I have recently purchased a '90 190 E 2.6 from a family member; the car is in excellent condition overall, with only 80,000 miles, but I have some concerns and questions re: the automatic transmission.

First, I have read several posts on this and other forums about modifying pre - '91 cars to start off in first gear. After driving a '92 model and experiencing much improved acceleration, I decided this is definitely a "mod" I'd like to make, but I don't really wish to spend $1300 or more on a new valve body, especially if replacing a spring (behind one of the pistons in the valve body) is all that needs to be done. Since the car will be in the shop for transmission service (fluid flush/filter replacement/ adjustment/ repair ?), it wouldn't take much more effort to make the change. I just want to be sure that I ask my mechanic to remove the right spring (or replace with a lighter one) ! Please let me know the details of this operation...

Also, I have noticed the "delayed upshift" feature when the engine is cold; before I read the manual, I thought the trans was failing... Under minimal throttle, even at subzero temperatures, the unit holds 2nd gear to nearly 4000 RPM, and then "kicks like a donkey" into 3rd. The local Mercedes dealer assured me this condition is "normal," and since it seems it's emissions related (a clever strategy to heat up the catalyst), I could probably live with it. It would be nice (esp. for that ice cold engine!) to lower that shift point a bit, though, and if the tranny started in first, it would upshift quicker, at a lower ground speed, and wouldn't give the impression that it was stuck in second gear...

One more oddity -- while accelerating quickly (say 1/2 to 3/4 throttle) away from an intersection, usually in hot weather, the car would downshift from 2nd to 1st, sloppily, in the middle of the intersection, hold first for a couple seconds, then shift back to 2nd. Unfortunately this is the situation where a single, abrupt shift would be appropriate, and would certainly help acceleration. Is this normal, too ?

Since the car will be in for service soon, it's a good time to address all of these things. And I have budgeted for the worst case, but hopefully I can get away with adjustments rather than overhaul! Any helpful advice would be greatly appreciated.

I am in the process of overhauling the tranny from my 87 420sel. Yes you are right, there is simple modification that forces the tranny to start out in first. I dont have the book in front of me at the moment but it seems like removing a check ball in the valve body is all it takes. The valve body is easy to remove, I would estimate 30 minutes max.

The delayed upshift might be corrected by adjusting the bowden cable and or modulator pressure. However I did notice that my tranny had a small component that compensated for temperature. Exacty how and what, im not sure - just that it cought my attention. I think your tranny is very similar to mine so the same things probably apply.

Your abrupt shift into and out of 1st could be normal depending on your foot. If you hit it hard from a stop and hold the throttle down, it will stay in first longer. However if you let off even a little bit it usually shifts into second. So if you want first, push hard and hold it. Many times if it goes into first, I find myself letting up just a bit and then it jumps into second. Too bad it cant read my mind.

Let me know if you need more info about the internals of the tranny. See if you can get the tranny number. Something like 722.4xx.

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I got too many cars!! Insurance eats me alive. Dave

78 Corvette Stingray - 3k
82 242 Turbo Volvo - Manual - 270k
86 300e 5 speed manual - 210k
87 420sel - 240k
89 560sl - 78k
91 420sel - 205k
91 560sel - 85k
94 GMC Suburban - 90k
97 Harley Davidson Heritage Softail - 25k
00 GMC Silverado 1 ton 30k

Disconnecting the shift hold is easy as pie. Just take off one plug connection on the front of the tranny. Driver's side.

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Benzmac:
Donnie Drummonds
ASE CERTIFIED MASTER AUTO TECHNICIAN
MERCEDES SPECIALIST 11 YRS

How hard is it to learn tranny repair? A guy at Aamco said they watch a video to learn. Any suggestions?