diff bolt specs

[birdman2447]

I snapped my lower diff bolt like alot of e36's do, and i am trying to source the bolt locally, do any of you guys know the exact specs of the bolt, i cant seem to find much info on it---thanks

[hinzm3]

I think it's #16 in the pic which sounds right- Hex bolt with washer M12X1,5X80 ZNS
BMW should have it in stock usually

http://realoem.com/bmw/showparts.do?model=BG93&mospid=47488&btnr=33_0371&hg=33&fg=1016

[clytle]

not exactly the "spec" way to do it, but i put a grade 8 construction bolt in there. had to do a bit of grinding on the head and the washer, but considering it wont break, its worth it.

[98Altima]

get the right bolt from BMW, i snapped that bolt over and over until i put the one in i have now ordered via BMW dealer. The bushing may be bad, but Ive put this bolt to the test and its been in over a year now.

[themadhatter]

not exactly the "spec" way to do it, but i put a grade 8 construction bolt in there. had to do a bit of grinding on the head and the washer, but considering it wont break, its worth it.
the upgraded bolt from the dealer should be a 10.9, the 8.9 bends too easily. both will still snap...ask me how I know.

[Spec3HOR]

lol just broke mine yesterdayt at the autox, im going to do waht RRT recommended and go with larger bolt.

[Blanchimont]

Tightening torque 52 ft. lb.

[joenationwide]

Get the bolt from the E46!

[birdman2447]

thanks for in info, my local napa had the 8.8 grade that will work for now, untill i get one of these ordered

http://www.fastenal.com/web/products/detail.ex?sku=11113250&ucst=t

hopefully the 10.9 will hold up, i dont even track or autox the car so really dont want to do the double shear upgrade for street driving

[284Shooter]

The grade 10 cost me $8 at BMW with my CCA discount. I just swap it once a year for good measure when I'm doing a nut/bolt.

[breakfast]

i just got the kit from radowski and it comes with an 8.8 bolt.
should be fine since the load is in more than one spot.

[themadhatter]

i just got the kit from radowski and it comes with an 8.8 bolt.
should be fine since the load is in more than one spot.
you'll be fine with it, I haven't broken a diff bolt since Mike installed his brace onto my diff.

[das borgen]

Get the bolt from the E46!
part number?
what makes it better?

[Spec3HOR]

Its larger, you have to drill and tap out your Diff cover for a M14x1.5 (thats the size of the E46 bolt). I am actually doing that this week. Trying to find a m14x1.5 tap in the NOVA area.

[CoolDad]

The bolt for our M3s, based on realoem, is an M12x1.5x80 and the one from an e46 (P/N 33172282077) is an M14x1.5x65. Now going to a class 10.9 14mm bolt, which requires drilling out the aluminum center sleeve of the front differential bushing along with drilling and tapping the diff housing for the bigger bolt, all makes sense to me. But how is the 15mm shorter bolt length acceptable? Going to McMaster or Fastenal for an 80mm long version seems to be required. Am I missing something?

[boredinmemind]

Bump!. im looking for the strongest replacement bolt i can get, i just drilled my old one out...

[98Altima]

absolute pita. I replaced mine with garbage 8.8 off the shelf stuff a few times, finally replaced with the stock part from bmw, and it lasted a good while, but still ended up bending. need to replace again. Root of problem is bushing, but that is a maajor pita to replace, at least i think.

[Tongboy]

a 12.9 replacement would be the best grade you could easily drop in - anyhting slightly larger with a washer on the back side would be a reasonable upgrade.

Mine is sitting with the slightest bend in it but it hasn't broken yet - and i'm +100torque over stock.

a good front diff mount will help a lot becuase it will keep the bolt from seeing much movement