[jollyman78]

So, I smacked my rear diff, and needed to reseal the cover. (http://thenewx.org/phpbb2/viewtopic.php?t=7850) I decided to put a shrockworks cover on it when I did the work...

I just finished the job a few minutes ago.
The concern I had about the diff cover was the bolts issue I heard about before... that they would strip/break before being torqued. I was careful to set my wrench to 31 ft/lbs. torqued all the bolts but one with out issue.
One this one bolt, I first spun the lock washer (should have been a sign).

I took it off, used the spare washer that came with it kit and started torquing again... it seamed to take a while. I check 3 other bolts to see if my wrench was off - they clicked where I expected.
...then I broke the head off the bolt.

I haven't filled the diff up, waiting the 24 hours to let it cure.
My question - am I fuk'd?

My options:
1. try to use a back-out and put another bolt in tomorrow before I full it up with fluid
cons - if it doesn't back out, I could need to drill/tap it out.

2. take the cover off and try to pull it out with vice grips; I think there's enough left that I can get to it.
cons - I need would have to re-clean (took an hour today) and re-seal the SOB again. This would also mean I'm not making it into work Monday.

3. leave it and fill it up tomorrow... the shrockworks cover is designed to put more even pressure all the way around. The bolt is one of the high ups, but not he top - would I be ok?
cons - if it leaks, I have to go back to options 1 or 2.

waddya think?

 

[Gerdo]

I see two choices. First try to, with a removal kit, drill (reverse drill) and use the extractor. If that doesnt work you can pull the cover and use some VGs to grab it and back it out. The problem with drilling it out first is that the bolt, if not removed, will now crush with the pressure of the Vice-Grips.

Personally I would remove the cover, cover the diff guts with a rag and clamp the VGs as tight as I could get them on the bolt. I would not just leave it and hope it won't leak, not an option in my book.

What grade are the SW bolts? Could they be too long and bottoming out?

 

[jollyman78]

not sure what grade they are... it has 3 dashes and say "JH" on it.

If it's soft enough to break at 31 ft/lbs, would it be soft enough to drill/backout... I REALLY don't want to pull the cover again; but will if I need to.

Iam also only assuming there's enough to pull out with a vice grip. The broken bolt head has about 5/8" of thread on it. Need to see how thick the shrockwork cover and diff cover are and I can see if there's enough left.

 

[jollyman78]

The ring on the shrockworks cover is 3/8" steel... that leaves me with ~1/4". Now, how thick is the stock cover...

 

[jollyman78]

no no no... I can't read a tape.

The broke off screw is 3/8". I don't think it's enough to pull out with a vicegrip... The lip is WAY thin; I think I'm left with trying the back-out bit.

...anyone know what grade this screw is?
According to this site, I think it's grade 5: http://volvospeed.com/Repair/boltgrade.htm

Is this soft enough that I can use the back-out?

 

[PaulXyZ]

Funny - I just spun one of my washers open just like that on my rear bumper. Never seen that happen before. Looks like a hardware quality issue.

 

[PaulXyZ]

not sure what grade they are... it has 3 dashes and say "JH" on it.

3 radial lines makes it a grade 5 bolt.

 

[jollyman78]

not sure what grade they are... it has 3 dashes and say "JH" on it.

3 radial lines makes it a grade 5 bolt.

Is grade 5 too hard to use a backout?

 

[PaulXyZ]

That struck me as odd so I just crawled out from under mine rear differential and mine are marked with 6 radial lines - grade 8 bolts. Grade 5 is 85,000 psi proof load, grade 8 is 120,000.

 

[jollyman78]

So, I got sent the wrong bolts with my diff cover?

Now I'm wondering if I should replace all 8 of them with grade 8 bolts...

 

[PaulXyZ]

 

[jollyman78]

Jim!!!!!

edit - Jim's a wonderful man! these are the right bolts (keep reading in the thread).

 

[BioTerra]

I just stripped the threads in the diff casing today when installing the skid. Not real sure why..wasn't cranking it much.

 

[jollyman78]

I just stripped the threads in the diff casing today when installing the skid. Not real sure why..wasn't cranking it much.

Sounds like you're worse off than me... gona pull and re-tap it?

 

[XterraPA]

Jolly:

Those are not the same grade bolts that shipped my Shrock rear diff cover. There is no reason that bolt should shear off like that. I would invest in a higher grade bolt and replace all 8 of them.

Sorry that happened, I wish ya good luck backing that bolt out.

 

[jollyman78]

Is it worth pulling the other 7 out and replacing them, or just replacing the one that needs it? The other 7 are torqued and in... my fear is breaking the nice seal that I just made with the RTV today :|

 

[XterraPA]

Well, think of it this way. If one of those bolts broke during installation, I would be worried of another one breaking out on the road or trail. This could cause a serious diff leak.

If you were to replace them one by one, your chances of loosening the seal will decrease. Worst case scenario is to redo your RVT seal.

 

[BioTerra]

My bolt didn't actually lodge in the housing so I am in luck. Will have a local shop re-tap the hole and put a new bolt in tomorrow.

 

[JIMBO]

:clown: Hey guys, I'm sure you realize-there is no reason for class 8 bolts in a non-supporting/non-pressurized/non-suspension-DIFFERENTIAL COVER--Stop making a big deal out of this and those bolts don't even REALLY have to be torqued, although it's a good insurance !!

--Either the bolt was a defective one, or you ran out of thread depth,or your torque wrench was inaccurate--

--On lighter vehicles with 9/16' bolts I've even used lockwashers on the bottom ring--

--Grade 5 bolts are plenty strong enough for a diff., Mr. Shrake didn't do anything wrong !!

-- --JIMBO

 

[XterraPA]

Jimbo, I am not saying ShrockWorks did anything wrong. But, there is no harm in using a stronger bolt.

I wouldn't use lock washers on the diff cover either. I didn't mention that before. Guess I should have.