Alfa Pages

[rallyboy77]

That is what happens when one of the bolts holding the crown wheel (gear) onto the differential comes lose. It managed to find it's way through the case, where the metal is like 10mm think! I have some pictures which I can post if you like.

My question is, what is the solution here. It's the second time those bolts have come loose, first time they have broken something luckly. They were cleaned, loctited with bearing fix and torqued correctly? Do I have to lock (safety) wire these things???

What is the solution?

(did I mention this is a rally car??)

Jez

[ZeNiTh-PbArM]

hi,

what loctite did you use? on "standard" gearboxes the factory glue on the bolts has a white color.
when you refit the bolts in place, please make sure that :
-all drillings have been thoroughly cleaned (using an tap & die set) and there are no remains of the old compound
-all bolts are clean, all of the previous glue shall be removed from the threads.
-the bolts are not damaged, the could have gained in length due to multiple torquings and the thread is out of spec ; check with a thread gauge and replace by new bolts if there is any doubt.
-clean any gearbox oil remains on the parts with alcohol or brake cleaner
-apply the strongest Loctite you can find (i use loctite 271, which implies heating the part to 300°C if you want to disassemble the parts in the future ; the loctite is red and pretty heavy!)
if all steps are followed this should be perfectly satisfactory. i assume you didn't modify the diff itself ( when fitting a limited slip diff, bolts and oil spec are not the same than with standard setup).
if the bolts come loose, it's either due to excessive vibration (read : balancig of moving parts) or excessive heat hence metal dilatation.

regards,
zp

[Graham]

I also have a rally sud and 33 and I have never had this problem? I do have a spare sud gearbox that you can have complete or just the case email me and we can arrange something for it.
_________________
5 Alfa 33's, 2 Suds God there is no help for me

Also own 2 Complete 16V Engines(Spare) And Have a Sud Rally Car in Production

[alfistjen]

As said above, maybe you could use the hardest locking loctite available. I work in a company that assembles busses, for some never-to-be-loosened parts we use green locktite, but forgot the number. Fact is that if you don't heat the glue to +300°C the head of the bolt will brake off before the thread loosens. Even on M24 bolts which we attempted to loosen with a 2 meter bar on the key.... pretty solid stuff, tested and approved

Regards!

Paul D.