Rear Diff Rebuild Parts

[C420sailor]

My original 8.8 rear (3.55 gears, open diff) has given me nearly 330,000mi of trouble free service. She's starting to get pretty hot on longer drives, and that hot oil is making its way out via the pinion seal (which I've recently replaced...still leaks...). Drained the oil recently to see that she's also starting to make some metal. 5,000mi old oil is grey/silvery with light use. She's earned a rebuild.

I've never done a car/truck diff, only helped a buddy do one years ago (I held the flashlight and passed tools mainly) but I've done a handful of motorcycle final drives so I get the basics.

Anyway, I'd like to order the parts now to have them on hand and I was hoping guys who have BTDT can advise me on anything I may be missing, and especially on any special tools I'll be needing.

In my rockauto cart I have:

-SKF master rebuild kit (pinion/differential bearings and races, pinion and diff shims, ring gear bolts, crush sleeve, pinion nut and seal)
-Differential carrier rebuild kit (four gears, cross shaft, bolt, thrust washers)
-Pinion yoke (old one is grooved from the pinion seal)

What am I missing?

I plan to buy a set of Ford OEM gears, and I very recently (within 5k miles) did the axle shafts, bearings, and seals---so they should still be good, I'll check and clean.

I have a dial gauge setup for measuring gear backlash, 1/4" beam torque wrench for setting pinion torque, gear marking compound. Any other special tools I'll need? Especially with regard to installing pinion bearings and setting pinion depth...

Appreciate this, guys. I hate digging into a job only to realize I forgot parts and/or special tools.

 

[donalds]

Everything in your cart is good
I would add
An 2 FORD crush sleeves
A FORD seal ...only...

Your diff
When you changed your seal did you install a new crush sleeve

I suspect that it wasn't
Now the preload in the pinion bearings is way to much now its eating its self

Trust me
The ford sleeve is way thicker than others
The seal is the only one I have had not leak

Like you said been there done that

 

[allmyEXes]

Following along. Ditto on the crush sleeve etc. Sounds like my 280k plus 8.8 is very wore out. I know that is configured way different than a 9 inch however I assume it will take big tools like a 3/4 inch breaker bar to crush the sleeve and some way to hold the pinion flange stationary while doing so.

 

[donalds]

some way to hold the pinion flange stationary while doing so.

I used a piece of flat bar steel drilled two holes then let the other end hit the ground

 

[allmyEXes]

@donalds Flat bar. Very good idea. I could see it resting over or under a ramp on a 4 post lift. On the flat bar, some that is 1/4" thick and how wide?
@C420sailor Thanks for letting me tag along on this if it is ok. I had it on my mind yesterday when I was listening to the different sounds that I am hearing pressing the gas and letting off of it.

 

[fast_dave]

Just sayin' - even with a diff out of the vehicle and on a shop bench and having the proper tools, crushing a new pinion crush sleeve is a muther%&*@#$

Do a write up w/ pics

 

[C420sailor]

Thanks guys! I will do a write up when I get it done. It’ll be a few months from now—driving the 5.0 until then.

I plan to weld up a nice yoke holder.

As for the crush sleeve, I used the marker/count the exposed threads method when I changed just the seal. It worked very well for me in the past, but who knows…maybe I messed it up.

Ford sleeve and pinion seal, aye

 

[donalds]

Flat bar. Very good idea. I could see it resting over or under a ramp on a 4 post lift. On the flat bar, some that is 1/4" thick and how wide?

2 inch / 1/8 in thick x 4 ft ace hardware drilled 2holes And a grinder

, I used the marker/count the exposed threads method when I changed just the seal. It worked very well for me in the past,

Its hit and miss but
You can't return the preload without a new sleeve its impossible to reuse it properly
Its critical

Ford sleeve and pinion seal, aye

A must trust me!!!
I will dig up a part number if youwant?

