pinion bearing preload

[fast94mustangGT]

Ok, so im putting together my rear-axle. Did research on the web, found a site with a 8.8 rebuild right up. it says new bearings get 24-28 in/lbs, old bearings to 10-14 in/lbs, which seems backwards to me. Also says with ford gears you can reuse the stock pinon shim. Well pinon is meshing at the heel of the ring gear(think its the heel, outer diameter of the ring gear). I have preload sat at 25 in/lbs, is that right? Everywhere i look on the web tells me something different. Did i preload it to much and pull the gear down to much? Or am i going to have to reshim the pinon?? Any help will be appricated.

 

[Aryan15]

Are you using the marking compound?

 

[fast94mustangGT]

yea, using gear marking compound. but i can't get the mesh pattern right without having crazy backlash. and once i got the back lash down to .009 the mesh pattern is way out, the ring gear is riding more towards the top of the pinon gear.

 

[Aryan15]

What ratio did you have and what did you switch to?

 

[EMW150]

Ok, so im putting together my rear-axle. Did research on the web, found a site with a 8.8 rebuild right up. it says new bearings get 24-28 in/lbs, old bearings to 10-14 in/lbs, which seems backwards to me. Also says with ford gears you can reuse the stock pinon shim. Well pinon is meshing at the heel of the ring gear(think its the heel, outer diameter of the ring gear). I have preload sat at 25 in/lbs, is that right? Everywhere i look on the web tells me something different. Did i preload it to much and pull the gear down to much? Or am i going to have to reshim the pinon?? Any help will be appricated.

The new pinion bearing preload spec should be a little tighter like you posted because they loosen up a bit in a short time. As far as being off on the pinion depth, did you use the same shim under the pinion? All the FMS gears I've ever had were fine with the shim that came out under the origional pinion bearing. That's not to say it doesn't happen. What is the backlash where you're seeing a good pattern? If it's out of range, you need to check to make sure the pinion bearing is pressed on tight to the gear or you may need to reshim the pinion.

 

[fast94mustangGT]

I had 2.73 and im changing to 3.55.

With the stock shim under the pinon bearing, Which was a .032" shim, i wasnt getting the mesh pattern i want with .016" of backlash. With backlash at .008 the pinon was meshing way to much towards the heel of the ring gear today i stepped it up to .035" and it helped but still wasnt happy with the mesh pattern and i had it down to .009 backlash, and when i went to press the bearing back off i bent the roller carrier. But im pretty sure ive got to down now, this is my first axle build so i kinda learnin. Thanks for the Help guys!

Kinda nice to post on Stangnet again, been hangin out at FBF here latley.

 

[1987stangman]

I had 2.73 and im changing to 3.55.

With the stock shim under the pinon bearing, Which was a .032" shim, i wasnt getting the mesh pattern i want with .016" of backlash. With backlash at .008 the pinon was meshing way to much towards the heel of the ring gear today i stepped it up to .035" and it helped but still wasnt happy with the mesh pattern and i had it down to .009 backlash, and when i went to press the bearing back off i bent the roller carrier. But im pretty sure ive got to down now, this is my first axle build so i kinda learnin. Thanks for the Help guys!

Kinda nice to post on Stangnet again, been hangin out at FBF here latley.

What write up was it? I used the MHD (Master housing demesions method) I also went from 2:73 to 3:55. Using the MHD method I even reused the carier shims and backlash was right in spec.

BTW: It is hard to remember, but I don't think the stock pinion shim was 035", it thought it was smaller. Been awhile though

 

[fast94mustangGT]

I used this right up...
http://http://www.angelfire.com/theforce/5ohcpa/cpa5ohtech001.htm

I got the mesh and backlash to a point where i was happy last night, had to use a crazy amout of pinon shim though, .039" worth of shim. The car does have over 200,000 miles though. But once its in im gonna take it for a quick spin just to see if i hear anything funny. Thanks for the help guys