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Diff bearing cap help

10K views 7 replies 4 participants last post by  girdnerg 
#1 · (Edited)
One of the differential bearing bolts sheered off, but I caught it before any damage was done. The head of the bolt was thrown into the diff cover and the oil was leaking on my exhaust, so the smoke told me something was wrong.

My question is about the diff bearing caps. I wasn't paying attention when I removed them as I was worried about looking for damage. But they had to be removed to get the rest of the bolt pulled out.

I found in the service manual that the cap arrows point outboard.
My question is which bearing cap goes on which side (left, right, or does it matter)?
They both have 3TAA then the arrows, but one has C89 and the other C84 after the arrows.

The diff was a rebuilt one from a member on this site (Teeps) back in 2009. I tried to contact him, but his email is no longer valid.
Thanks for any help.
 
#2 ·
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#3 ·
The arrows always point out on the caps..The numbers mean squadoosh
I seem to recall there being corresponding markings on the caps and the gasket surface side associated with that side..
Clean the gasket suface well to see if you can find any..

If you still can't find any corresponding markings, then you could try Plastigage..

Basically, you're just going to lay a piece of Plastigage on the carrier bearing..Then torque to spec..

If you have the cap on the correct side, it should be a straight line with no taper..

Like this:


If the cap is on the wrong side, the Plastigage will taper when it gets torqued to spec..

Like this:


It's important getting these caps on the right sides..They are machined to fit the differential one way..
Put them on wrong, and you risk destroying your carrier bearings..





Rayo..
 
#4 · (Edited)
The arrows always point out on the caps...

Rayo..
They didn't in mine, they both point the same direction. I guess that doesn't mean someone had been in there once and put the one on wrong. I marked them with a punch. There was also a line of brown paint on one, the line continued onto the housing. I didn't put it together wrong (from how I took it apart).
 
#5 ·
girdnerg said:
I found in the service manual that the cap arrows point outboard.
My Ford Service Manual says the arrows point outwards..It Does Not say there are exceptions to this rule..

Here's a scan of that page from the Ford Service Manual:





Rayo..
 
#6 ·
My Ford Service Manual says the arrows point outwards..It Does Not say there are exceptions to this rule..

Here's a scan of that page from the Ford Service Manual:
http://i790.photobucket.com/albums/yy188/Rayo187/Differential Bearing Caps Arrows_zpsodu8nhsq.jpg

Rayo..
That's disconcerting. I have the service manual as well, in book form. For as worn as the clutch packs were I can't see that anyone had had the carrier out for anything, but there's no way to tell. I wonder if I should go back in...
 
#8 ·
I was able to match which side is which by markings when the bolt broke off. I also had my brother come down from another city as he has experience rebuilding diffs in fork lifts. All seems well now.

Now to the WTF happened to begin with. Since one of the bolts was broken, I bought a whole new set of the same length. I got them at a specialty shop, so they are harder than stock. After running a tap through the holes, I put it all back together.

Funny thing is the new bolts would bottom out with about a quarter inch gap from the cap. We ended up having to get shorter bolts. Since mine was rebuilt, I can't figure out how he got the longer bolts to torque. must've used air or something. That would explain why all the bolt holes had to have the tap run through them (the old bolts wouldn't even go back in once removed). I think the longer bolts were just barely holding the caps on, but then again it lasted since 2009 and I drive it hard.

I'll get the diff back in this weekend, but I'm having some work done on the knuckles, so I won't be able to drive it until next weekend.

I'll report back with the results.

Thank all of you very much for your help,

Rob
 
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