MeanWS6

Finally got the vids of my day at the track.
Go to my yahoo briefcase, click on the "trans" folder and right click, save as on the vids
Link to trans



You can see just how bad I was bogging until second gear. Best I could get was a 1.7 60ft on ET streets and traction was not a problem.

This is my 4th "built" 4L60e, hopefully a TH400 will last more than a few months and net me better 60ft times

cablebandit

iTrader: (37)

who built your other trannies. I am trying rock-on transmissions in tx...it'd be great if we could see whos didnt work

SmokingWS6

iTrader: (1)

Are you spraying out of the hole? From the video it looks like you launch in 2nd then it downshift to first, followed by upshift to 2nd again. Unless you have tuning the tranmission will defualt to 2nd gear if u stall it up to long waiting for the tree to come down. I have a friend here who gets a 1.55 60' wheels up on the bone stock transmission with a pye4400 converter.


Definately look into tuning isssues with the transmission

Edit: watched the video again, 4l60e's do not bog like that. its either the 2nd gear start protection or an n20 issue.

MUSTANGEATER

iTrader: (10)

I am in the same boat I have opted for the TH350 talk to Jay @ Billingsley racing he'll help you out and is close by.

MeanWS6

all of those runs where NA, and from idle or a low stall

Colonel

Yep, that's a 2nd gear start followed by a downshift into 1st. It's easy to tell. Just count the shifts. There should only be two shifts in a 1/4 miles. 1-2 and then 2-3. Listen to the second and third videos against the silver 'Vette. After launch it shifts from 2-1, 1-2, and then 2-3.

The PCM can force it if you stall too high for too long or the driver can force it by having the selector in 2nd (common after a burnout) in '00 and later cars. Of course, yours is a '99 so that doesn't apply to you. Perhaps your rebuilder has something amiss in the valvebody causing it to do that? Odd.

One thing I can tell you for sure is that a 4L60-E launches aHELLUVALOT quicker than a footbraked 2.48 1st TH-400. I mean, it ain't even close.

gator's 99TA

iTrader: (2)

agreed with colonel. a 4l60e with that big 3.06 first gear will always launch hard, damn hard compared to the th-400 with the same rearend gearing. guys upgrade to the 2.75 first gear just go get a chance of hitting it hard out of the hole with a th-400.

MeanWS6

well, another problem this trans is giving me is when I am driving around town say 20-30 mph and go WOT it will not downshift. It lags for about 3-4 seconds and then shifts.
Would a bad valvebody cause this?

Colonel

That's almost certainly a valvbody problem. There could be a tiny piece of trash in a bad spot or it could have been assembled incorrectly.

MeanWS6

Guess I can take her into the shop and pull the VB then, glad I was able to get those vids and show you guys.
I still like the idea of a TH400 - eliminating all electronics, but with the GV OD unit it was getting pricey. I just want a rock solid trans that I can just go with and forget about any problems with the thing

MeanWS6

this was the gearing I was planning on going with for better launching, what do you think?
2.75 (possibly 3.00)
1.57
1.00

gator's 99TA

iTrader: (2)

who is going to get you a 3.0 1st gear out of a TH-400???

MeanWS6

no one yet, just found that gear while doing research on the TH400. so someone has done it here, let me see if I can dig it up again.

(we need a Trans FAQ)

Navy David SS

iTrader: (13)

Here ya go

http://ckperformance.com/gm_th400_stg4.html

Not sure what I would have cut for 60' with an A4. But with DA at 4000+ a small 100 shot I cut a 1.45 60' - with a TH-400

David

john kilgore

l make them.