First post/auto tranny issue

[xtrythis1]

Hey guys first post here! Just bought a 88 325i auto convertible for $1100 and had the transmission not want to select any gear once it got hot in traffic, got it towed home. Since then I've changed the fluid/filter and cleaned the pan. I used dextron 4 fluid according to other fourms. It hasn't missed any gears or slip anymore but seems to shift very early around 2000rpm even under full throttle while in D. I've been using the manual selector to pass and get going if i need too and shifts fairly hard/quick. Is there any way to change the shift points to shift later while in D via a valve or switch? Also I've put about 3.5 quarts of fluid in for it to show correctly on the dipstick. Any help would be appreciated!

JP

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[msservices]

There should be a detent cable from the trans to the throttle body. 4hp22 trannys seem to always shift early, and if that cable is not intact and adjusted just right, it won’t downshift when you put your foot into it. The way I remember mine connecting inside the trans pan, it seemed as though it could easily come unhooked inside the trans if it was disconnected from the throttle end and tension was released

[superj]

I was going to say adjust your shift cable. And make sure the switch iss et right under the pedal, if yours has it

[msservices]

And if anyone knows how to actually adjust the shift points, or increase the converter stall speed, on the 4hp22, I am all ears

[xtrythis1]

Awesome thanks for the input. I'll have to look into which one is the shift cable.

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[xtrythis1]

There should be a detent cable from the trans to the throttle body. 4hp22 trannys seem to always shift early, and if that cable is not intact and adjusted just right, it won’t downshift when you put your foot into it. The way I remember mine connecting inside the trans pan, it seemed as though it could easily come unhooked inside the trans if it was disconnected from the throttle end and tension was released

How did you find out if it was connected/disconnected inside the transmission? I adjusted the cable both ways today and no improvement in downshifting or shiftpoints.. :/

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[msservices]

If there is spring tension on the cable (at the throttle body) then most likely it is at least connected inside the trans. However, adjusting it requires finding the point in the cable travel where the resistant( or actuation of the detent mechanism) is felt and making sure the cable pulls past that point at full throttle but without maxing out the cable travel itself. Maxing out the cable adjustment would ultimately stretch, and break the cable, but allowing too little throw on the cable would result in symptoms like yours.
The push button under the gas pedal is a spring loaded mechanical stop that mimics, and backs up, the actuation of the detent mechanism in the trans, so when you floor it you don’t always downshift the trans or stretch the cable. What I would do is loosen the locknut on the threads going into the floor pan, and turn the pedal stop clockwise until it no longer affects the actuation of the detent cable. Then, if or when, you get the trans downshifting again (by driving it with light pressure on the gas pedal only), you can park the car and screw the pedal stop back out until it comes back in contact with the bottom of the pedal and actuate in sync with the detent mechanism that you know now works.
If it still doesn’t work after you isolate the pedal from the pedal stop, then you may have a bigger issue in the trans itself

[xtrythis1]

Ok. I'll check that. I've been driving it around just shifting it manually with no problem but no kickdown in D. Also noticing it wants to start out in second sometimes.. Would replacing the cable do any good? How hard is it to do that? Do you have to take the pan off to set the new one?

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[msservices]

You would have to remove the trans pan to get to that end of the cable, unless the trans was out from underneath the car, I think one could manipulate the hook, but I would not replace the cable until you are absolutely sure it’s adjusted right. Meaning that, if you rule out the adjustment then it’s assumed that the cable is doing it’s job, and that there is another issue beyond the cable in the detent system itself.

[xtrythis1]

Roger that. Thx for the help!

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[superj]

And I bet you are going to have more trans troubles, sonce it starts in second sometimes.

[Jeffnhiscars]

3.5 quarts is only a partial refill as they hold considerably more. You may want to just drain and refill once or twice to at least have marginally cleaner fluid. As superj said, once they start acting up your best case is usually to keep an eye on it and hope it doesn't get worse. I've changes valve bodies with good results but there is so much else that can go sideways on these.

[msservices]

Someone on here might a spare trans sitting around from all the manual swaps that take place. My experience is they are usually sold cheap or given away free for the hauling.

[superj]

I need one if someone here in texas has one or two sitting around. my youngest son wants his super e as an auto

[xtrythis1]

Hmm. Maybe I'll try draining and filling again. Or just adding more fluid. I just did a 300 mile road trip last weekend and treated it like a manual. Ran fine and always stayed in gear. So starting to think its kickdown related or a bad valve when the shifter is in D. Will continue screwing with it until I'm tired of putting up with it.

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[xtrythis1]

Update! I change my oil yesterday in the engine and figured I'd try to readjust the kickdown cable the other direction (threaded housing toward the tranny) which worked! My problem is it's still wants to start off in 2nd gear but the kickdown from 4th to 3rd and 3rd to 2nd works now so maybe if I change the fluid out again it'll clean out that valve for first gear?

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[xtrythis1]

Or should I reuse the current fluid?

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[superj]

change the fluid a time or two more and then change the filter, also. give it a chance to push anything out

[msservices]

My vote is to adjust the cable a bit more and reuse the new fluid

[xtrythis1]

Will do. Maybe I'll adjust the cable more and drain and reuse the fluid. Will post results next week.

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