I have extra parts I have because
I didn't replace the crush sleeve 2 times
Then one ford seal then I did it rite and bought extra parts because I was second guessing myself

 

[allmyEXes]

The crush sleeve part number is the same as what I recently used in a 1970 9 inch. I believe the part number that starts with a "B" is from the 1950's.

 

[donalds]

The crush sleeve part number is the same as what I recently used in a 1970 9 inch. I believe the part number that starts with a "B" is from the 1950's.

So does that mean my truck identifies as vintage lol

 

[CDW6212R]

Good stuff, I'm very interested too. I have at least two front D35's to build, and I'll be swapping 3.07's into my 98 project truck at some point(for the 6R six speed trans). I've looked at the tools to do the R&R and bearings, crush sleeve etc.

I've watched the process of the crush sleeve at a Ford dealer by a trusted shop foreman. They use a long bar tool made for it, over four feet long. It's done underneath with the vehicle in the air, by hand pulling down on the bar. Leverage is the key to that deal, it all sounds "interesting."

 

[donalds]

Good stuff, I'm very interested too. I have at least two front D35's to build, and I'll be swapping 3.07's into my 98 project truck at some point(for the 6R six speed trans). I've looked at the tools to do the R&R and bearings, crush sleeve etc.

I've watched the process of the crush sleeve at a Ford dealer by a trusted shop foreman. They use a long bar tool made for it, over four feet long. It's done underneath with the vehicle in the air, by hand pulling down on the bar. Leverage is the key to that deal, it all sounds "interesting."

It took over 200 pounds of force to tighten it

 

[Mbrooks420]

C

So does that mean my truck identifies as vintage lol

In a lot of states your truck is a Classic.

 

[C420sailor]

I’ll probably just be a lazy **** and order them at the dealer

I’ve read that if you use Ford gears, the pinion shim that is in there will either be perfect or damn close. Apparently there is very little difference in tolerance between gear sets, it’s mainly the housing. All bets are off with aftermarket gears. We shall see.

I bought an extra set of pinion bearings that I’m going to use as set-up bearings just in case.

The last one was fed a steady diet of 80/90 oil. Gonna start this one on 75/140 syn per the updated recs.

 

[donalds]

Sounds like ur on track ;-)

 

[C420sailor]

The time for the job is slowly approaching.

I dropped by the local Ford dealer to order the ring/pinion set and the pinion seal. They had the seal in stock, but the parts guy insisted the gear set was ‘obsolete’.

“You’re telling me Ford doesn’t make a 3.55 gear set for the most popular axle they ever made?”

“That’s what the computer says.”

A quick Google reveals Ford Racing gear sets…not sure if they’re the same as OEM? I don’t need anything fancy, but I’d prefer OEM over aftermarket for both quality and ease of setup…

 

[Mbrooks420]

The time for the job is slowly approaching.

I dropped by the local Ford dealer to order the ring/pinion set and the pinion seal. They had the seal in stock, but the parts guy insisted the gear set was ‘obsolete’.

“You’re telling me Ford doesn’t make a 3.55 gear set for the most popular axle they ever made?”

“That’s what the computer says.”

A quick Google reveals Ford Racing gear sets…not sure if they’re the same as OEM? I don’t need anything fancy, but I’d prefer OEM over aftermarket for both quality and ease of setup…

I am a fan of factory parts, but there are several good gear suppliers.

 

[C420sailor]

I’m just being lazy. I know that if I get factory gears, the existing shimming will be damn close. This is my first car/truck rebuild (I’ve done ton of motorcycle final drives), so I’m trying to minimize variables.

Plus, factory gears lasted me 330k!

 

[Fix4Dirt]

would a lo mile one suffice from JY? looking at tousleyfordparts from a quicn search i can only find 373 410 and 327 gears, but no 355!!! unless it doesnt specify in description, got a PN for it?

 

[Mbrooks420]

8.8" 3.55 RING GEAR AND PINION

8.8" 3.55 RING GEAR AND PINION|Ford Performance Parts

performanceparts.ford.com

Claims made in the USA at Ford’s Sterling plant.