E90Post
 


GT Haus
 
BMW 3-Series (E90 E92) Forum > E90 / E92 / E93 3-series Powertrain and Drivetrain Discussions > N54 Turbo Engine / Drivetrain / Exhaust Modifications - 335i > Auto transmission slipping. I'm opening it up. Advice?



Reply
 
Thread Tools Search this Thread
      06-19-2012, 06:43 PM   #1
love2drive
keeps cars too long.
 
Drives: 2007 E90 335i
Join Date: Jan 2010
Location: Chicago

Posts: 72
iTrader: (3)

Auto transmission slipping. I'm opening it up. Advice?

I'm going to crack open my 6HP19 tranny this weekend so would appreciate advice. I've been experiencing slip from 1-2 and 2-3, i.e. the engine revs between gears. As others with this issue have reported, the tranny does better under heavy load and when warm. No rough shifting, just slip under light load. And I have under 30k miles, dangit.

Leaking Mechatronics Sleeve is well know. Mine leaks so I'm replacing.

Dealer parts guy also said they change the Mechatronics Seal Adapter (on top of mechatronics assembly) fairly often, confirming what zigsman has posted elsewhere, but the parts guy didn't convey much confidence. I figure I'll replace it since I'm in there anyway.

So My plan is to replace the Sleeve, Seal Adapter, Filter/Pan, and top off with 6L of Pentosin ATF-1.

Anything else I should consider given the symptoms since I'm going to be in there?

Anyone know how to tell if the fiber clutches are worn, or does that take a lot more disassembly?

Thanks for help.
love2drive is offline   United_States
0
Reply With Quote
      06-19-2012, 08:26 PM   #2
bv1
Private First Class
 
Drives: 335i Coupe AT
Join Date: Jan 2011
Location: Toronto

Posts: 167
iTrader: (0)

Exactly my problem, and exactly my approach. I've got all the parts and fluid just haven't gotten around to it yet.

My trans has been slipping for a while now but hasn't got any worse.

Has your fluid level ever got low in the past?

If the clutches are worn there should be gunk at the bottom of the pan.
__________________
|Cobb AP / JB4 | DCI | BMS WW Meth Kit | AMS FMIC | Macht Schnell 3" DP |
bv1 is offline  
0
Reply With Quote
      06-20-2012, 02:26 AM   #3
love2drive
keeps cars too long.
 
Drives: 2007 E90 335i
Join Date: Jan 2010
Location: Chicago

Posts: 72
iTrader: (3)

Yes, I suspect fluid may be low since the undercarriage shows a lot of leaked oil. I'm hoping its as easy as changing these parts and the fluid. A rebuilt tranny would be costly.Seems like a recall is in order due to the leaking sleeve.

I'll let you know this works.
love2drive is offline   United_States
0
Reply With Quote
      07-06-2012, 05:18 PM   #4
love2drive
keeps cars too long.
 
Drives: 2007 E90 335i
Join Date: Jan 2010
Location: Chicago

Posts: 72
iTrader: (3)

I did the work last weekend and thought I'd share results, FWIW.

Drained out under 5L of fluid, which looked pretty good to me. I have an 07 with <30K miles.

I replaced the mechatronic adapter sleeve because I had a leak. I also replaced the mechatronic adapter seal, which requires you to drop the mechatronic assembly then carefully retorque it in place. All reasonably priced torque wrenches I could find were inaccurate at 8Nm, so I did it by hand. Not recommended, but far better than using a Harbor Freight torque wrench.

Refilled with ~4.8L of Pentosin ATF-1. I'll probably support the car at an angle and try to get a bit more in.

Reset transmission adaptations using BT scan tool.

Results: Initially the slip in lower gears was better, but still there. I was bummed. A few days of driving and it is nearly gone, if not back to the way it always was. I can't really call it slip because under load the tranny does not slip at all, none, never, and I'm FBO with meth and JB4. I would characterize it as late shifting that allows a slight RPM blip between shifts.

Whatever happened, the problem is resolved. My recommendation to others experiencing this would be to just do the fluid change, replace the sleeve because they leak, but don't drop the mechatronic and do the other seal. I suspect that replacing half of the fluid (about all we can get out, that isn't in the torque converter) and filling to proper level will address the problem.

I'm pretty disgusted by a <30K mile transmission having any problems whatsoever. GM and Ford have been making flawless AT for decades, so it's the last point of failure I'd expect on a BMW. I'm hoping this was more of a software issue, and will look more into that, but strange that a fluid change would address it.
love2drive is offline   United_States
0
Reply With Quote
      12-05-2012, 05:00 PM   #5
zigsman
Private
 
Drives: 2006 330i E90
Join Date: Jan 2012
Location: Arizona

Posts: 74
iTrader: (0)

Quote:
Originally Posted by love2drive View Post
I did the work last weekend and thought I'd share results, FWIW.

