Rear end bearing question.

[Mad Hatter]

I have about 25,000 miles on my 2012 Boss and have been hearing a little more noise from the rear differential lately. The car is tracked about twice a month and I thought it would be a good idea to change the rear bearings etc. On taking off the Diff cover everything looked very tidy with no wear on the rear gear and the oil all clean. Should I postpone the bearing change? or go ahead form a preventative point of view?? When I spin the rear wheels by hand, I can hear a slight raspy sound on one side, I expected to see some bits of metal in the oil but it was all clear.

 

[TMSBOSS]

If you are hearing a bearing noise, don't wait on the bearing to fail before replacing.

I would replace now since you have the cover off.

 

[k98dave]

Sounds like it may be an outer axle bearing. On all the 8.8 rears Ford used the axle itself as the inner race of the outer bearings. Pull the C clip and slide the axle out to inspect the surface the bearing rides on to see if its scored. Changing the outer bearing/seals and axles is a lot simpler than the carrier /pinon bearing and required no gear lash set up.

I have about 25,000 miles on my 2012 Boss and have been hearing a little more noise from the rear differential lately. The car is tracked about twice a month and I thought it would be a good idea to change the rear bearings etc. On taking off the Diff cover everything looked very tidy with no wear on the rear gear and the oil all clean. Should I postpone the bearing change? or go ahead form a preventative point of view?? When I spin the rear wheels by hand, I can hear a slight raspy sound on one side, I expected to see some bits of metal in the oil but it was all clear.

 

[Mad Hatter]

Sounds like it may be an outer axle bearing. On all the 8.8 rears Ford used the axle itself as the inner race of the outer bearings. Pull the C clip and slide the axle out to inspect the surface the bearing rides on to see if its scored. Changing the outer bearing/seals and axles is a lot simpler than the carrier /pinon bearing and required no gear lash set up.

Yup the outer bearing was dead. Shaft was ok though at least with no wear. Going to go ahead and change all the bearings since its all apart.

 

[k98dave]

Yup the outer bearing was dead. Shaft was ok though at least with no wear. Going to go ahead and change all the bearings since its all apart.

My experience is just replace both outer bearings/seals. If the gears show a good pattern and back lash why fix whats not broken?

 

[C7 B8]

I had my axle bearings and seals replaced. Mechanic told me the bearing still looked good but the seals weren't properly seated from factory which caused fluid leak. Easy job actually but messy work I didn't want to touch.

Great time to flush and use all new fluid too. For track car, I flush every year ~6-8 events.

 

[Mad Hatter]

Since I had the complete bearing kit, went ahead and changed everything. Hope I dont regret it!! I generally like the don't fix it if it aint broke philosophy!

 

[TMSBOSS]

Did your noise go away?

 

[Mad Hatter]

I will know tonight when we finish!

 

[TMSBOSS]

Good luck!! ;D

 

[Mad Hatter]

Thanks! the play in the axle is gone and the sound as well. Was a little strange to only hear the engine for a change, The rear gear whine was quite noisy and now its completely gone.