Rear gear install questions

spacebarn007 · Jun 21, 2013

Getting ready to install 3.73 rears in my 2011 automatic. I bought 2 quarts of royal purple 75w-90 gear oil. Will 2 quarts be enough or should I have bought 3... also is 75w-90 the correct weight? I did not buy the ford racing friction modifier is it needed with the royal purple gear oil? One last questin will I need a new pinion bearing?

Riptide · Jun 21, 2013

Skip the modifier with royal purp.

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wbt · Jun 21, 2013

spacebarn007 said:
Getting ready to install 3.73 rears in my 2011 automatic. I bought 2 quarts of royal purple 75w-90 gear oil. Will 2 quarts be enough or should I have bought 3... also is 75w-90 the correct weight? I did not buy the ford racing friction modifier is it needed with the royal purple gear oil? One last questin will I need a new pinion bearing?

2 qts. with the friction modifier will be fine. Yes use the friction modifier even though they say the oil contains it.

Yes on the new pinion bearing. I would also recommend using a pinion bearing spacer vs. a crush sleeve. If you haven't done an 8.8 gear install before I would recommend searching google.

Marc s · Jun 21, 2013

1: 2.5 qts needed.
2: No friction modifier needed with Royal Purple but I use it anyway.
3: You can re-use the pinion bearings if you can remove it without damage.
4: If you re-use the pinion bearing, use the pinion shim that came off of the pinion and set the pinion preload to 15 inch pounds. The pinion shim needed is based off of the housing and the pinion bearing thickness. If you are re-using the original housing and bearings, the OEM pinion shim has to be the correct one. If you are using FRPP gears, identifying the pinion shim has nothing to do with the pinion gear. (I hope this makes sense)
5: If you use a new pinion bearing, you will need to check pinion depth and use the correct shim and then set the pinion preload to 25 inch pounds. The pinion depth formula is 2.50 - pinion depth + 2.00 - 4.415 = pinion shim thickness.
6: Set backlash at .008-.012.

OneQwkStang · Jun 21, 2013

Its easier when you just start doing it....but it sucks when you got it all back together and find out you didn't do it correct.

CPRsm · Jun 21, 2013

I bought the tools for pinion depth years ago and still haven't learned how to use it. Buddy of mine laughs and talks shit. "Pinion depth tools are for people who can't read patterns." Lol He likes to talk shit to his chassis building buddy who uses one. Would be nice if I could get the pattern right the first time though lol

86GT351 · Jun 21, 2013

CPRsm said:
I bought the tools for pinion depth years ago and still haven't learned how to use it. Buddy of mine laughs and talks shit. "Pinion depth tools are for people who can't read patterns." Lol He likes to talk shit to his chassis building buddy who uses one. Would be nice if I could get the pattern right the first time though lol

No Pinion Depth Tools are for thsoe who try and do it right.

I alsways minimially replace the Pressed Pinion Bearing. It can be removed but can damage the cage taking it off!

Whiskey11 · Jun 21, 2013

Curious, has anyone used a Crush Sleeve Eliminator kit with their 8.8? My rear end is in dire need of a rebuild (Tee Hee! :asskiss3:

) and I was thinking about getting rid of the crush sleeve entirely. It certainly would make it easier to rebuild my rear when I need to!

CPRsm · Jun 22, 2013

Nitrostang Racing said:
No Pinion Depth Tools are for thsoe who try and do it right.

Do or do not. There is no try. Still gotta read the pattern!
Honestly of all the guys I know who setup professionally, I think only two know how to use them.

BruceH · Jun 22, 2013

Whiskey11 said:
Curious, has anyone used a Crush Sleeve Eliminator kit with their 8.8? My rear end is in dire need of a rebuild (Tee Hee! ) and I was thinking about getting rid of the crush sleeve entirely. It certainly would make it easier to rebuild my rear when I need to!

I have a solid spacer. One time I had a quiet set of 4.56 gears until I went to the track. Only made three passes and had howling gears on the way home. The crush sleeve crushed some more and there was a whine on decel from that time on. The solid spacer didn't take away the noise. However, the current gears have the spacer and have been to the track without issue.

wbt · Jun 22, 2013

Whiskey11 said:
Curious, has anyone used a Crush Sleeve Eliminator kit with their 8.8? My rear end is in dire need of a rebuild (Tee Hee! ) and I was thinking about getting rid of the crush sleeve entirely. It certainly would make it easier to rebuild my rear when I need to!

Sure. I have used a solid pinion spacer for quite some time. Using the Ford service tool for pinion depth makes that part of the job much easier.
http://compare.ebay.com/like/271040567771?var=lv&ltyp=AllFixedPriceItemTypes&var=sbar

A good read on the procedure:
http://www.fordracingparts.com/download/instructionsheets/FordInstShtM-4209-8.pdf

86GT351 · Jun 22, 2013

CPRsm said:
Do or do not. There is no try. Still gotta read the pattern!
Honestly of all the guys I know who setup professionally, I think only two know how to use them.

