Which BM autos are better/worse - GM or ZF?

[pundit]

I've read many times about the poor reliability of ZF4HP22 autos.
However that seems to be more of an issue with the earlier (pre '87) ZF's commonly failing due to the 'A' clutch problem. Though it does happen with the later trans it seem less frequent. Bear in mind that most of our 'vintage' bimmers are hitting the 15 year+ mark with maybe 200,000 mls or more on the clock.
However I seem to see at least as many posts concerning failing GM autos. Is this most likely simply due to the mileages now being clocked up or do the GM's have their own failings?
My ZF4HP22 currently has 175,000kms on it. (About 110,000 miles)
From experience I would expect an auto trans to survive at least 300,000+ kms (200,000 miles) before needing a rebuild. Of course if mine fails before this I will be peeved but, would a GM last any longer?... AND bear in mind a GM is quite a bit more expensive to rebuild. So is a GM equipped E34/E32 really any better on the hip pocket maintenance wise than a ZF4HP22. I somehow doubt it from what I've read here. ;)

[Kalevera]

This seems to be a hotly debated topic. I guess I could be biased given that my 1500-mile, Jan 05 installed ZF reman blew out at about this time of night last saturday night (yeah - a fun evening was had by all). Despite the "fix" being installed to prevent the a clutch issue, I think that's what happened on the last one. Right now, the $tealer's sticking another one in under the 2 year, unlimited mileage warranty. I'll go get Fritz on Monday lunchtime....hopefully.

The ZF "value line" reman costs ~ $1600 in the US. It actually is a robust auto, despite the design flaw. My original one did ~ 220k, and that was with some SERIOUS neglect from the PO. The key is to change the fluid and filter every 15,000 miles. Compare that to the standard trans that Chrysler (prior to Benz days)/GM/Ford installs....that's pretty good.

Actually, I think the GM trannies are cheaper to rebuild in the states, partially because people here know more about them. I guess the dynamic could be different in other countries, no?

Take care of your slushbox -- it'll stick around if you do :) Meanwhile, I'll see if I can get >1500 miles out of my next one.

best, whit

[pundit]

This seems to be a hotly debated topic. I guess I could be biased given that my 1500-mile, Jan 05 installed ZF reman blew out at about this time of night last saturday night (yeah - a fun evening was had by all). Despite the "fix" being installed to prevent the a clutch issue, I think that's what happened on the last one. Right now, the $tealer's sticking another one in under the 2 year, unlimited mileage warranty. I'll go get Fritz on Monday lunchtime....hopefully.

The ZF "value line" reman costs ~ $1600 in the US. It actually is a robust auto, despite the design flaw. My original one did ~ 220k, and that was with some SERIOUS neglect from the PO. The key is to change the fluid and filter every 15,000 miles. Compare that to the standard trans that Chrysler (prior to Benz days)/GM/Ford installs....that's pretty good.

Actually, I think the GM trannies are cheaper to rebuild in the states, partially because people here know more about them. I guess the dynamic could be different in other countries, no?

Take care of your slushbox -- it'll stick around if you do :) Meanwhile, I'll see if I can get >1500 miles out of my next one.

best, whit
I've been quoted around $2000 AUD (about $1600 USD) to rebuild a ZF4HP22 here in Oz. This is apparently by a ZF trans specialist. GM quotes seem to range between $4000 to $5000 AUS... about double the price. I think the catch is with the ZF is who does the rebuild, do they know about the 'A' clutch issues and to make sure you get a modded trans if it hasn't already been done. My feeling is you would not want an unmodified older series reco C/O 4HP22 supplied by some bolt out/bolt in trans shop who buys it cheap from an uneducated trans rebuilder.

[632 Regal]

send it over, after rebuilding my rear end from scrap pieces them big gray mystery boxes cant be that far off of regular transmissions. Just cause someone hasnt dont a rebuild thenselves dont mean you cant...look at Whit. I mean If I rebuilt one and it failed at 1500 id be kicking myself in the head trying to figure what I did wrong. I guess that leaves me some goals, I'll start collecting dead ones, buying rebuild parts and sell them when yours go wrong...hmmm that might actually be a good idea here.

[Kalevera]

Jeff, the only problem is that they're not worth rebuilding to begin with ;)

First chance I get, I'm converting the car...

