Transmission or transfer case?

[Mafian]

After traipsing through many threads on transmission and/or transfer case issues I couldn't find something that fully matched up with my issues so I thought I would start a new thread. I have the E53 diesel with ZF 6 speed.

My issue: Under medium to hard acceleration (through the lower gears especially) there is a slipping feeling as well as a mild shudder, first gear is the worst, it doesn't really change with the increase of rpm and feels more like a 'load based thing'. This is sometimes accompanied by a rougher than normal gear change between first and second but not as bad after this. On low throttle openings everything feels normal. Under higher loads at normal cruising speeds (climbing steep hill/bridge) whilst the revs don't move much more than normal/expected (no real slipping feeling) you can sometimes feel a slight shudder ie drive is not as 'smooth' as normal. The difference doesn't really change much between cold or warm. Sometimes when going up our steep driveway you can feel a slip before it 'takes up' as normal. This is rare though and the torque converter still 'takes up' as it should at 1,200 rpm. There are no obvious, abnormal noises, other than the ones in associated with the shudder.

Background: Car has done 138,000km. Mechatronics replaced 40,000km ago (it went into limp home). When this issue first started happening I had the transmission serviced (with oil change) and the adaptation program reset. No fault codes have come up at any stage. Transmission specialist (they do a lot of ZFs) couldn't really see anything obviously wrong inside when looking and said the fluid whilst a little darker than normal was well within specification/expectation. This service didn't really change things much.

Basically I thought I would put it out to the community if anyone else has experienced something similar and what was done to repair it. I am just looking at possible ideas before taking it to a service department/specialist for further fault finding and spending any more than I have to trying to fix it!

Any assistance is appreciated. Sorry for the 'war and piece' novel!

[williamx5]

Good day!

Your picture looks like you have a 2004 or newer, which would make all my thoughts on this a little iffy!! My first E53 was a 2001... Silver... Picked it up pretty cheap from a dealer in Illinois... Had a slipping and thumping upon medium to hard acceleration... No issues at all doing the normal gentle take-off... I had to replace the transfer case chain that was stretched... The issue I have here is that you have a 2WD until you need more traction... So, unless the rear tires are slipping by more than 5% difference from the front, you won't be in AWD and you probably won't suffer from a stretched chain in the TC...

Everything I read in your symptoms say stretched TC chain... But unless the TC is locked in AWD all the time, I'm just having doubts that is the problem...

Any others out there have insight?!

Good luck!!!

Cheers!!

[Mafian]

Thanks William for the response. I guess we are the only people who have ever had this type of problem! I'm thinking I'll start with easy then work my way up by starting off with changing the transfer case oil and see how it goes from there!

[TwinTurboGTR]

While William is spot on right, it doesnt apply to your E53. Pre facelift used the old school method of chain and gears. Your's is utilizing Xdrive which is using clutches. Just like your tranny.

"Now for the symptoms, it sounds like you have 2 problems going on.
Under medium to hard acceleration (through the lower gears especially) there is a slipping feeling as well as a mild shudder, first gear is the worst, it doesn't really change with the increase of rpm and feels more like a 'load based thing'. This is sometimes accompanied by a rougher than normal gear change between first and second but not as bad after this."

This sounds like the the friction material is shot on first and second gear. May be time for a rebuild.

The second problem: climbing steep hill/bridge) whilst the revs don't move much more than normal/expected (no real slipping feeling) you can sometimes feel a slight shudder

Now if the engine is under load under low RPMS( Now I am not familiar with an E53 diesel. I am going to assume 1500 is fairly low and high i somewhere around 5500.) That shudder may be from engine misfire, but since its not creating enough counts for the sensors to pick up, it will not show a money light nor flash and detonation code. So there may be some carbon build up in the intake causing the symptoms you mentioned.

I would def check engine first. Since it could be something you could do at home and only cost you time. Get that straightened out first and see if the situation gets better. If not, then you've narrowed it down to the driveline.

From the drive line, start narrowing down the transmission, isolate the Transfer case, and figure out if you have any tranny codes.

Hope that helps.

