Pinion Preload?

[Drg racr]

What is the correct procedure for setting pinion preload on the 8.8"? The pinion bearings were bad, so I have new inner and outer bearings, seal, crush sleeve, axle seals and diff gasket.
I'm not changing gears at this time, the 3.27's are fine.

[mutantcapri1979]

http://www.angelfire.com/oh5/cpa5oh/cpa5ohtech001.htm

[4SPDFOX...+1]

So tight that it cannot turn. Even when the car is in gear and the gas pedal is fully depressed. That'll do it.

[gt pony]

With new bearings- 25 to 30 inch lbs.

[turbostang500]

With new bearings- 25 to 30 inch lbs.

Just a note....this is turning torque. The amount of torque required
to spin (not start) the pinion gear. Usually measured with analog (i think)
torque wrench.
Didn't know if ya knew that or not so I wanted to mention it.

[82gt1]

torque the pinion nut to 180-210 ft #s. and check the teeth mesh with axle paint /grease if the teeth arent making a perfect pattern you are wasting your time and money replacing the bearings as they will wear out again in short order.

[gmatt]

I have not used this item but I have heard good things about it;
Ratech crush sleeve eliminator: http://www.ratechmfg.com/fordspbs.htm

[wman24]

The sleeve eliminators work great. Nice part is you can set preload with pinion seal out then pull yoke and put seal in when you have the shims you want. I'v seen people leave the preloads loose because seal drag is percieved as preload.

[Str8sixfan]

Anyone know the factory pre-load for the pinion on a Mark VII 8.8? I found two different documents (one an official Ford manual, but not specific to that era of 8., and they were 14-29 and 14-28 ft lbs respectively. Does this sound right?

[gt pony]

Those specs are correct for an 8.8" regardless of the application. Believe me, I've setup more 8.8s than I can remember as a tech.

[KevinVarnes]

Anyone know the factory pre-load for the pinion on a Mark VII 8.8? I found two different documents (one an official Ford manual, but not specific to that era of 8., and they were 14-29 and 14-28 ft lbs respectively. Does this sound right?

I'm sure you'd figure it out, but that should be in-lbs not ft-lbs.

[Str8sixfan]

Yea, I'm so used to the other...but I get it now. It's "turning torque" so there's kind of two different things to check for. Thanks everyone.

[wraithracing]

Also keep in mind that the range takes into account both used and new bearings. Used or worn bearings would generally be set at the lower end and new bearings at the upper end. I generally shoot for 25 inch/lbs with new bearings and races. Sometimes a bit more depending on how things go together, but I generally won't go any lower. Most good working 8.8's that I have checked that have miles on them, then pinion preload is around 14-16 inch/lbs. Good Luck!

[gt pony]

One more thing I'd like to add to this thread is the backlash setting. The service manual recommends .008 to .012" it's been my experience that the lowest it should be is anywhere between .012 to .015". If you set it within the suggested lower settings it can have gear whine and also whine especially in third gear. I found this out the hardway/ lesson learned. They just like a little more backlash than the factory recommended settings for some reason. Hopes this helps.

[Str8sixfan]

Also keep in mind that the range takes into account both used and new bearings. Used or worn bearings would generally be set at the lower end and new bearings at the upper end. I generally shoot for 25 inch/lbs with new bearings and races. Sometimes a bit more depending on how things go together, but I generally won't go any lower. Most good working 8.8's that I have checked that have miles on them, then pinion preload is around 14-16 inch/lbs. Good Luck!

Good to know. Specific to my application, this is all fallout from replacing the leaking pinion seal.