Drained out under 5L of fluid, which looked pretty good to me. I have an 07 with <30K miles.

I replaced the mechatronic adapter sleeve because I had a leak. I also replaced the mechatronic adapter seal, which requires you to drop the mechatronic assembly then carefully retorque it in place. All reasonably priced torque wrenches I could find were inaccurate at 8Nm, so I did it by hand. Not recommended, but far better than using a Harbor Freight torque wrench.

Refilled with ~4.8L of Pentosin ATF-1. I'll probably support the car at an angle and try to get a bit more in.

Reset transmission adaptations using BT scan tool.

Results: Initially the slip in lower gears was better, but still there. I was bummed. A few days of driving and it is nearly gone, if not back to the way it always was. I can't really call it slip because under load the tranny does not slip at all, none, never, and I'm FBO with meth and JB4. I would characterize it as late shifting that allows a slight RPM blip between shifts.

Whatever happened, the problem is resolved. My recommendation to others experiencing this would be to just do the fluid change, replace the sleeve because they leak, but don't drop the mechatronic and do the other seal. I suspect that replacing half of the fluid (about all we can get out, that isn't in the torque converter) and filling to proper level will address the problem.

I'm pretty disgusted by a <30K mile transmission having any problems whatsoever. GM and Ford have been making flawless AT for decades, so it's the last point of failure I'd expect on a BMW. I'm hoping this was more of a software issue, and will look more into that, but strange that a fluid change would address it.

A couple of questions for ya:

Isn't your car still under warrantee? If so, I'd let the dealer take care of it (as much as I would hate to do it) in order to "preserve" the warrantee.

Second, How did you fill the transmission? Did you fill it when the car was off, then start it and let it run for about 5 min and then top it off with the car running? Your "slipping" issue sounds like it could simply be low fluid level. These trannys are a PITA to fill so if you don't get all the fluid in that it needs, you will end up with shifting issues. And based on the fact that the seal adapter was leaking, this really supports the theory of low fluid.

If your oil and pan looked good when you pulled it off (no sludge and shavings at the bottom of the pan and magnets) then the problem is not likely your gears or clutches (which is a good thing).

It may be a software issue, that was the first thing I had updated because it was the easiest, but it really sounds like a fluid level issue to me.

Mike
zigsman is offline  
0
Reply With Quote
      12-05-2012, 05:03 PM   #6
///M3NACE
Banned
 
///M3NACE's Avatar
 
Drives: E36 M3, E36 Vert , E90 N52
Join Date: Oct 2006
Location: Downers Grove, IL

Posts: 3,907
iTrader: (5)

miles don't mean shit. Its 4 year from in service date. I have a 06 330i bought in 05 in march the first e90 ever practically created. Depends when the in service date was. I've had my car 7.5 years and 53k on it.
///M3NACE is offline  
0
Reply With Quote
      12-05-2012, 05:59 PM   #7
rismo
Captain
 
Drives: BMW E92 335
Join Date: Jul 2008
Location: Europe

Posts: 834
iTrader: (0)

And my AT was just gone internaly... much worse then we expected.
Gears 1 and 2 were completly burned away, gears 3-5 90% gone. Car was still doing pretty good, even my specialized ZF engineer was surprised, he drove the car upfront.

I did extend the life of the gearbox by renewing the oil 3 times, but after the third time it just took a week before it started to slip again. It started to slip 60.000km before I had to replace it. I was FBO for 80000km and tuned for 140.000km.

Just to manage your expectations.
__________________
BMW 335 E92 08 - Full options - RIP
BMW 335 E92 09 - Full options - DKG - Procede Rev 3 - Vishnu Meth and Chargepipe - Forge Diverter Valves - Vishnu Flex Fuel Kit- AR Catless DP - Afe Intake - Helix IC - Ar Oil Cooler - PPK Water Cooler - M3 Suspension - JRZ RS1 Shocks - Eibach Pro Springs - Drexler LSD - BMW IS Exhaust - EBC Yellow Brake Pads - Stainless Steel Brake Lines - M101 Wheels - Michelin PSS - M-Tech Body - M-Strutbar
rismo is offline  
0
Reply With Quote
Reply

Bookmarks

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 -5. The time now is 09:37 AM.




e90post
Powered by vBulletin® Version 3.7.0
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
1Addicts.com, BIMMERPOST.com, E90Post.com, F30Post.com, M3Post.com, ZPost.com, 5Post.com, 6Post.com, 7Post.com, XBimmers.com logo and trademark are properties of BIMMERPOST