-nose pliers and turn them in with a wrench from the top. There is also enough room here to put the bolts back with a ¼-inch drive socket and ratchet, but a wrench will be needed for final tightening. Then the brake band and linkage go back in place, and the gear box is ready to go back into the chassis.

The biggest part of this job is getting the front universal joint apart and back together. I have seen a special service tool for this job that looks like a heavy C-clamp. One of these would simplify the job considerably. If it allowed separation of the joint with the drum attached, it would save several hours’ labor.

Now I know why so many of these transmissions still leak at the back. I would never tackle one of these in the frame.

Good Luck

[grey beard]

If any of you are interested in this stuff, the speedy sleeve that fits our Pilothouse transmission yokes is a Chicago Raw2hide part number 99159. This sleeve repairs the groove that gets worn in the old yoke from the seal lip and saves buying a new yoke.

Good Luck

Edited June 3, 2010 by grey beard

[JoelOkie]

If any of you are interested in this stuff, the speedy sleeve that fits our Pilothouse transmission yokes is 99159. This sleeve repairs the groove that gets worn in the old yoke from the seal lip and saves buying a new yoke.

Good Luck

Dave, Thanks for the tutorial and sleeve number...I got it to do sooner or later. Joel

[grey beard]

I don't mean to go natteing on about something no one else is nterested in, but here's jow this job fell out, finally. The new U-joints that fit our trucks are a Chicago Rawhid numger 1-1612BF. I realize your mileage may vary, but for a benchmark to shoot at in your home area, my cost for this part was $36.00, exactly one half the price our friendly Massachusetts Bandits want for the same part in a plastic bag with no number on it. Go figure.

If you have access to a torch, it is best to cut the old U-joint cross out, as opposed to banging or pressing it apart. This saves considerable stress on the old yoke. Once the old joint is out, polish up the yoke and the new joint caps press together just fine using a bench vise and a few properly-ized sockets.

Bernbumm has the gasket set. if you go to all this work, might as well have the right gaskets. I glued them all in with the same Aviation cement. This baby should never leak a drop, if I have anything to say about it.

TThese rear seals are a bear to get in. I tried a large socket, a press, a vise anf finally wound up just banging it in by hand with a soft-faced hamjer. DO use sealer on the outside perimiter of the seal. I used Permatex Aviation gasket cement.

Good Luck

[Merle Coggins]

I found it interesting how your drive shaft connects to the trans output. Apparently the 3 speed transmissions are different than my 4 speed in that area. I also understand there's a difference in the u-joints between my late 1950 model truck and the '48-early '50 trucks. Mine uses u-bolts to connect the u-joint to the diff input flange, like on modern vehicles. At the trans there is a companion flange that bolts up the the output/brake drum. 4 nuts come off of the studs and the flange comes right off with the shaft. Once the shaft and flange have been removed the output flange/drum retaining nut is exposed. It sounds like this job would be easier on my 4 speed, although with a 4 speed and Fluid Drive my brake drum is VERY close to the cross member. I'd have to remove the cross member to be able to remove the drum. And of course the cross member supports the front of the fuel tank.

[JBNeal]

Yessirree, this here was a real chore as I recall. I replaced my seal with the transmission in the truck, and removing the brake drum from the yoke was a protracted cussin' match because of limited access and a previous repairer's head-rounding procedure. When I worked on this in '98, I remember being able to pop the old seal out after removing the brake bracket, and the National seal # that was barely legible could be used to order a new one from Purvis Bearing Supply up the road. I don't remember the cost back then, but I figger that seal & the pinion seal set me back about the same $$$ as all the other front & rear wheel & axle seals combined.

When I tear into the '48 here in a few weeks, I'll be documenting seal numbers a little better this time. In '98, all I did was label the new seal part box with location on the truck and kept all those little boxes stashed in a plastic container in the barn. When I went to check some numbers a few years ago, I found that a no-good varmint had chewed a hole in the plastic container & made a nest of those boxes, shredding my 'documentation' & excrementin' all over the remains. This time around I'll jot down numbers in a notebook and keep it in the house.

[grey beard]

Merle,

If you check the parts book illustrations, the three speed front yoke is retained to the output shaft by the big nut. Yes, you can remove the nuts on the brake drum that go through the fl[ange, but the U-joint must still be separated from the front yoke to get the nut off, which then allows the front yoke to come off. The nasty part of this issue is that the drum covers nearlyhalf of the U-joint, making it difficult to get to it.

