• Mustang Forums
  • 1996 - 2004 SN95 Mustang -General/Talk-
  • SN95 4.6L Mustang Tech

8.8 Gear Pattern

  • Thread starter Thread starter letumeternum
  • Start date Start date Aug 4, 2021
L

letumeternum

Member
Jan 1, 2017
12
2
13
Aug 4, 2021
#1
  • Aug 4, 2021
  • #1
Hi all

I've been working on putting together a completely new rear end for my 04 and am currently at the stage of adjusting the backlash and pinon depth.

The axle housing I had purchased bare over a year ago (so no pinion spacers to compare with). The carrier I chose was the T2R (M-4204-T31H) with a ford performance 4.10 ring and pinion set (M-4209-88410).

As for the other hardware:
Axles (Moser Engineering A883153)
Ford performance ring and pinion kit (M-4210-C3)
Oil Slinger (Yukon Gear & Axle YSPBF-023)
2x C clips (Yukon Gear & Axle YSPCC-010)
Crush Sleeve (Yukon Gear & Axle YSPCS-002)
Reluctor ring (Ford part # F4ZZ2C189A)
Dust Shield (Ford part # E6TZ4859A)
Pinion Nut (Ford part # 389546)
Inner pinion Bearing (Ford part # 9L3Z4630A)
Outer Pinion Bearing (Ford part # B7A4621A)

The Ring and pinion set came with both a crush sleeve and Pinion nut, same with the Ford performance ring and pinion kit giving me 3 of each. I purchased an extra inner and outer pinion bearing for sacrificial pieces to help me get the proper pinion depth.

I also used the Ratech 10006 pinion depth tool to help me try to reach a proper depth, which after multiple attempts I finally think that I reached using 0.039" of spacers. At this point I have two concerns, my first is as per the ford manual the pinion bearing should be at 16-29 in-lbs of preload. At 10 in-lb I gave the tinniest turn and manage to bump it all the way to 29-30 in-lb. Is it ok for me to be at this slightly higher preload or should I undo it, throw in a new crush sleeve and go again? Second is that I noticed in a few guides it was recommended that silicone be placed on the teeth of the pinion gear when meshing it with the pinion flange to prevent oil from leaking by, I neglected doing this, should i be concerned?

Finally I get to the main point of this thread, here is the gear pattern I have with my current setup, using a dial indicator I am getting 0.0075" of backlash reproducible in 4 separate spots.



I painted them several times and ran them back and fourth with load on the ring gear, here is the pattern I think that I'm seeing (red shade).

 

Rdub6

So while I wait to figure out my rear end issues
5 Year Member
Dec 29, 2017
3,949
2,932
153
Long Island, NY
Oct 13, 2021
#2
  • Oct 13, 2021
  • #2
I just happened to find this thread, and I’m surprised you got no answers. I’m probably a little late as it’s two months later.
I just rebuilt my 8.8 (first time ever doing one), and from all the articles and videos I’ve watched, I think you look pretty good with the pattern.
I’d have to go back to my notes to see what the backlash spec is, but I thought I remembered 8 thou being the low end.
At .0075, I’d probably leave it.
Eric the Car Guy did a video series that was invaluable to me as I rebuilt mine, and definitely worth checking out on Utoob.
 

manicmechanic007

5 Year Member
Sep 26, 2017
2,524
709
143
Roy, Utah
Oct 13, 2021
#3
  • Oct 13, 2021
  • #3
Run it and see if it howls
I see nothing wrong with your setup
 
You must log in or register to reply here.

Similar threads

O
8.8 Pinion Nut Leak
  • OX1
  • Jan 3, 2026
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
Replies
15
Views
713
1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- Jan 5, 2026
OX1
O
J
2004 Mustang 3.8L V6 vibrations above 65 MPH and differential leaks
  • joeybuddy96
  • Mar 16, 2026
  • SN95 V6 Mustang Tech
Replies
12
Views
371
SN95 V6 Mustang Tech May 5, 2026
joeybuddy96
J
3
Eight inches is enough for me...
  • 351MooseStang
  • Nov 27, 2025
  • 1974 - 1978 Mustang II Talk & Tech
Replies
5
Views
498
1974 - 1978 Mustang II Talk & Tech Mar 2, 2026
Bullitt347
S
Drivetrain 8.8 Pinion and 302 rear main seal leaks after replacing. 93 5.0 with t-5
  • Steigy4827
  • Jun 23, 2025
  • Fox 5.0 Mustang Tech
Replies
10
Views
607
Fox 5.0 Mustang Tech Apr 1, 2026
Steigy4827
S
Drivetrain 8.8 trac lok spider gears..
  • rednotch
  • Oct 28, 2025
  • Fox 5.0 Mustang Tech
Replies
2
Views
263
Fox 5.0 Mustang Tech Oct 28, 2025
rednotch
Share:
Bluesky Email Share Link
  • Mustang Forums
  • 1996 - 2004 SN95 Mustang -General/Talk-
  • SN95 4.6L Mustang Tech
Menu
Log in

Register

  • Forums
  • What's new
  • Media
  • Resources
  • Contact
  • Sponsor
X

Privacy & Transparency

We use cookies and similar technologies for the following purposes:

  • Personalized ads and content
  • Content measurement and audience insights

Do you accept cookies and these technologies?

X

Privacy & Transparency

We use cookies and similar technologies for the following purposes:

  • Personalized ads and content
  • Content measurement and audience insights

Do you accept cookies and these technologies?