trans issue on the 4.6is

[rrich49132]

How many of you with a 4.6is have had trans issues. I keep hearing that the trans is a time bomb that goes around 75K miles? Is this true? Should I stay away from buying one with 80-90-100K miles if the trans has not been rebuilt?

I read about one quote of 8K from the dealer. I would hate to buy something and be dealing with this in a year or two.

[duboy]

Originally Posted by rrich49132

How many of you with a 4.6is have had trans issues. I keep hearing that the trans is a time bomb that goes around 75K miles? Is this true? Should I stay away from buying one with 80-90-100K miles if the trans has not been rebuilt?

I read about one quote of 8K from the dealer. I would hate to buy something and be dealing with this in a year or two.

We just got our 4.6is about a month ago, 97K miles on the original tranny. so far no issues, but going to keep our eyes/ears on it. PO had the transmission flushed/serviced at about 75K, and he did a fair amount of towing an open trailer with his E36 racecar on it and the occasional boat. We're still on the honeymoon phase with our 4.6is so maybe i'm not the best example to go by, but yeah. so far pretty solid.

[Weasel]

I bought my 4.6is two and a half years ago at ~70k miles and now have just over 100k miles with absolutely no problems from the transmission. It is all original and the only thing I did was a pan drain and fill about 5k miles ago just for the hell of it. The fluid that came out at 95k miles wasn't really dark or burnt and still looked and felt pretty good for being that high a mileage. I am not light on the throttle and do tow a small trailer (4x8) with it almost every weekend currently.

The main thing to worry about with the 4.6is tranny is if the torque converter goes out and throws metal shavings in the fluid to the rest of the tranny. But when the TC goes out it makes a whine under throttle that sounds like a twin screw supercharger... so if you catch it quick you can replace it and save the tranny.

[RRATS4]

Greetings all...I have a 2003 4.6is Dinan S3 (Superchanged). I do love it. Anyway, I've had it for just over 2 years, and I recently had the Service Engine Soon light come on. I was in the middle of trying to get it smogged when this occured. I brought it to Bullet Performance in Costa Mesa, Ca. They plugged in their code reader and it indicated it was a Torque coverter lock up fault do to excessive slippage. Performance wise, I've not noticed anything except there is no change in RPM or gear shirt when I change between Sport and Drive on the freeways..other than that, it's still driving great. So they said it would be best to replace the transmission as it comes with a new torque converter and that if I just replaced my torque converter, my existing tranny may not take to it to well due to the introduction of new fluid..etc. So even though its more expensive to replace the trans, its cheaper in the long run.....does anyone have any suggestions? My buddy suggested I change my fluid and filter and see what happens first....any help would be appreciated...

Neal

[JCL]

I wouldn't bother to change the fluid and filter, you would be throwing away the money IMO.

Torque converters can fail, particularly on the 4.6. If you catch them soon enough they won't necessarily have damaged the rest of the transmission.

Something to be aware of, though, is that the torque converter lock up is controlled by a solenoid in the transmission. If the problem is with that solenoid and not the torque converter itself then you may not know that until you put a new torque converter in and find that it doesn't fix the problem. Then you have to pull the transmission again. It could be worth trying to just do the torque converter, as a calculated gamble, but it would be safer to do the transmission (and get a rebuilt torque converter at the same time). You don't need to buy an exchange transmission, you can have yours rebuilt for less $$ by a shop that is familiar with the ZF transmission.

[RRATS4]

Hey...that's good to know on the fluid change. Nothing really crazy is happening with the tranny other than what I already said. I'm going to take it to a shop tomorrow morning and get a second opinion on the best corrective action. Maybe they can rebuild it or know another shop that can rebuild it for less than buying a new one...what do you think?

[RRPhil]

In case it’s of interest, when the ZF 5HP24 transmission started production in 1996 it was quoted as having a maximum input torque capacity of 420Nm.

When it was specified by BMW against the 440Nm M62 engine it’s torque rating, as luck would have it, suddenly became 440Nm (hence it was designated the A5S440Z).

The 4.6is engine produces (at least) 480Nm peak torque.

It could be argued, therefore, that the old transmission is being somewhat ‘overstretched’ in this application.

To beef it up, ZF fitted the 4.6is transmission with a larger L51-type 12” torque converter (and therefore a bigger bellhousing). The D brake - used in 3rd & 5th gears - had an extra clutch plate in it (5 plates instead of 4) and the upper valve block was modified to accommodate revised designs for the B & E clutch valves.

To differentiate between them the 4.4i E53 transmission is an ‘029’ model and the 4.6is is an ‘034’ model.

Phil

[J.Belknap]

Thanks for the ZF details Phil!

[RRATS4]

So with my issues, how do I know which ZF transmission I have in my X5 4.6is? Do I have the "034" model?

[c4racer]

120K miles here - no issues, never changed fluid. So far so good. I don't expect it to last forever - will just rebuild when it fails. Love my 4.6is!!