700r4 problems

[66gmcguy]

I have a 1983 Blazer with a 6.2 diesel and 700r4. When taking off from a stop, the transmission starts out in 2nd instead of 1st. It will only start in 1st gear if I manually shift it into 1st. It seems to only do this after the trans warms up a little bit. Otherwise, everything else seems to work normally. The shifts feel good, no slipping, and the fluid is clean and full (checked when running and warm.) It downshifts if I step on the accelerator when climbing a grade or trying to pass someone. The problem is only when coming up to a stop and trying to take off.

Any thoughts what this might be?

[kwmech]

How well does reverse work?

[Just call me Sean]

Check the adjustment and operation of the TV cable.

[Accelo]

There is a one way sprag, Input Forward Sprag , its part of the input shaft has failed.
Cheers. Maybe the wrong signature in this case!

[Morgsie]

there's actually 2 sprags and the one that is the issue is in bottom geartrain, not the input drum. this is the lo roller clutch. when you pull the lever into manual low the low/reverse clutch pack engages and is why you are getting forward movement. this clutch pack is only engaged when lever is in manual low. time for teardown

[66gmcguy]

Originally Posted by kwmech

How well does reverse work?

Reverse works fine.

[66gmcguy]

Thanks for the replies. I've heard it could be the governor sticking. Does that seem plausible?

[Morgsie]

no

[66gmcguy]

Well, I inspected the governor and found that the valve was stuck. Cleaned it up and made it move freely, changed the fluid and filter and it seems to be shifting great now. Drops down into 1st normally, and actually shifts a bit smoother. Not counting my chickens just yet since I've only put about 40 miles on it since tinkering with it, but I'd say it's fixed. Thanks for all the replies.