Swamp Donkey died while on the highway, Transmission?

[Flyin Tyes]

Since your seal is leaking (so is mine) why not pull that assembly off. You need to change the seal anyways. That would let you see how many shavings there actually are.

Tried to pull rear drive shaft. bolts were pretty stuck. no rattle gun. after the TC drain plug magnet was clean I didn't work too hard? Suggestions removing the drive shafts? should I be trying to hold it from spinning while loosening the nuts?

 

[Flyin Tyes]

I meant to ask earlier.........

Have you had someone in the truck with it running and in gear and checked to see if the FRONT driveshaft was turning?
YES. COULDN'T SEE ANY SHAFTS TRYING?

The reason I'm asking is because if a front drive plate on the hub is sheared, the front CAN turn by having the VC inside the TC working like it should. When working properly, you can jack up ONE wheel and that wheel will spin with it in gear, but the truck will not go anywhere if it has an open diff and unlocked CDL.
HAVE NOT TRIED THIS.

 

[Eicca]

Subscribed for more good reading.

 

[Flyin Tyes]

here is the AT section of the FSM
FSM AT Section - Google Drive

If no to #1&2 then reference pages AT-15&16
HAVE NOT GONE THRU ALL STEPS AT-15-16
NOT SURE WHAT I CAN STILL CHECK WITHOUT REMOVING OR OPENING...?

 

[ppc]

Tried to pull rear drive shaft. bolts were pretty stuck. no rattle gun. after the TC drain plug magnet was clean I didn't work too hard? Suggestions removing the drive shafts? should I be trying to hold it from spinning while loosening the nuts?

If the wheels are on the ground then the driveshafts should not rotate. Disconnect from the transfer case first. You may have to move the truck a foot or two to rotate the shafts enough to get at all the nuts.

 

[Marine7]

If your tires are on the ground, truck in park, and your driveshaft is spinning..... you found your problem!

 

[SmokingRocks]

AT 15-16 specifically the second problem listed and the last item in the chart both are symptoms you explained and both say to check the manual shift linkage then if thats fin inspect the parking lock paw.

But yea just as Marine7 said if your drive shafts are spinning and the rig is not moving forward your driveshafts are toast.

 

[BILT4ME]

I think there is getting to be a descriptive communication problem here.

I will watch from the sidelines......

 

[Flyin Tyes]

sorry I wasn't clear. the drive shafts aren't spinning free, just a slight rotation before they put pressure on the differential and TC. But with the bolts a bit rusty and tight, wasn't sure how much pressure is okay or should I try and hold them while I loosen.
However after not finding more shavings in the TC, I felt more certain that the problem is the transmission and stopped trying to get the shaft off.
I will see if I can continue with the transmission troubleshooting steps on AT-15-16 and will check the hydraulic pressure.

 

[Flyin Tyes]

thanks for all of the help and suggestions. I found a used trans/TC still together from a wreck. Given my carport tent and the fact that salt lake is having an actual winter, decided to drop both off at a local shop to swap them. Hopefully this works out to be a good decision.
I will update with results and hopefully the cause of the problem.
Thanks again.
Jake

 

[Eicca]

Remind me again, did you check the front drive flanges....? Does it move with CDL locked?

 

[Flyin Tyes]

Which flanges? at the u-joints? I couldn't find anything physically wrong anywhere. Nothing I did made a difference. No drive forward or reverse. Doesn't have a manual locker switch, but when shifted in/out of low I could hear what sounded like the motor engage the lock, still no drive.

 

[Eicca]

Which flanges? at the u-joints? I couldn't find anything physically wrong anywhere. Nothing I did made a difference. No drive forward or reverse. Doesn't have a manual locker switch, but when shifted in/out of low I could hear what sounded like the motor engage the lock, still no drive.

Ah ok then. The drive flanges are under the dust caps of the front hubs. It's where the axle shaft drives the wheels. Sometimes one can strip out and spin all your power out that side. But if it didn't move in low, unless the CDL didn't engage properly for some reason, then something else is up.

 

[Flyin Tyes]

I didn't check them

You can do all of the trans tests, may find problems, but not likely to solve the main problem. Looking at the posted clues, this is one of the most important ones.

The auto trans is effectively in neutral when the motor is off, this is why they have a park pawl. So the park pawl has to be on the output of the trans. For the park pawl to skip when engaged, that drum is spinning. To be spinning, the trans has to be working and something is disconnected between the trans output and the wheels. In this case, the driveshaft isn't spinning, so has to be between The trans output and the drive shaft flange, in other words, transfer case or trans output shaft broken or splines stripped.

I visited two local transmission shops. When I explained what happened and what the symptoms were (no drive and grinding going back into park), they both immediately thought something in the T-case and likely the splines were the cause. I hope that the swap goes well, then I can take my time to examine my original units and if possible get them working, keep for backup or sell to another cruiser owner in need.
Jake

 

[Eicca]

I missed the part where you said it did make grinding noises when going back into park. That (to me) definitely puts highest suspicion on the t-case.

 

[SmokingRocks]

Why?

The park paw is in the transmission, the transmission should transfer 0 drive to the tcase when shifting into park like literally zero. If it is then theres an issue with the transmission.

I suspect line pressure is gone.

I guess the only way it could be the tcase in this instance is if it had catastrophically failed and the transmission is just spinning the t-cases input shaft with nothing to resist it.

But in this case you could shift into neutral (would stop sending power to the tcase) then shift immediately to park. It wouldn't grind if its really the tcase because the transmission output shaft would not be spinning.

 

[Eicca]

Why?

The park paw is in the transmission, the transmission should transfer 0 drive to the tcase when shifting into park like literally zero. If it is then theres an issue with the transmission.

I suspect line pressure is gone.

I guess the only way it could be the tcase in this instance is if it had catastrophically failed and the transmission is just spinning the t-cases input shaft with nothing to resist it.

But in this case you could shift into neutral (would stop sending power to the tcase) then shift immediately to park. It wouldn't grind if its really the tcase because the transmission output shaft would not be spinning.

Because if the transmission is functioning fine in drive, but the t-case is broken, the parking stop mechanism will still spin. When putting it back in park after drive, it'll rattle until it catches.

I did that on accident to my mom's 100-series. I had the t-case in neutral and the trans in drive. I shifted back to park so I could shift the t-case and when I did it made a grinding/clattering noise because the trans was still spinning when I shifted to park.

 

[SmokingRocks]

yup read the second half of my post

It'll be interesting to see what he comes up with.

 

[Flyin Tyes]

Rolling again. Transfer case. Decided to have the shop use my original transmission and the Tcase from the salvage yard. So now I have a used transmission (anyone in need?) and a box of gears.

 

[Flyin Tyes]

melted