MFactory Diff Exploded - Need help finding OEM Replacement

[asbrr]

Hi Guys,

I bought a used MFactory Helical diff 3.5 years ago and swapped out my stock 128i manual's diff for this one (same 3.23 ratios as factory 128i, the MFactory diff came inside a manual 328i pumpkin).

I'm on the hunt on car-part.com now for a replacement, and based on some quick research using RealOEM and:

http://www.bokchoys.com/differential/GearRatios.htm

Seems I'm limited to E90/E91/E92 Manual 328i, E90 Manual 325i, Manual E85 Z4 3.0si, or obviously another manual 128i. I'm in Toronto, Canada - we got the 323 here as well and based on RealOEM the final drive is the same but BMW part numbers and weight are different than a 128i - so I'm unsure if this will fit?

I also see some E46 models have the same final drive like 325xi, or even an E36 M3 manual. Do those diffs fit as well?

I'm looking to keep the ratios stock, and just go back to a stock BMW open diff at this point (spent way too much money on the car this year).

I've also reached out to MFactory support to see if there is anything they can do warranty-wise.

Any help is appreciated, thanks in advance.

[ShocknAwe]

Same thing happened to me recently. Glad you're ok.

I'd stick with same part number builds or your prop and axles may not line up.

[Rmtt]

Originally Posted by asbrr

Hi Guys,

I bought a used MFactory Helical diff 3.5 years ago and swapped out my stock 128i manual's diff for this one (same 3.23 ratios as factory 128i, the MFactory diff came inside a manual 328i pumpkin).

I'm on the hunt on car-part.com now for a replacement, and based on some quick research using RealOEM and:

http://www.bokchoys.com/differential/GearRatios.htm

Seems I'm limited to E90/E91/E92 Manual 328i, E90 Manual 325i, Manual E85 Z4 3.0si, or obviously another manual 128i. I'm in Toronto, Canada - we got the 323 here as well and based on RealOEM the final drive is the same but BMW part numbers and weight are different than a 128i - so I'm unsure if this will fit?

I also see some E46 models have the same final drive like 325xi, or even an E36 M3 manual. Do those diffs fit as well?

I'm looking to keep the ratios stock, and just go back to a stock BMW open diff at this point (spent way too much money on the car this year).

I've also reached out to MFactory support to see if there is anything they can do warranty-wise.

Any help is appreciated, thanks in advance.

I have my old one that came out of my 2011 manual that I pulled with about 65K on the clock. I bought one off of Ebay out of an auto that was in a front end collision for about $350 shipped that had 21K miles on it because I wanted 3:73 gears. It was the first mod I did to the car. Not hard to change, just cumbersome because of the weight. I changed mine out on jackstands.

I would take $100 for mine + shipping just to help a fellow member out, but I can't imagine what shipping costs would be from South Carolina to you. It was nice and smooth with no issues whatsoever although I only put about 3-4K miles on it. But the guy I bought the car from was very anal about the service of the car, and said he didn't drive the car hard at all. He had an M3 as well. I believe him as I have all the old 5K mile oil change records.

Maybe you can find one on ebay that would be cheaper overall if it were closer to you as you know how much they weigh . Only thing I would do with mine if someone else got it would be recommend that they replace the gear oil although some never change the fluid.

Only issue I have is I leave for vacation in a day and won't be back until the 19th. If you were interested I could see what it would cost to ship through work as we get a discount (UPS)....I just have to pay for it. I'm not quite sure how it works now at the border with shipping stuff.

Just hit me up later if you are still looking and interested.

[spidertri]

Oh wow, how did the diff fail?

I've been looking at LSDs and want to make sure I get one that'll last. From what I've read Mfactory has great customer service, hopefully they'll help you out.

[asbrr]

Originally Posted by Rmtt

I have my old one that came out of my 2011 manual that I pulled with about 65K on the clock. I bought one off of Ebay out of an auto that was in a front end collision for about $350 shipped that had 21K miles on it because I wanted 3:73 gears. It was the first mod I did to the car. Not hard to change, just cumbersome because of the weight. I changed mine out on jackstands.

I would take $100 for mine + shipping just to help a fellow member out, but I can't imagine what shipping costs would be from South Carolina to you. It was nice and smooth with no issues whatsoever although I only put about 3-4K miles on it. But the guy I bought the car from was very anal about the service of the car, and said he didn't drive the car hard at all. He had an M3 as well. I believe him as I have all the old 5K mile oil change records.

Maybe you can find one on ebay that would be cheaper overall if it were closer to you as you know how much they weigh . Only thing I would do with mine if someone else got it would be recommend that they replace the gear oil although some never change the fluid.

Only issue I have is I leave for vacation in a day and won't be back until the 19th. If you were interested I could see what it would cost to ship through work as we get a discount (UPS)....I just have to pay for it. I'm not quite sure how it works now at the border with shipping stuff.

Just hit me up later if you are still looking and interested.

