# TH400 neutral in 3 while coasting? 71 LeMans with a new 468...



## Rnmdad (Jun 15, 2019)

Just got the engine in, is being driven for break in. First issue, shift points are low, no change from the old 389. I planned a new governor for when I reseal the tail housing, already has an adjustable modulator that I’ve screwed with. Big issue though, cruising around 30mph, let out of the throttle to get in to decel, trans goes into neutral. Back into the throttle, 3 engages. Shifts are not sluggish, does not slip under load, TCI break away converter that was behind the 389 with no issues. Looking for ideas, hoping the trans can stay in the car. 

Thanks
Jeremy


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## PontiacJim (Dec 29, 2012)

Rnmdad said:


> Just got the engine in, is being driven for break in. First issue, shift points are low, no change from the old 389. I planned a new governor for when I reseal the tail housing, already has an adjustable modulator that I’ve screwed with. Big issue though, cruising around 30mph, let out of the throttle to get in to decel, trans goes into neutral. Back into the throttle, 3 engages. Shifts are not sluggish, does not slip under load, TCI break away converter that was behind the 389 with no issues. Looking for ideas, hoping the trans can stay in the car.
> 
> Thanks
> Jeremy
> ...


I am not a trans specialist, but I was able to find this on the web. Maybe some of the suggestions here may help as the same conditions in the post sounds like yours?









TH400 goes into neutral with rpm drop in drive gear


i have a 77 pontiac grand prix with 74 pontiac 400 engine and a 76 pontiac grand prix TH400 with a fairbanks stage 4 shift kit and stock conveter. the transmission and shift kit have been great since the rebuild / install in the mid 90s. the car has sat for about a year in need of an engine...




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## Rnmdad (Jun 15, 2019)

Symptoms definitely seem consistent with mine, thank you


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## LATECH (Jul 18, 2018)

One way clutch not holding ( sprag)


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## Rnmdad (Jun 15, 2019)

LATECH said:


> One way clutch not holding ( sprag)


Looking at the flow charts, the sprag acts in 2nd speed, looks like the direct clutch is the 2-3 shift element?


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