Any tricks or tips on removing top diff bolts?

[butters]

I'm in the process of a swap on my 318i, engine is out and I'm tidying up and finishing removal of the driveline.... But I've hit a wall at the rear diff.

The rear/upper diff mounting bolts area in such a tight area, I can't see any good way of applying the necessary (90 lb-ft) torque to break them free. By removing the wheels, I could extend my socket wrench with a bar and get enough leverage to break the front diff bolts. At the rear/top, only a box wrench will fit. I have been soaking them in penetrating oil for a couple days now, hopefully that helps my cause.

If anyone has any great ideas, please let me know!

Btw I'm on my back in the garage of course... no lift

[Wishno87]

I just have a box end wrench and I cut the other end off. Then I put a long square pipe over it. Easy peasy.

[kalib0y]

I use a box end wrench and a rubber mallet.

[E30SPDFRK]

Grow some non-girly arms.

If you don't have sufficiant time for that, use a combination wrench with the box end on the bolt, then link another box end into the open side for extra leverage.

[jlevie]

Drop the subframe a few inches and you'll have much better access to the bolts. Support the subframe and trailing arms with jack stands or blocking so you can use a floor jack under the differential.