Transmission input shaft bearing.. new rear main seal also?

[spdweb.net]

Never a shortage of pictures here. The rear input shaft bearing and the seal/gasket kit were not in stock. They said everything should be shipped by Friday.

I have been trying to see if I could find anything that would have made the bearing fail. I haven't found anything thus far. I do see the clutch was recently replaced. I would say it has less than 10k miles on it so I will be reusing that. All the alignment pins were in place. The rear main seal also looks new and is not weeping so I will leave that alone.

What sealant do you all suggest for the transmission reassembly?

Here are some pics of the process so far.



Neat way to organize the bolts. Had my wife take these shots and I printed them out at work.


Broke open the bearing to check out the insides


The inner race of the rear bearing


Outer race


Ball bearings


Clutch has very little wear, fly wheel has no ridge at all and I can still see where it was resurfaced, pressure plate looks practically new.












Rear main seal. I believe this may have been changed when the clutch was changed. Looks to be in good shape so I will just leave it be.

[Legacy777]

Nice pictures!

Yeah that inner race and the bearings look pretty chewed up and pitted. There may have been some dirt/gunk in there that caused the accelerated wear, or it might have been a defect in the material/bearing.

[spdweb.net]

I am going to guess that it was some problem with the hardening process of that inner race. Going by how far gone the inner race was and the outer race is mostly intact. The ball bearings are certainly chewed up as well though.. its hard to tell what started to fail first.

Hopefully I will get it back together next week some time. I'll take some more pics when the parts come in.

Thanks again for your help. Even though I don't have a 89-94 BC-BF(BJ) Legacy lol

This is the only forum I could find where people were not jerks.

[Legacy777]

You're welcome, and glad to help.

[spdweb.net]

Alright... parts came.. all pressed together. (Pics soon) Happen to know the torque for the end nut? I have seen 40ftlb, 86.4ftlb, and "Its torqued to like 250ftlb" That last one I doubt is anywhere close but it was posted on a forum. I torqued it to 40ftlb, but I am having trouble holding the shaft still in the vice for anything over that. It's staked to the shaft at 2 points (like a hub nut) to keep it from spinning off so I don't really see where a really high torque is too much necessary. As long as its snug and staked correctly its not going anywhere.

Thoughts?

[Legacy777]

You can d/l section 3 (trans) of the liberty manual and see what it says in there. It should be the same as our cars.

http://main.experiencetherave.com/subar ... tion_3.zip

[spdweb.net]

Alright... I got everything put back together last week.. Here are some pics of the highlights.

Replaced:
Both input shaft bearings
Input shaft seal
Both front half shaft seals
Output shaft seal
Various other seals and gaskets
Pilot bearing
Throw out bearing
Checked gears for wear
Checked all other bearings for wear
Checked syncros

Got everything assembled and installed. Input shaft bearing noise is gone. What I do notice now though is a hum or "singing" (similar to tire noise) which only occurs in 3rd, 4th, or 5th gear under light to moderate load, and only between the speeds of 30 - 40mph give or take. The noise is speed dependent and the pitch/frequency rises as speed increases. It is accompanied by a slight high frequency vibration that can be felt through the center console and a tiny bit in the gear selector. Most pronounced in 4th gear by far. Under light load in 3rd for instance the noise will be slight starting at 30mph, getting louder in 4th and then almost disappearing in 5th until going away completely over 40mph. If I drive spiritedly and hold 3rd until after 40mph, I do not notice any noise at all.

My thoughts are possible front or center diff.. however.. Usually as far as I know, any differential noises are present at all speeds or even louder at higher speeds. I can not pinpoint the noise at all while the car is on jack stands as there is not enough load on anything. Another thought was possibly incorrect front diff backlash as I did remove the adjustment rings to install new seals however they were marked and put back to the same spot.

Here are some images of the internal assembly and new bearings.

[Legacy777]

Thanks for the follow up and the pictures!

I'm assuming you torqued the main shaft bolt appropriately. Are there any shims or backlash checks on the mainshaft? I don't know if bearing widths change much and if that could affect anything. As you pointed out differential backlash would be my first thought, but if everything was put back together properly then I'm not sure.

It almost sounds like a natural frquency somewhere in the drivetrain. It vibrates/resonates at a certain speed and once you pass that critical speed, everything's good again.