Transmission jolts while downshifting after fluid change very odd!

[Radekxpl]

This past week I was changing transmission fluid since car has 70k and I do decent amount of towing so I though it would be a good idea. So I got the car on 4 ramps this way it's level, while doing the procedure I noticed few odd things; 1) while draining the old fluid, first I decided to loosen the fill plug ( wanted to make sure there's no problem braking it free before loosening the drain plug draining fluid and having no way to fill it back up if fill plug was sized) upon loosening fill plug about half a quart of fluid drained just from fill plug (it was gushing out when I took fill plug out not just dripping, which I though this was very unusual since per the manual there should not be oil above the fill plug if fluid level prior was at a correct level, this wasn't just small amount of fluid above the fill plug quite a bit of fluid came out just but undoing the fill plug about half quart or more, this seemed very odd to me. 2) Second upon draining the oil pan all off the oil that came out from oil pan and fill plug int total only 4 liters came out, which again seemed odd since transmission holds 8.7 liters and I only got 4, I know that most people get about 5 to 6 liters out since its impossible to drain all of it, but I only got 4! that less then half of total capacity. 3) When performing the fill procedure with ISTA (wraming up fluid to 30-40C going through all the gears reving to 2000 rpm for 30 sec ect) I was only able to put in 3 liters back into the transmission upon reaching required operating temperature, that 1 liter less of what originally came out. At this point started to get worried something is not right. Lowered the car took it for a drive around the block raised it back again and check the fluid again, upon undoing fill plug fluid was just slowly dripping out of the fill hole which per manual is at correct level, so I bolted everything back up, and rest adaptations as well for the tranny. But still have this filing something was very strange about this.

Did some driving past 2 days and I notice when coming to a stop when transmission is downshifting from like 3 to 2 or 2 to 1 theres this jolt happening now which was not there prior to fluid change, also when auto/stop function is on when you come to stop and release the brake car starts it there a jolt forward as well, which was not present before changing the fluid. Otherwise everything is normal up shifting is smooth and normal just like before.

Has anyone experienced any of these symptoms before? At this point I'm just trying to pin point a resolution to this issue, did some googling but came up short

By the way I used the ZF 8 fluid which is the same as factory and my car is X5 35d never had any shifting jolting issues before.

Any pointers possible solutions greatly appreciated.

[blasterman78]

Was this the first time the fluid was changed? Seems very odd that do much came out of the full plug. I did my a while ago but didn't have this issue, my process was pretty straightforward. I would say to check the fluid again since you have driven it some. I did that in mine because I wanted to be sure it was at the right level. I believe there is a trans oil cooler that has a valve that opens at a certain temp level. There is a video on YouTube by Weberauto that describes the process for ZF transmissions. Hope you get it sorted out.

[Radekxpl]

Originally Posted by blasterman78

Was this the first time the fluid was changed? Seems very odd that do much came out of the full plug. I did my a while ago but didn't have this issue, my process was pretty straightforward. I would say to check the fluid again since you have driven it some. I did that in mine because I wanted to be sure it was at the right level. I believe there is a trans oil cooler that has a valve that opens at a certain temp level. There is a video on YouTube by Weberauto that describes the process for ZF transmissions. Hope you get it sorted out.

As far I am aware it did not look like it was changed before, I have the car since it had 38k so I do not think there would have been trans fluid at such a low mileage then. Yea that is very odd imo as well for so much oil coming out of fill plug, even though so much oil came out fill plug altogether for the whole transmission drain it was only 4 liter in total which is very low as well that not even half of transmission hold which is odd as well. How much transmission fluid did you drain from your when you did the change?

[turboawd]

Just to be clear, you were adding/topping off the fluid while the engine was running?

[Radekxpl]

Originally Posted by turboawd

Just to be clear, you were adding/topping off the fluid while the engine was running?

No, once temp got to desired operating temp I shut if off and checked the fluid then.

[Sophisticated Redneck]

Originally Posted by Radekxpl

No, once temp got to desired operating temp I shut if off and checked the fluid then.

