Ok some of u may already know about my delema on my 4l80e swap. 4th time its comin off within 4 months! Anyway I thought it was maybe a bad rebuild but the guy swears it looks perfect inside the transmission and surely my 4.8 cant tear up a 4l80e in the first 30 minutes of driving with a very light foot. I have come to the conclusion its the converter coming out of the tranny?? We had to use 3 washers to get the converter to set in the trans just enough to keep it in the pilot hole still. Am I using the wrong flexplate with this converter? Its a P.I. 9.5" converter to fut the ls1 3 tab flexplate. I noticed when I was driving the truck after getting it back t it was vibrating pretty bad like an unbalanced or bent driveshaft. I drove it no faster than 30mph with less than 3k rpm throttle for 1/4 mile and suddenly the rpms jumped up and trucl felt like it was in neutral. Has no gears anymore. NEED HELP PLEASE!!

 

Take a picture of the flexplate and the converter. Have you taken the trans apart? Pump failure?

Chris

 

What year 80e is it? It sounds like you have a 99-02 80e which requires a spacer iirc

 

I think it is an 06 4l80e but I could be wrong. I bought it from tarinitup maybe he will chime in yet. I dont have any pictures of the flexplate but it is the stock one from my 03 4.8 whick im using without the spacer.

 

If you use a conversion converter you won't need any spacers.

I used a Yank 3 bolt converter in the 4l80e with no problems. And now I have the updated 6 bolt factory flexplate in there.

As far as the trans goes, what's the obsession with "built" trans. Just get a good junkyard pullout and either shift kit it or leave it alone.

 

Yep 05+ 80e out of Chevy express van.

 

The 4.8 should have the curved flexplate. So if the PI had the LS style front cover it should be fine. If you take a picture of the converter I can tell if it has the right bolt pattern. How much did you have to shim it?

Chris

 

It is a curved flexplate. We shimmed it with 3 washers so I would say 5/16"-3/8". I will take pics tonight if I get a chance.

 

https://www.performancetrucks.net/fo...verter-481086/



Thats the link to the converter I bought.

 

How about another pic, more of a side view of the engine side.

Chris