Rebuilding differential

Scores · 07-19-2020, 02:39 PM

Hey everyone,

My differential main bearings are making a lot of noise, finding a used differential is ridiculously hard and everyone wants 1500-2000, in my opinion that's to close to a turner differential or an OS Giken.

I have really enjoyed the stock differential, so my question is, has anyone tried rebuilding their stock diffs?

I found this website that says it sells everything you need, https://www.bearingkits.co.uk/UPRATE...O-USE/1584.htm anyone have experience with them? Or has anyone had any success with other companies packages?

Any help would be greatly appreciated

Redd · 07-19-2020, 06:14 PM

I used a rebuild kit from diffsonline. No issues, kit was complete. Had it done when I installed my 3.45 FD and Giken LSD.

Scores · 07-24-2020, 07:10 AM

Found a used unit with 55xxxkm (front end collision) on it for $600, screaming deal.

What's the best differential fluid to used? I used Redline before and it may have lead to cooking my main bearing.

STooK · 07-25-2020, 09:12 PM

Quote:

Originally Posted by Scores

Found a used unit with 55xxxkm (front end collision) on it for $600, screaming deal.

What's the best differential fluid to used? I used Redline before and it may have lead to cooking my main bearing.

$600 is worth the risk IMO. A new rebuilt diff will run you $1600 so you save a grand.

Best fluid to use is the Castrol Syntrax Limited slip. No need to waste money on the BMW one that costs $190.

By the way, what kind of noises were you hearing with your old diff? Did you install the new one yet? And if you did, did that resolve the issue? I'm asking because I think I have a bad diff also.

Scores · 08-01-2020, 05:39 AM

Quote:

Originally Posted by STooK

Quote:

Originally Posted by Scores

Found a used unit with 55xxxkm (front end collision) on it for $600, screaming deal.

What's the best differential fluid to used? I used Redline before and it may have lead to cooking my main bearing.

$600 is worth the risk IMO. A new rebuilt diff will run you $1600 so you save a grand.

Best fluid to use is the Castrol Syntrax Limited slip. No need to waste money on the BMW one that costs $190.

By the way, what kind of noises were you hearing with your old diff? Did you install the new one yet? And if you did, did that resolve the issue? I'm asking because I think I have a bad diff also.

When I wasn't on the gas I would hear a loud whine kinda like a whoop whoop whoop sound. I installed solid differential bushings it made the noise VERY noticeable. My mechanic said it sounded like a main bearing.

Diff just came in last night, had it shipped across the country. When it's installed and I get to go for a drive I'll let you know.

Scores · 08-10-2020, 05:06 PM

Quote:

Originally Posted by STooK

Quote:

Originally Posted by Scores

Found a used unit with 55xxxkm (front end collision) on it for $600, screaming deal.

What's the best differential fluid to used? I used Redline before and it may have lead to cooking my main bearing.

$600 is worth the risk IMO. A new rebuilt diff will run you $1600 so you save a grand.

Best fluid to use is the Castrol Syntrax Limited slip. No need to waste money on the BMW one that costs $190.

By the way, what kind of noises were you hearing with your old diff? Did you install the new one yet? And if you did, did that resolve the issue? I'm asking because I think I have a bad diff also.

New installed and it's a big difference in sound. No more bearing howl, just lsd whine (solid diff bushings)

I would suggest doing it if you're still hearing your rear end getting louder and louder

STooK · 08-11-2020, 09:12 AM

Quote:

Originally Posted by Scores

New installed and it's a big difference in sound. No more bearing howl, just lsd whine (solid diff bushings)

I would suggest doing it if you're still hearing your rear end getting louder and louder

That's awesome! Glad it worked out for you.

7cowie · 08-14-2020, 09:24 AM

hopefully you're going to find what works for you... the diff on my 5 series also was problematic and when trying to rebuild it nothing worked... had to pay a huge amount of money... https://suppsforlife.to/
but i hope that's not going to be your story.

tdott · 08-14-2020, 10:43 AM

Rock Auto seems to list all of the bearings now.

I think Timken was the OE supplier also.

amrazM · 08-19-2020, 06:33 AM

a good option for the future is to buy an e46 m3 diff and hang onto it, you can rebuild or upgrade the diff unit itself and fit it into the e9x m3 housing.

tdott · 08-19-2020, 08:06 AM

Quote:

Originally Posted by amrazM

a good option for the future is to buy an e46 m3 diff and hang onto it, you can rebuild or upgrade the diff unit itself and fit it into the e9x m3 housing.

AFAIK
The LSD unit is the same as E9x and E46. It's the same Torque sensing Torsen LSD.

E39 M5 is a clutch type diff that is usually swapped into e9x m3 housing to convert to a clutch type lsd.

nrubenstein · 08-19-2020, 11:28 AM

Quote:

Originally Posted by tdott

AFAIK
The LSD unit is the same as E9x and E46. It's the same Torque sensing Torsen LSD.

E39 M5 is a clutch type diff that is usually swapped into e9x m3 housing to convert to a clutch type lsd.

