General Motors 8L90 Overhaul Part Three: Valve Body Overhaul

[@JASPACB750RR]

So after watching this whole series, what would you say is the most common cause of the 8L90 failures? I know there’s something like 270 TSBs for this transmission. Some people on the web are saying a flush and fluid change with a better fluid fixed the problem as GMs initial fluid wasn’t up to snuff. Others are saying the harness failures. Others are just saying it’s just hard shifting, bucking, slipping, jumping between gears and seems as if the TCM don’t know what’s going on. And through multiple rebuilds or “fixes” it’s still having the same issues. GM had a class action suit on this trans and pretty much said, “it’s not our fault, we didn’t engineer the transmission, it shifts and works, but the problem is an engineering issue and therefor not on us” Pretty much screwing over all the owners of any Sierra, Silverado, Yukon, Tahoe, Escalade, etc with a 5.3 from 15+ and 6.2 from 15-18. Luckily my 6.2 Sierra is a 2020 and has the 10L90 in it and so far with 80458 miles it’s still going strong. And for probably half those miles it’s towed at least 7k lbs.

[@douglashogue9495]

Who builds the most up to date version of this transmission and a really great torque converter

[@rizalsaiful6058]

So wee need regular cleaning or service for bodyvalve? Or we need which symptoms to start this cleaning??

[@RBroosh]

Quick question…I accidentally broke off the G solenoid connector for the wiring harness (according to your video it is the default on/off solenoid) on my 8L90 valve body. Can I replace that single solenoid without replacing the whole valve body? I would assume so. That particular solenoid was not covered in your video. It seems I’m not the only one to do this removing the pan. Please help!

[@YourTransmissionRepair]

Great video!

[@pat14lang]

What kit part numbers were used and/or other parts that are not sold in the kits? I came across only two kits. But Sonnax has everything listed individually or so it seems. I’m trying to buy everything needed, even if I end up with extra parts. Just want to do it one time and reinstall

[@MrCorpsy1]

Can the solinoids be removed with valve body installed?

[@johnkassis1426]

just the small bolted on ones G and H all others the valve body needs to be cracked open in halves

[@ozonepower4034]

I need a work visaCan I get a car mechanic job?

[@jonathanshaw5563]

𝐩яⓞ𝓂𝓞Ş𝐦 💯