Author Topic: Gearbox Trouble - Continued - Please Help - Update on Symptoms  (Read 3000 times)

Pawel66

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An update on symptoms after this morning look: the gearbox is shifting gears higher, but at very high revs and very rough.

It looks like the main thing is too high pressure that we cannot adjust as it does not react neither to adjustment screw turning nor to rod lengthening.

Any clues now?

I had my automatic gearbox refurbished (reputable shop). We installed it back in the car. We went through the pressure adjustments by the book. Yesterday, after a couple of rounds we managed to adjust shifting - it did shift up and down just great, nice and smooth, kickdown working - everything great.
This morning my mechanic took the car for a ride. Made about 2 kilometers. Then from the standstill the car moved, shifted up to 3rd gear roughly and did not shift up anymore. It now shifts up but at very high revs and roughly.

We checked the pressure - it is high on idle, vacuum off, over 6 bar. It does not react to adjustment screw turning - neither direction. It does not react to the linkage rod shortening/lengthening - just stays high.

We have dismantled the diaphragm housing to see if everything is moving there - but it looks ok as far as we could tell.

Any clues what it might be?  :-[

« Last Edit: July 16, 2015, 09:30:44 by Pawel66 »
Pawel

280SL 1970 automatic 180G Silver
W128 220SE
W121 190SL
G-class

ja17

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Re: Gearbox Trouble - Continued - Please Help - Update on Symptoms
« Reply #1 on: July 17, 2015, 13:50:02 »
Maybe a stuck valve in the valve body.  Some times debris lodged in the radiator (transmission tube) moves back to the transmission and causes problems. 
Joe Alexander
Blacklick, Ohio
1969 Dark Olive 280SL
2002 ML55 AMG (tow vehicle)
2002 SLK32 AMG (350 hp)
1982 300TD Wagon turbo 4spd.
1963 404 Mercedes Unimog (Swedish Army)
1989 flu419 Mercedes Unimog (US Army)
1998 E430
1974 450SLC Rally
1965 220SE Finback

Benz Dr.

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Re: Gearbox Trouble - Continued - Please Help - Update on Symptoms
« Reply #2 on: July 17, 2015, 15:29:26 »
I had the same thing recently and it was a loose wire at the connection block on the trans.
1966 230SL 5 speed, LSD, header pipes, 300SE distributor, ported, polished and balanced, AKA  ''The Red Rocket ''
Dan Caron's SL Barn

1970  3.5 Coupe
1961  190SL
1985   300CD  Turbo Coupe
1981  300SD
2013  GMC  Sierra
1965  230SL
1967 250SL
1970 280SL
1988 560SEC

Pawel66

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Re: Gearbox Trouble - Continued - Please Help - Update on Symptoms
« Reply #3 on: July 18, 2015, 11:20:55 »
Thank you, gentlemen!

The stuck debris is the shop theory - they will look into that next week if we do not find anything simpler before. The gearbox was refurbished after the aluminum hydraulic clutch ripped open. Cooler, lines etc. were cleaned but there is always a chance that some debris was left somewhere.

The wiring - we will double check all connections at all ends of the wires, thank you for this tip.
Pawel

280SL 1970 automatic 180G Silver
W128 220SE
W121 190SL
G-class