Depends on which tool you have.

I have something like this that my wife bought for me one year as a present that I have used once!

This is the tool that I use and it is really a no brainer to use.

You install the components as shown in the picture. Then you simply take a feeler gauge and check to see what shim is needed between the head of the part where the pinion goes and the shaft between the carrier bearings.

As fot reading the pattern. This is also very critical but can be compensated for a bit in the side to side or backlash adjustment.

I also have the proper tools for checking the rolling pinion torque!

Whiskey11 · Jun 22, 2013

BruceH said:
I have a solid spacer. One time I had a quiet set of 4.56 gears until I went to the track. Only made three passes and had howling gears on the way home. The crush sleeve crushed some more and there was a whine on decel from that time on. The solid spacer didn't take away the noise. However, the current gears have the spacer and have been to the track without issue.

Well, if I'm going to do this I'll be doing it with a new gearset (sticking with 3.55's for several reasons related to racing classes). At least with the crush sleeve eliminator I can learn to setup a rear end PERFECTLY without having to worry about the damn crush sleeve headache and if it holds bearing pre-load better through it's life the better. I'm sick of having an 8.8 that whines (it's faint now but it's gotten louder and louder) and I'm sick of pinion bearings on Ford differentials sucking (my 06 V6 had the stock rear end rebuilt 3 times under warranty before they just replaced the whole rear axle assembly). I'm hoping that will take care of it.

I have the technical skills and most of the tools to be able to setup a diff, the crush sleeve was just the biggest concern of mine since I can be a bit ham fisted at times... I will probably replace all the bearings and seals and rebuild the T-Lok too while I'm in there. Might as well make it like new!

CPRsm · Jun 22, 2013

Nitrostang Racing said:
Depends on which tool you have.

I bought a Mark Williams deal which was supposed to be nice. I opened the box once. "Oh pretty" and closed it again lol

Nitrostang Racing said:
I also have the proper tools for checking the rolling pinion torque!

Yuuuuup. A tool that cost me over 300 dollars and I only use it on rearends. Come to think of it that's something I see garage guys mess up. One of my customers burned his up in about a mile iirc. 25ft/lbs of break away force he used. Welded that bearing real nice like lol.
If you do run a solid pinion spacer, measure the old crush sleeve as a reference point to start to find preload.

Riptide · Jun 22, 2013

Extra friction modifier caused a problem with mine. YMMV but I think its a mistake to add it unless its chattering.

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Whiskey11 · Jun 22, 2013

CPRsm said:
I bought a Mark Williams deal which was supposed to be nice. I opened the box once. "Oh pretty" and closed it again lol

Yuuuuup. A tool that cost me over 300 dollars and I only use it on rearends. Come to think of it that's something I see garage guys mess up. One of my customers burned his up in about a mile iirc. 25ft/lbs of break away force he used. Welded that bearing real nice like lol.
If you do run a solid pinion spacer, measure the old crush sleeve as a reference point to start to find preload.

Definetely will be measuring the crush sleeve and going from there. Im assuming the torque spec to use with the solid spacer is included in the instructions? I know its 25 inch pounds of rolling resistance but what about the pinion nut itself?

CPRsm · Jun 22, 2013

I crank that fucker down w an impact. Rolling resistance is all that matters. 40-120ft/lbs will yield the resistance if it's right. Make sure there is a locking compound on the nut and crank it down. Not sure what an official spec is though. Use the old nut for test fit also. Run off and on the old pinion to remove the compound as much as you need to make it easy.

kdanner · Jun 22, 2013

Nitrostang Racing said:
This is the tool that I use and it is really a no brainer to use.

You install the components as shown in the picture. Then you simply take a feeler gauge and check to see what shim is needed between the head of the part where the pinion goes and the shaft between the carrier bearings.

I use that Ford tool also. Right shim the first time, every time!

Rear gear install questions

spacebarn007

Junior Member

Riptide

Will work for Mustang.

wbt

Senior Member

Marc s

NASA AIX

OneQwkStang

Improving the Breed

CPRsm

Senior Member

86GT351

Senior Member

Whiskey11

SCCA Autoscrosser #23 STU

CPRsm

Senior Member

BruceH

BBB Big Bore Boss 322

wbt

Senior Member

86GT351

Senior Member

Whiskey11

SCCA Autoscrosser #23 STU

CPRsm

Senior Member

Riptide

Will work for Mustang.

Whiskey11

SCCA Autoscrosser #23 STU

CPRsm

Senior Member

kdanner

Senior Member

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