1972 Cj5 - T15 Transmission Rebuild

Got my trans and xfer case out for install of master rebuild kits on both.
Both master rebuild kits purchased from Novak.

Note: When I first got the jeep out of the pasture sitting for about 12 years, both trans and xfer case had about a gallon of water in them which is why some gears hubs have some rust that I believe I can get off with scotch brite.

Starting on transmission first, popped the top cover and found some issues and would like to have thoughts on my questions below.

1. Is it normal once the xfer case is removed from trans to have a bunch of front/back play. I measured it with dial indicator and it is about .052 end play, but was thinking this is not an issue once the xfer case is bolted back on trans.

2. On the below pic one of the "synchronize rings?" appear to have been ground off about 5 teeth. The pic is the first gear front of trans and did not look right to me. But checking with Novak support they replied that it is normal and is done for assembly.

Is it part of the 1st gear (machined as one) Or, is it separate item possibly called first and reverse sliding gear.




Thanks for any input.


1972 Jeep CJ5 - 304v8 - T15 - D20

 

When I rebuilt mine about a year ago, if I remember correctly, that has to be there so the entire shaft assembly can be removed and clear the reverse idler gear. One thing I learned, save everything that you remove, some parts may have to be reused, mostly the rings that hold the gears on the shafts at different spots. I took and old broom handle and attached to my workbench sticking straight out. I put the parts on that stick in order as I took them out, with all the parts removed it's easy to lose track of what goes where. Pictures and masking tape to mark parts was very helpful. Good luck.

 

That cutout is factory done for assembly and disassembly purposes as Flatlander said. It is there to clear the counter/cluster gear assembly in the bottom of the transmission. That is part of the input gear which is 3rd gear in your T-15. The synchronizer ring is the brass yellowish colored part. The part that engaged the gear is the synchronizer sleeve.
Your description is backward. First and reverse is at the rear of the transmission, second is in the middle, and 3rd (high gear) is at the front.

 

Thanks Nickmil. I am waiting on parts now for the T15 and moved over to the Dana 20. Did not create new post as this is dealing with same T15/Dana20 combo.

The Dana 20 transfer case is giving some trouble trying to remove the shift rails. I can pull the cover up about an inch and that is it. I am thinking it is because the detent balls/springs are still in there but I thought there should be threaded caps to remove, appear to be plugs(like freeze plug). Shift rods for some reason are extremely difficult to move any direction now. Before disassembly I could move them slightly in/out about an inch or so.

Do you know if I take these plugs out will that give access to the spring and ball? I cannot find any info on how to get the shift rails out and new plugs this small are not in the master rebuild kit. The second pic also shows how far I can pull the shift assembly out of the case itself and stops.

 

This is interesting, I will need to disassemble my D20 soon. I have never worked on one. I have worked on lots and lots of D18's that had the screw in plugs. I had also just assumed the D20 were the same. Hopefully someone will have had experience with these.

 

I don't have the service manual right in front of me, but if I remember right the shift rods have to be rotated some to remove, in which case they have to be separated from the shift lever assembly which allows them to rotate independently. Someone may correct if that isn't right. I believe that if the rods are rotated to a round section, and not where there is a depression in the shift rod, it would depress the ball and detent spring and allow the rod to slide out. I think the press caps stay in place and just hold the spring and ball from falling out the back side. They (spring and ball) are put in place from the top side, where those plastic dust caps are and then the rods are re-inserted and the ball and spring have to be pushed down with a pick or something and the rod slid over the top of them, without the ball flying across the room. I couldn't get my shift assembly apart so I just left everything in place because it was shifting okay. I am going from memory out of manual a year ago or so, and may be all wet. I highly suggest getting the factory service manual for your year of jeep, it has saved me many times over. found my in flea-bay. Good luck.

 

Thank you.

 

Good info here: https://oljeep.com/index.html

 

Bolt the front output housing back in place with a couple bolts. Turn transfer case upside down and remove all gears and output shafts and rear output. Put the front output shift rail in neutral position. Remove set screw for rear output shift fork. Slowly rotate that shift rail back and forth. A screw driver or punch in the linkage hole works well for this. The detent ball and spring are between the housing (in a machined recess) so will likely come flying out when the shift rail clears it. A bunched up shop towel to catch it is helpful. Once the rear fork and shift rail are removed, rotate the front output fork and shift rail so you can access the set screw and remove it. Then you can remove that rail and fork. Again, the detent ball and spring May come flying out. Then you can remove the front output housing. There are interlocks between the shift rails but are captured in the front housing. There are machined passages for them and can be removed if you remove the soft plugs. Those tiny soft plugs are a bear to find so if you can avoid removing them, I’d recommend it. The plastic plugs above the shift rails just push in but the holes are threaded. Jeep just went cheap on the plugs which lets water and other crap in. IH Scouts used steel threaded plugs and are much better. Some applications used a switch in these holes for indicator light on the dash.

 

You guys are spot on and much thanks. Doing how Nickmil said and rotating each shaft gets the poppet out of the detent and the rod pulls right out. Yes, those poppets come out like they are late for dinner but the bunched rag captured them, then used a small pick and pulled the spring out.

And you were right, you do not have to remove those tiny plugs unless you wanted to take the longer "pills" out but mine are moving back and forth smoothly and I am not taking the little plugs out.

Just FYI, the Master Rebuild kit I purchased from Novak did come with new Aluminum threaded caps to replace the plastic ones.

So I have 2 more questions if you guys don't mind.

