My 00 Silverado has over 200k on the stock 4L60E, and basically stock 4.8L. Only mods done to them are - CAI, removed cats, magnaflow muffler (SI/DO), vette servo, trans cooler, trans temp gauge and some exterior mods.

My question is, what should I do, and not do with the transmission? Last time I changed the fluid (<10k miles ago) it was really clean. Tranny doesn't slip at all and feels really strong. My GFs father has a 03 silverado 1500 with around 70k, and his transmission feels horrible compared to mine.

The engine I am not as concerned with since I will be putting in a freshly rebuilt 5.3 in a couple of weeks. I just got HP Tuners so am looking to play around some, but not destroy the transmission at the same time.

 

If your not scared to replace it, just go ahead and tune it. Its days are numbered either way. my dads 2004 5.3/4L60E has 210k on it and its all stock. I tuned it back when it had ~80k miles on it.


Could always throw a corvette servo in it and baby it.

 

I am alright with swapping it with a 4L80E (just need to research the swap more and find out what year 4L80Es will bolt up) but I am moving 1500 miles in June so the trans has to last until atleast I get to my new house.

I love my Vette servo - been in for around 12-18k miles now. Best thing I have done next to the 14BSF swap...

 

Just bout any one of them will swap in..

i used a 2004. But i believe 1998+ will do. Theres a certain range of years that the Park Neutral saftey switch has no bolt hole provisions. So besides that, they all with work.

 

Damn .... if I knew that I would have kept the 4L80 out of my old 6.5 diesel lol

I wasn't sure if any 4L80e would bolt up or not - I do recall something that the old 4L60E single piece bell housing did not bolt up to the 4.8/5.3s at all.

 

GM has never changed bellhousing bolt pattern.. you can bolt a allison to a 2.5 in a S10 if you wanted.
the 4L80E i have is a one peice case so im not sure what thats all about.

 

I don't recall 100%, I was looking at putting in a newer 4L60E in my old 94 1/2 ton that I had. Was told the bellhousing on the newer 4l60E did not bolt up to the 350.

Nice to know that any 4L80E will work... time to find a cheap one to start building

 

Theres goin to be one bolt hole at the top thats not used on the old SBC stuff, but it will bolt up. Controlling it and getting the right converter are the other parts of the equation.

 

Thanks. I will keep my eyes open for one then