You have to do it while the engine is running unfortunately. Otherwise you will get a false reading as the oil rushed back to the pan.

I'll take this time to say a big FU to ZF/BMW for not putting a damn dipstick in so we can fill the transmission from the engine compartment like a human and not under a 5300lb truck with the engine running and hot exhaust running right next to you like some deranged animal.

Near 100K vehicle and they can't provide a way to fill the transmission other then to be underneath it while it spits in your face and the engine is running?!?!?!...

/Rant off

In general, ZF8HP70's & 75's with the standard plastic pan use approx 4.5 liters per oil/filter change. If you loosen the valve body another 1 to 1.5 liters will come out. If you are putting in more or less then this (+/- a liter) then something is wrong.

[smyles]

In BMW defense, they specifically tell you it's lifetime. Why would they facilitate the opposite?

[Radekxpl]

Originally Posted by Sophisticated Redneck

You have to do it while the engine is running unfortunately. Otherwise you will get a false reading as the oil rushed back to the pan.

I'll take this time to say a big FU to ZF/BMW for not putting a damn dipstick in so we can fill the transmission from the engine compartment like a human and not under a 5300lb truck with the engine running and hot exhaust running right next to you like some deranged animal.

Near 100K vehicle and they can't provide a way to fill the transmission other then to be underneath it while it spits in your face and the engine is running?!?!?!...

/Rant off

In general, ZF8HP70's & 75's with the standard plastic pan use approx 4.5 liters per oil/filter change. If you loosen the valve body another 1 to 1.5 liters will come out. If you are putting in more or less then this (+/- a liter) then something is wrong.

That would make sense, when car is running oil gets stucked in by the tranny and therefore oil level is lower while running. If I was checking with car not running oil rushed back into the pan giving me false impression that is was full which in fact it wasn't since I was not checking when it was running. It would also explain why there was so much oil coming out of the fill plug while I was draining it since the car was not running therefore all the oil came back from transmission and flooded the drain plug. Thanks for clarifying this, so this means I'm actually probably low on oil, o boy hope this did not harm the transmission in anyway.

[turboawd]

Yes you're definitely low. Turn car on and top off the fluid. Wrap a towel around exhaust pipe so you don't burn yourself.
The transmission is hydraulically operated, and the pump sucks up fluid when it's running, and sends the fluid throughout the trans and the valve body inside.

[turboawd]

On the bright side, a firm shift isn't as bad as a soft shift that is slipping. It's the slipping that will kill the clutches inside the trans.

[Sophisticated Redneck]

Originally Posted by smyles

In BMW defense, they specifically tell you it's lifetime. Why would they facilitate the opposite?

One would think, ZF Friedrichshafen , the manufacturer of the transmission, would know their own product better the BMW. ZF Highly recommends you change the oil at 70k. Yes this is a case of nothing more then a marketing ploy by BMW. There is no such thing as lifetime fluid, unless your idea of lifetime is 70,000 miles.

And this does nothing but damage both BMW and ZF. Because of this marketing BS, the ZF will face unusually high failure rates and will grow to have a piss poor reputation for being toss away transmissions.... All thanks to an fraud of a marketing campaign.

I am at a loss as to the purpose of this marketing campaign...We purchase a BMW for it's amazing engineering and superior way they drive and handle...we become attached and enjoy them so much that most of us take great pride in maintaining a finely tuned machine, oil changes are at the least of our concerns and gladly excepted..Be done by your own hand or paying someone else, I don't think any BMW owner views it as a unnecessary task or inconvenience...rather the care and feeding of a machine we truly enjoy. These are not economy minded Hyundai's (I own both so I can say that.

[Sophisticated Redneck]

Originally Posted by Radekxpl

That would make sense, when car is running oil gets stucked in by the tranny and therefore oil level is lower while running. If I was checking with car not running oil rushed back into the pan giving me false impression that is was full which in fact it wasn't since I was not checking when it was running. It would also explain why there was so much oil coming out of the fill plug while I was draining it since the car was not running therefore all the oil came back from transmission and flooded the drain plug. Thanks for clarifying this, so this means I'm actually probably low on oil, o boy hope this did not harm the transmission in anyway.

