Not at all. After dealing with my own trans issues, I am not surprised in the slightest. ZF fluid should only continue to be used on a meticulously maintained transmission. Fluid every 60-80k miles depending on usage according to zf.

That said, I would never refill a trans with zf fluid. I am currently running pentosin, liquid moly, and Valvoline in 3 different zf transmissions. Have tried all the fluids, zf, unscientifically, was the thinnest. And again, unscientific, but I think the weak link in zf autos. But take that for what it's worth... Some guy's opinion on the internet. :dunno:

So you are agreeing that ZF fluid ruins transmissions?

Because that is what he said.






If you really meant to say 'once transmissions begin to fail, thicker fluids can help control issues', then say that.

I said what I meant to say. Both of the above.

ZF fluids can "ruin" a trans, meaning cause it to failsafe or have less than optimal shifting behavior if the clutches/solenoids/etc can't maintain pressure. And thicker fluid can help control issues. Even on a meticulously maintained trans... I would not run ZF fluid.

If you want me to clarify the general statement "ZF fluid ruins transmissions." Then, no ZF fluid, by itself, does not ruin a transmission. Under zero wear conditions it is sufficient. But I do think it contributes to wear over the years.

Again, I am no trans expert though, and have experience on only 5 ZF (x4 6HPs and x1 8HP) transmissions. So can only relay my opinions. All are free to maintain their vehicles as they see fit.

I wonder if your mechatronic to case seal(s) are weak and the heavier fluid is masking the issue?

So the issue has come back again, this time with redline fluid. I am so upset with this car. :banghead:

Still, compared with the terrible trade in value, and the used car market, it'd be worth it to put another trans in. I just wish I understood wth is going on that is ruining now 2x transmissions.

Maybe on a used trans, never used the ZF fluid? Go straight to redline? :dunno:

Miles? What trade-in numbers are you getting?

Does the fluid look contaminated? Cross-contamination from trans cooler?

You may have to share what you’re currently experiencing to refresh this thread

120,500 miles, best trade value was ~$8,500. Comparable X5s go for $12-18K.

Fluid is always clean, no particles, clear, normal, correct level. Trans cooler has had 5 fluid changes at this point, can't be contamination.

Vehicle drives well for first 5 mins from cold-start, then starts progressivley shuddering more and more as it warms in all gears at medium-to-light load, especially 1500-2500rpms. Basically when accelerating normally from a stop light it's the worst.

I imagine the torque converter lock-up is slipping due to inadequate pressure from the internal oil pump, especially since oil viscosity becomes thinner as it warms up. But I don't know why, or have proof of this.

Ouch.

I’m not 100% but I think the TCC is full lock up almost immediately in 1st, and stays locked through all gears. Do you have Carly or something comparable? You should be able to see tcc pwm data or a % tcc request. Watch/log what it does when you experience the hesitation.

And still no codes at all?

Any update on this x5?

We were on the highway last month, got rear ended. Car was totalled. Ended up being a blessing in disguise. Took payout and bought a 2020 X3 with 20k miles.