I had my vacuum modulator valve replaced a month ago and a couple of weeks later my reverse started slipping to were it is now no reverse. All other forward gears are fine , shifting is good , the shop wants to rebuild it to the tune of $1,500.+ , can I adjust it to work or do they just take a dump without warning like this? Could it be the valve they replaced? The car only has about 160,000 miles I'm the second owner, and the orig. owner took excellent care of it.Any thing I'm over looking or ? Thanks to any and all help. C.W.

There is a band adjustment just for Reverse. ON the rt side of the trans just above the kickdown solenoid.

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MERCEDES Benz Master Guild Technician (6 TIMES)
ASE Master Technician
Mercedes Benz Star Technician (2 times)
44 years foreign automotive repair
27 Years M.B. Shop foreman (dealer)
MB technical information Specialist (15 years)
190E 2.3 16V ITS SCCA race car (sold)
1986 190E 2.3 16V 2.5 (sold)
Retired Moderator

I want to thank so much for be the first person to be straight with me and piont me in the right direction! You saved me big $$$$'s and restored my trust in at least 1 honest mechanic in this world. My problem was the adjusting bolt was loose and about to fall out!!! But I never new it was there it was covered by dirt and oil! And not even 1 of the mechanic's I asked even looked there! They all just said I needed a rebuild! Thank you very much for your help! M.B.DOC!

I had the same problem (no reverse) in my '76 450SLC. I had asked my friend who now does only bakes/front end work and he said he didn't know what was wrong but would look into it. Since he no longer does full mechanic work I didn't want to impose upon him so I took it to one of those "only work on transmission places" and asked if they could take a look and tell me if the problem was internal or external. They told me it was internal and would have to rebuild the unit. I opted not to do that at the time. The next day I took the car to have the balancing/alignment etc. done and my friend handed me a piece of paper. It was an email that explained how to adjust the band externally. He had asked a friend, who is very into MBs, just what the problem was.. and his friend had gotten the info, and printed it out for me. Now, I'm not saying the "transmission place" people were dishonest, I just don't think they had the knowledge to handle the situation. I had asked if they worked on MB Xmissions and they assured me they knew all about them. Obviously not. It's nice to have friends and honest people around you. Since the incident I have passed this knowledge on to other MB owners hoping it may save someone a rebuild when all they might need is an adjustment.

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Nello Tare

1982 300D (266,001 mi.) looking and running great

Previously owned:
1976 450 SLC
1983 300D
1976 300D
also
1982 Jaguar XJ6 (loved, but gone)

I jsut made a posting about a related problem with my 1976 230.4. Is the bolt in the same place on my model ? Do yo mean to the right of the tranny when looking at the car or from sitting inside the car ?

Thanks,

AARON ROCHARD

1976 230.4 W115

Just to round the corners a bit on this info.

The adjustment is on the passengers side of the tranny. It is the forward most band.

The original band bolt has a break off head; which is usually broken off leaving nothing to tighten the adjustment with. We usually notch the end of the bolt with a carbide cutter and use a screw driver. This really only works if you know the feel on the adjustment as no torque can be read.

An overtightened band will self activate locking the tranny; a very disturbing occurance (ask how I know).

We have made that adjustment over a hundred times thus we have saved that many from the lechers.

A BIG NOTE; This whole discussion ONLY APPLIES to 722.0/1/2 transmissions. It does not have anything to do with 722.3/4/5/6 transmissions. This means NOTHING after 1981 except 240D!

BTW, another possible occurance of no reverse on those early trannies comes from a broken rev band servo piston. This also can be fixed from outside.

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Steve Brotherton
Continental Imports
Gainesville FL
Bosch Master, ASE Master, L1
33 years MB technician

Just successfully cured reverse gear slippage using the described band adjustment...

Steve, you gave a warning about overtightening this band adjustment. "An overtightened band will self activate locking the tranny; a very disturbing occurance (ask how I know)." What happens if you do this?

Thinking about taking my next vacation in Gainesville.... thanx for all the great contributions to this forum!

When the band self activates as do brake shoes in self activating drum brakes the trans winds up in two gears and the output is zero. That means the rear wheels stop.

I have only experienced it at parking lot speed, luckily. The rear wheels just stop.

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Steve Brotherton
Continental Imports
Gainesville FL
Bosch Master, ASE Master, L1
33 years MB technician

Used to be you could order those bolts in the non broken off form. I think I still have a couple in stock. They are pretty dusty.

I've bought alot of cars over the years for a song, because they were either badly diagnosed or the owners didn't want to spend the money to have the car professionally checked out. They saved money by having it checked by a friend of the neighbor's who knew something about cars.

Peter

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