The stock diff is not torsen / helical.

tdott · 08-20-2020, 03:46 PM

Quote:

Originally Posted by nrubenstein

The stock diff is not torsen / helical.

Yea sorry, M variable was what they called it, mixed it up.

But yea E46m /e9xm diff has the same lsd unit.

Scores · 08-24-2020, 06:28 PM

Quote:

Originally Posted by tdott

Quote:

Originally Posted by amrazM

a good option for the future is to buy an e46 m3 diff and hang onto it, you can rebuild or upgrade the diff unit itself and fit it into the e9x m3 housing.

AFAIK
The LSD unit is the same as E9x and E46. It's the same Torque sensing Torsen LSD.

E39 M5 is a clutch type diff that is usually swapped into e9x m3 housing to convert to a clutch type lsd.

Really? The m5 diff fits into the subframe?

pbonsalb · 08-24-2020, 06:46 PM

The way I read what is written in the quoted text above is that the E39M5 clutch type diff unit fits into the E9x M3 differential case, not that the E39M5 diff fits the E9x M3 subframe.

Scores · 08-24-2020, 06:48 PM

Quote:

Originally Posted by pbonsalb

The way I read what is written in the quoted text above is that the E39M5 clutch type diff unit fits into the E9x M3 differential case, not that the E39M5 diff fits the E9x M3 subframe.

Ahhh okay, thanks for clarifying that

amrazM · 08-25-2020, 05:12 AM

Quote:

Originally Posted by pbonsalb

The way I read what is written in the quoted text above is that the E39M5 clutch type diff unit fits into the E9x M3 differential case, not that the E39M5 diff fits the E9x M3 subframe.

correct, you extract that unit and rebuild it and put it into your diff housing

07-19-2020, 02:39 PM	#1
Scores Private 31 Rep 73 Posts Drives: 08 E92 M3 Join Date: Jun 2018 Location: Kingston iTrader: (0)	Rebuilding differential Hey everyone, My differential main bearings are making a lot of noise, finding a used differential is ridiculously hard and everyone wants 1500-2000, in my opinion that's to close to a turner differential or an OS Giken. I have really enjoyed the stock differential, so my question is, has anyone tried rebuilding their stock diffs? I found this website that says it sells everything you need, https://www.bearingkits.co.uk/UPRATE...O-USE/1584.htm anyone have experience with them? Or has anyone had any success with other companies packages? Any help would be greatly appreciated
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07-19-2020, 06:14 PM	#2
Redd Brigadier General 3900 Rep 4,164 Posts Drives: 2010 BMW E92 M3 Dakar Edition Join Date: Jul 2015 Location: Malaysia iTrader: (0)	I used a rebuild kit from diffsonline. No issues, kit was complete. Had it done when I installed my 3.45 FD and Giken LSD.
	Appreciate 1 Scores31.00 Quote

07-24-2020, 07:10 AM	#3
Scores Private 31 Rep 73 Posts Drives: 08 E92 M3 Join Date: Jun 2018 Location: Kingston iTrader: (0)	Found a used unit with 55xxxkm (front end collision) on it for $600, screaming deal. What's the best differential fluid to used? I used Redline before and it may have lead to cooking my main bearing.
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08-14-2020, 09:24 AM	#8
7cowie Registered 2 Rep 1 Posts Drives: 5 series, want to get M3 Join Date: Aug 2020 Location: USA, IL, Chicago iTrader: (0)	hopefully you're going to find what works for you... the diff on my 5 series also was problematic and when trying to rebuild it nothing worked... had to pay a huge amount of money... https://suppsforlife.to/ but i hope that's not going to be your story. Last edited by 7cowie; 11-25-2020 at 08:20 AM.. Reason: grammar
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08-14-2020, 10:43 AM	#9
tdott Brigadier General 3943 Rep 3,988 Posts Drives: M3 Join Date: Nov 2010 Location: South FL / 6ix iTrader: (4)	Rock Auto seems to list all of the bearings now. I think Timken was the OE supplier also. Attached Images __________________ N/A S65 Headers Before/After Dyno Results
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08-19-2020, 06:33 AM	#10
amrazM mTekMods 2142 Rep 2,902 Posts Drives: like a granny. Join Date: Jan 2010 Location: Manhatan iTrader: (1)	a good option for the future is to buy an e46 m3 diff and hang onto it, you can rebuild or upgrade the diff unit itself and fit it into the e9x m3 housing. __________________ 2011 Frozen Black/Fox Red E90 M3 650+WHP G-Power Supercharged First DCT to Manual Conversion Worldwide KW CS, BBS RI-A, BW Headers, Snow 2.5
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08-24-2020, 06:46 PM	#15
pbonsalb Lieutenant General 5234 Rep 10,614 Posts Drives: 18 F90 M5, 99 E36 M3 Turbo Join Date: Feb 2011 Location: New England iTrader: (4)	The way I read what is written in the quoted text above is that the E39M5 clutch type diff unit fits into the E9x M3 differential case, not that the E39M5 diff fits the E9x M3 subframe.
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