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-   -   Trans won't downshift from 4th to 3rd (http://www.peachparts.com/shopforum/tech-help/38261-trans-wont-downshift-4th-3rd.html)

Tom Pawlik 05-21-2002 11:19 AM

Trans won't downshift from 4th to 3rd
 
My 95 E420, 62K won't downhift from 4th to 3rd when slowing to stop or going around a corner,when I re-apply the throttle it klunks into 3rd. If I manually downshift when going around a corner the trans goes into 3rd smoothly as it should automatically. Except for this issue. the trans works perfectly. Can anyone diagnose this, or does anyone know an honest transmission shop in the Cleveland, OH area?
TYIA.

jsmith 05-21-2002 12:07 PM

don't let anyone without Mercedes training near your car. there are only two external adjustments on the tranny, everything else is internal. part throttle shift points and shift quality are the two things you can adjust.

do a search look for "bowden cable" or "throttle pressure cable" and "vacuum modulator" specifically by stevebfl, one of the moderators and the resident expert on these trannys. your symptoms sound familiar and i wouldn't be surprised if some adjustment is all that's needed.

Tom Pawlik 05-21-2002 02:43 PM

Thanks Joe. I have adjusted the bowden cable to control the smoothness of upshifts but, it has had no effect on the downshift issue. I will do a search for the modulator valve. Also I should have asked if anyone knew an honest "M-B" trans shop. I learned that the hard way three MB ago! Thanks again.

jsmith 05-21-2002 04:15 PM

technically it's the vacuum modulator that controls the shift quality. the bowden cable adjusts the shift points at part throttle which may cause a feeling of abruptness / harshness in the shift if for instance the upshift point is too low. check this thread out for correlations of upshift / downshift while adjusting the bowden cable:

http://www.peachparts.com/shopforum/tech-help/28537-harsh-4-3-part-throttle-downshifts.html?highlight=downshift+bowden


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