Car hard to push in neutral looking for suggestions

Dragsinger · 05-11-2009, 11:59 AM

checking pre-load for pinion bearings and side bearings is your next move.

You will find differences of opinion on the amount of bearing pre-load used with differential setups. Personally, I like to run very light bearing pre-loads for the pinion bearings and spool bearings.

For the pinion bearings, I use a solid sleeve [factory crush sleeve is not used] and experiment with shims at the solid sleeve until a very slight amount of drag is felt. For me, it is a "feel job" I suspect it would just register with an inch pounds wrench, maybe 2 inch pounds.

The side bearings will be only slightly tighter [more pre-loaded] than the pinion bearings. Again, a "feel job" that comes with experience. I think you mentioned having a 8.8 Mustang rear? If so, the side bearing shims will "tap, tap, tap" in place without much effort, using a small hammer.

The above steps require patients, expect to change both pinion and side shims several times while sneaking up on the amount of pre-load. Of course, all the while arriving at the proper gear mesh pattern.

And speaking of personal experience, I have successfully used this method for many years in many applications. Also, never experiencing any shortened gear life nor breakage.

Once the gear/bearing setup is complete, before installing the axles, you can VERY easily turn the pinion flange. To my thinking, anything tighter is wasting power.

05-11-2009, 11:59 AM	#10
Dragsinger VIP Member Join Date: Jul 2008 Location: Liberty City [East Texas] Posts: 1,760 Likes: 5 Liked 99 Times in 60 Posts	Re: Car hard to push in neutral looking for suggestions checking pre-load for pinion bearings and side bearings is your next move. You will find differences of opinion on the amount of bearing pre-load used with differential setups. Personally, I like to run very light bearing pre-loads for the pinion bearings and spool bearings. For the pinion bearings, I use a solid sleeve [factory crush sleeve is not used] and experiment with shims at the solid sleeve until a very slight amount of drag is felt. For me, it is a "feel job" I suspect it would just register with an inch pounds wrench, maybe 2 inch pounds. The side bearings will be only slightly tighter [more pre-loaded] than the pinion bearings. Again, a "feel job" that comes with experience. I think you mentioned having a 8.8 Mustang rear? If so, the side bearing shims will "tap, tap, tap" in place without much effort, using a small hammer. The above steps require patients, expect to change both pinion and side shims several times while sneaking up on the amount of pre-load. Of course, all the while arriving at the proper gear mesh pattern. And speaking of personal experience, I have successfully used this method for many years in many applications. Also, never experiencing any shortened gear life nor breakage. Once the gear/bearing setup is complete, before installing the axles, you can VERY easily turn the pinion flange. To my thinking, anything tighter is wasting power. __________________ Larry Woodfin 471W