[thetyrant]

Ok looks like im going to have to replace/rebuild my atc450 transfer case on 2011 30d x3, its grinding at low speeds and ive tried changing oil twice and re-calibrating etc but no joy so its coming off.

Ive had prices for new exchange unit complete with controller but dont know if i can program/encode it with ISTA i have and/or what is involved exactly, that is whats causing me most concern with replacing it?

Other option is to repair and open mine up see if i can find the faulty parts, ive found a supplier here in UK who has parts as well as complete units and it should be much cheaper to repair if just needs bearings/chain/clutch etc, dont think i need to encode controller then either ?

If anyone has done either and can offer guidance its much appreciated

[carmoongia]

There is a video I have seen on you tube have a search good luck

[thetyrant]

Originally Posted by carmoongia

There is a video I have seen on you tube have a search good luck

Thanks yes i think ive seen that a non-english speaking guy for and E70 version of the ATC450? link here -

.

Cant make out what he is saying but plenty of info and good to see it all apart and then built back up.

[carmoongia]

This may help a little every bit of information is helpful

https://www.bimmerfest.com/threads/a....889775/page-3

Good luck

[thetyrant]

Thanks ive had a good read of that what will be interesting to see if mine has wear in same place, hopefully not!

Plan to get it off and open it this weekend see what i can find.

[Ralph11]

Hi, what kind of additional tests and analysis did you do for your issue? Did you read out the failure codes, do you have warning/failure lights, like 4x4/brake/abs or other?
Did you check the actuator? Did you reset the tv oil after you changed it? I also overhauled my transfer case recently, due to the 3 lights mentioned above, but it was not the issue, my tc looked pretty good for 215000 Km but since I had the parts and a press I overhauled it anyway, but still the lights 😡…. So in my case it was unneeded…. I would recommed before you overhaul yours check the rest before, often it is the actuator of the tc….. cheers Ralph

[Ralph11]

In my case it was a atc400, not sure if 450 has also actuator like 400….

[thetyrant]

Originally Posted by Ralph11

Hi, what kind of additional tests and analysis did you do for your issue? Did you read out the failure codes, do you have warning/failure lights, like 4x4/brake/abs or other?
Did you check the actuator? Did you reset the tv oil after you changed it? I also overhauled my transfer case recently, due to the 3 lights mentioned above, but it was not the issue, my tc looked pretty good for 215000 Km but since I had the parts and a press I overhauled it anyway, but still the lights 😡…. So in my case it was unneeded…. I would recommed before you overhaul yours check the rest before, often it is the actuator of the tc….. cheers Ralph

There are no error codes, its a bit of a story but basically dealer i bought car from initially fitted 2 tyres the wrong size and when i test drove it had the famous shudder/misfire under acceleration.

Dealer changed tyres after i suggested it might sort it and it did so i took the risk that no serious damage was done and bought the car.

Straight after purchase i put 4 brand new tyres on ( all 4 same on this version not staggered) and car seemed ok but still felt a bit of vibration on coasting and tight turning so changed the transfer box which helped but didnt cure it all.

Few weeks on the car started to make a whine/scraping noise when decelerating from around 20mph, changed prop bearing and guibo but no different.

Last straw (should maybe of been first!) was to pull fuse 37 to disable the transfer case control unit, with this done the car drives silent with no issues other than being 2wd and lots of warnings on dash now due to transfer not being active, this is what has made me think something is roasted inside the transfer case.

Will get it apart see what i find.

[Ralph11]

Hi, sounds like there is a mechanical issue with your transfer case, still very strange that there are no warnings on at all…. You mentioned changed transfare box, you mean the tc actuator motor which drives the tc clutch mechanism? Did you recalibrate afterwards, not sure if your version also has an actuator resistor installed, to match the tc, if yes, you used the original one and it was OK during calibration of the actuator motor? I am just burnt with all actions I had and no improvement afterwards, remove and overhaul my own tc…. One more thing, did you check the other parts in the line for frontwheel drive, when you disabled tc? The tires and wheels you have on now are on the list of your X3 type and OK to use?

[Bdavi011]

So this may or may not help since the most I have ever done on my transfer case is just a fluid change. But, my friend drives a 4 series x drive and he was having the same issue with the noise and the low speed shudder. He said it happened after he drove through a large puddle of water.

He at first suspected it was the transfer case and he would disconnect the wire to it and the car would drive fine. He deducted that it was the front differential that was bad. I was dead set that it was the transfer case. Anyway, I helped him replace the front differential and the car drives smooth and the issue was resolved.

Now I'm not saying it's the differential but maybe change the fluid and see if there is a bunch of metal material in the old fluid?

Good luck.