Oh man that would be perfect - I'm sending you a DM right now..

[asbrr]

Originally Posted by spidertri

Oh wow, how did the diff fail?

I've been looking at LSDs and want to make sure I get one that'll last. From what I've read Mfactory has great customer service, hopefully they'll help you out.

I wouldn't say it's necessarily the LSD portion that failed, mechanic hasn't opened it up to diagnose, feels like a gear tooth broke off, not sure due to what though. As I mentioned I bought mine used, so who knows how good/bad the condition was or if it was abused prior. It ran just fine for 3.5 years including a few DE days at the track.

The Mfactory helical diffs for 135i cars had a manufacturing defect early on but that was corrected..

Helical diffs in general are low maintenance and reliable..do your research on your particular application and see what the problems are...

[ShocknAwe]

What happened when yours failed?

[asbrr]

Originally Posted by ShocknAwe

What happened when yours failed?

First started about 2 weeks back, reversing out of driveway, and when I hit the "bump" at the end applied a bit more throttle to get out of the rut and heard a "bang" from the rear end like I hit something....and at the same time had no reverse (but was in gear still with the clutch out!!!). Took it out of gear, clutch out and then back into reverse, and had reverse drive again no issue.

Happened again a few days later, felt a bang, no reverse drive but still in gear. Out of gear back into gear no problems. Drove gingerly and dropped the car off at the mechanic - asked them to change transmission and diff fluid (had been a couple of years) and look for any metal bits. All came out clean.

Then last night driving, this time in 2nd gear maybe, coasting (using engine braking) as I approached a stop sign on a downhill, heard/felt another massive bang from the rear like I hit something. Pulled over looked under the car fully expecting a mess of metal and oil - nothing. Drove forward slowly and now a repeating and loud "thump" from the rear end which goes up in frequency with speed.

Got the car up on a flatbed to my mechanic, he basically confirmed something internal to the diff blew up. He hasn't opened it up to confirm what. Spoke with MFactory support (synchrotek in Cali), and Dave said based on what it sounds like I broke a tooth on a gear somewhere.

Nuts because my car is low powered, and I don't do any drifting or hard launches - it's my daily driver and the worst I've done is some DE days and a few lazy drifts in the snow.

My guess is that the diff was abused in its previous life - may be the ring and pinion / something other than the LSD itself who knows.

[asbrr]

Related question: Should I replace the Diff bushing while this thing is out? I'm thinking just a set of fresh OEM pieces, the car has 150K kms on it, figured the old bushings are tired/worn by now? Anything else that is easy/should be swapped at the same time??

Thx
Ash

[ShocknAwe]

Originally Posted by asbrr

Related question: Should I replace the Diff bushing while this thing is out? I'm thinking just a set of fresh OEM pieces, the car has 150K kms on it, figured the old bushings are tired/worn by now? Anything else that is easy/should be swapped at the same time??

Thx
Ash

I'd replace with OEM. Thanks for reminding me, I need to do the same while mine is out.

[ShocknAwe]

Set of Lems on FCPEuro for ~$35. Need 2 small ones and 1 large.

[Rmtt]

Rear diff should be heading your way today. Let me know how it works out for you or you have any issues. But my original one was smooth as silk. When I replaced it, I opened the drain plug to look at the fluid and it still looked in surprisingly good shape.

[asbrr]

Rmtt you're the man!

[Rmtt]

Originally Posted by asbrr

Rmtt you're the man!

Just happy to help out a fellow member. I've been in that position before, and it sucks. I'm glad it worked out. I just ask that once you get it.....everything looks good..... and you're happy, just leave me I-Trader feedback and I will do the same for you.

Hope to hear the car is back on the road soon!

[houtan]

Originally Posted by ShocknAwe

Same thing happened to me recently. Glad you're ok.

I'd stick with same part number builds or your prop and axles may not line up.

Your m-factory diff broke?

[ShocknAwe]

Originally Posted by houtan

Your m-factory diff broke?

Cars been sitting at my shop with a totally locked rear end for the better part of 2 weeks. New diff isn't here yet so hard to say 100% that's what it was, but it's pretty suspicious. Had to get my buddy to come pull the car straight with his truck when it happened, was unnerving to see the car dragging without the wheels moving.

[houtan]

Originally Posted by ShocknAwe

Cars been sitting at my shop with a totally locked rear end for the better part of 2 weeks. New diff isn't here yet so hard to say 100% that's what it was, but it's pretty suspicious. Had to get my buddy to come pull the car straight with his truck when it happened, was unnerving to see the car dragging without the wheels moving.

Oh wow that sucks. Please let us know what you find out.

[HP Autosport]

Wavetrac limited slip differential review. Check out his video, like and subscribe!

[chris82]

Originally Posted by HP Autosport

Wavetrac limited slip differential review. Check out his video, like and subscribe!

What is this trash post? Go start a new thread if you want to advertise a product, or at least post it on the 2 series forum