Well I finaly got to make a couple passes at the local track last friday only to be disappointed in my trans. the trans is a stock 4l80e that probably still has under 50k miles.my first pass trans was shifting good but I wasnt gettin on it hard.(no spool off the line with a 13.3 1/4 mile time). Second pass it started slipping as soon as it shifted into 3rd so I let off right away. I let it cool down and checked the fluid level. It was good oil looked new and didnt smell burned. I tried it one more time and it did the same thing so I,loaded it up n took it home.

I asked a few local people wat to do and they told me I need a shift kit. My question is will a shift kit be enough? I plan to go up on boost maybe 15#s max right now im at 10#s. I dont know wat my hp numbers are but im guessing its around 450rwhp give or take as of now.

If I could get a few people to chime in an tell me wat I need to do to hold up at least 600rwhp. I know I wont get that much out of my truck but it would be on the safe side.

 

Try taking the pan off and see if there's any clutch material in it or in the fluid. My guess is if its slipping it might need to be rebuilt

 

Typical of a stone stock 4L80E. Throw in a Transgo HD-2 kit and have at it again (fixes your issue without pulling the trans apart).

 

Thanks guys ill tear it open soon maybe I can have it running by this friday n make a pass again.

 

Did you ever do the shift kit? I've done two of those already, pretty straight forward. I actually enjoyed doing them! lol

 

No I didnt do anything to it yet. im gonna get it built now with a transgo shift kit and some internals to hold atleast 800 rwhp just to be safe.

 

Direct clutch is burnt.. Dual feed the directs or use the HD-2 kit.

 

Ok I got the transmission completely rebuilt with a shift kit and it still wont take 3rd or 4th gear!

 

Is that a new symptom or is it the same as before. The way you worded that it sounds like it is the same, but that's not what you spoke about in your original comments.

If it was shifting into Direct and Overdrive (3rd and 4th) prior to the build then I would suggest that there is a line pressure leak somewhere, most likely in the valve body. The next thing for you to do is to get a pressure gauge on the unit and go from there.

If you are able to do that, give me a call when you are running it and I'll help you diagnose it. I'm curious to know who did the build.

g

 

its doing the same thing now after the rebuild as it was before I brought it to the transmission shop.(scott green out of lubbock texas built it). It sounded like the trans didnt even need a rebuild though but he went ahead and replaced the clutches and refreshed the trans along with installing a shift kit. I am getting the truck back tonight and I will try to get a pressure gauge on it. Where would I need to mount it anyway? Thanks for all the help so far