shifts in and out of 4th?

[turbodave231]

I have a question for the experts. My 87 T has the original BRF trans that was rebuilt before I bought it. The trans shifts firm and at the right times under all conditions.

Here is the problem, when the trans shifts into 4th gear under light throttle, it will drop back into 3rd briefly and then shift into 4th and stay there. This only happens when it is a normal 3-4 shift and not after a forced 4-3 downshift.

It is kind of annoying and I'd like to fix it. I have not had a pressure gauge on it yet to get an idea what is happening with line pressure during the event.

Anybody ever run into this before? What did you find?

 

[Phoneguy]

i had this problem with an Art Carr NLU converter.

 

[turbodave231]

What fixed the problem?

Nobody else has any input????

 

[Phoneguy]

Nothing fixed it. I called Art Carr myself and he said that he was aware of it and just the way the converter worked. Mine hunted between 3rd and 4th at about 65mph. At 55 mph it would only shift to 4th if you goosed it. At 70 it was ok usually.

Bryan