Quote:
Originally Posted by guyonabuffalo
Hi everyone.
Most of my activity here is regarding W123s but I am currently considering buying my friends W124 E420.
It has almost 100K miles, is in great shape and he usually gets everything taken care of right away - so I am confident about regular maintenance.
However; it has recently developed a transmission issue. I have searched this and other forums for a similar problem but it seems most folks have different issues with the 722.3/4
It currently shifts nicely through all gears; however once in top gear and doing 50mph+ I activate the kickdown, the engine seems to rev up but the transmission doesnt drop down for a second or more. There seems to be a substantial lag between kickdown activation (revs going up) and the transmission actually engaging. From the little driving I did in his car, I remember it shifting through all gears quite nicely and shifting down nicely as well. Just the kickdown thing is off. He had both the switch and the cable replaced not too long ago.
Any thoughts?
|
goab:
With regards to downshifts, it may be helpful to understand that a 4-to-3 downshift will occur at part throttle, i.e.,
before the KD switch is activated, up to about 75MPH. To activate the KD requires completely depressing the throttle pedal.
If a part throttle downshift occurs, there will be an increase in RPM with very little increase in perceived acceleration. If, in fact, the transmission downshifted only part way (into a false neutral), there would be a very large, runaway, increase in RPM. If that occurred as the result of a full-throttle, kickdown, downshift, the RPM would increase so quickly that it would hit the rev-limiter. You would be quite aware of the sudden increase in engine noise, followed by the stumbling and misfiring caused by the rev-limiter.
05-09-2018, 12:42 PM
Hybrid Mode
