722.5 Auto box misery

[rayhennig]

Hello All,

My current problem applies to a 1991 300CE-24 with 104 engine and 722.5 5-speed auto box.

Auto box is misbehaving.

1. Starts fine, up changes quite smoothly and at correct speeds.

2. At the 3 to 4 up-change point, it engages 4th for about half a second then changes to 5th.

3. Switching from D to 4th with the lever has no effect, it remains in 5th.

4. Down-changes are very slow and only happen when very low road speed is reached.

5. Manual selection of 3rd results in 3rd being selected after around 2 seconds (very slowly). If

left in 3rd, it behaves musch as it should short of being reluctant to select 2nd except at very

low road speeds.

6. Kick down (foot flat to the floor) results in 2 or 3 seconds of 'thought' and then off we go!

So, basically, everything seems to work but in some cases completely at the wrong time.

My feeling is that this is a vacuum related thing. It's as if the gearbox is entirely unaware of

the position of the accelerator and thus when I am hoping for a down-change.

If anyone can shed any light on this, I should be forever endebted.

My thanks in advance and regards to all.

RayH

[mbdoc]

Have you tried overfilling the trans by 1/2 qt?

On that trans there is a plastic container in the rear of the trans that holds about 3/4 qt of extra fluid. It dumps that fluid to raise the level when the trans gets HOT.

Also the computer will store codes when there is an electrical issue.

[rayhennig]

Thank you, sir, for taking an interest.

I have never heard that! Could that be an issue with downchanges and the 4th/5th problem - or should I say the almost immediate change to 5th from 4th.

Would that affect the inability to select 4th, even when 4th is selected on the lever?

If you have time, some more detail would be much appreciated.

My best to you.

RayH