[Mafian]

Well for anyone interested to know I started with the simple before moving onto to bigger and more expensive jobs as there were and have never been any fault codes displayed in DIS or INPA throughout this whole situation to guide me on where to start. I decided to pop into the local $tealership and purchase a 1L bottle of transfer case oil (AU$63) and then I set about replacing the easiest thing I could.

When I dropped the oil it was quite dark almost black (new oil more like honey) and had a slightly burnt smell (new oil was sweet). Once it was filled with new oil I got the laptop out and reset the VTG adaptations on DIS then went for a test drive. To say there was a difference is an understatement! During the first 'power' run it had a very slight shudder in first but considerably better than it has been for a long time. By the time I got to number 4-5 'power' run (time for the oil to circulate etc) the original problem was pretty much gone and it was back to normal. Each run it was getting better and better.

Hopefully that was the cause of the problem and it doesn't come back for a long time!

[omodos]

Mafain I think I am treading the same path too at 105,000 miles same gearbox....perhaps a coincidence but got both front tires replaced and as soon as drove off i could hear a sort of low key rumbling up fron't, put it down to the tire tread style being noisier.

After 2 mins of driving noise was gone, BUT since then and because I have driven car for good part of 14 years nearly, i know and feel when something is different. Its when I am in low gear in traffic nearly idling along and hit the pedal lightly i can only describe it as a slight rumble, then all good when I take off, i will check too if i have same symptoms as you when it is under load and on inclines....

Hmmm reading around a bit could maybe becos i have fitted other tires up front not exact same tread as rears....didnt know the xdrive was that sensitive

[wpoll]

Originally Posted by omodos

Mafain I think I am treading the same path too at 105,000 miles same gearbox....perhaps a coincidence but got both front tires replaced and as soon as drove off i could hear a sort of low key rumbling up fron't, put it down to the tire tread style being noisier.

After 2 mins of driving noise was gone, BUT since then and because I have driven car for good part of 14 years nearly, i know and feel when something is different. Its when I am in low gear in traffic nearly idling along and hit the pedal lightly i can only describe it as a slight rumble, then all good when I take off, i will check too if i have same symptoms as you when it is under load and on inclines....

Hmmm reading around a bit could maybe becos i have fitted other tires up front not exact same tread as rears....didnt know the xdrive was that sensitive

xDrive won't be bothered too much by the mis-matched tread (unless it's VERY different, producing massively different traction on slippery surfaces). It's more likely to be upset by rolling circumference differences. As long as your tyres are all the same rolling circumference (within 1-2%) you should be OK.

[omodos]

Originally Posted by wpoll

xDrive won't be bothered too much by the mis-matched tread (unless it's VERY different, producing massively different traction on slippery surfaces). It's more likely to be upset by rolling circumference differences. As long as your tyres are all the same rolling circumference (within 1-2%) you should be OK.

Ta for reply, re-cap replaced nearly balding fronts (that WERE same tread and make as rears that are still good and in place) to different brand tread up front with same amount of meat as rears now....to be 100% though on rolling circumference I would have to measure but how far out can one brand be from another as size 235/65 r17 is 235/65 r17, the treads are different front and back for sure...but the worn fronts were way out compared to rears good tread

For sure worn fronts compared to good rears there was at least 3-4mm difference in tread depth...(and no odd behaviour of x5)

All way during school run and off to office and back home again all good, on way back to office up a slight incline i get a slight shudder at 1400-1500pm that goes after this rev range...dunno coincidence that this happened soon as I replaced those front tires? i was told changing tires this way was roll of a dice....as per mafian at higher revs motorway speeds all good... i will keep and eye on it and see and hope dont do any damage leaving as is

[omodos]

Getting sad now.... as reading up further from other bmw forums seems that this is an issue on other xdrive cars too, and me going and putting on tires with a different tread and possibly size has thrown things out, if there is a mis match in size and fronts are less than 2mm than rears the transfer case will spin the wheels faster to compensate?


https://f30.bimmerpost.com/forums/sh....php?t=1393497

Hmm and please see this by Q7silver posted , Im gonna have to go try measure rolling circumference first and make sure they are rears/fronts are within 1% of each other. And checking tire pressures too...wish me luck