1G AWD Tranny Binding

[DSM AWD TSI]

I recently purchased a 91 Talon shell that came with an AWD Tranny. Today I decided to clean up the tranny a little and so I was shifting through all the gears and turning all the shafts when I noticed that I couldn't turn the transfer case output shaft.

So, I took off the end cover to see what was going on inside. With the end cover off, the transfer case output shaft spins normally as well as the input shaft in each gear. Just to make sure I hadn't been hallucinating before, I put the end cover back on and tightened the bolts. Now, neither shaft spins! (In any gear as well as neutral!) However, even though the transfer case output shaft won't budge turning in either direction, it has a little in-and-out play.

Is the end cover too tight? Is some internal measurement off? What should I do?

Thanks in advance for letting me know what I need to check out in there or how to proceed.

 

[twicks69]

It is supposed to have a bit of in/out play due to the nature of the design. As for the transmission binding up, taking off the 5th gear cover does not give you enough insight into what may be causing the problem inside the transmission. You will need to remove the end shaft nuts, 5th gear assembly, and the viscous coupler, then the intermediate case section to get access to the center differential and have a better view of the main gear clusters. It could be a shredded center differential, or a worse problem such as a bearing failure or gearset with damaged parts.

 

[donniekak]

If everything turns freely with the cover off, but has a lot of resistance when bolted together, you may have tightly shimmed bearing preloads.

 

[DSM AWD TSI]

So if I can turn everything easily by hand with the cover off, in every gear and neutral, but nothing turns by hand with cover on then how do I find out if that is just awesomely tight shimming or overly tight shimming or other obstruction or something? Should I slap a clutch on for better leverage and try to turn it with that? Thanks guys.

 

[twicks69]

How were you turning it before???? There is supposed to be resistance by hand -- are you using a splined socket or clutch disk to rotate the input shaft with the transmission fully assembled?

Here is a tool I made that I use either with a torque wrench or simple ratchet or breaker bar to rotate the transmission input shaft quickly and easily (see pictures below). There are also several specialty tool splined sockets that can fit onto the input and intermediate end shaft splines, the input shaft splines or the output shaft splines.

As for bearing preloads, the only effective way to find out where they are currently at would be to remove the 5th gear assembly and viscous coupler, then remove the intermediate case section that houses the outer input shaft/intermediate shaft/center differential tapered roller bearing races and shims.

Then, remove the bearing races and shims, and reinstall the bearing races with 3/32" diameter rosin core solder on the center differential between the bearing race and the case section (where you would normally have the shim), and 0.062" diameter solder on the input shaft and intermediate shaft between the bearing race and the case section. You will use two ~1/2" long pieces equally spaced from each other on each bearing race and keep the solder off of gaps in the case section as well as off of stamped letters/numbers on the bearing races. This way you will have a better chance at getting accurate numbers for the solder test utilizing a micrometer for measurement.

With the solder installed (use a bit of grease, or petroleum jelly, or assembly lube to hold the solder in place while you install the case section onto the races/solder), do not reinstall 5th gear assembly or viscous coupler. Instead, reinstall the 5th gear cover with the fasteners torqued to 29 ft/lb and then remove the fasteners and 5th gear cover, then the case section with the bearing races and solder, then extract the bearing races and gently measure the solder pieces for thickness down to the ten-thousandth and take an average thickness of the two pieces per bearing race to get a baseline "zero preload" number to work with. Then measure the thickness of the associated shim per bearing race to see where the existing shims are for endplay/preload values.

Now, we can see what we are working with.

 

[DSM AWD TSI]

Yeah I was just trying to turn it by hand and it would NOT budge at all. I thought that it was normal for them to turn very easily because I have turned at least 3 different AWD Trannies by hand like that when messing around during clutch jobs or whatnot.

Ok, I will try to turn it via some kind of leverage tool. If it turns at all I will then consider doing the shim size test since it sounds a bit past my current expertise level. If it is REALLY stuck and doesn't turn at all I guess that will suck for me...

Thanks a lot for your detailed instructions and help!