Adjusted throttle control rods to spec, shift quality diminished

[MikeTangas]

Now that the major work is done on the 560 I started finishing off the small stuff. I started by thouroughly cleaning and lubing the throttle linkage. Then I checked the rod lengths against the book and found all to be shorter than book, except for the long rod to the relay lever (it was too long). The worst was the connecting link from the accelerator control shaft to the fulcrum lever (the spring loaded rod).

Most of the rods were only short by a mm or two, but the rod to the fulcrum lever was a good 10-12mm short. After adjusting to proper length throttle response was great. A lot of improvement could also be due to the clean/lube job though. During the test drive I noticed the silk smooth shifts were gone. The tranny slammed into gear at each shift, even worse under hard acceleration. Returned home double checked lengths and studied the situation.

I took a gamble and started shortening the rod to the fulcrum lever back toward where it was, and as I shortened it the shifts became smoother. I still have a little slam under hard acceleration, but it is smooth enough to hold out till the weekend.

I decided that adjusting this connecting link somehow changed the relationship of the fulcrum lever to bowden cable for the tranny. Just how I'm not sure yet. If I set the rod to length I assume I will then have to adjust the bowden cable to smooth the shifts, or I could just leave the connecting rod short.

I also wonder if the PO's mechanic might have dinked with the connecting link to compensate for a misadjusted modulator. Opinions anyone, am I on the right track or am I upsetting the apple cart?

[greenacres2]

Mike,
I adjusted mine to spec recently. The rod to the fulcrum was the only one that was right length, but when I lenghtened the rods to the throttle body and cruise control actuator(?) the fulcrum closed and so I had to shorten the slide adjustor to the Bowden cable to compensate. Result was the shift timing was later, which felt mor correct and got closer to spec, but shifts became sloppier-especially the 2-3 which now flares a lot. I'm waiting for a pressure guage I ordered last week to check the modulator pressure before I make any other changes.

No expert here, but checking the modulator pressure seems like a logical step. If you sort yours out before I get mine dialed in, I'd appreciate knowing the lengths you end up at.

[MikeTangas]

Vacuum line to the modulator is intact. I did replace the rubber connector today, just because it was a little hardened.

I studied on the bowden cable today. I cannot see where the adjustment is made (but then again I didn't pull the air filter housing either). Once all the rods are set to length, be it to a set measurement or a "without tension" adjustment, then the adjustment is made to the bowden cable as a last step.

Proper procedure is to move the relay lever (that the bowden cable is attached to) toward the passenger fender (if LHD) until it touches the idle stop of the transmission. Attach the connecting link free of tension; adjust if necessary.

As I read/wrote the above paragraph, it dawned on me that the connecting link had a slide adjustment and a set screw. They way I am reading this is once everything is adjusted (throttle rods), the connecting link (#22) is not connected to the relay lever (#23), the lever is moved gently to the right until it touches the stop, then #22 is attached. If anything has to be moved to make the attachment then the length of #22 is adjusted so the end fits on the ball stud without tension and the bowden cable is now adjusted.

I'll try making this adjustment perhaps on Sunday. No car work Saturday - it's the first pistol match of the year and I haven't practiced at all - been too busy repairing a car . After that I'll study up on the modulator itself.

Again, this procedure is listed for the 126, may not apply to other models.