Autobox problem - rebuild hasn't cured

[Marshy]

OK, so I've had this problem since getting the car 17000 miles ago... about time to try and nail it down. 1993 540i with the 5hp30 tranny.

There were a few non-smooth shifts in the box when I got the car at 115k miles, but nothing unexpected for a car of that age. The bad shift was on 3rd to 4th. Full-throttle changes were perfect, it's part throttle (and sometimes no-throttle) changes that were rough as all hell, sometimes enough to induce severe driveline shunt and once (at some speed) bad enough to very briefly lock the rear wheels.

I put up with it for ages until I had reverse gear go south on me at which point a rebuild was obviously mandatory. 1100 pounds later for a full rebuild, reverse was back and all shifts were perfect... but the 3rd-4th shift was still problematic (albeit not quite as bad as before). They've since had two or three more goes at it without luck.

While I should perhaps go legal on the auto shop, I haven't got the energy for it and I suspect they're plain out of ideas. Come to think of it, I still have 2000 miles of a 12000 mile warranty left to run. The rebuild covered valve body, friction materials, new torque converter, blah blah blah.

So... any ideas out there as to what would cause 3rd to 4th to be so bad?

[Jon M.]

One has to look to the electronics. If the transmission computer is getting faulty signals it could easily cause rough or mistimed/inappropriate shifts.

I don't know what inputs that transmission takes, but it most likely takes at least throttle position, speed at the differential, engine rpm & who knows what else.

I had a bad throttle position sensor that was causing intermittently poor downshifting - rough with clunks, mistimed, etc.

If those items weren't changed, I would start there. Or get in contact with Kirt Koeller - someone around here will have his contact info. - He knows everything about these transmissions, and helped me with mine.

[Marshy]

To update on this: the auto shop are taking the car in for another crack at things: their first shot will be sending the valve body off to be properly tested in some sort of rig that can test it under all sorts of conditions.

Will see what comes of this. To be absolutely fair to the auto shop, they agreed to take the car in with no grumbling or unpleasantness despite the undoubted pain and heartache it's already caused them with repeated revisits. I'm sure they're out of pocket by now. So, kudos.

[Tiger]

I would contact Kirt on this matter... It seems to me they did do a valve body rebuild... I am not so sure what else they did... but it seems to me that your 3-4 shift is rough is a sign that the seal on clutch pack has not been changed. With a leakage at partial throttle, the engagement is definitely NOT smooth...

Whereas under full throttle, the pressure is enough to execute a perfect shift. I think they messed up when they did a overhaul for you. Not all the shop change everything inside the tranny... Why do you think they only offer 1 year/12.000 miles? Because they know it will fail afterward...

If you compare a rebuild to a new car tranny... a new tranny has everything new in it... and it will last 100,000 miles no problem... whereas a bad rebuild will only last 13,000 miles... and sometime you got a good rebuild... will last you 75K miles but not so often get tested... because like anyone else, we tend to get a newer car if not a new car soon afterward... not alot of people keeps cars forever...

[KurtM]

help in solving the problem by having them contact Kirt directly. It could end up saving both you and them a lot of headaches and find a solution for your car.

My $.02 worth

Kurt
95 525ia

[632 Regal]

I agree with contacting Kurt (Kirt Koeller
europetransman@hotmail.com
direct (616)748-5735)

and going from there as to solve major headaches, there is the valve body issue with them trannies and also there are more than a few electronic servos involved with the programming. That on top of a rebuild from anyone but a dedicated Getrag rebuilder you could have a multidude of simple problems.

Call Kurt or have your shop do it, save everyone some and also educate them on whats going on...education is expensive.

[Marshy]

The people I used are experienced ZF rebuilders and the work I had done was a full rebuild including the valve body, friction materials, clutch packs etc. I've tried contacting Kirt in the past but have never had a reply: I wouldn't blame him actually since I'm in the UK and there's no way he'd end up getting paid work from me due to the atlantic ocean being in the way...

[Gearhead]

I'm going to revive this thread to see if anyone else has had this 3-4 upshift issue. I have the same exact problem. Just rebuilt the valve body this past weekend using the ZF 5HP30VBK kit. Overall, the issue has lessened substantially, but it's still there. While I did get Kirt Koeller's info from another post, I thought maybe someone here might have found a solution.

Thanks guys!

