SSHD front diff repair

JPV · Feb 6, 2022

If you are going to use synthetic gear oil I recommend using the Permatex Ultra Gray high torque gasket maker on the Banjos, it for some reason seals better with synthetic then the blue stuff. With regular 80w-90 it doesn't seem to matter. It sure sucks when you get it all together and get a leak there!

coastlogger · Feb 6, 2022

Yep I think it would be ( actually I could have used the whole power divider assembly)but marginally since there's enough metal in the damaged diff that I'd have to disassemble it to clean. And it has some minor chipping on driven gear.So I decided to do this. Quite a project since I have to remove the 5.29 from diner trucks as well as install them.Working alone too,has it's challenges .A few more days I guess.

coastlogger · Feb 6, 2022

Thinking of eliminating gaskets for power divider shifter and output shaft ring.using rtv sealant instead . Good or bad idea?

Pops52 · Feb 6, 2022

I have always thought a gasket was best. But I would probably follow advice from TS.

mekanik · Feb 7, 2022

I have put quite a few together with RTV and never had a leak.
Ultra Grey is great stuff, put a thin layer on both surfaces.

There is a procedure for adjusting the stop bolt on the power divider shifter.
With the power divider engaged turn the stop bolt in until it touches the end
of the shaft then one more full turn and tighten the lock nut.

Truck Shop · Feb 7, 2022

Napa brand {The Right Stuff-gray} I use it on Series 60 rear structures and drive housings, but clean
the surface with alcohol.

coastlogger · Feb 7, 2022

Thanks for this.

coastlogger · Feb 7, 2022

The u joints I've been separating have been really stuck in the yokes,except for maybe two. Rust I guess. I'm going to clean them up and reuse.How tight should they be I wonder?I can of course clean sand polish etc till they're loose but don't want to overdo it Should they go together with just hand force or?

JPV · Feb 8, 2022

I like to be able to just lightly tap them in, a little never-seize helps also. If you don't have the lock straps for the cap bolts use blue loctite on the bolts. A lot of new u-joints don't come with the straps, just a little loctite already on the bolts. In my experience that is not enough, I apply my own as well and haven't had any problems. I no longer use the straps even if I have them.

coastlogger · Feb 8, 2022

Thanks. great advice.
Today's "discovery" :my old diffs (the ones I took out)have different tooth counts. One large gear (front)has 43 teeth and one (rear)has 39 teeth. By my calculations that makes a 4.33 ratio on front and 4.30 on back using different pinion tooth counts .Now why in heck would that be? Replacement 5.29 diffs have same tooth counts ( maybe)I had the front installed when I discovered all this so tooth counting less straightforward on that one.
Got the rear diff in today. Will be running tomorrow late I hope.

coastlogger · Feb 8, 2022

Oops I see that's backward. Front had 39 teeth and back had 43 teeth.miller time.

JPV · Feb 8, 2022

I put a two speed in one time and screwed up installing the shift motor. The rear was stuck in high, when you put them in low range and locked in the interlock it was very obvious something was wrong. As far as your tooth counts I haven't run into that but I guess I have never thought count, I guess I should!

Truck Shop · Feb 8, 2022

Freightliner shop just did that mistake on one of ours under warranty. Couldn't believe they didn't look at
the vin sheet.

coastlogger · Feb 9, 2022

My point ( I think) is that the ratios are very very close but not the same.Im guessing they're made that way for a reason?I guess the interaxle diff could easily look after the slight difference ,unless in lockup of course

repowerguy · Feb 9, 2022

coastlogger said:
Thanks. great advice.
Today's "discovery" :my old diffs (the ones I took out)have different tooth counts. One large gear (front)has 43 teeth and one (rear)has 39 teeth. By my calculations that makes a 4.33 ratio on front and 4.30 on back using different pinion tooth counts .Now why in heck would that be? Replacement 5.29 diffs have same tooth counts ( maybe)I had the front installed when I discovered all this so tooth counting less straightforward on that one.
Got the rear diff in today. Will be running tomorrow late I hope.

Me personally I would put it together and never think another thing about a small difference like that. We all have effectively done the same thing when we put new tires on one axle, and run out what’s left of the remaining tread on the other axle.

Truck Shop · Feb 9, 2022

Ford for years used 4.10 in the front and 4.11 in the rear of a 4x4.

Pops52 · Feb 9, 2022

I drove, then owned a 79 Pete with SSHD 4:11s in the rear and 4:10 in the front. It happened after busting a tooth thru the power divider case. Mechanic put in a 4:10 and never said a word. Only had an issue when the PD was locked in while on hard ground, then it made the drive train tight and hard to shift. Had to stop and back up a ways to loosen things up or it came out with a huge bang!! Otherwise I never knew it was different. Sold the truck to a guy up in Washington in 95.

SSHD front diff repair

JPV

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coastlogger

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coastlogger

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Pops52

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mekanik

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Truck Shop

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coastlogger

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coastlogger

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JPV

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coastlogger

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coastlogger

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JPV

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Truck Shop

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coastlogger

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repowerguy

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Truck Shop

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Pops52

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