[thetyrant]

Originally Posted by Ralph11

Hi, sounds like there is a mechanical issue with your transfer case, still very strange that there are no warnings on at all…. You mentioned changed transfare box, you mean the tc actuator motor which drives the tc clutch mechanism? Did you recalibrate afterwards, not sure if your version also has an actuator resistor installed, to match the tc, if yes, you used the original one and it was OK during calibration of the actuator motor? I am just burnt with all actions I had and no improvement afterwards, remove and overhaul my own tc…. One more thing, did you check the other parts in the line for frontwheel drive, when you disabled tc? The tires and wheels you have on now are on the list of your X3 type and OK to use?

Yes it does seem like its something worn and rubbing inside the TC, not enough to trigger any codes on system but they will only show when either controller fails or clutches get so worn it can not position them correctly as far as i understand it.

Ive not changed or removed the TC or controller yet only changed oil and removed fuse to stop it activating.

I did change oil and recalibrate afterwards in ISTA.

Tyres are correct size and rating and all brand new made in same month etc so think i can rule them out.

[thetyrant]

Originally Posted by Bdavi011

So this may or may not help since the most I have ever done on my transfer case is just a fluid change. But, my friend drives a 4 series x drive and he was having the same issue with the noise and the low speed shudder. He said it happened after he drove through a large puddle of water.

He at first suspected it was the transfer case and he would disconnect the wire to it and the car would drive fine. He deducted that it was the front differential that was bad. I was dead set that it was the transfer case. Anyway, I helped him replace the front differential and the car drives smooth and the issue was resolved.

Now I'm not saying it's the differential but maybe change the fluid and see if there is a bunch of metal material in the old fluid?

Good luck.

Thanks i have wondered about front diff and if i dont find anything worn in TC i will go there next, my understanding is TC is a lot more susceptible to issues than the diff though which is far simpler in design. We will see

[thetyrant]

Not an easy thing to video but if you turn it up you can hear scraping/squeaking sound on this video i took with my phone, worst from around 25secs onwards

[Ralph11]

Not sure, it looks like you never checked the tc servo actuator, or? If not it looks like a very hot kandidate to cause your issues…. Again, i have a 400 tc on e83 and this uses most likely a different actuator servo motor, mine had worn gear inside which I changed, but still did not get rid of my 3 light warnings….. you mentioned that the tires and wheels are good, i meant if they are on the list of your car, basically allowed by bmw, to be used on your F25, just to clarify…cheers.
Attached picture of mine tv actuator (white background) and most likely yours, please check.

[thetyrant]

F25 actuator is totally different to the eariler car like yours and is as per that bottom picture i think, no gear to wear like the E83 but i will be running the tests on it also.

Tyres are not approved bmw tyres but are correct size and rating and its been same on 2 different sets so im 99% sure they are not a factor, if i get nowhere with anything else i will look into them again though maybe try borrow someones wheels to try, i know on the cars with staggered size wheels/tyres the approved bmw tyres are much more critical but mine is not one of these.

[thetyrant]

Small update for those interested and following..

Pulled the TC off this weekend, rotating it from all inputs/outputs once off the car felt ok. i know thats not much of a test however it was a positive start at least, however before i opened TC up i did a good visual and feel of everything else connected and found the UJ on the front propshaft (end where it connects into the TC) was very stiff and notchy so the bearings on that have failed and could well be the cause of my issues which makes more sense so thats no1 suspect now!

Ordered a Febi/Bilstein propand mounting bolts as due to way bearings are staked on OE prop its not simple to rebuild, new shaft from BMW was getting on £1000! but the febi was £260ish and should be ok i think.

Will update once fitted and fingers crossed all is smooth and quiet once more!

[Ralph11]

Fingers crossed that this was it, i think this fits very likely to the issues you have, hopefully 😉…. Cheers

[thetyrant]

New front propshaft fitted and it looks to of sorted the issue, only got 5 miles on it so far but all seems good so far

[Ralph11]

Super, 👍….. good that you did not open the tc 😉

[thetyrant]

Originally Posted by Ralph11

Super, 👍….. good that you did not open the tc 😉

I was kind of looking forward to exploring inside it but also pleased i didnt have to i guess.

Ie got 50miles or so on it now with not a peep from it so hopefully thats this one done, still waiting on new prop to front diff bolts from BMW before i can get all the underside covers back on and lean on it harder, reused old bolts to test for the noise but will get new bolts in as soon as they arrive for peace of mind.

Interestingly the Febi prop has larger outside diameter on the UJ and runs very close to gearbox compared to the OE part, plenty of clearance but wouldnt want it any closer, will get a pic when im back under there if i remember.

[383vett]

Good job!

[Ralph11]

So you basically changed the big bearing for the front wheel driving axle?
The tc‘s seem to be fairly robust, if you sometimes change the oil…. Mine only had some pitting marks on one of the actuators, bearings and clutch looked still very good, since I had the kit I changed everything except of the actuators…. But at the end no impact to get rid of the 3 lights I have…. Wasted time and money but gained experience 😉…. I reused the bolts and did drive 4000 Km afterwards with no issues… Still have until July to fix my issues as per my post, but so far nobody responded…. Cheers