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-   -   Shifting problem...internal or external (http://www.peachparts.com/shopforum/showthread.php?t=276699)

JackG 05-01-2010 04:32 PM

Shifting problem...internal or external
 
82SD
Shifter was rebuilt because of excessive slop
and it was not going into 4th gear.3rd gear
was iffy.

Now, after new bushings, it will shift into all 4
gears IF you pull out slower that a 240d going
up hill on a Sunday drive.

Any attept to pull out normally will result
in the car hanging up in 2nd gear to about 3500rpm
before banging into 3rd. 4th is not an option as for
as this is concerned.....it just won't go.

I have zero back ground on the car other than
the bushings I installed.

Is this an internal problem or vacuum?.....or other?

BoiseBenz 05-01-2010 08:20 PM

I would disconnect the bowden cable at the linkage and see if that helps. If it does, that would point to an adjustment issue (too tight).

toomany MBZ 05-02-2010 09:59 AM

Or you can turn in the Bowden cable (wire) to shorten the time between shifts.

Brian Carlton 05-02-2010 10:53 AM

It would appear that you've got more than one issue. The proper term when the engine runs away between shifts is "flaring". Clearly, it's got the traditional 2-3 flare.

This situation is typically caused by wear internal to the transmission, however, it can usually be managed via the adjustment of either vacuum or modulator pressure, or both.

Vacuum is the simplest to adjust and it involves reducing the vacuum to the modulator. This requires a proper Mityvac for making the adjustment. Do a search in the archives about adjustment of the VCV and the procedure is fairly straightforward. If you get stuck, repost on this thread and I'll assist you with it.

If you wish to make a quick check to see if the vacuum will help, just disconnect the vacuum line to the modulator under the hood. With no vacuum, your 2-3 flare should be eliminated or severely reduced. However, it will likely be banging on all downshifts, thereby requiring some vacuum adjustment to get the proper compromise.

If the vacuum doesn't give the necessary benefit, it's time to make a modulator adjustment and increase the modulator pressure somewhat.

JackG 05-03-2010 07:31 AM

Quote:

Originally Posted by Brian Carlton (Post 2459903)
The proper term when the engine runs away between shifts is "flaring". Clearly, it's got the traditional 2-3 flare.

No, it is not flaring, it is simply stuck in gear. Not shifting at all.

Brian Carlton 05-03-2010 08:56 AM

Quote:

Originally Posted by JackG (Post 2460319)
No, it is not flaring, it is simply stuck in gear. Not shifting at all.

If it's not flaring, and won't upshift, take a look at the kickdown switch. Beneath the accelerator pedal is a switch that typically gets contaminated with dirt and debris and gets stuck in the closed position.

However, this switch usually affects all gears, not just 3 and 4.


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