[terryjm1]

Was pulling a 5000 pound trailer when I hit a traffic back up. I went from about 20 MPH to zero several times. Each time I slowed down it felt like I was going over rumble strips. I thought maybe it was the pavement but I hit several other slow traffic spots and the same issue occurred. Is this the dreaded converter shudder?

 

[Minimax16]

Unfortunately it sounds like your torque converter is shot. Mine did the same thing at 50k. I have a 2016 2.8 l with a 6l50

 

[terryjm1]

When not pulling a trailer, it seems fine. Did you first notice it pulling a trailer and did it worsen.

 

[Minimax16]

I have pulled 5000 plus lb trailers with my truck before and they're just a little extra vibration but nothing serious. The straw that broke the camel's back was I am tuned and deleted on the hot tune the torque converter just couldn't handle the extra power. I just babied the truck along for a few months and got the torque converter change for a Billet unit so far so good.
Don't wait too long to get your torque converter changed if it comes apart it's going to be much more expensive to fix it. I would definitely go with a Billet unit the OEM torque converters are trash.

 

[terryjm1]

I’m still under warranty for a couple years. Not yet tuned. I was planning the next time I had a trailer hooked up to take it to the dealer and take the tech for a drive. Where did you get the billet unit?

 

[Minimax16]

The transmission shop ordered the Billet torque converter for me I believe he told me it was a Sonnex unit. You can give the dealer a try if I were you I would. The only bad thing about that is they're going to put an oem torque converter back in it and you may be right back in the same boat later on. There's also another company out there in Charlotte North Carolina called Rev they make Kick-Ass products but they're stupid expensive we're talking almost $2,000 for a triple disk unit and unless you're just doing something crazy like a twin-turbo setup I don't see the value.

 

[Redman]

I had my transmission shutter when it shifted and carried it to the dealership and they said the fluid was burned. They were going to rebuild it but ended up installing a new transmission. It’s a 2017 Z/71 with 52,000 miles. I don’t tow more than a boat or a side by side. I thought it was just a freak until I read these posts.

 

[GMforlife]

These transmissions destroy fluid. When mine starts acting funny I just pump out 6 quarts of fluid and replace it with fresh fluid. I am at 70k miles and it has worked 3 times now.

 

[aggieengnr]

These transmissions destroy fluid. When mine starts acting funny I just pump out 6 quarts of fluid and replace it with fresh fluid. I am at 70k miles and it has worked 3 times now.

What fluid should be used in these transmissions? Mine is starting to shudder on me.

 

[GMforlife]

What fluid should be used in these transmissions? Mine is starting to shudder on me.

Dexron 6 is fine.

 

[Burgess159]

I like AMSOIL products

 

[terryjm1]

I just finished 3 long trips towing trailers. The first trip was about 1000 miles pulling about a 3000 load. It was pulling an open uhaul two axle trailer. I had the same “shudder” on deceleration at low speeds in heavy traffic. I had what I thought was light shudder going uphill at higher speeds. The next trip was pulling a 4500 pound car on a uhaul tow dolly about 550 miles. Same light “shudder“ going uphill. Next trip was 1100 miles pulling a single axle 3500 pound box trailer without brakes. No shudder whatsoever with the box trailer. So, both the uhaul open trailer and the tow dolly have surge brakes. I’m beginning to wonder if the “shudder” I experienced had nothing to do with the tranny at all and is related to the uhaul surge brake system. The original trip where it occurred the worst was a 350 mile trip with a 4200 pound car on a uhaul 2 axle trailer with surge brake. I’ve towed with uhaul surge brake trailers many times with other trucks and never experienced this. I wonder if it has something to do with the TCM not understanding the surge brake. I dunno...

 

[craps]

Dexron 6 is fine.

Red Line is also very good.

 

[turbodiverart]

Red Line makes a Very High Temperature synthetic, you can buy it thru Summit. I always used this in my diesel Suburban since the 4L80e is known to get very hot when the converter is not locked up. I had an extra cooler and I would frequently see temps in the 260's when not locked up. The fluid would never come out burnt. If I towed all summer to the track I would change the fluid and filter every year after about 15,000 miles. Never had a problem with the transmission for 300,000 miles before eventually having it changed but that was cause I went a long stretch of not using the truck and I think I dried out a seal. If the Hi Temp Red Line is compatible with our transmissions I plan to do the same with the Colorado which I just got 2 weeks ago.

 

[Duken4evr]

Remove the plastic panels behind the grille in front of the radiator. They block airflow to the trans cooler. I have no idea why they are in there, taking them out drops trans fluid temp 15F easy. Use a needle nose pliers to squeese the clips, push the released panels out through the bottom past the soft rubber gasket and throw the damn things in the trash.

I just put a PML deep pan on mine, running Mobil 1 LV HP (meant for the shuddering 8 speeds) and the trans shifts noticibly smoother and quicker. Tow/Haul mode no longer feels like a dump truck. Better fluid (Redline, Amsoil, etc) is a good investment for these transmissions.