Another mod?

Thank you for the explanation! I don't run it hard enough to where I think it will be an issue. I'll consider myself warned though. I may exploring an option for different gears here sometime soon anyways, so I may be tearing it down sooner than I thought.
 
If I was you I would just move the carrier over .008 that will add .006 to your .004 to give you .010. You got the adjustable shim packs right? You don't have to run the car hard to heat up the rear it heats up just driving down the road. No problem for the info I like to help.
 
Yes I did get the shim packs, however I have no hoist. So I'd have to bring it in to a shop to have that done, as I don't want to tear it down to remove the pumpkin again. The stock shims are in there now. The carrier was EXACTLY the same size as the stock one. The diff fluid had never been changed before (it looked like it needed changing when we drained it out.

So given that the diff and the shims were exactly the same, do you think the rear was running on .004 backlash for the last 134000 miles?
 
OK back to basics here. Did you check backlash before you ripped apart? You always should. If you did you would of seen that stock BL from ford was .010 to .012. And sence yours is now .004 then everything is not the same cuz if it was you would have .010 BL. The carrier can have the same overall length as the old one but the ring gear surface can be diffent spot then old one. Hence left or right couple thousands. Thats why every set of gears has to be SET UP. Its called machine tolerances they all vary just a smidge. No 2 parts are 100% the same. I am a Class A prototype machinist also so I know alot about tolerances. So to answer your ? no I don't think your rear was running .004 BL from ford for 134K Also on every rear I have done 90% 8.8 and 7.5 fords none ever came stock .004 BL. I'm just shooting you info please don't think I'm tell you what to do with your car its yours.
 
No, not at all. I appreciate the insight, as I had never even seen inside the rear end until we tore into this one. Did we measure BL on the stock setup? No. We should have though.

Ugh, I really don't want to take it all apart tonight.
 
What I recommed is call any shop that sets up gears and ask them what they think of .004 BL. It only takes couple minutes of your time. I'm just looking out for you. You might have no problem with it but all my time researching and doing these never seen .004 BL and I myself would not feel good sending out a car with that.
 
Just a FYI on this. My buddy tried to save 50 bucks and have someone else do his gears. 2005 stang 8.8 4.30's. He mentioned all kind of problems from noise to whine to heat. I pulled it apart and they had BL set to .004. After driving the car couple miles you could not hold your hand on the diff cover or burn your hand up. I set up gears again and set BL to .011 and cool running now. They never set pinion depth and never set BL. They just took out old gears and slapped in new ones.
 
Just an fyi here too. I've had this installed for over a year with no Ill effects. It's been confirmed that the .004 bl is okay by quite a few reputable sources.

Could be different with mustangs and 4.30's.
 
I check my temp orally. :p


Seriously though, no I haven't. I suppose I could, once I get the damn thing running again lol.
 
Just wanted to give anyone a heads up on this thats all. I have not been able to find Fords BL specs for our new 8 inch rears. The 8.0 and 8.8 are almost the same as shown that the 8.0 rear can take an 8.8 diff. All ford gears specs call for .008 to .015. thats 9",8" 7.5 and 8.8 rear ends. Also all aftermarket gear sets are cut and designed with the BL of .008/.012. But the chevy new 10 bolt has a real small BL but the ring gear is the size of a frekin bagle. I don't know how camaro's don't blow those things out like butter.
 
Just an fyi here too. I've had this installed for over a year with no Ill effects. It's been confirmed that the .004 bl is okay by quite a few reputable sources.

Could be different with mustangs and 4.30's.

I just checked my Lincoln CD manual and it states clearance of .008 to .013 with .010 being preferred.
 

I have an account on there and you can find some real useful info from their tech section..

has anyone used this? Mobil 1 75W-140, also what additive is best, trying to find out info regarding the lsd install.. am i better off buying new bearings since they're inexpensive? after its on jacks, only ones side of the axle has to be taken apart? thanks

You can get what your comfortable with.. 75W-140 is the spec.. Motocraft makes their own you could buy.. I would buy new bearing since your in there.. Both side have to be taken out..
 
The dealer gave me 80-90 instead of 75-140, saying that there's less chatter when using 80-90 with the additive.

And used the motorcraft friction modifier additive as well. Small bottle. About 4 oz or so. Stinky isht.
 
Look up Eric something.. He just posted a LSD install like 1-2 weeks ago.. Instead of pressing the axle shafts out, he left it all together
 

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