5hp30 tranny, 53K miles on Pennzoil

[Mr._Graybeard]

Just thought I'd flog a dead horse a bit on the old transmission fluid debate.

My '95 540i just turned 145K, with 40K miles since the last transmission fluid change. I replaced the OE Shell fluid with Pennzoil Multi-Vehicle ATF at about 87K miles, and then changed it again at about 104K.

Draining the fluid this time, I decided to do a pre-emptive valve body rebuild because of the mileage on the car.

The fluid that came out looked just slightly burned -- what went in looking like cherry cough syrup came out with a slightly orange hue. It was clear and smelled OK -- well, about as good as it smelled when it was fresh.

The magnet in the pan had just a dusting of iron on it, far from the furry look it had when I opened it up 53K miles ago. Overall, it all looked quite clean and very satisfactory.

The torque converter has wanted to unlock in fairly low-torque situations as long as I've had the car. It's had me adjusting the throttle while driving to accommodate the whims of the transmission. Fortunately, Bimmernut archives link to ample how-tos on doing the rebuild. They're very helpful, and I'm grateful to those who took the time to post them.

The valve body internals were quite clean -- a couple points with small accumulations of iron mud here and there, but overall not needing any significant cleanout. I had a couple cans of brake cleaner handy to blast out the goo, but I didn't find anything worth going after with a chemical flush. Neither check ball showed any appreciable wear, but the big channel gasket was kind of brittle.

I've driven about 100 miles since the rebuild, and the torque converter seems to want to drop out of lockup a lot less. Of course there's an adaptive feature to the transmission control, so we'll see if there's any further change on tap in the coming miles.

I think maybe a 40K interval is a little long for the Pennzoil product -- 30K miles might be more appropriate. But the transmission seems to be holding up very well on it.

[shogun]

Thanks a lot for this info.
I may add some things from own experience on a E32 750il Alpina B12 5.0. Tranny is a 4HP24, torque converter is from Alpina.
Bought about 2 months ago. From 1988, about 180.000 km on the clock.
Changed the transmission oil immy after buying, probably the first time since 1988.
The fluid was darker than the new 'cherry cough syrup', but no burnt smell. The 2 magnets in the oil pan showed some fine 'dusting' of iron in it.
Filter I did not change at that time. I changed the fluid only, plus cleaned the magnets,
used compressed air to blow out the fluid from the cooler lines and the transmission oil cooler, torque converter as much as possible.
Then I filled Chevron Automatic Transmission Fluid MD-3
https://www.cbest.chevron.com/msdsSe...searchScreen=Y
I used that one for just one reason, it was the cheapest I could get at COSTCO and actually the only one they had when I went there.

After 5-8000 km I changed it again on last Saturday, same procedure as before, but now also the filter+O-ring. Oil was almost looking the same colour as when it was filled, some more dust of metals again in the magnets, but that looks normal like wear and from the cleaning process with the new fluid.

Then I also removed the valve body and tested the valves and cleaned the channels, no balls changed, no orifices, also not the large gasket between the 2 big parts. Just to see if there is any dirt inside.
Looked good.
Now it runs much smoother, I would say perfect like a new one. Before the shifting was often like a shock when switching gears.
In my opinion - and I now have opened quite a number of 4HP22/24 ZF transmissions-, a new fluid cannot harm a transmission like some people still believe. It cleans the valve body and all these small channels from deposits which accumulate over the years.
And if a transmissions fails after an oil change, it was not because of the oil change, but that was indeed anyway the end of the tranny.
Flushing seems also a good idea, at least if you have the possibility to flush the torque converter and the oil cooler and the oil cooler lines.
And now I used the same Chevron stuff. I have no comparable figures with regards to a specific transmission oil to be better or not, so that I leave to other experts.

[Tiger]

Definitely 30K on Pennzoil is necessary... can you imagine 'lifetime' on that same fluid? OE fluid is also semi-synthetic like the Pennzoil.

When I had Kirt rebuild the valvebody, he replaced everything... speed sensor, valves, wires... etc. The tranny was soft on engagements before the rebuild and after rebuild was a solid engagement... still is. So I don't know what you have replaced on your valve body... don't forget the other things.

[Mr._Graybeard]

Definitely 30K on Pennzoil is necessary... can you imagine 'lifetime' on that same fluid? OE fluid is also semi-synthetic like the Pennzoil.

When I had Kirt rebuild the valvebody, he replaced everything... speed sensor, valves, wires... etc. The tranny was soft on engagements before the rebuild and after rebuild was a solid engagement... still is. So I don't know what you have replaced on your valve body... don't forget the other things.

I just did the valve body kit, no wiring, solenoids or speed sensors replaced so far. Kirt told me that the main pressure valve and shift selector valve can develop wear and affect shifting. The VBK comes with replacements.

I'll keep observing the changes in performance (as the driver, do I have any other choice? ). I can't say the TC is disengaging without a little bump, but the lockout process does seem better. Then again, the difference is mostly subtle, and a PITA car repair project can sometimes have a placebo effect on me. I wish it were fixed, therefore, it is...!

I'll be back under the car in 30K miles. If something is still amiss (I was wondering about the solenoids too), I can get at it then.

[Mr._Graybeard]

Changed the transmission oil immy after buying, probably the first time since 1988.
The fluid was darker than the new 'cherry cough syrup', but no burnt smell.

Someone had done a service to the transmission in my 540i before I bought it -- I found an aftermarket filter when I opened it up -- but I suspect they retrieved the original fluid and put it back in, per what I believe was BMW's recommendation at the time. It was the color of coffee when I drained it.

[Tiger]

Yep, same here... coffe with lots of suspended coffee grinds.

[charlie]

anyone have issues with the tranny going in and out of lockup a bit harder than normal even after doing a VB rebuild? I wonder what that could be?

I just did the valve body kit, no wiring, solenoids or speed sensors replaced so far. Kirt told me that the main pressure valve and shift selector valve can develop wear and affect shifting. The VBK comes with replacements.

I'll keep observing the changes in performance (as the driver, do I have any other choice? ). I can't say the TC is disengaging without a little bump, but the lockout process does seem better. Then again, the difference is mostly subtle, and a PITA car repair project can sometimes have a placebo effect on me. I wish it were fixed, therefore, it is...!

I'll be back under the car in 30K miles. If something is still amiss (I was wondering about the solenoids too), I can get at it then.

[Tiger]

Call Kirt

[Mr._Graybeard]

anyone have issues with the tranny going in and out of lockup a bit harder than normal even after doing a VB rebuild? I wonder what that could be?

Yeah, Kirt would be the guy to ask. He told me once that the clutch surfaces in the torque converter can wear to the point where they go out of tolerance, and the transmission controls can't adjust enough to shift smoothly.

But it can be frustrating working as a shadetree mechanic on these things. About all you can do is to try one thing, and that doesn't help, try something else -- hopefully, starting with the least expensive step and working your way up. And of course, do as much research as you can.

Here's an interesting narrative with references to the 5hp30: http://continentalimports.com/ser_ic100076.html

Brotherton says one of the solenoids is supposed to apply the torque converter lockup fractionally. Hmmm...

Here's a PDF that has some applications worth study: http://www.e38.org/electran1.pdf

HTH