Yet MORE C6 questions.

[Wyreth]

Ok so, got the VRV dialed, (shift points are very nearly perfect) and took it on a 30 mile test drive today. There is an issue.

Once the trans hit operating temp, it stopped wanting to downshift into first when I stopped. If it was a slow light, about 30 seconds to a min after I stopped, it would kick me in the pants. Or if it was shorter, it would lug a moment, THEN downshift into first, and take off like a banshee. I tried shifting it into first manually, and that made no difference. (I did adjust the shift linkage per ATSG manual instructions, and it feels/acts dead on)

The two things that it comes to in my head are, the intermediate band is too tight. (I did 15in/lbs, then loosen 1,1/2 turns) However, I used a HD kevlar band when I rebuilt. Is the adjustment different because of the extra grip?
OR is the servo drain passage is partially blocked?

Thats all I can think of from the symptoms, but I'm not an expert. What does the collective think?

DIFINITIVELY I am NOT dropping the trans a 5th time.

 

[Hydro-idi]

I do know the recommended torque for the band adjustment is 10 lb/ft then backing out 1.5 turns. I recently did this to my transmission and it took the slip out of my shifts. I am no expert, but it seems like there is an issue with the vacuum setting or a possible air leak somewhere. I would check the rubber lines as well as making sure the modulator is functioning and adjusted properly. If all those items are good to go, there is an issue with the pressure IMO, because transmission oil will thin out when hot and naturally decrease line pressure a bit. If this is the case, either pump is unable to build necessary pressure or there are issues with the valve body. Hope this info helps

 

[Wyreth]

Modulator is tested, and good. Lines as well, and they are sealed. The VRV is new, was tested, and is good. Currently set at 13hg @ hot idle. (which IIRC is right about the specified 6.9hg with control bloc)

Main pump is rebuilt, new seal, bushing, gears. Control pressure test is on the high side of the normal range when hot.

As to the torque spec, my shop manual agrees with the 10 ft/lbs, dunno where I got 15 IN/lbs. However my shifts are snappy and firm, it is just the band does not release properly. Or that is what it acts like. Which is even stranger, considering it is set lower, it should be a little sloppy.