4L80E diagnostic

[RedHeartbeat]

Well, I tore the 80e apart today to install all the new transgo goodies, the 4L80e-HD2 kit and the 48MOD vacuum shift pressure regulater kit. While inside the transmission I found that it had been rebuilt before. So much for the 80e's being bullet proof. Again, this unit is a 2002 model. One thing that has me concerned is the fact that the Transgo instructions show to leave the check ball out in the valve body's reverse gear fluid circuit, using 7 check balls instead of 8. I drilled the throttle body spacer plate out to .120" hole diameters in the 1-2-3 clutch circuits, installed the purple spring in the torque converter pressure relief spring, followed all the instructions to make this thing shift HARD! I set the 48mod kit to shift hard, using the stock length pin in the modulator, 1.405" long I believe it was. That's supposed to be almost like putting it into a manual shift pattern. Tearing the trans apart to install the HD intermediate snap ring and direct clutch springs was a bit much but should be well worth the effort. I had to build a few tools to get things apart, like pulling the trans pump and compressing the direct clutch spring pack. Drilling the valve body for the Transgo kit was a bit nerve racking and some of the hole sizes they specified were special number size bits that not many places carry but I happen to have from past projects. Precision Industries had instructions online on how to prepare the 80e pump, also. All this stuff took about 8 hours today, with the trans out of the truck. I guess it would take about 4 hours to do the kit in the truck, not installing the larger snap ring and direct clutch springs.

Something else I noticed in the transmission was plastic accumulater pistons. I should have bought aluminum pistons but I haven't heard of these plastic ones breaking like in the 60e's.

[Ramsey]

hey red i was told by vince at flt to only drill the hole in the plate to .o84 " because thats whats causing the trannies too break easier ,shifting too hard .he said hes had plenty of practice on this and that size hole is ideal as a precautionary measure and wiil still shift hard.2 cents .do you have another plate u could drill.mine was at 0120 and was way too hard of a shift ,i couldnt even relax at all driving it and it has broke sevaral trannies,so i sent my valve body too flt for 120 bucks they rebuilt it for me..and dont use as many washers as they say either.

[RedHeartbeat]

Washers? LOL, this is an 80e not a 60e. I'll play around with it and see how it goes. Do you have a stall converter in your truck? The stall in my old 60e softened the shifts.

[Ramsey]

sorry i never had a 80 i didnt realize they werent the same parts EXACTLY.i had a stall and it still wasnt that soft.sorry forgot u were on an 80.and enough of the[ lol] not everyone is 101 yrs old and have read or worked on these things all our lives DAY AND NIGHT.LOL

[RedHeartbeat]

yeah, this is the first 80e I've been inside of. The concepts are the same with all transmissions but things are done differently internally in the 80e than the 60e. The parts look very solid. I can't wait to feel the shifts of this big beast. The current 80e thats in the truck right now was pretty nice, can't wait to feel the difference with the shift kit, vacuum mod and 3600 rpm 9.5" stall converter.

[Chevy366]

I did the .096 "firm" size holes on my 80e , was way to much for the street , chirped second every time it shifted , but Greg you may like it that hard .
I shot penned the holes back to the "average" hole size (.076) , and if I want more kick I do it through the tune .
But the Instruction say if you are using a "off-road use and with small diameter high stall converter make holes .120" .
And you about right 4 hours in truck application .

[RedHeartbeat]

I didn't realize your truck had the 80e trans, Gibb. How's it holding up? I was surprised this 2002 trans I bought had been rebuilt.