[EvenKeel]

Originally Posted by insanecoder

I dunno the circumstances under Polo08816's tranny fail (and would like to hear the details)
but I guarantee you one thing..
if you don't replace the tranny fluid at reasonable intervals
your sludge buildup will guarantee your tranny fails

BMW doesn't make these units and even ZF (the manufacturer) suggests every 60k miles on change
keep in mind in the good ole dayz tranny oil was changed much much earlier
synth oils have improved since BUT are not IMMORTAL

caveat: if you've let the tranny go over 90k (which already sounds ridiculous to me) or so without tranny fluid changes.. yes you may be risking some failure
the point is to not get to that point

By the way, have you changed the fluid on your vehicle? Any adverse effects?

[insanecoder]

Originally Posted by EvenKeel

By the way, have you changed the fluid on your vehicle? Any adverse effects?

your indy is saying once the clutchpack is worn then just throw the unit away.. wonderful our modern society wonder how long the landfills last
meanwhile we buy new cars just because the clutchpack is gone

no adverse effects from having the proper clean oil..
and yes I've changed mine at 2k (this is overkill as I've posted in other threads)
and every 30k thereafter (since I do a drain instead of flush)
now each dealer service cost ~$800 to replace tranny fluid/pan so I can understand why most people are not willing to do it

[Polo08816]

Originally Posted by EvenKeel

By the way, have you changed the fluid on your vehicle? Any adverse effects?

Originally Posted by insanecoder

your indy is saying once the clutchpack is worn then just throw the unit away.. wonderful our modern society wonder how long the landfills last
meanwhile we buy new cars just because the clutchpack is gone

no adverse effects from having the proper clean oil..
and yes I've changed mine at 2k (this is overkill as I've posted in other threads)
and every 30k thereafter (since I do a drain instead of flush)
now each dealer service cost ~$800 to replace tranny fluid/pan so I can understand why most people are not willing to do it

The only caution I will add is that you have to be "very" correct about the amount of ATF you need to replace what came out of the car. It seems that if just filled it to the fill hole and ran the ISTA procedure to get more ATF into the torque converter (at the correct temperature), you will still end up with 0.5L-1.0L less than what came out of the vehicle. I highly recommend using a measuring jug when you drain the ATF to know exactly how much came out and fill it with that amount. There's a chance it will exceed the height of the fill hole. That's my personal experience.

Perhaps someone who is more knowledgeable than me can provide an opinion on whether it's safer to be slightly over the correct quantity than slightly under the correct quantity.

[EvenKeel]

Originally Posted by Polo08816

The only caution I will add is that you have to be "very" correct about the amount of ATF you need to replace what came out of the car. It seems that if just filled it to the fill hole and ran the ISTA procedure to get more ATF into the torque converter (at the correct temperature), you will still end up with 0.5L-1.0L less than what came out of the vehicle. I highly recommend using a measuring jug when you drain the ATF to know exactly how much came out and fill it with that amount. There's a chance it will exceed the height of the fill hole. That's my personal experience.

Perhaps someone who is more knowledgeable than me can provide an opinion on whether it's safer to be slightly over the correct quantity than slightly under the correct quantity.

Thanks

Polo.....what do you believe was the cause of the 8HP45 failure on your vehicle? If hindsight was 20/20; would you perform the fluid change again?

[Polo08816]

Originally Posted by EvenKeel

Thanks

Polo.....what do you believe was the cause of the 8HP45 failure on your vehicle? If hindsight was 20/20; would you perform the fluid change again?

Without being able to inspect the internals of the transmission, I can't say for sure. I'm sure being low on ATF didn't help. Tracking the car a lot also does not help.

At this point, I'm not sure I would do the fluid change again because if I can get another 80k out of the transmission for a total of 180k on the odometer, what's the point? To get another 20-40k miles? The life expectancy of the car is pretty much over at that point.

[EvenKeel]

Originally Posted by Polo08816

Without being able to inspect the internals of the transmission, I can't say for sure. I'm sure being low on ATF didn't help. Tracking the car a lot also does not help.

At this point, I'm not sure I would do the fluid change again because if I can get another 80k out of the transmission for a total of 180k on the odometer, what's the point? To get another 20-40k miles? The life expectancy of the car is pretty much over at that point.

Fair points. Thanks for clarifying.

[jsouth]

Originally Posted by Polo08816

I highly recommend using a measuring jug when you drain the ATF to know exactly how much came out and fill it with that amount. There's a chance it will exceed the height of the fill hole. That's my personal experience.

And how, exactly, would one fill the ATF above the fill hole unless it was done in outer space in the absence of gravity?

[Polo08816]

Originally Posted by jsouth

And how, exactly, would one fill the ATF above the fill hole unless it was done in outer space in the absence of gravity?

So the fill hole is on one side of the car, I can't remember which at the moment. You can adjust the contact pads of your 2 post lift in such a way that the side with the fill hole sits higher than it normally would on a complete level surface. Then I used a Motive Power Fill device (pressure fed) and inserted it into the fill hole. I followed the BMW procedure until the level reached the fill hole (still not enough). I placed a paper towel around the fill hole and just filled it with about 0.5L more than it should take. Then you just have to be quick about installing the drain plug. You'll probably lose 0.5-1.0L in that process.

