PDA

View Full Version : Diff Bolt


twacker
05-05-2005, 09:42 AM
SOB...I have gone through 3 diff bolts in 3000 miles. You would think that my car lives at the drag strip but it doesn't. The last bolt snapped when I shifted into 2nd kinda hard. Granted, my engine is modified but is this normal?? Looks like a support bracket is my answer. What's the best one out there??
FastrTHNu
05-05-2005, 09:46 AM
SOB...I have gone through 3 diff bolts in 3000 miles. You would think that my car lives at the drag strip but it doesn't. The last bolt snapped when I shifted into 2nd kinda hard. Granted, my engine is modified but is this normal?? Looks like a support bracket is my answer. What's the best one out there??


thats pretty odd that your snapping them that fast... :dunno


check out AA's site. www.aatuning.com

I plan on ordering the support they make with in the next week...
B.Watts
05-05-2005, 11:19 AM
Sounds really odd...either your driving is the problem or you have another problem with the car that is leading to the bolt problem. You shouldn't be breaking diff bolts in 1000 miles of driving.
95beema
05-05-2005, 11:40 AM
Is your car tubbed with slicks? lol . How are you driving the car?
deviousbmw
05-05-2005, 12:02 PM
I broke 2 before I replaced the bushing. What a PITA. The problem is once you break the bolt all the rattling around wears out the bushing. When the bushing gives more it is easier to break the bolt the next time. I have the AA diff support bracket now. Bushing is not expensive but just a pain to replace. I feel this is your problem though.

John
96cosmosM3
05-05-2005, 12:37 PM
I got 140k and 50+ drag strip runs on the orginal diff bolt, I agree with the above post that you must have bad bushings and/or something else causing it to move around.
twacker
05-05-2005, 02:19 PM
Well I doubt it's my driving, but everybody probably thinks that. Keep in mind I have 280WHP going through the drivetrain. Looks like the consensus is that I replace bushings and add a AA mount.
twacker
05-05-2005, 02:24 PM
Would a LTW CNC Machined Aluminum Flywheel add to the problem??
B.Watts
05-05-2005, 02:45 PM
Keep in mind I have 280WHP going through the drivetrain.

There are plenty of people running that much power and not breaking diff bolts every 1000 miles. There's something else wrong.
auto_pilot
05-05-2005, 02:48 PM
PM TheMadHater (BFC MOD)...He could probably point you in the right direction.
shim
05-06-2005, 05:57 AM
active auto DSB
Chongus
05-06-2005, 08:07 AM
Yup. i was breaking front diff bolts and it was irritating. Goe a AA DSB and nevr had a problem since
ErstealM3
08-17-2005, 04:09 PM
i broke a bolt now my car makes a vibration in first gear,only when i get on it, off it, then on it hard,its almost a knocking.....help
thanks,
eric
95beema
08-17-2005, 11:11 PM
i broke a bolt now my car makes a vibration in first gear,only when i get on it, off it, then on it hard,its almost a knocking.....help
thanks,
eric

Put a new diff bolt in and you should be golden. Dont drive till you do.
BaLLZacK
08-17-2005, 11:15 PM
Yep I snaped a bolt dragin, AA DSB is the way to go but since you broke it twice definitly get that bushing replaced aswell, its what caused it to break the second time.

ALi
///MPwr
08-18-2005, 01:30 AM
At my mechanic's the other day I saw a Dinan SC E36 M3 that had broken its diff bolt. They were going to have to take the diff off and get the broken piece out. I ordered the AA diff support the moment I got home. The price of the bracket is a fraction of the cost of what it would be to take the diff off, disassemble and repair. Consider it preventative maintainence.