If you must drive it before you can add oil, Brake gently and avoid any downhill slopes like the plague. The oil pick up is at the very end of the transmission pan and it will most likely be sucking air under such circumstances.

[gvarr03]

I recently did my tranny fluid change and it was doing the same as you described.. Now when you did reset the adaptations did you PROPERLY do the re-learn procedure? I forgot to do that and my car was downshifting roughly. Then after resetting it again and doing re-learn function it's performing much better. Keep in mind it may take up to 1000 miles for a tranny to properly adapt for your driving style etc.

[Radekxpl]

Got home lifted the car again, recheck oil while car was running at designated temperature and sure enough it was low, got another 1.25 liters in the tranny while running. Now it should be fine at least the amount of oil I drained vs refilled now matches which is a good sign. Going to test drive it tomorrow morning to make sure everything works like it should.

Thank you to everyone who gave tips to resolve this issue 👍 much appreciated.

[Radekxpl]

Originally Posted by gvarr03

I recently did my tranny fluid change and it was doing the same as you described.. Now when you did reset the adaptations did you PROPERLY do the re-learn procedure? I forgot to do that and my car was downshifting roughly. Then after resetting it again and doing re-learn function it's performing much better. Keep in mind it may take up to 1000 miles for a tranny to properly adapt for your driving style etc.

I reset the adaptation but I did not see any option for re-learn procedure. Where or how do you perform re-learn procedure?

[Sophisticated Redneck]

Originally Posted by Radekxpl

I reset the adaptation but I did not see any option for re-learn procedure. Where or how do you perform re-learn procedure?

According to ZF, for th 8HP you need to find a nice long stretch of flat road with no stops and used 25 percent throttle and accelerate to 55mph, then let it coast to a crawl, do not brake during the coast so it downshifts by itself. Repeat this at least 3 times, then again in the sport modes.

If you can't do this, the transmission will eventually relearn but take much longer to do so

[smyles]

Originally Posted by Sophisticated Redneck

...
I am at a loss as to the purpose of this marketing campaign.....

When was the last time you've heard of a failed BMW/ZF transmission caused by original fluid?

Exactly.

[Radekxpl]

Originally Posted by Sophisticated Redneck

According to ZF, for th 8HP you need to find a nice long stretch of flat road with no stops and used 25 percent throttle and accelerate to 55mph, then let it coast to a crawl, do not brake during the coast so it downshifts by itself. Repeat this at least 3 times, then again in the sport modes.

If you can't do this, the transmission will eventually relearn but take much longer to do so

Was not aware of this procedure at all, will do, thanks again for all the help. drove it this morning and now everything seems back to normal, just need to re-learn adaptations and that's it

[Sophisticated Redneck]

Originally Posted by smyles

When was the last time you've heard of a failed BMW/ZF transmission caused by original fluid?

Exactly.

BWHAHAHA! I am on the road right now but when I get home tonight I will be happy to educate you my good sir and provide links to all of the transmission failure threads. One need only type in ZF8 transmission problems and see the absolute plethora of issues caused by oil well passed it's service life. Mine is one of them, solenoid failure and burnt friction at 110k until I became aware of BMWs BS.

I pity anyone who would believe the marketing hype over the FACT that ZF themselves recommends you change at 70k. But go ahead and keep drinking that sweet sweet BMW Kool aid and believe someone in BMW marketing over the actual ZF engineers if it makes you feel better.

Below is the official documentation from the manufacturer instructing to change every 50 to 75K.

[Sophisticated Redneck]

Originally Posted by Radekxpl

Was not aware of this procedure at all, will do, thanks again for all the help. drove it this morning and now everything seems back to normal, just need to re-learn adaptations and that's it

No problem happy to help

[Sophisticated Redneck]

[turboawd]

Good video