Does anybody know how much preload there should be on the carrier bearings?

I have been told that it should be so tight that you can barely turn it by hand, is this true? Seems to me that would wear out the bearings too fast. No?

I am talking about drag with NO pinion installed yet, just the carrier.

I do them seperate, that way its more accurate. Once I get the shimming right on the carrier, then I will remove it and do the pinion. Then take a drag measurement of them together.

Any suggestions? Thanks!

 

There is no drag measurement or turning torque like a pinion preload. You just lay the carrier in the housing with bearing and cups. Put a .265 or whatever shim thats close to that size on the left side. Then install the thickest shim on the right side that will slide in by hand pressure only (hopfully you have a stock of different size shims to do this). Then to get the preload or case spread as it's called, add .006 to each side. I've made a video on setting up a 8.8" that details this and more which I sell on eBay sometimes and if you have any other questions about 8.8" installation email me at KENNETHL6@prodigy.net .

 

What you just described I do not agree with.
If that carrier is shimmed only hand tight that allows for slack side to side when one wheel is pulling. This will chip pinion teeth. I have learned that the hard way. The carrier HAS to crammed in there, my question was "how crammed in there does it have to be?"
So thank you for the input but I am not gonna throw away another set of gears by not shimming it right.

Where is DIFFMASTER he would know!?!

Help!

 

Well, from what i know, I bought his video. He is a ford senior master technician with over 30 years of experience.



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I aint arguing his credentials, I just dont agree. I have had so many people tell me that the carrier has to be very snug, but we installed it that way anyhow (how he said) twice now, pinion teeth keep chipping off. So this time I am going to do it differantly.

I am sure we had everything else right... Pinion depth was perfect, pinion drag was 25in/lbs, backlash was .005. Grease pattern was good on coast and drive. The only thing I can think of is that the carrier preload needs to be tighter!

Any other suggestions?

 

Hi jberylecrider, maybe I wasn't clear. when you find the thickest shim that goes in by hand pressure you have no side play but no preload yet either. Then I say to add .006 to that on each side, which is .012 total. That .012 will make the preload which you will know when you have to hammer the last shim in. If this setting is done right you will not be able to pull the carrier out by hand once the shims are installed. This method of shim loading is direct from any Ford manual written from 1980 to the present. The 7.5" has the same spec. and the 9" which uses adjusting nuts instead of shims normally has a case spread of .008 to .016 which is measured with a dial indicator between the bearing caps. I hope this has clarified the question.

 

Yes Sir it did! Thank you for replying, sorry for arguing.
I guess I read wrong, or mis-understood.

How hard should it be to turn the carrier once this is done?
With no pinion load.
Thanks guys!

 

Jberylecrider, 25 inch pds is too tight for pinion preload, reduce that to 15 inch pds, you will need a new crush sleeve. The 8.8 is designed to run .008 to .018 backlash, I set them at .008, no less. As far as the carrier brg preload is concerned, most factory manuals give a spec that is too tight for my tastes, and it shows every time we tear one down to re-bearing. The way I do it is this: With pinion installed, install carrier, get backlash close with some preload on carrier, carrier should not fall out, nor should you need to pry it out, grab it with both hands and give it a yank, if it comes out with a little effort, good, if it falls out,increase shim thickness until you have some resistance, all the while maintaining your backlash. When you have the backlash and light carrier bearing preload obtained add .003 to eash side shim and you will be fine. Good Luck

 

One more question... I am putting in Precision 4.56 gears with an EZ locker, I have the correct carrier, but heres the thing:
It seemed like I had to move the pinion back away from the ring gear to get the correct pattern, but there were no shims on the pinion. What do I do if this is the case? Theres no way to move it back any further, right?

Thanks guys all of you helped out a great deal, as always!

Will be doing this rearend for the 3rd time tomorrow, saturday.

I will let you guys know how it went.

 

Any way you can take a picture of the pattern and e-mail it to me? Precision usually sets up with a .016 to .024 depth shim.

 

Maybe I was wrong, maybe the pinion needed to come in towards the ring gear. Should I start with a .016 shim behind the inner pinion bearing? Cause I dislike taking it apart 10 times. What is your recommendation for shimming starting points all around ?

Thank you!

 

Start with the .024 shim and go from there.

 

So place .024 shim on pinion, then press on the bearing with shim under it?

Another thing, what should I start with on the Carrier shims?

Thanks for all the help!

 

Hey Kennethl6. Thanks for the info on rear ends. I have a 97 f150 that is roaring. I am going to have to do a rebuild on it if they keep the truck. One question. Do I need a tool to spread the case to do this. Thanks

Dave Powell

 

Hi BossHoss, Ken here, if you have an 8.8" there is no need for a spreader. Only the alloy cases as in the Mark 8, Cobra and new IRS Explorer 8.8" use a spreader. The setups on those rears are different than the iron cases as well. If you go to my web page you'll find a few general facts about the 8.8" rear and C6 transmission which I add to from time to time. Go to http://pages.prodigy.net/kennethl6/ give it a look.....Ken.