reverse issue after rebuild

[faranks]

So after rebuilding the 5HP24 tranny in the wife's '00 4.4, it will not go into reverse first thing in the morning, unless you apply the slightest backwards finger pressure on the shifter. Once it warms up, it functions properly all day. The only damage I saw inside was a snapped o-ring between the A-B clutch baskets and the subsequent axial needle bearing failure that separates the two. I replaced all o-rings and gaskets, put it back together no prob.

At first I thought it was just a bit low on ATF, and the heat expansion made up the difference, but I have put as much ATF as it will take under proper fill procedure.

The only other anomalies are that the passenger mirror no longer dips down when reverse is selected, and the dash indicator shows "R" when initially selected, but then goes out.

Otherwise, it drives perfect, and the downshift problem it had before was corrected. Any thoughts?

[TriX5]

Have a look at the electrical connectors, maybe you have a bad contact. Did you clean out the valve body?

[faranks]

Would those problems go away once it's warm?

I did not disassemble the valve body, just hosed it w/contact cleaner.
I have disconnected/ inspected/ and reconnected the main round molex connector.

Do you have any idea if the tps looking sensor that is on the passenger side of the shift rod linkage has any control over the solenoids? This is all I could think of, but a BMW tech friend of mine said that assembly is only responsible for the dash light indicator ( but we know that BMW techs are not authorized to do anything but replace transmissions).

[diyanich]

After my box was rebuilt shifter has more play,it engages properly though.
I would go and ask the shop to rectify the issue.

Originally Posted by faranks

Would those problems go away once it's warm?

I did not disassemble the valve body, just hosed it w/contact cleaner.
I have disconnected/ inspected/ and reconnected the main round molex connector.

Do you have any idea if the tps looking sensor that is on the passenger side of the shift rod linkage has any control over the solenoids? This is all I could think of, but a BMW tech friend of mine said that assembly is only responsible for the dash light indicator ( but we know that BMW techs are not authorized to do anything but replace transmissions).

[faranks]

No shop, did it myself.

[diyanich]

I see.
If you had a faulty Lever position sensor you wold get no luck starting the X.
So my thought is still the bad alignment where lever meets the tranny.

Originally Posted by faranks

No shop, did it myself.

[swissfrank]

you need to adjust the shifter linkage and range sensor (#5 in the pic) on the transmission. remove cover(#9 and bolts #10) undo the adjustment nuts for both the range sensor (#6) and shifter linkage(#8 on second pic) and manually put the range selector into R both on the transmission (#4 on second pic) and the gear shift lever in the car, adjust the range sensor(#5) so it also reads R on the dash, tighten everything up and you're good to go.

[faranks]

sounds great swissfrank, that was the little push I needed to dig into that side. I figured that w/o a computer hooked up I may do more damage than good, but that sounds very simple.

Still odd that a bit of heat makes the problem go away, might have something to do with me using a different ATF (Castrol) and having a different expansion rate than the ESSO. I'll hopefully give it a shot tomorrow and report back. Thanks!

[SlickGT1]

Originally Posted by faranks

sounds great swissfrank, that was the little push I needed to dig into that side. I figured that w/o a computer hooked up I may do more damage than good, but that sounds very simple.

Still odd that a bit of heat makes the problem go away, might have something to do with me using a different ATF (Castrol) and having a different expansion rate than the ESSO. I'll hopefully give it a shot tomorrow and report back. Thanks!

I think you are just heating up the contact on that sensor, it expands and makes the proper connection. I don't think its actually the oil, just the trans gets warm, thus warming up that range sensor.

Swiss makes a good point.

[swissfrank]

Originally Posted by faranks

sounds great swissfrank, that was the little push I needed to dig into that side. I figured that w/o a computer hooked up I may do more damage than good, but that sounds very simple.

Still odd that a bit of heat makes the problem go away, might have something to do with me using a different ATF (Castrol) and having a different expansion rate than the ESSO. I'll hopefully give it a shot tomorrow and report back. Thanks!

yes please report back for the good of the community.

however I had the same issue where i didn't adjust the cable/sensor properly immediately after my rebuild, and it would stay in reverse while in park. adjusted everything and went through the ranges just to confirm P was P and R was R etc, etc, all good afterwards. I think your might just be on the verge of mis-adjustment, hence why the slight back pressure on the shifter in your case is enough to please the gear lords and make it work.

Good job on your rebuild, I am glad more and more people are comfortable with working on their transmissions!