Hello all. I have an interesting issue. 97 Legacy outback wagon Automatic shuddering while pulling of the line in first gear. Feels like a bad trans mount in an old RWD car. Problem goes away with the FWD fuse in. There is also a slight shake at 60 in AWD but it is also gone in FWD. Unfortunately I did not drive it prior to pulling the motor for head gasket replacement except to drive it onto a Uhaul transporter for the 70 mile ride home where my daughter broke down.

As I said, runs like a scalded dog in FWD but shudders in AWD in a straight line or turning unless on a gravel road. Shudder goes away then also but cant get up to 60 to check a tire shake. (I am not that nuts).

 

One more thing. When trying to get a rounded nut off on the bottom left bellhousing the axle slid out some with the stub shaft. As this is my only Auto roo I do not know if this is supposed to happen. I did end up pulling the left axle to gain access to the rounded nut. Everything went back together in their original orientation. 

 

Any help or ideas would be helpful. I do have the option of bidding on a couple wrecked roos for parts if necessary.

Ok after driving it to work tonight the wheel shake is still there in front wheel drive just not as pronounced. Can the trans pan being pushed up a little cause some of these shuddering issues? It is a possibility that it got pushed up a little when pulling the engine for the head gaskets. 

from what I've read - there is VERY LITTLE clearance on the other side of the trans pan and if it is visibly dented upwards, solenoids can be damaged, wring compromised, etc.

 

might be an easy fix though with a new pan and solenoid set from a wrecked car.

Well the Transmission is the issue. Pan is not bent and after getting of the phone with my daughter I just found out it has had these symptoms for about 6 months. I am going to let her take the car back to school and hunt for a good used trans. After I get that I will get the car back and change it out.

Is there a bad vibration in D stopped at idle? Sounds like it could be a bad front axle, usually an aftermarket unit is the culprit.

 

I will have the front end off the ground and check how much play the axle joints have. Excessive slop or too tight of clearances cause a shake.

Is there a bad vibration in D stopped at idle? Sounds like it could be a bad front axle, usually an aftermarket unit is the culprit.

 

I will have the front end off the ground and check how much play the axle joints have. Excessive slop or too tight of clearances cause a shake.

No vibration at all at Idle. Axles have been in there since before I got the car. No slop in the axles. There is just a slight shake around 60 to 70 mph.

Before I disabled the AWD there was a bad shudder when pulling off the line. It went away with the fuse put in. I also discovered this morning if you manually downshift the trans is makes a racket and it is not a good racket. It did not do that last year. Fluids are full and good. If I can get a good used trans and not have to give the old one as a core I may tear into it and look into rebuilding it. I can always hope it is easy to rebuild as a Torqueflite....

replacement trans must be the same final drive ratio. places like car-part.com or LKQ 'should' have inventory that's correct. Or maybe find someone on craigslist that is parting-out a similar model.

 

just to be clear - all 4 tires are the same brand/model/size and near each other in wear right? critical on AWD cars.

I had a similar problem, and I had really hard time figuring it out. All the tires appeared identical, but I ended up have tread separation.

All four tires are the same brand, size, age and pressure. Just recently rotated. Problem started before the tire rotation. 

Trans is on its way out. If you manually down shift the trans in AWD or FWD it sounds like it is coming apart at the seams. It does still shift in auto.

I would check for a bad u-joint on the rear driveshaft. Those can be difficult to check with the driveshaft in the car so you might want to pull the whole thing out to heck it thoroughly.

You can remove the rear half and drive the car and see if it makes a difference.

Check the joints for play, also move them around by hand and check for rough spots. A u-joint can also seize and cause vibration problems.

I've also seen a sticking rear brake caliper cause the same issue.  Upon on inspection one of the four pads was way more worn than the rest.  Replaced the calipers and the problem went away.