[ryan roopnarine]

I've been quoted around $2000 AUD (about $1600 USD) to rebuild a ZF4HP22 here in Oz. This is apparently by a ZF trans specialist. GM quotes seem to range between $4000 to $5000 AUS... about double the price. I think the catch is with the ZF is who does the rebuild, do they know about the 'A' clutch issues and to make sure you get a modded trans if it hasn't already been done. My feeling is you would not want an unmodified older series reco C/O 4HP22 supplied by some bolt out/bolt in trans shop who buys it cheap from an uneducated trans rebuilder.


the gm units have their own "a" clutch , ie the pendulum shift. scott council, who rebuilt his gm, said that the insides were great at 150k miles, just that the seal involved in the issue had bit the dust. in the states, its like $150 for the rebuild parts. the gm tranny is also the one in the US isuzu trooper, cadillac catera, and something else. the only problem is that once the rebuilder sees the magical "roundel" symbol, the cost to rebuild, as well as complexity of doing it increases exponentially (wonder why :D ). i think it costs like 2k usd to get a rebuild done in the us.

[Kalevera]

The other thing is....if you get it rebuilt, make sure you get a good warranty.

[pmlmotorsports]

My own 2 cents worth...ZF trans are very problematic, especially the electronic version incorporating the manual "shift" mode sport/normal/economy. Yes, even the newer post '88 models suffer the same "A" clutch pack issue. I myself have had a few 535i automatics, and even though I reside where a highly reputable ZF rebuilder is located, I have had rebuilds fail within 2 years on EVERY unit I've owned. Some have failed within 3 months!!! Although I have never owned a BMW with an automatic GM transmission, I've decided to never buy an automatic transmission BMW again. To be honest, I CAN'T BELIEVE THE GM TRANSMISSION COULD BE ANY WORSE. THAT WOULD BE IMPOSSIBLE FROM MY EXPERIENCE WITH ZFs.

[Randell]

$3000AUD to rebuild my ZF that had 265000km on it

lasted 3 months... then the torque converter decided it didn't feel like unlocking... i know now that 'warranty' repairs involve checking EVERYTHING that costs less to the shop than another rebuild, and when they finally exhaust every option in the book, they'll rebuild it again... i can understand why they do this, because if they rebuilt it and the problem was somewhere else it'd suck, but this is a looonnng boring wait

almost 3 months and counting... i wonder what it's like to drive an E34 again.........

[Kalevera]

...They're taking 3 *months* to get the car back to you?!

Doesn't sound like a reputable shop, mate. All of this makes me happy that I've got the 2 year BMW warranty on mine. Let's hope ZF knows how to rebuild their own ****.

best, whit

[Randell]

...They're taking 3 *months* to get the car back to you?!

Doesn't sound like a reputable shop, mate. All of this makes me happy that I've got the 2 year BMW warranty on mine. Let's hope ZF knows how to rebuild their own ****.

best, whit

yeah, it's a long story... they originally said my idle was bad, which i insisted wasn't the case because it was fine in P or N. but i took it to my mechanic (non-bmw) who said it didn''t look like the transmission but he couldn't tell where abouts it was stuffing up.. so it went to a bmw specialist who said it was the transmission, then it went back to the transmission shop, where they looked at it, called another bmw specialist and asked him, he said it's the idle, so i took it to him, he cleaned out the ICV (which was absolutely choked), made the idle perfect but didn't fix the problem... so after THAT, it's been at the transmission shop for 2 weeks... it's taken so long to do all of that because i've been travelling interstate for work in that time...

they think something electronic is making the torque converter stay partially locked... sigh...

this sort of thing seems to be a regular occurance with warranty repairs though, i was talking to a guy at work who had a problematic yamaha motorbike, he said every time it stuffed up they'd start at the cheapest potential solution and work their way up.. makes sense, but it's such a long wait... i've totally forgotten what it's like to drive that car :(

[pundit]

yeah, it's a long story... they originally said my idle was bad, which i insisted wasn't the case because it was fine in P or N. but i took it to my mechanic (non-bmw) who said it didn''t look like the transmission but he couldn't tell where abouts it was stuffing up.. so it went to a bmw specialist who said it was the transmission, then it went back to the transmission shop, where they looked at it, called another bmw specialist and asked him, he said it's the idle, so i took it to him, he cleaned out the ICV (which was absolutely choked), made the idle perfect but didn't fix the problem... so after THAT, it's been at the transmission shop for 2 weeks... it's taken so long to do all of that because i've been travelling interstate for work in that time...

they think something electronic is making the torque converter stay partially locked... sigh...

this sort of thing seems to be a regular occurance with warranty repairs though, i was talking to a guy at work who had a problematic yamaha motorbike, he said every time it stuffed up they'd start at the cheapest potential solution and work their way up.. makes sense, but it's such a long wait... i've totally forgotten what it's like to drive that car :(
It comes down to one thing. DIAGNOSIS! Most people can fix something once it is determined what it is that's causing the problem. But what is it with this 'Suck it 'n' See' (but you still pay) method of car repairs? Sure if you take something hi-tech to a backyard mechanic then the 'Suck it 'n' See' method is what you stand to get. Although the stories I here of authorised dealers doing the same thing should result in prosecution. If they can't fix it they shouldn't be allowed to charge for their incompetence.