325ix front diff reinforcement help

[PartyMarty]

I have a 1989 325ix. It is a turbo car pushing approx 400 hp. The front diff is the weakest link in the all wheel system. What can I use guys? I am looking to modify the internals of the diff only. Not getting into changing the cars all wheel infrastructure. Having a hard time finding out what guys are doing. Any info would be greatly appreciated...gearsets, machining required, whatever needs to be done inside the diff housing only. Driveshaft is already lengthened, and the rest of the drivetrain is mint.

[flyboyx]

there have been tons of threads about this already over the years. you can search.

the reality is that unless you have about 15k to throw at designing custom parts, your best bet is to just buy a couple extra front diffs.

[PartyMarty]

That doesn't answer anything I asked. I don't want opinions please just facts.

[iXguido]

this gives a little insight as to what breaks http://www.r3vlimited.com/board/show...7&postcount=41

the guy mentioned in that post (mw044) has made a thread here but the pictures are missing of his modification. http://www.e30tech.com/forum/showthread.php?t=78337

no one has figured out a permanent solution yet but the guys that are breaking things are putting out double the power that you are. I personally haven't heard of guts in the 400hp range busting front diffs.

[PartyMarty]

Thank you. I am determined to make it work so as soon as I come up with or find a solution it will definitely end up here. When? Well it's going to be a while 😉

[The Dark Side of Will]

That doesn't answer anything I asked. I don't want opinions please just facts.

Lol. The FACT is that there is no proven, reliable, easy method. There isn't even a proven, reliable, difficult method. There's nothing. So what he told you is pretty true.

Do a 24V swap and go with E34 or E53 front drive hardware.
The Quaife for a Z3 1.9 will work in the E53 front diff.

So far the only successful 24V swaps have involved either frankenpan or cut firewall.

[stonea]

That doesn't answer anything I asked. I don't want opinions please just facts.

He did give you the facts. There is no proven way to reinforce the front diff. If there was we would all be doing it.

[nando]

I remember the pictures of what mw044 did, but I don't think it really worked - basically the little spider gears broke, so I think he cut up another diff carrier to add another set of spider gears. Not sure if it was just not aligned or what, but the first one blew up right away.

I think he built another one - not sure what happened to it, I haven't seen him post in ages - maybe it worked the second time, but AFAIK, he's the only one who's ever tried it, and it didn't look easy.

[Northern]

There are a few people who have done the same thing with the front diff so far. They usually seem to post in obscure groups on Facebook (ugh.)

IMO, the best idea I've seen so far was one who made a jig from an old cut up ring gear in an attempt to align everything correctly. The finished pictures looked good, but I've heard nothing since.

[iXguido]

I remember the pictures of what mw044 did, but I don't think it really worked - basically the little spider gears broke, so I think he cut up another diff carrier to add another set of spider gears. Not sure if it was just not aligned or what, but the first one blew up right away.

I think he built another one - not sure what happened to it, I haven't seen him post in ages - maybe it worked the second time, but AFAIK, he's the only one who's ever tried it, and it didn't look easy.

He ended up giving up on the e30ix parts and now he's using e34ix front diff and oilpan.

[litu]

Not sure was this mw044 last evolution in that front diff

Front diff had double amount of spider gears and 30mm steel girdle with locating studs. Broke few spur/pinion gears within a weekend had enough

I have seen mw044 is using these now days

but new drivetrain will consist of e9x 335i double clutch gearbox, e70 x5 atc700 xdrive transfer case, custom driveshafts, e34 525ix front diff. Both diffs with zf clutch type lsd.

There is welded oilpain etc etc.Some custom parts, work.
What i have heard, you should go e34 front diff, that can handle that power better..

[The Dark Side of Will]

The Quaife for a Z3 1.9 will work in the E53 front diff.

However, if using the E30 or E34 T-cases, using the E53 oil pan and diff will require a U-jointed driveshaft.