1. The two aluminum covers for the end of the shift rods came out which I wanted to do as the kit came with new ones and these were scored and dented and leaking. What is the best way to put the new ones in without crunching them like an accordian? They are aluminum and I "think" I can use the right size deep socket to fit on shoulder and tap them in. Sound about right?

2. I disassembled the rear output shaft to install new bearings/seal etc. It has a metal speedometer gear and one shim on the yolk side of the gear and zero shims behind it. There were tiny pieces of a shim that were all over the place. Not sure where it all went but I found 3 small pieces of the entire shim. Looking at diagrams and the TSM, it doesn't state how many shims there should be, but a few YT videos I have watched had 1 shim on the yolk side and 3 shims between speedo gear and shaft. Is there a standard on these shims with it being a metal gear as to how many?

 

Sorry, I never got that far into mine. I just did a cleanup, new bottom gasket and repaint. Sounds like you're on the right track with the caps though.

 

The shift rail caps from the factory are steel not aluminum. After removal and thorough cleaning of the case and caps I put a small smear of sealer around the outside of the cap where it goes into the case and gently drive them in with a deadblow hammer or rubber soft faced hammer until they bottom out. Check the new ones with a magnet, they should not be aluminum.
Regarding the rear output shims, they go between the step on the shaft and rear outside output bearing.

There is not a set number or thickness of shims. This has to be adjusted to set the bearing preload/clearance mentioned above.

I’d highly recommend getting a Factory Service Manual as all this, with good diagrams, is covered and is extremely helpful in performing these types of services.

 

Nickmil, Thanks for the response. I do have the TSM in book and CD format. Amazing things happen when you actually open them up and do a little reading.

I got the transfer case all back together except for the rear output shaft assembly. I did notice in the TSM it shows 2 of the shims between speedo gear and shaft and 1 shim in front towards yolk. I am going to go with this and assemble/torque and check the end play.


PITA part about this is if the end play is not within spec having to press bearing back off etc.

 

I got the rear output shaft put together, bearings pressed etc. I put 2 shims behind the speedo gear and 1 shim in front(yoke side).

After torquing everything down, cover 30lbs, yoke nut 150lbs, something is definitely not right. It take lots of effort to spin the yoke. Damnnnnnnn..

So I re-read Nickmil response and didn't register where you said the shims go.
"they go between the step on the shaft and rear outside output bearing"

On teardown there were no shims between the step on the shaft and rear outside output bearing.

Tomorrow I will tear the output shaft back out and I am going to remove the 2 shims from behind the speedo gear. I am thinking I will leave the 1 shim in front of speedo gear(yoke side) because originally it only had that one in front of speedo gear, and re-assemble.

Any other thoughts on why it would be so tight? I verified each step pressing races that they seated fully and bearing look great sitting in the race.

 

Diagram of the Dana20. Shims do not appear to be on the step portion of shaft???

 

I must have been thinking of the Dana 300 as that’s been the last several transfer cases I’ve done. That old timers disease. As per the diagram you want them either between the speedo drive gear and inner bearing or between the drive gear and outer bearing. You can split the shims up like they have in the diagram but it just makes it harder to set things up. I generally put them between the speedometer drive gear and outer bearing. Less to remove when making changes to get the setting right. With new bearings I set endplay at zero endplay with no preload. New bearings will wear some and endplay will increase a little bit. Others might disagree but it’s worked for me for 30 years or so.
I apologize for any confusion on this. It’s much easier when I have a diagram or the parts in front of me. Problem is as I do less of this I’m having to refer to diagrams or parts more and more as the stuff “fades away”. One thing I’ve found helpful to save time is if you have a press, install everything but the yoke in the press and see what endplay is with light pressure applied to the bearings then adjust until no endplay and no preload is applied. This has speeded things up for me and it’s already I. The press if things need to come back apart. You don’t wear out the nut or output shaft threads this way also. Once you have it adjusted where you want it then install the seal and yoke and torque the nut appropriately. Lube the seal, use sealer on the yoke splines, and a dab of threadlocker on the nut.

 

No apology needed at all. You input is valuable and helps me learn. I will try your preload method. I do have a press. Thanks for your feedback.

 

Happy to help. When you are putting pressure on the outer bearing in the press start really super light, rotate the housing, add a little more pressure, rotate housing (I do it while rotating the housing). Rinse and repeat. This does a couple things. One, keeps from damaging the bearing and race if there are not the correct thickness of shims, and two it helps center and fully bottom out the race and bearing in the housing. It’s really frustrating when you think you have it set right and it loosens up when everything finally seats in place.

 

So I tried the way you mentioned, in the press, rotating as it went in, bearing seated and looks good.

I have 4 shims on the "yoke" side of the speedo gear and none on the back side.

With bearing pressed in, housing spins real nice. I installed the seal, yoke, washer nut. I tested the tightness as the nut contacted the yoke and it immediately began to get tight to turn. I spun the nut on to about 80 ftlbs and tested it and could not move/spin the shaft or housing.

I am not sure what to do at this point, get more shims and try ?

I have verified several times that the races are fully seated, speedo gear slides on snug, takes both hands to put it all the way down.

I have tried moving shims before and after speedo gear but I get the same type of tightness as soon as the nut contacts the yoke to begin tightening. Am I correct in the thinking that shims on the yoke side of speedo gear is what should be setting up for endplay? If that is the case, do I need to look at getting more shims?

Below is a pic of the output shaft apart.
Left to Right
Seal- Bearing- 4-Shims- Speedo Gear- Bearing- Shaft gear

 

I would agree it appears like you would need more shims. But let's see what Nick says.