Ok well i redid my rear end about 30,000km ago with new crown and pinion...new carrier with 3 clutch packs..spider gears...etc

well coming home the other night i heard some sort of clunking and was not sure what it was...i drove home slow(about 20km) and only heard it about 4 times...well i got home...checked a bunch of things could not find the reason it was making the noise...so i popped off the rear cover only to find there was only 2 of the 10 bolts left holding my crown to my carrier....has anyone ever had this occur?....all of the bolts fell out...two broke off and there was still 2 left in there holding it all together.

i am not sure why it occured...or why it took 30,000km for it to happen?....i mean i dont grandma drive my truck...but i dont abuse it either....i drive it hard when i want and thats about it.

i was just checking to see if anyone else has had this problem or not? if so would you reccomend that i put new bolts in there? or just replace the 1 broken one?....i was inspecting the crown/pinion and internals and did not find anything damaged...i did not think there would be as the crown and pinion are pretty hard metals...

but i guess anyone have reccomendations? are these bolts expensive? should i get new set from ford...or jobber? my gearset is a Motive Performance 3:55...should i get Motive bolts?...maybe i should have not reused my original bolts?

not sure os any information would help.

THNX
Duggy

 

I don't think I would have re-used the same bolts. I would have went with new ones and torqued them to spec and also used a locking compound. I have never heard of this happening to an 8.8in rear.
Rich

 

Either they were not torqued sufficiently or the shorter bolts were used where the longer ones should have been.

yes the crown and pinion gears are hardened but if a crown bolt went through there, chances are you got a chipped tooth. I would inspect the gears carefully.

If the gears appear fine, get some new bolts, torque them down and don't be shy with the thread locker.

How do you tell whether you need the longer bolts or not? Good question. Normally I compare the thickness of the factory differential crown gear mating surface to the new one. If the new one is thicker, then I go with the longer bolts.

 

ya i inspected carefully and everything seems ok...i think i caught it before it got to serious.

ya we used the same bolts...red loctite(plenty) and tourqued to spec...i guess i just should not have used the same bolts.

i went and purchased a new set of bolts and went heavy on the loc-tite and tourqued up properley so we will see how it holds together right now.

THNX
Duggy