siideways

So here's the deal. I found a super low-mileage C36 (it sat for 3 years) w/ the 5-spd tranny, but it's acting funny. When driven normally, tranny shifts just fine. However, it's when you let off the throttle and then get back on it, or floor it, that it hunts around for the proper gear (read LAGS) and then bangs into gear...ouch. This tranny had its fluid flushed, filter replaced, etc. just a couple months ago by a dealer, who recommended that the car be driven for a few thousand miles and then have the tranny fluid re-flushed.

Does this sound possibly (even remotely) like it could be electronic? i.e. TCU acting up, fluid intrusion into tranny wiring harness, bad ground/electrical? Or is this definitely mechanical and therefore a ticking bomb? Could the tranny possibly perform/get better w/ more miles on it since it hadn't been driven in so long? i.e. tranny reset that some of you guys have talked about?

All input welcome and appreciated!

amg801

how does your car go when you get on the gas? does it accellerate fine?. only because recently i had i similar sounding problem and it would jerk and shift really rough and bang into gear. It turned out to be the MAF sensor was kaput. i was told by a wise merc mechanic that the maf acts as the load sensor for the transmission at low speeds.

siideways

The dealer already did a full diagnosis, and there were no codes/check engine light, hence not a MAF issue. It looks like it might just be something mechanical...hopefully something as simple as a valve body?

hoontastic

sux - i hope you get to the bottom of it. I wish there was a tru plug and play 5/6spd manual conversion for our cars. A manual option, LSD, and true defeat of ALL traction control. That would give your e36 a run for its money then.

Ausmbtech

It certainly sounds like it would be a good idea to get your valve body overhauled. They have some wear points and springs that can break over time as well as a piston sometimes sticking. Since it works normally it most situations I'd presume there is nothing wrong with the mechanical side of the transmission and the fault lies with the hydraulics (valvebody).

Especially being one of the first valvebodies in your car if you can get a later one (W140 270 06 06 from memory) and get that overhauled then that would be a much better option. The valvebodies were the same between almost all 722.6's until about 2001.

yamadjs08

Have you unhooked the battery and reset the ECU? Try that and see if it relearns the shifting patterns and becomes a bit smoother.

Although many say the 5-speed in the 97 C36 isn't as reliable as the 4-speed, I believe otherwise. My 97 C36 has 170k miles and shifts perfect, and I beat it daily. My good friends 97 C36 has 246k miles and he bought it with 170k miles and he is much harder on it than me. I'm talking about hitting kickdown at least once a day, if not many times a day, it has probably see the 155mph speed limiter 10 times at least. They are strong transmissions if they are properly maintained...

Benzonline

+1

tri-star tech

It sounds like it's low on fluid

siideways

No, as I mentioned, the tranny was just recently flushed by a local dealer. I'm hoping it really isn't a mechanical issue, and instead more of a hydraulic issue, i.e. valvebody.

tri-star tech

That doesn't mean anything. They could have under filled it. Unless I checked it with my own eyes I wouldn't take anyone's word for it.