R3VLimited Forums

Go Back   R3VLimited Forums > E30 Technical Forums > Engine & Drivetrain > Transmission & Driveline

Reply
 
Thread Tools Search this Thread
Old 11-24-2018, 11:51 AM   #1
muppetman342
Member
 
Join Date: Oct 2017
Location: Charlottesville, VA
Posts: 44
Thumbs down Broke Diff Cover

Alright guys, here's a new one: I'm pressing in a new diff bushing, got it in ~99% of the way, then *plink* and this happened: https://photos.app.goo.gl/hGp82M2pB2wzgDhP7

The fact that it's still gapped with the bushing now removed makes it seem like that piece was already under stress. I wonder if I tweaked it when removing the old bushing or something?

Anyone else had this happen to them, have a diff cover for sale (already got a post up in the classifieds), or have any advice on how to avoid this when I inevitably do the same job on the new diff cover?
muppetman342 is offline   Reply With Quote
Old 11-29-2018, 01:34 PM   #2
AndrewBird
The Mad Scientist
 
AndrewBird's Avatar
 
Join Date: Oct 2003
Location: Portland, OR
Posts: 11,721
Cast aluminum inherently has stress in it, so the gap isn't all that surprising.

Was it a stock bushing or aftermarket?
__________________
AndrewBird is offline   Reply With Quote
Old 12-02-2018, 07:26 PM   #3
muppetman342
Member
 
Join Date: Oct 2017
Location: Charlottesville, VA
Posts: 44
It was an aftermarket bushing, Corteco to be specific.

I posted up about this problem on the r3v facebook page, to which multiple other people came out saying they had the same issue with Corteco diff bushings.

I called FCP telling them the story to which they immediately covered the cost of the used cover I bought on eBay and shipped me a new BMW bushing at no charge. They also pulled the Corteco bushing from the site, pending investigation of this issue. FCP is the real MVP here, seriously, who else would pay to replace a 28 year old part that I didn't buy from them!? Any other company would have laughed at me and told me some bs about me being an idiot and not knowing how to use a press. They gave me no fuss, and made the situation right. Love them so much.

Anyway, I took some measurements when I had both the Corteco and BMW bushings in hand: interestingly neither is perfectly round, I found the Corteco one to be 3.338" at it's widest point and 3.328" at it's most narrow, the BMW one is 3.324" at it's widest and 3.321" at it's most narrow. When pressing in the BMW bushing, it went in with noticeably less effort and didn't break my diff cover, so I'd call that a win.

tl;dr Don't buy a Corteco diff bushing, it will destroy your diff cover
muppetman342 is offline   Reply With Quote
Old 03-03-2019, 07:17 AM   #4
Five5peed
Noobie
 
Five5peed's Avatar
 
Join Date: Apr 2018
Location: Midwest
Posts: 18
3x the roundness error and a larger nominal diameter
As an engineer, this doesn’t surprise me. What does surprise me is there is not THAT much difference between the two samples...just enough to take it over the edge.



Sent from my iPhone using Tapatalk
Five5peed is offline   Reply With Quote
Old 03-03-2019, 08:48 AM   #5
jeffnhiscars
R3V Elite
 
jeffnhiscars's Avatar
 
Join Date: Jun 2011
Location: Officially Tampa
Posts: 5,672
Corteco is OEM but nothing surprises me any more. I had mine pressed in by my machinist who probably has a more delicate touch.
__________________
Deck Lid and soft top Shocks on hand

Seat shocks on hand for immediate shipment
https://www.r3vlimited.com/board/sho...86#post4944786
Alice the Time Capsule
http://www.r3vlimited.com/board/showthread.php?t=360504
87 Zinno Cabrio barn find 98k and still smells like a barn. Build thread http://www.r3vlimited.com/board/show...20#post3455220
jeffnhiscars is offline   Reply With Quote
Old 03-04-2019, 10:07 AM   #6
reelizmpro
R3V OG
 
reelizmpro's Avatar
 
Join Date: Dec 2003
Location: LA-SoCal
Posts: 8,681
Interestingly, when looking for a diff bushing I noticed parts houses were blowing Corteco's out for $20 each while OE BMW Corteco's were still 3-4x the price. After some research I found that people were having the same problem with the bushing being slightly oversized and cracking diff covers. I opted to go with the Powerflex diff bushing for $40.
__________________
"I'd probably take the E30 M3 in this case just because I love that little car, and how tanky that inline 6 is." - thecj

85 323i M TECH 1 S52 - ALPINEWEISS/SCHWARZE
88 M3 - LACHSSILBER/SCHWARZE
89 M3 - ALPINEWEISS II/M TECH CLOTH-ALCANTARA
91 M TECHNIC TURBO - MACAOBLAU/M TECH CLOTH-LEATHER
reelizmpro is offline   Reply With Quote
Old 04-09-2019, 11:24 AM   #7
LowR3V'in
No R3VLimiter
 
Join Date: Feb 2004
Location: WestSide
Posts: 3,863
Send a message via AIM to LowR3V'in
i bought some cortecos for my e36 cover.
they were slightly slightly too big so the metal around the bushing pealed back like lead.
luckily the metal was very soft and the cover was ok with it.

it seems like the rubber is softer then the oe but maybe it's because of the old rubber dried out.
__________________
LowR3V'in is offline   Reply With Quote
Old 04-09-2019, 11:27 AM   #8
LowR3V'in
No R3VLimiter
 
Join Date: Feb 2004
Location: WestSide
Posts: 3,863
Send a message via AIM to LowR3V'in
Quote:
Originally Posted by reelizmpro View Post
Interestingly, when looking for a diff bushing I noticed parts houses were blowing Corteco's out for $20 each while OE BMW Corteco's were still 3-4x the price. After some research I found that people were having the same problem with the bushing being slightly oversized and cracking diff covers. I opted to go with the Powerflex diff bushing for $40.



you think corteco puts crap versions out for aftermarket only?
__________________
LowR3V'in is offline   Reply With Quote
Old 04-09-2019, 11:47 AM   #9
reelizmpro
R3V OG
 
reelizmpro's Avatar
 
Join Date: Dec 2003
Location: LA-SoCal
Posts: 8,681
Quote:
Originally Posted by LowR3V'in View Post
you think corteco puts crap versions out for aftermarket only?
Although I can't say for sure it's the case here (OE BMW parts haven't been that high quality these days) ...OE BMW part versions are typically subjected to stricter QC standards and only the best parts qualify. The rest are offered up as OEM parts. OEM parts offer the same function at a lower price, however, sometimes depending on the part...the parts aren't as good as OE BMW. It could be a minor blemish or a critical flaw. For example, Laso water pumps for the S14 many years ago were known to leak. Many people experienced the same problem so now only OE BMW Laso's are recommended. It could have just been a bad batch but who's going to take a chance overheating their S14 to find out?
__________________
"I'd probably take the E30 M3 in this case just because I love that little car, and how tanky that inline 6 is." - thecj

85 323i M TECH 1 S52 - ALPINEWEISS/SCHWARZE
88 M3 - LACHSSILBER/SCHWARZE
89 M3 - ALPINEWEISS II/M TECH CLOTH-ALCANTARA
91 M TECHNIC TURBO - MACAOBLAU/M TECH CLOTH-LEATHER

Last edited by reelizmpro; 04-09-2019 at 12:02 PM.
reelizmpro is offline   Reply With Quote
Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -7. The time now is 01:38 PM.


Powered by vBulletin® Version 3.8.10
Copyright ©2000 - 2019, vBulletin Solutions, Inc.
Copyright 2004 - 2020 R3VLimited LLC