John

[Tiger]

Did you change the speed sensor, wire harness, or the selenoids

[whiskychaser]

Did you change the speed sensor, wire harness, or the selenoids
Surely speed sensor or harness would chuck a transprog message? Maybe not the solenoids though. Have resistances been checked? Any fault codes in the EGS (or whatever they call it for later cars)? Found some good info for my tranny on scribd earlier but the poster ran out of steam before he got to the 5HP30. Think OP was there before me? Now if it was a 5HP18 I'd say the E clutch hasnt got enough ATF pressure or its fkd. Fortunately I know little about the 5HP30 so my thoughts are easily ignored

[Gearhead]

Tiger. As Whisky pointed out, no transporg message. But I did ohm test all 8 EDS/MV units. They were all consistent. Thought about applying 12v to each of them to check for actuation, but seeing as how 5 are variable bleed/pulse width modulation, I didn't figure I'd be able to tell much other than on/off.

Whisky, like I just mentioned, everything ohmed out good compared to one another. If I remember correctly, 6.5 ohms across all 3 MV units, and like 131.5 across the other five. That 2nd number could be wrong, but they were consistent. Funny you mentioned scribd. I was just out there today and left a comment asking if that same guy could post the last part of that valve body manual containing the 5HP30. You made me crack up with your "easily ignored" thoughts though. Thanks for the laugh!

[Marshy]

Well, this is a blast from the past. I'm afraid I never did get to the bottom of my issue: the transmission people gave up in the end, and I ran out of money and enthusiasm for chasing the issue down, partially due to an abrupt change of job a couple of months after I started this thread.

I've still got the car five years on, though it's been parked a while. Just about to see if it'll still pass its MOT inspection. If it does, and someone gets somewhere with this problem, I'll be very interested...

That's once I've solved the oddball electro-mechanical issue with the ABS/ESP on my current daily driver. It never ends does it?

[bmwrp8]

Well, this is a blast from the past. I'm afraid I never did get to the bottom of my issue: the transmission people gave up in the end, and I ran out of money and enthusiasm for chasing the issue down, partially due to an abrupt change of job a couple of months after I started this thread.

I've still got the car five years on, though it's been parked a while. Just about to see if it'll still pass its MOT inspection. If it does, and someone gets somewhere with this problem, I'll be very interested...

That's once I've solved the oddball electro-mechanical issue with the ABS/ESP on my current daily driver. It never ends does it?

We had the same problem but in a different car. It's a '91 galant. Had the tranny changed and still the 3rd and 4th gear changes veeerryy roughly. We changed the trans. computer box and the problem went away. We ended up having a refund for the tranny that we got and we just bought a new wiring harness just to be sure.

[whiskychaser]

Yeah I saw the post on scribd and thought it must be you:D My partner thinks I'm a loony as I've got a my second 5HP18 in bits in the shed. You never know when you might need a part though do you?:D
Marshy: we all know England is full of 540's in barns just waiting for somebody to discover them;) You havent thought to sell it though?

[Ross]

Many rebuilders will replace all the solenoids as a matter of course as they are magnetic it is nearly impossible to remove all the debris from them.
I wonder if a balky solenoid has been the issue all along?
Whatever indicates throttle position to the trans also needs examination; cable, switch, etc.

[Gearhead]

Okay guys, after a lot of digging (OCD comes in handy at times) I found a document on the 5HP series of ZF transmissions that I think has what I need to figure this out, but I need you to double-check my logic.

First, I'm making an assumption on how to read the selenoid/clutch logic chart I've attached. The legend states "X" = active (pressure build-up) while "-" = inactive. So without more detail and knowing that the 5 pressure regulators are PWM (pulse width modulation) units, I'm assuming that "-X-" would mean that during the shift from 3rd to 4th, pressure regulator #4 initially starts out inactive, then graduates up to active and holds while in gear, then graduates down again. While I like that approach, it doesn't hold much water when you look at selenoid valve #3 in D5 since the selenoids are on/off only.

Can any of you help me read this chart? My instincts tell me pressure regulator 4 (EDS 4) is the culprit, but I have to be sure before forking out $180 on a hunch.

Thanks!

John

Oh, and the document I mentioned earlier can be found here: http://www.europeantransmissions.com/Bulletin/DTC.BMW/BMW%20Transmission%20Specifications.pdf

[whiskychaser]

I've seen the chart before but never read it like that. Pressure regulator 4 isnt supposed to be working in 4th so I dont see its at fault? I didnt know they used PWM but isnt that just a clever way or opening or closing a valve in a controlled way? If you didnt have that and all the valves slammed shut then the gears would go in with a thump wouldnt they? Maybe I'm being stupid but you just rebuilt the VB with a pucker kit so shouldnt that obviate any problems?