Easier diff install with studs

#1

Someone years ago told me about putting studs in to the diff instead of using bolts. The idea is that the studs make it much easier to get the diff in place. If you’ve ever installed a diff before, you know that getting the first diff bolt threaded in can be a bear. I went looking for 12mm studs but all I found locally was pressfit studs for wheels. I installed them buy threading them up from below. These worked fine in front but not for the rear of the diff. You can do the same thing with some long 12mm bolts.

But today I found that Condor, a SpecE30 sponsor, sells a kit for this. https://www.condorspeedshop.com/products/12mm-differential-stud-kit

#2

It’s been almost 2 years since I removed/reinstalled the diff on my car, so I’m probably not remembering something, but if the diff isn’t lined up perfectly (or close) to begin with, don’t you risk rubbing the threads up against the subframe mount holes and flattening them (the threads on the studs) out?

Or is there something specific about the diff installation that I’m not remembering?

(edit: not shitting on the idea, btw… I dig it. Anything to make routine stuff easier is a win for me. :slight_smile: Just curious about the threads.)

Som

#3

It’s just a matter of putting a bolt into a hole. Not even a threaded hole, but a hole plenty big enough for the bolt to pop thru easily. It’s not something that should involve 20 false starts that might cause wear. Get the diff into position and all 4 bolts will pop thru. Quick and easy. Don’t forget the studs are made of much harder steel then the subframe.

#4

I think I was misremembering the difficulty. I think the issue I’m remembering is getting the subframe + diff back in together. Doing it that way I seem to remember sliding the diff bushing into the mount part being a bit difficult (while making sure the subframe bushings fit, too).

But yeah, thinking more on it, as a standalone job, there’s nothing special (fit wise) about the diff swap on its own (other than threading the bolts, which this solves).

Som

#5

Subframe going back into place with diff already attached? That would be a bastard. No thanks.

#6

Heh… Yeah, no kidding. It was my first time and was doing it solo. Reassembling everything off the car was a huge plus. Also, with the diff, the whole assembly balances pretty perfectly on the jack. That said, wiggling everything in place was a pain in the ass. Though I’ve heard others who didn’t have nearly as hard a time with that part. shrug

Som

#7

Scott, remind me to show you the Diff Girdle this weekend.

RP