My new joint went in with just my fingers - seemed almost too loose, until I realized that there are two surclips that must go on eac side of each cap, wich snugh the whole thing up jicely. I still used the old cross-boltec locks and bolts, even theough they are not necessary on this new joint. Mine is now fready to go back into the truck. Anxious to drive it, but I['ve also got two rear mounts and an upper main sewal behind the flywheel to change while the box swap is going on.

Lots to do befire the Macungie PA show in two weeis. . . . . .

[grey beard]

Merle,

If you look carefully at your own photo of your rear trans output area, the front U-joint yoke is splined to the output shaft and held in place with a large nut. The only way to get the yoke off the trans is to separate the joint. It looks like it unbolts, but it does not. It's a real bummer to get off.

On top of all that, the e-brake drum is held to the front yoke with four 3.8-inch bolts that come in from the front, and they have nuts on the back sides. The nuts are fine thread and the bolts have special shoulders on them where they pass through the drum and yoke. This all means that the only way to get the front companion flange off is to separate the front joint. Once the cross is out of the way, you have access to the big nut.

I checked the parts book and the three and four-soeed boxes even use the same yoke and rear bearing retainer, so yours is just like mine. It's hard for me to believe anyone could design somethig this hard to service.

My next job is relacing the top half if the rear main seal, behind the flywheel. As I remember, this is a fun job too, because there are nuts on those bolts on the crank that have a very tight fit. I'll be glad when the job is finished.

[HanksB3B]

Drop the drive shaft by removing the 4 nuts that secure the u-bolts of the universal joint to the differential then remove the 4 bolts holding it to the e-brake drum. This shoul take less than 15 minutes. Unless you like games like Rubic's-Cube I wouldn't touch all the clips required to dissassemble the front u-joint. I started to on my B3B then pondered about it and decided removing the drive shaft was a whole lot easier. Hope this is helpful and works on your model.

Hank

[Merle Coggins]

Hank,

The B1's and early B2's didn't have the u-bolt clamps at the diff end of the drive shaft. Those earlier trucks have a type of u-joint that requires pressing them in and out of the drive flange in order to seperate the shaft from the diff.

As for the trans end, Dave, the companion flange DOES come off of the drum by removing the 4 nuts. At least it does on mine. I know because I've had it off more than once. I don't have any good pics of it. Below is the best I have. If you look close you can see the studs sticking out the back and you can also see the yolk retaining nut in the center. Maybe yours is different than mine, I'd have to check the parts book myself when I get time.

[JoelOkie]

You know....that little drip in that seal doesn't look nearly as bad as I was thinking Well not really, I am going to attempt it sometime soon. I have the 4 speed in a 49 B1B. Am I likely looking at Dave's removal then, or Merle's, as I have the Cleveland cross U's?

[Dave72dt]

I'd start with taking those 4 bolts out. Both methods end up taking them out. Rust and tight fits can make them feel like one piece. If you can get by without disturbing those needle brgs, it'll be time well spent.

[grey beard]

Once opon a time I used to think I was fairly good at communicating my thoughts. Now I'm beginning to wonder . . .

Hank, pleasee re-read my entire thread over again from the top. Pulling the four bolts and nuts off of the front Yoke LOOKS like it should do the trick, but sadly such is not the case. Pleasee trust me on this, I've just soent quite a few hours working through this thing on a bench. In the truck it would be a nightmare, unless you are truly gifted as a contortonist.

Going back together, the same -lousy order or progression were necessary. First the drum goes on the back of the tranny, loose. Then the front yoke goes on and the big nut and washer, plus the cotter pin. Then the U-joint goes back onto the front yoke. Finally, the drum can be rebolted back onto the front yoke, but only after the joint has been reinstalled.

If any of you guys can pull your front companion flange off the transmission without first splitting the front joint, please let me know what I've been a'missin'.

Good Luck

[HanksB3B]

Sorry if I was mistaken as Merle pointed out the following to me:

Hank,

The B1's and early B2's didn't have the u-bolt clamps at the diff end of the drive shaft. Those earlier trucks have a type of u-joint that requires pressing them in and out of the drive flange in order to seperate the shaft from the diff.

My B3B driveshaft was attached with 2 u-bolts (4-nuts) in the rear and the 4-nuts holding the driveshaft to the e-brake drum. In order to drop my transmission for my clutch job I first tried to "follow the book" and unfasten the circlips to disassemble the front u-joint. For me, it looked like a no-brainer to simply remove the driveshaft without agonizing over the u-joints. It worked for my B3B, but according to Merle it's not so for B1's and early B2's

Hope it goes smoothly,

Hank

Edited June 11, 2010 by HanksB3B