300E Trans. upshift

[esm6869]

I recently had the front pump replaced on my '88 300E, with a new gaskets, filter, fluid... Ever since then, when shifting from 2nd to 3rd gear, the trans feels like it is slipping until the RPMs climb to 3000 and then it catches into the next gear. If I accelerate to where the 2-3 shift occurs above 3000 RPMs, there is not hesitation or slipping feel. Is there something that is out of adjustment? I don't believe the trans is going out on the car, for example, if I floor it and engage the kickdown from 1st gear, it will sometimes squwak the tires shifting from 1st to 2nd.

Any help would be appreciated.

[Mike Richards]

If the problem surfaced AFTER the repair, have the shop review their work/materials.

[jsmith]

do a search on "flaring". technically, it's not really slipping but the engine revs up before engaging the next gear. i believe there are adjustments you can perform on the vacuum modulator. look for Steve B.'s posts on this, you'll probably find out all there is to know...

[KNanthrup]

THIS EXACT THING HAPPENS TO ME. Sorry, got a little excited, but I have this same problem. It's not a huge mechanical problem/big deal, but it does get a little annoying and I'd like to know what's wrong. It seems to be worse when the car is cold, like when i first start it up and pull out, it seems to take the longest to catch 3rd gear, then when it's warmer it does a lot better, but still a noticable slip. I've been told that the hydrolic pressure may need to be increased or something, but I don't know much about it myself. I'd like to know if anyone else has this problem and has had it diagnosed or fixed.


'86 300E

[TICOBENZ]

I own a 87 300E and something very similar hapens to me, mostly when driving like an old lady, if I pull out on drive, there is some hesitation and it revs up a little before shifting, but after that it shifts just fine, but when I floor it there is no problem and I do not have trouble upshifting. Some versions I have heard that there is a cable that goes from the throtle something to the trans, another diagnosis was that the trans was rebuilt not using original blue box parts, Ive had this problem since I bought the car 2 years ago and it hasnt gotten worse.

[esm6869]

Turns out the vacuum module was bad. Had the module replace and that took care of the "flaring". Now I just need to swing by the mechanics garage to have some fine adjusting done. Now the shift from 2nd to 3rd will throw you into the back seat. Hopefully we'll get it adjusted today. Thanks for all the suggestions and Steve's explanation of the adjustments on the module were right on!

[KNanthrup]

oh, wonderful. this is good to know because mine still does it and i was thinking of going and having it fixed. can you tell me how much having that replaced cost you? did you take it to the shop? any info you can give me would be great because i need to have this done soon. thanks.

[esm6869]

The vacuum module (although FastLane has it cheaper) was billed to me by my mechanic at $47.99. I was charged one hour of labor at $62.00 and $14.00 for the MB trans additive for non-slip. As the non-slip additive gets worked into the trans, it is becoming smoother and less violent on the upshifts. The greatest difference now is when I engage the kickdown switch and floor it, the shifts are crisp and clean. It's a lot of fun

One thing is very clear, the flaring is gone.