adam5743

iTrader: (3)

I noticed a slight squealing sound that gradually got worse so I brought it to the shop. It turns out that 3 of the 4 crank bolts are broken and the belt was rubbing on the housing. Any thoughts on what might have caused this? I think this problem started a few months back when I first heard the squealing sound and had the belt replaced. Is there any chance this could have caused further damage or that there is another problem that caused this?

56k mi EVO VIII, HKS 272s and exhaust are basically the only modifications for at least 3 years and 30k mi. New ACT clutch & flywheel installed last month.

Aman

iTrader: (23)

either drill and rethread them.. or do a timing belt job while you are in their and replace the crank sprocket.

n2oiroc

iTrader: (33)

either they were overtorqued by a wide margain, or something is really out of balance. could be the clutch even.

barneyb

Not common but it has happened to a few owners. I can't suggest anything except having it fixed.

dsmfan95

iTrader: (27)

I had this problem. I'm not sure how your under drive pulley is but I'd replace it and your timing sprocket. I also went to a hardware specialty store and got some stronger bolts as well as some loctite to make sure the vibrations didn't back the bolts out (another problem I had before I had a bolt snap off). I put a Fluidampr on when I replaced the pulley and haven't had a problem since.

Also I'd recommend pulling your timing cover and inspecting your timing belt to make sure it is ok. I had a few chunks taken out of mine and decided to replace the belt at the same time.

rdt1

iTrader: (8)

Buy a new one, save your time and drill.

grahamab

iTrader: (10)

you're not the first....

https://www.evolutionm.net/forums/ev...-fell-off.html

https://www.evolutionm.net/forums/ev...l-off-wtf.html

had this happen a couple years ago. removed the sheared bolts, replaced the crank pulley with a fluidampr, and added high quality bolts.

dsmfan95

iTrader: (27)

This seems to an issue mainly on 2005 Evo 8's. Interesting.

Drexel_Evo

Damn bro, I'll be sure to watch out for that!

Mwolf83

I had this happen on my 1g DSM along time ago too, bolts were torqued to spec, never did figure out what caused mine.

DOUGLAS

iTrader: (19)

I had the main timing sprocket bolt loosen up causing not only the timing belt to skip but the sprocket to eat away the keyway on the output end of my crank (2003 VIII). Aside from everything else for my build I decided on a Fluidampr with ARP main and auxiliary bolts.