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[Randall921]

3.91

1. Bigjae46
2. Bigjae46
3. robgill
4. Heirforce1
5. Randall921

[Actuary]

Add me to the list for 3.91

[enjoy_m3]

Can someone remind me, the e9x and e46 m3 R&P are interchangeable right? I have a friend with a e9x m3 that may be interested in a 3.91.

Also, I might be able to provide a bearing package if you guys are interested (koyo bearings). I can look into it

[HighOnLSB]

Clicked through the options too fast on the site and accidentally committed to 4.10 gears.

Would be interested in 3.91 instead, also curious how payment will work for this group buy.

[ATB88]

For those planning on having a local shop do the install, I recommend finding a place that is guaranteed that they'll do it (and for a good price) before committing. In my (limited) experience finding a place willing to do rebuild work on an M diff isn't as easy as you might expect. I had a hell of a time finding a place that would do it in LA. Almost every BMW place that got recommended to me told me that they don't do diff work anymore because it's not worth their time for what they'd charge because it's so finnicky. Standard transmission/diff shops didn't want to touch it because it was BMW/M. I only ended up finding one place in the LA area that would do it, and they charged a lot (wanted $600-$700, diff already out of car and parts provided by me, to do pinion and output bearings/seals, no ring and pinion swap or anything else).

This is super dependent on where you live, of course, but before my experience I just kind of assumed that of course I'd be able to find a place that would do my diff around here. Turns out it wasn't easy even in a huge city. Ymmv.

[Cubieman]

For those planning on having a local shop do the install, I recommend finding a place that is guaranteed that they'll do it (and for a good price) before committing. In my (limited) experience finding a place willing to do rebuild work on an M diff isn't as easy as you might expect. I had a hell of a time finding a place that would do it in LA. Almost every BMW place that got recommended to me told me that they don't do it anymore because it's not worth their time for what they'd charge because it's so finnicky. Standard transmission/diff shops didn't want to touch it because it was BMW/M. I only ended up finding one place in the LA area that would do it, and they charged a lot (wanted $600-$700, diff already out of car and parts provided by me, to do pinion and output bearings/seals, no ring and pinion swap or anything else).

This is super dependent on where you live, of course, but before my experience I just kind of assumed that of course I'd be able to find a place that would do my diff around here. Turns out it wasn't easy even in a huge city. Ymmv.

I want to go from 4.10>3.91 but what you just described is what has me 50/50. Probably just send the R&P to Diffsonline.com and have them do it, around $1300 iirc.

Although for the price one could grab this R&P and re-sell at cost if the installation isn't practical.

[bigjae46]

I built my own diff. Not the easiest thing to do because there’s very little info. If you have a press, dial gauge, beam torque wrench...then it’s something that can be accomplished with some patience.

There is going to be some adjustment if you’re swapping in a 3.91 or 4.10 so you’ll need shims and there will be some trial and error. The LSD carrier isn’t exactly light or easy to handle.

It can be done. I wouldn’t call it difficult...just requires patience.


Sent from my iPhone using Tapatalk

[ATB88]

I want to go from 4.10>3.91 but what you just described is what has me 50/50. Probably just send the R&P to Diffsonline.com and have them do it, around $1300 iirc.

Although for the price one could grab this R&P and re-sell at cost if the installation isn't practical.

Yeah I mean diffsonline isn't a bad route. But also just call around a few shops in the area and ask around about it. I wouldn't be surprised if it's easier to find a place willing to do it in less densely populated areas. I feel like all these places in LA become specialized in more "mainstream" repair work not because they can't do more complicated stuff but because they have enough customers that they can just choose what they will/won't work on because they'll still have a full schedule and just assume you can find someone else in the city to do it if they think it's a PITA. Whereas I'd expect shops in less dense areas to be willing to take on more things if they can do it just to be able to have the work. Honestly really curious if others have experienced the same difficulty finding someone to work on their diff as me or if LA's just weird ¯\_(ツ)_/¯

[enjoy_m3]

ATB, mind me asking what shop did the work on your diff? I'm looking around for shops that can help with backlash adjustment.

Or if Bigjae46 has any tips and tricks on how to check the backlash and pinion pre load.

[EthanolTurbo]

I'm also interested in finding a SoCal shop for my 3.91 swap and rebuild.

[Cubieman]

NEW EUROCONNEX GB:
FORGED MOTORSPORT FINAL DRIVE GEARS & PINIONS (3.45, 3.62, 4.10)

So just to be clear, we need to get 20 people together on the 3.91's for the $559 price? I see that the 20 piece requirement had been met for the 3.45/3.62/4.10.

I am making my mind up today and would be #7 for the 3.91's.

[ATB88]

ATB, mind me asking what shop did the work on your diff? I'm looking around for shops that can help with backlash adjustment.

Or if Bigjae46 has any tips and tricks on how to check the backlash and pinion pre load.

The place I mentioned earlier that wanted $600 for labor on bearing swap was Marc Norris at Bavarian Workshop in Woodland Hills. Nice and knowledgeable guy when I spoke with him on the phone. Sounded very confident that he knows how to dial these diffs in. Here he is on Leno with a heck of a 2002: https://www.youtube.com/watch?v=ICMS...ture=emb_title

We were gonna go with him, but, then, while I was doing my 6MT swap at a DIY garage in Baldwin Park, there just so happened to be a bunch of guys setting up their new shop next door (412 Motorsport: https://www.yelp.com/biz/412-motorsport-baldwin-park) and their owner Sam was super helpful and gave me some tips for the swap. I told him about my difficulty in finding a place to work on my diff and he offered to do the bearing job himself, while I finished my swap, and he did it on the cheap ($300ish?). But he said that was much cheaper than he'd normally charge for this work. I think this was before their shop was even open to the public I have no idea if their shop normally offers this service or if he was just doing me a favor while his shop was still getting off the ground because he was bored? Either way, good guy and it's worth giving 412 Motorsport a call to ask. But FWIW I really don't know their overall track record on diff rebuilds, just that mine's still going 25k miles later and that they're super friendly guys

[enjoy_m3]

Thanks ATB, keep us updated with your diff if anything. I'll give both shops a call and talk them to see which I may be more comfortable with.

I'm also interested in a 3.91

1. Bigjae46
2. Bigjae46
3. robgill
4. Heirforce1
5. Randall921
6. Enjoy_m3

[Epoustouflant]

So just to be clear, we need to get 20 people together on the 3.91's for the $559 price? I see that the 20 piece requirement had been met for the 3.45/3.62/4.10.

I am making my mind up today and would be #7 for the 3.91's.

That's the correct understanding. We have reached 20x for 4.10 - 3.45 is following up. I will have to create a different GB listing once we have enough 3.91 - I will most likely cross post this into the E46 M3 Facebook Groups afterwards to help us reach 20x.

[maupineda]

That's the correct understanding. We have reached 20x for 4.10 - 3.45 is following up. I will have to create a different GB listing once we have enough 3.91 - I will most likely cross post this into the E46 M3 Facebook Groups afterwards to help us reach 20x.

What is the next step now? Will we get the invoice to pay? Or how does it work?