'88 560SL transmission question
 

I've searched the entire site, which is great, and previously posted this question on the SL thread, receiving one response which I appreciated. However, I still feel uncomfortable and am reposting here. My apologies for being a nuisance.

My SigOther has the above car with 103k miles on it, previously owned by the local MB sales manager and ostensibly serviced religiously per schedule. I don't doubt that as the car is pristine. My question about the transmission is that the upshift seems to be incredibly "solid" between all gears even during light to moderate acceleration. There is no delay or slippage in the shift between any of the gears, nor does it seem to delay the shift for higher RPM's; on the contrary, it seems remarkably swift and almost harsh accompanied by a physical feeling of a forward surge on the car coincident with the gear change. There are no mechanical sounds which would indicate a problem, only the single physical "bump and surge" associated with the gear change. The shift seems much smoother on a manual downshift under constant throttle or deceleration.

Perhaps this is normal for the beast as opposed to American slush pumps, but this being my first MB experience I'm concerned. I've a '71 Jag XKE which I personally restored (manual transmission) so I'm not totally ignorant, but this is most perplexing to me as I would have expected MB to provide a smoother gear change.

Thanks for any responses to this paranoid, non-specific "problem of perception."

When I bought my first 560SL (a 1988 with 70Kmiles) it exhibited what I would call relatively harsh shifts, at times. Not always, but often enough to make me question whether the tranny was going bad. My mechanic said it was normal. That was nearly eight years ago and it now has 110K miles on it and is still going fine (and shifting the same way). I also bought an 87 560SL with only 38K three years ago and it does shift a bit more smoothly, but it too is relatively harsh. I think it is just a fact of life with these cars. They sure improved things in later years--I have a 94 E320 and it shifts remarkably smooth--almost imperceptible.

I recently aquired a 380 SL (74,000 mi) with the harsh shifting problem you describe. I was advised to do a transmission service b/4 anything else. Consists of changing fluid AND filter. That made an immediate improvement and the shifts seem to have gotten smoother since then. It's still not what I would call silky smooth, but I don't think that's the nature of these transmissions.

There is also the transmission modulator adjustment that you might look into also. (adjusts the pressure)

I've got a 1983 190e auto with just 43,000 miles up. Only had her for 6 months and like you was concerned about the less than smooth gear change.
It is as previous posts have said "the nature of the beast" and I'm now accustomed to it. Yes, I made lots of enquiries via various forums (this is the best, by the way) and contacted a local independent MB service shop for advice.
They changed the atf and filters and checked every thing over and road tested, and I was assured all was well, ie, "they all do it" was the message from them.
There is an adjustment on the vacuum modulator which I'm told can effect smoother changing, but I haven't bothered myself. Lots of posts and threads on the procedure if you care to have a go.
All the best, enjoy your car. Dave. UK.

MB's early automatics, eg the 4-speed in the Pagoda-vintage cars, were designed not for smoothness but to lose minimal energy in the tranny and to shift faster than a manual could be shifted by a skilled driver--"faster than the fastest hand" is a phrase I seem to remember from a Road & Track test. Obviously, MB has evolved its technology and its goals, but the 107 comes from a time when speed and efficiency were still more important than Caddy-like smoothness.