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71 220D shifting solutions?

Submitted by abadeker on 22 April 2010 - 7:23am.

1. Tranny shifts immediately from 1 to 2 in nearly all situations short of full throttle.
2. When driven with lever left in 4th position, shifts well from 2 to 3, but shifts too soon to 4th.
3. When driven with lever left in 3rd position, shifts hard from 2 to 3.
4. I've adapted by starting out with lever in 4th position (to ease 2-3 shift), then moving lever to 3rd position and keeping it there until I'm ready for 4th.
5. This has the Bowden cable. Indicator window isn't accurate -- is off by 1 gear.
Car has 105,000. Sits idle most of year, unfortunately. But shifting never improves/degrades with use.
Filter and fluid done several years ago, but no other repairs that I know of.
Should I start with vacuum hoses, modulator rebuild, or ?

Thanks in advance.

‹ 1992 300D Steering Box - The Saga Continues 1984 300D Rear shoe brake replacement adjustment. ›

Troubleshooting shift problems on older automatics

22 April 2010 - 8:47pm
admin

A 71 220D does not use vacuum to control its shifts. Nor does it have a bowden cable. It uses a rod to regulate control pressure. This rod runs along the right side of the engine and is adjustable. There could also be something wrong with your modulating pressure. Even though there is no modulator, the internal pressure can be checked and adjusted but will require a special pressure gauge and attachment fittings. I recommend you ready my Diesel Transmission Tuning Manual in order to troubleshoot your shift problems. Information in the this manual covers checking and adjustment of the control pressure and modulating pressure. You may want to consider an additive clean-out and discussed in the manual or in my tips section on the website.

Thanks, Kent. That clears

24 April 2010 - 4:48pm
abadeker

Thanks, Kent. That clears away some of the fog for me.

Andy

220D shifting solution

31 July 2010 - 4:11am
abadeker

Hi again:

I've read your manual and adjusted the control rod. But the throttle linkage, with that vertical "damping rod" (my term) that has a plunger arrangement, complicated things. I had to pull the horizontal throttle rod forward to reattach the ball to the bell crank that meets the control rod, which then affected the tranny control rod position. So I don't know that I've got it exactly where it should be, per your instructions.

I DO know that the shift pattern is better -- except that it stays in 2nd too long, even under moderate throttle, particularly when cold. 3rd to 4th is much better, and the tranny downshifts under full throttle, which it never used to do.
So do you have any advice for improving the 2nd-3rd shift, or should I just continue to fiddle? I can't damage the tranny, can I, with my tinkering?

This has 100,000 miles on it. Gets driven only in summer, unfortunately.

Thanks!

Andy Badeker