Spacing E36 subframe down

[dburt86]

Guys,

I need to space my subframe down a bit to gain clearence from the tunnel to the driveshaft.

The e90 bolts, how much longer are they then the studs? With the combo of bushings i have now, the studs are just barley long enough so before i go buying the e90 bolts, i want to confirm they are considerably longer then the stud.

If not, ill source a bolt, but kind of need a starting point.

[beeasy]

bolts for e90 are m12x127. I dont see a length listed for e36 studs but the e36 bolts are m12x116.

[dburt86]

I think people are using the front subframe bolts which are 145mm.

Assuming the the stock rear bolts have enough thread engagement, that would make them about an inch longer. Which would work well.

[someguy2800]

McMaster Carr, any bolt you want.

[dburt86]

McMaster Carr, any bolt you want.

Exactly what i though, except i cant find ANY m12x1.5 lol

I got some 150mm 10.9s coming from Fastenal. I figured id get them longer and if they are too long i can add a washer or 2 or cut them down.

[pbonsalb]

Take a 1/4 inch long drill bit, remove bolt, drill through bushing hole through trunk floor. Take 1-1.5 inch metal hole saw, use hole through floor as pilot, drill out the thin sheet metal floor, and you will see the subframe threaded receivers. If not fully tapped, tap them m12x1.5 from the trunk. Practice threading bolt from above and then install from below. Any extra length will just stick through. Weld up some reinforcing if you want, maybe a bar across the bottom tied into some verticals tied into a rear strut brace.

[EMC]

I drew up a set of solid sub-frame bushings and made them extend further on the top side, but put a deeper countersink on the bottom side. This way I could use the stock bolts/nuts. I'm not sure if that's an option for you.
I lowered the subframe about 11mm and I have a 3.5" aluminum driveshaft with enough clearance. It's still tight, but 1/8" clearance is all you should need if the rear end is solid mounted.

[dburt86]

I drew up a set of solid sub-frame bushings and made them extend further on the top side, but put a deeper countersink on the bottom side. This way I could use the stock bolts/nuts. I'm not sure if that's an option for you.
I lowered the subframe about 11mm and I have a 3.5" aluminum driveshaft with enough clearance. It's still tight, but 1/8" clearance is all you should need if the rear end is solid mounted.

What would a guy have to do to get a step file of those puppies? or maybe even a real set?