I'm learning as I go here, so please bear with me. I've looked to see if anyone has duplicated this complaint, but really haven't found anything that describes my "intermittent" situation.
On my 85 300SD (W126), when I start her up in the morning and I roll away, it seems as though the shifts are as sweet as pie (no flaring and no harsh shifts), but once it begins to warm up, they seem to get a little sloppy. Is there a specifice somethig that causes that. I've even tampered with the valve modualtor on the transmission, and althought the sifts are more firm (for the most part), after have been driving for a while, they tend to get sloppy (flaring) again. Also, if the tranny goes into forth and suddenly I need to accelerate to downshift, it seems as though the gear drops very harshly??
Ive checked the fluid at normal op temp and all is correct. What could be causing this?? By the way that trasmission had a valve body upgrade, vaccum modulator upgrade and a B2 piston upgrade. Im stommped!

__________________
Robert Ayala

1985 300SD (W126) 300K miles

have you adjusted the bowden cable, and measured the vacuum at the modulator at no throttle, 1/2 throttle and full throttle?

__________________
'82 300SD - 361K mi - "Blue"

"Good judgement comes from experience. Experience comes from bad judgement."

listen, look, .........and duck.

Check Bowden cable and vacuum as suggested.

Then, an idea only...

My 86 300SDL has an engine-temperature vacuum switch which ports vacuum to the modulator when the engine is cold to produce softer shifts until the transmission fluid warms up and 'softens' the shifts on its own. If your '85 has such a switch, check to see if vacuum is indeed shut off when warm.

Last, check this link for the K1 spring discussion

Transmission flare fixed! (K1 spring kit)

Maybe something in this will help.

Best Regards,
Jim

Guys thank you for your quick response. As far as the Bowden cable, it it fairly much at its limit. I've had to stretch it from shifting too early. Now the Vaccum pressure, I have not checked for lack of a vaccum gauge. Maybe I need to get one and follow the intructions I found in one of the threads here. The other thing that was mentioned about the K1 spring, I think that is beyond my techincal expertise. Plus I dont recall if that was already done to it with all the updates that were performed on it last year when I got it from my Dad.

__________________
Robert Ayala

1985 300SD (W126) 300K miles

Autozone will lend you a Mity-vac for no charge.

Thanks! I never thought of that. Now if I am correct it should be between 12 - 14 inches of vaccum for the tranny modulator??

__________________
Robert Ayala

1985 300SD (W126) 300K miles

You might find this article to be helpful:
http://transmission.articles.mbz.org/adjust/

Thanks Tangofox,

I'll give that a try as soon as I get a break from this hectic week. THanks for your help!

__________________
Robert Ayala

1985 300SD (W126) 300K miles

You may have a problem with your vacuum transducer switchover valve. That valve is controlled by coolant temp sensor. That valve switches from a different vacuum source as your temp rises.

That makes more sense to me too, "my123ca", but I have no Idea where this sensor is. Do you know where I can find this?

__________________
Robert Ayala

1985 300SD (W126) 300K miles