[cxp213]

Originally Posted by Polo08816

So the fill hole is on one side of the car, I can't remember which at the moment. You can adjust the contact pads of your 2 post lift in such a way that the side with the fill hole sits higher than it normally would on a complete level surface. Then I used a Motive Power Fill device (pressure fed) and inserted it into the fill hole. I followed the BMW procedure until the level reached the fill hole (still not enough). I placed a paper towel around the fill hole and just filled it with about 0.5L more than it should take. Then you just have to be quick about installing the drain plug. You'll probably lose 0.5-1.0L in that process.

Wouldn't it just be better to follow the official instructions from ZF and BMW? You won't be able to tell if you've the correct amount, if you put the car at an angle when filling.

[Polo08816]

Originally Posted by cxp213

Wouldn't it just be better to follow the official instructions from ZF and BMW? You won't be able to tell if you've the correct amount, if you put the car at an angle when filling.

After 3 separate attempts on 2 different cars, I am not able to put back the amount of ATF I drained even having the car hooked up to ISTA and following it step by step.

[cxp213]

Originally Posted by Polo08816

After 3 separate attempts on 2 different cars, I am not able to put back the amount of ATF I drained even having the car hooked up to ISTA and following it step by step.

That doesn't sound good. How many quarts was the difference?

[sspade]

I have an interesting take on this procedure from my dealer that I will share with the group in another thread...

[cxp213]

Originally Posted by sspade

I have an interesting take on this procedure from my dealer that I will share with the group in another thread...

OK....? If you're not going to share the info or even link it here, then why post in this thread?

[sspade]

Originally Posted by cxp213

OK....? If you're not going to share the info or even link it here, then why post in this thread?

LOL.... I know right. I just need more time to actually type it out... will link it... just got a response from SA...

[perryo91]

Originally Posted by cxp213

OK....? If you're not going to share the info or even link it here, then why post in this thread?

Originally Posted by sspade

I have an interesting take on this procedure from my dealer that I will share with the group in another thread...

Lmao I think sspade just wanted some attention and is probably nothing relevant to replacing the fluid DIY.

[Polo08816]

Originally Posted by cxp213

That doesn't sound good. How many quarts was the difference?

About 1 quart every iteration. Probably the amount in the cooling/heat exchanger.

[insanecoder]

Originally Posted by Polo08816

About 1 quart every iteration. Probably the amount in the cooling/heat exchanger.

You are supposed to top off the fluid a second time whilst the engine is running and cycled through the gears.. did you do that?
If not then the missing quart may be there

[montr]

Originally Posted by insanecoder

You are supposed to top off the fluid a second time whilst the engine is running and cycled through the gears.. did you do that?
If not then the missing quart may be there

I did an ATF and pan/filter change on my 335d at around 100 K miles. Transmission is a 6HP26 and process is the same as the 8 speed ZF transmission.

Yes, the transmission takes a lot more ATF when engine running and going thru all the gears (10 second each).

I rigged a funnel with a long plastic tube (from Home-Depot). I was able to fill the transmission by gravity, with the funnel secured on top of engine. I had a catch pan under the transmission to catch the overflow. This made it much easier than pumping the ATF up from under the car. When I put the new pan, I tightened the bolt in the right sequence.

I took my time and the whole thing was done in about 2 hours.

[jsouth]

Originally Posted by Polo08816

About 1 quart every iteration. Probably the amount in the cooling/heat exchanger.

Did you watch the Chrysler ATF video (second video above)? For about the final five minutes, he addresses that issue, which is not mentioned in the ZF procedure but makes sense.

My thinking is this:

• Change pan/filter
• Refill
• Cycle through gears, engine running, recheck
• That completes the BMW procedure, but there may be air in the cooler and hoses
• Drive it until full temperature is reached, ensuring that the cooler thermostat is open and purging air from that part of the system
• Let cool and re-check

[montr]

Originally Posted by jsouth

Did you watch the Chrysler ATF video (second video above)? For about the final five minutes, he addresses that issue, which is not mentioned in the ZF procedure but makes sense.

My thinking is this:

• Change pan/filter
• Refill
• Cycle through gears, engine running, recheck
• That completes the BMW procedure, but there may be air in the cooler and hoses
• Drive it until full temperature is reached, ensuring that the cooler thermostat is open and purging air from that part of the system
• Let cool and re-check

On the last step. If you open the fill plug while engine is not running and not going thru all gears prior, the level will be above the fill plug. You need to have the engine running to completely fill the transmission.

[Polo08816]

Originally Posted by insanecoder

You are supposed to top off the fluid a second time whilst the engine is running and cycled through the gears.. did you do that?
If not then the missing quart may be there

Yes, I did.

[sspade]

https://f30.bimmerpost.com/forums/sh...8#post23932788