W124 - Shifting issues from 3rd to 4th

[95E320cab]

This may be a little long, but I'm going to try to document all the conditions and symptoms of my 95 E320's transmission.

Last spring I had the reverse clutch rings, filter, etc replaced in my transmission. It was making a rattling noise in reverse that took a while to diagnose properly. Had the work done by a guy that was referred to me as a MB transmission expert. I do think he knew his stuff. He diagnosed and replaced the clutches without issue for about $600.

Almost immediately after the transmission work I began the process of removing, rebuilding and replacing the hydraulic cylinders on the convertible top. I ran into some obstacles and the car was offline for about six weeks.

Once the roof was back on and running I began to notice intermittent shifting issues. (Just to clarify, the car has a five speed automatic. Normal conditions, the car stars from a standstill in second gear.) As a percentage, I'd say about 5% of the time, the transmission seems to "stick" in third gear. This occurs during normal, easy acceleration as well as more rapid acceleration. I can rev to 5,000 rpms or higher and it doesn't shift. I can usually slow to about 1,500 rpms and nurse it to shift. Occasionally during this condition I stop the car, like at a traffic light, then proceed. Sometimes the transmission will shift normally after stopping, sometimes not. Also, I've noticed when slowing down when the gear is stuck in third, the transmission makes a hard downshift as I'm coming to a stop. Shifts from 2nd to 3rd, 4th to 5th seem normal, if not occasionally a bit harsh.

When this first occurred, I contacted the transmission repair guy. He suspected that some of the clutch material had made its way into the valve body, and that we needed to rebuild the rest of the transmission. I suspect something less expensive, or at least I hope for it, like vacuum lines. I hoped that driving would resolving the issue, since it's a second car. BTW, it has about 137,000 miles on it.

The most curious thing to me is the intermittent occurrence. Seems like if something was wrong, it would be wrong all the time. I've done lots of searches, here and on other forums, but there aren't many transmission problems that are documented all the way to resolution. I have checked the kickdown switch - pulled out the carpet and trimmed where it might be binding, blew some compressed air into it, and a quick shot of switch cleaner. I know that's not a sure fix though.

I'll be talking to him again in the next day or two. Meanwhile, if you have any suggestions or similar experiences, I'd appreciate your input. I'll get back on here with the resolution as soon as it's worked out. Thanks.