2001 E39 530d se Auto transmission problem

[malky 77]

I am having a problem with the auto transmision, in reverse it makes a constant clunking noise and i can feel it vibrating, and in drive when i accelerate hard it jumps into neutral usually around 3500 revs, it dosent do this in sport or manual modes.It also feels like the gears are slowing the car when lifting of going down hill. Does any one know what could cause this im keeping my fingers crossed its not a new gearbox as i just bought the car 9 months ago.

[duggan776]

Have dealer check tranny fluid level.

[318is-joe]

I am having a problem with the auto transmision, in reverse it makes a constant clunking noise and i can feel it vibrating, and in drive when i accelerate hard it jumps into neutral usually around 3500 revs, it dosent do this in sport or manual modes.It also feels like the gears are slowing the car when lifting of going down hill. Does any one know what could cause this im keeping my fingers crossed its not a new gearbox as i just bought the car 9 months ago.

What mileage has it done? As Duggan776 said first step would be a fluid check maybe a change..

[malky 77]

thanks guys will try that, i had a diagnostics check on it today was told it is showing an abs fault and an electric fault in the gearbox but would need further investigation.

[malky 77]

sorry joe missed the mileage its just turning 89000

[Brimstone]

It doesn't sound good. Reverse is often the first thing to go on these GM autoboxes but an ABS fault won't help it at all. This sounds more like a broken gearbox however.

[318is-joe]

The missing reverse, is not a symptom in the GM boxes - It is a problem with the zf units. You have a GM unit in your motor and at low mileage 89,000 I'd suspect a failed pressure converter.

If reverse goes on a GM unit it is usually the pressure regulator / converter / lockup clutch. Item 4 in this drawing.
http://www.realoem.com/bmw/showparts...38&hg=24&fg=15

This is probably what's giving you the electric a fault in the box.

But get the fluid level checked first, then look at this - You'll have to drop the pan / filter and remove the valve body to change this regulator, sounds worse than it is - but is not the complex.
Find out the BMW Pt number on the label on the box pan - BMW claim it is lifetime fill "Special oil" - but this is a marketing spin - there are a few types of fluid used, but are mineral base Dex III modified a little. Can help you with this if you need it.

[Brimstone]

I've seen two 3.0i petrol X5's with no reverse gear but not as yet a diesel although I've seen a 525d that didn't reverse. Like the ZF boxes, the GM units can also try and engage both reverse and first gear when a ballbearing sticks in the valve body due to gumming up - a great advert for changing auto gearbox oil.

[318is-joe]

I've seen two 3.0i petrol X5's with no reverse gear but not as yet a diesel although I've seen a 525d that didn't reverse. Like the ZF boxes, the GM units can also try and engage both reverse and first gear when a ballbearing sticks in the valve body due to gumming up - a great advert for changing auto gearbox oil.

Interesting one Brimstone - Thanks for that - duly noted.
This would be more repairable though than the ZF failures where the reverse clutch carrier hub disintegrates though. Not completely beyond the realm of a competent mechanic, without the entire GM or ZF corporate toolkit behind him.

[Brimstone]

Not completely beyond the realm of a competent mechanic, without the entire GM or ZF corporate toolkit behind him.

That's me b*ggered then!