Another late season BB driveline failure.

My trans is half gone after racing today. No issues until today. Trans is a T400 with a manual/automatic valve body that has had some upgrades, sprag, normal performance mods, etc by a friend who builds racing transmissions with no doubt in their credibility. Converter is a 9" spragless. I had put a Transgo kit in it before he rebuilt it.

Anyhow, I know my car very well and I could tell something was wrong when I got to the track. First thing I noticed was when I put it in D or R, it would take about 3 seconds to "go" in that gear. Burnout, passes, was fine. But I could tell something was different.

On the 6th pass I shifted into third and right after that it free-reved and I backed out and coasted onto the return road. Didn't feel like 3rd was there. After I stopped it had 1st and 2nd.

I did drive the 10 miles home slowly and here were the symptoms:

Sometimes it felt ok (not getting into it much anyhow). Sometimes 2nd or third slipped and first too I believe. Sometimes it would be slipping and then "grab" that gear and be kind of ok. It almost felt like it "could" be ok sometimes, but definately about 3 grand it would slip at light throttle sometimes. Converter flashes to 4500 so it is hard to tell.

Pulled the dipstick and it does smell somewhat burned.

Probably have 100 passes on it this year.

Any thoughts on what might be wrong. It is coming out for sure but just curious.

One more question, when my buddy built it, he kind of wanted to go full manual valve body. I think I will now. Car is driven 10 miles back and forth to the track and that is all it ever sees. Goal is the most reliablity I can possibly have with a 10 second car. Any reasons not to? I am somewhat aware I'll have full pressure all the time, but like I said, the sees less than 1k miles a year and that is going back and forth to the track.

I was hoping to get 200-250 passes out of the tranny without issue. Is that reasonable with a 10.7 3600 lb car?


I will say I had a weird deal first thing when I put it in this year. With the dipstick "full", it slipped a little when stone cold. I ended up putting 2 qts in over that and that went away and I had no problems this year. This was a dipstick and tube I bought from the GM dealer, so I am assumed "full" was correct. Maybe that has something to do with it?


Any reason NOT to run a deep trans pan? Have stock one nowl

Thanks for any comments.

Hi Doug, just fyi. I don't think Jake is around much anymore. We got into a private dispute about vendor bashing and methinks he has chosen (unfortunately) not to participate here anymore as his last post was Sept 30.

I didn't agree that his concern was valid at all (can provide the details should need be, but would rather let things go) and we both came away rather offended.

Al

You have mail Doug.

Thanks guys, hopefully Transman can chime in. Just curious what it might be.