Frontline fab rear diff cover Pre-load bolts

[Corey N]

Installing a Frontline Fab rear diff cover on my 2g in a few days and am hoping to gather more info regarding the load bolts that put pre-tension on the bearing caps and adjusting/setting them properly. I've done some google searching with no luck and got no response when I emailed Frontline Fab. Is there a proper torque specification or some kind of measurement I take when installing it to make sure everything is put together properly? Any help is appreciated. Thanks in advance!

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[TSiAWD666]

The preload bolts are tightened hand tight. That's it.

The cover has a number of major design flaws I've found from years of ownership.
1) The preload bolts can easily work their way loose with the single non-lock nut Andrew provides, at least on my evo 8 clutch pack diff. Switch that to a nylock.
2) The preload bolts holes leak fluid fairly easily, possibly because they work loose really quickly and maybe with the nylock they won't and then won't leak. The preload feet are very close to the diff cover on the inside so right now I'm testing simply putting some o-rings around the preload bolts that get slightly compressed when the cover is on but the jury is still out on whether this solves the problem (I only had really one track session with it but no fluid so far).
3) The brass breather filter up top also leaks plenty of fluid if you're really pushing it (might never affect a drag car but it does my track car). The fix for that is to add a hose around it that extends a bit vertically. This is a fix I learned from BMW racers. This lets fluid "burp" out of the filter, collect in the tube, then trickle back down and into the case.

I brought #1 and #2 to the attention of Andrew at Frontline many years ago but he never cared to address them. #3 is more of a recent discovery when pulling the rear subframe to install solid subframe bushings.

 

[Corey N]

Got these instructions straight from Frontline Fabrications this morning.

 

[91talonts1]

Probably want to put some thread sealant on the load bolts. I don't have one of these covers but Curries and Strange covers have a similar design and they leak without it.

 

[Corey N]

Installing this now and I feel like I'm missing something..... The load bolts stick out from the cover so much that there's no way for the diff to sit all the way in the subframe and get even remotely close to the mounting bolts. What am I missing?

 

[91talonts1]

Pretty sure you gotta cut holes for em in the subframe, I could be wrong. I know I've seen pictures of that done though.

 

[Corey N]

You don't think that would cause any problems in regard to structural integrity and whatnot? I'm no engineer nor making tons of power, but I'd just hate to ruin a perfectly good subframe that I've already painted and pressed solid bushings into. Thanks for the help guys!

 

[TSiAWD666]

You have to cut holes. It's fine.

Measure twice, cut once or else you'll end up with an oblong hole like I did making it fit in there