Viscous coupling failure?

[Jward408.jw2]

Ok so the noise is definitely coming from the right rear hub area. Is there anything specific that I need to know before axle replacement? I know a lot of things vary from year to year, model to model. Should I be looking for a specific axle or are these pretty much universal throughout the eagle family?

[AMC of Houston]

All Eagle rear axles are the same; year-to-year, and side-to-side.   But it has to come off an Eagle; other AMC passenger car axles won't work (even tho some Hollander mis-info says otherwise).  If you get a left side axle (preferred), you'll still have to press off the hub to get the backing plates swapped out (and of course put a new bearing on it while you're at it).    Also going back together be sure to set the axle end play per the TSM (no shims go on the right side; only the left).  You'll find that usually will have to reduce the shim pack thickness due to normal wear on the diff spacer block).

And don't put the new bearing on backwards!!   I've seen it done by AMC-inexperienced shops!!   Outcome wasn't pretty.....

Good luck finding an axle (they're out there).

[MIPS]

For curiosity sake (you can't really drive the car right now anyways), raise and support that corner with a jackstand and then give the wheel a good wiggle and pull. If the break is on the outside portion of the shaft the wheel and drum should pull right off.

[Jward408.jw2]

It’s actually drivable in 4wd the front axles are popping so I’m sure they’re due for replacement also but it drives fine. Even in 2wd it does excellent until a hill. I can’t find an axle for the rear anywhere though.

[vangremlin]

I can’t find an axle for the rear anywhere though.

You could try car-part.com.  They sometimes have those hard to find parts available used.  Good luck!

[Thack]

There is one more option for what’s going on, the transfer case is in 4WD and the diaphragm in broken. When you select 2wd the axle disconnects and the viscous coupler is supplying power to the rear but losing power to the open front. It would make taking off and loads feel like it was slipping. Changing the selector to 4WD would close the open power loss and would drive pretty much normal. To confirm this look at the transfer case lever in both 2wd and 4WD to see if it has moved.

Tom H

[rmick]

ATTACHEMENT

[Jward408.jw2]

Ok, I feel like such an idiot for this but the selector lever wasn’t locking fully into 2wd. I’d like to apologize and thank everyone for their advice. I was poking and prodding around under there yesterday and took the transfer case cover off to see the selector better and cleaned it really good there was debris caked up on the lever/nut and the rod didn’t seem to be getting the vacuum it needs to fully shift it.

[AMC of Houston]

Glad it was an easy fix!!    Here's hoping you never experience the dreaded right axle failure!!

[Jward408.jw2]

Manually locked it into 2wd and took it through a gravel parking lot. It’s definitely locked in.

[Jward408.jw2]

Good news is I located a 1988 parts car nearby good motor trans vtc and diff.

[vangremlin]

Glad it worked out for you.  You're not the first one to experience that problem!

That parts car will come in handy!

[MIPS]

I found that after 35 something years it's worth the time to remove both SelectDrive actuators, clean and lubricate the shafts. The front one especially as it has a vent that allows road dirt into the shaft cavity can and will seize it up. Likewise inspect the rubber grommets that connect the various rigid plastic lines to the steel lines. I've had a set which were deformed and swollen from soaking up too much rubber softening engine additives over the years.
The system runs off manifold vacuum and uses a vacuum reservoir as a booster. Neither actuator needs a strong vacuum to operate, just a constant vacuum. Take a small piece of vacuum line and you should be able to operate both using your mouth.

[vangremlin]

Take a small piece of vacuum line and you should be able to operate both using your mouth.

May I suggest using a piece of "fresh" vacuum line?