Every now and then when I floor my '85 300D, it downshifts but then refuses to upshift. It was an intermittent problem and I thought since mine was a CA emissions model I thought it was something in the egr computer. I even had a switch wired into the "secret" fuse located behind the glove box so everytime the tranny would stick, I could just switch it off and it would shift fine. Then I read somewhere in a post that there was a kickdown switch under the accelerator pedal. I never knew there was that there even was a switch like it. I had the problem again recently and this time I remembered to check out this switch. It indeed was sticking on occasion. So...if you ever have a problem like it won't shift, check out the switch. It may save you an expensive trip to a transmission mechanic.

__________________
DJ


84 300D Turbodiesel 190K with 4 speed manual sold in 03/2012

I have to laugh at this post.

I have been troubleshooting a problem for a new member for almost three weeks and he was determined to find the problem in the vacuum system on an '85 CA 300D. It's a completely different system from all other 123's. So, after we go over it thoroughly, I realize that his problem is not the vacuum system at all.

The damn thing won't upshift.

So, I suggest that he disconnect the kickdown switch and what do you think happens??

He was quite shocked about the whole thing.

Damn switch almost caused another member down in Texas (IIRC) to sell the vehicle.

I don't think a vacuum problem would ever affect the tranny on an '85 model, at least not in any way that would prevent it from shifting.

__________________
DJ


84 300D Turbodiesel 190K with 4 speed manual sold in 03/2012

.........................you got that right, LOL.

Quit making fun of me

I do think though that the Vac can affect things, as when you pull the Vac line things get a bit nutz. But maybe not so much shift timing. I got that 85 CA vac system PEGGED though.

How do you switch out the kickdown switch? Just a couple o' nutz or is it a twisty of sorts. Be nice to have an idea before I go crawling around in the slush.

We are not making fun of you. It's kind of like deja vu where this damn switch has returned to strike another member with the wrath of the transmission Gods.

Kinda trying to make light of the situation. You've done an excellent job of methodically working the problem diligiently until you found the culprit. If I was aware of the how late the shifts were, we could have avoided most of that. I was thinking the shifts were 500-1000 rpm late, as an example. Actually, they were at or near redline. A different set of data!

The benefit is that you now know much more about the vacuum and boost systems than you ever did. It will benefit you in the future.

I've never pulled the switch, myself, so I can't guide you there. If I had to guess, I would say that M/B would use two or three fasteners to hold it to the floorpan.