Reverse Delay

[ArnZ!]

hey guys

This is another one of those autotragic reverse gear problems again except for the 4hp22 on my m30

Recently its been having a hard time engaging reverse. When cold it engages straight away. After driving it up to operating temp, reverse engages straight away too. But leaving the car to sit after 2-3 hours it takes 10 or so seconds to get into reverse.

I checked the fluid levels and they seem fine. I cleaned the shifter switch and adjusted the shifter cable and all are fine IMO.

Now according to this pdf file

http://www.europeantransmissions.com....BMW/92-12.pdf

During the road test it may be noted that there is no engine braking in manual first or second gear.

After taking my car for a drive i tried this and i still do have engine braking. So my F clutch probably is still okay right?

So im not sure really but do you guys think maybe my valve body needs cleaning/rebuild? Obviously im going to take this to an auto specialist but i would just like to hear your guys opinion first.

[shogun]

first of all check the ATF, as I already said to Bruno. General rule: if it does not smell burnt, if it is not completely dirty and a lot of metal in the pan, I would try a valve body rebuild. That is done in a few hours usually. Much smoother shifting, provided of course there is no damage to the clutches.

I am an amateur repairer, we have done abt 10 4HP22-24 so far. So maybe a pro chimes in with better comments.
But from this little bit of experience I can tell you, that a valve body cleaning helps often, but of course not always.

This might help you
http://www.zf-transmissions.com/troubleshooting.htm

[ArnZ!]

Yeah i had a look at that website and ive checked my stall speed and fluid levels and everything looks fine.
Im thinking about taking the car into an auto specialist to see what the pressure is when in reverse. Im thinking its a bit low which the bentley manuals says its the valve body or ATF pump. I doubt its the pump because drive ability in forwards gears are all fine. I also doubt its the F clutches as i still have engine braking in 1st and 2nd gears.

[paanta]

If you've done 10 of the same transmission, I don't think you count as an amateur anymore. :)

[bubba966]

Sounds to me like a worn check ball in the valve body. Happens frequently to 5hp30's over time. Valve body rebuild takes care of it.

[ArnZ!]

Unless theres someone that exactly knows the problem then id get the valve body done. I too believe its just the valve body but i cant justify spending 450 to get it rebuilt then that not being the problem.....

I was speaking to 5 or so automatic places here where i live and some say definately clutches. Other say give it service and it might clear up. Another one says it might be valve bodies. Another says its definately not valve bodies. Even one place didnt know the 4hp22eh could be pressure tested........ wtf

So far my options are

Basic Service $121
Valve Body Rebuild ~$450
2nd hand box ~$650
Rebuild +$1300

[dreman77]

hey bud,

at least you got quoted 1300+ for a rebuild. i got quoted between 3 - 4 1/2k and thats after shopping around

[ArnZ!]

hey bud,

at least you got quoted 1300+ for a rebuild. i got quoted between 3 - 4 1/2k and thats after shopping around

Yeah these auto transmission guys make some good money dont they. For 1300 i reckon they would just do the most basic of rebuilds, whilst reusing parts and such. A decent rebuild that replaces most parts would be around 3000 so thats pretty realistic.

[nirvana19]

When was the fluid last changed? I recently had my transmission fluid flushed which made the shifting significantly smoother,.

To those who know more, if the problem is the valve body would flushing the transmission possibly help clear up the problem and potentially help diagnose, or on the other hand if the problem is the clutches could this exacerbate it? At around 120 dollars it seems as if it would be worth a try, at least that's probably what I'd do if unsure and concerned about the cost. From what you describe I assume the transmission shifts fine otherwise and the problem is quite isolated to reverse after sitting for a while?

Also I'm far from an expert but I feel I've read about similar problems being attributed/remedied by the valve body, just don't want to mislead and pretend I have any idea why.

[ArnZ!]

Fluid was last changed about 4,000kms ago. With new filter.

Flushing the gbox sometimes breaks up the slug a bit too much and can clog the valve bodies sometimes. But people have done it with great results. Here in oz a flush costs $250 so its a bit of money.

I think ill just change the gbox with a low km unit if it gives me further grief.

[ArnZ!]

Took it to get serviced today. Opened up the old filter and within 4,000kms there is already a bit of bearing cage or something and a bit of clutch material in there. The guy said 300,000kms is pretty much the life expectancy of these boxes.

[dreman77]

Took it to get serviced today. Opened up the old filter and within 4,000kms there is already a bit of bearing cage or something and a bit of clutch material in there. The guy said 300,000kms is pretty much the life expectancy of these boxes.

well if 300k is the supposed life of the g/box, i should still have about 60+k of life left. unfortunately dont think thats the case. :( good luck on finding your g/box. i'm still lokking for one here in wa

[BigKriss]

so hows it running now?

[ArnZ!]

Same as before. And to be honest i think it is slipping when cold in reverse when i think about it.

[ArnZ!]

UPDATE:
The car is at the transmission shop getting open heart surgery. The seals were rock hard. Reverse clutches were worn out, "a" clutch pack were on the way out. Would've prob only lasted another 2000kms according to the re builder. The basket had grooves in the inside bit and same where the stator goes. So thats getting all fixed.

Should be back later this week which is the only good news i guess.

[ArnZ!]

Update: Got the transmission rebuilt, seals were hard, reverse clutches were worn out, a clutches were on the way out (prob another 2k kms left) stator tube was worn, reverse basket was worn and valve body gasket was baked on real hard. Those were all the problems. Now im 2.5k lighter in my bank account but i got a smooth shifting transmission.

[dreman77]

Update: Got the transmission rebuilt, seals were hard, reverse clutches were worn out, a clutches were on the way out (prob another 2k kms left) stator tube was worn, reverse basket was worn and valve body gasket was baked on real hard. Those were all the problems. Now im 2.5k lighter in my bank account but i got a smooth shifting transmission.

damn mate, 2.5k.... i hope that lasts another 300 k km

[ArnZ!]

should last another 300k kms. lol well i hope so. by that time the car will prob be on second engine.....