Torque Converter Shudder...Best Course of Action?

[Fjs0001]

So in my 09 Yukon 2wd, for a while now I have been noticing a little jerk when slowing down for red lights and was thinking that something might be going in the engine/trans mating department. It shift great as far as I can tell. I towed a super light trailer the other day. 5x10 angled iron trailer with my riding lawn mower on it, not heavy. I was leaving my friends house and I got the rumble strip effect. Got home took the trailer off and it drives fine. I had a 16 Sierra that had the torque converter changed out under warranty for the rumble strip effect so as soon as it happened I immediately thought torque converter. I have a friend who has a shop (not trans shop) who will do a torque converter for me and while he's in there, rear main and oil pan gasket and flush and filter the trans for a good price. Im thinking of having him do that and then if that fixes it great, if it doesn't then to the trans shop it goes I guess. Any one have any luck in changing just the torque converter? The fluid is nice and red changed every 30k, doesnt smell burnt or anything. If the torque converter is failing I'd like to get it before it takes everything else out. Any flaws in this logic?

Two bottles of the lube guard fixed my torque converter shudder in my Escalade, but my transmission still lost all forward gears eventually. All my problems started because the radiator sprung an internal leak and put coolant into my transmission. I was able to band-aid that transmission for awhile before it finally bit the dust.

I had a 2008 Pontiac G8 V6 where the torque converter started unlocking/locking all the time between 45~55mph. I replaced the torque converter only for it to start doing it again 9k miles later. If I had kept the car I planned on adding a transmission cooler. I ended up selling it because it started having more issues than I cared to fix. The guy I sold it to replaced the ATF and has been driving it around fine as far as I know.

If I were you and the ATF is burnt, I'd change it out and add a transmission cooler. If the ATF isn't burnt then I'd add the Lube Guard shudder "fix". Then one more if that doesn't help. If I still had issues then I'd go the route you suggested but add in a transmission cooler.

 

[olliec420]

Two bottles of the lube guard fixed my torque converter shudder in my Escalade, but my transmission still lost all forward gears eventually. All my problems started because the radiator sprung an internal leak and put coolant into my transmission. I was able to band-aid that transmission for awhile before it finally bit the dust.

I had a 2008 Pontiac G8 V6 where the torque converter started unlocking/locking all the time between 45~55mph. I replaced the torque converter only for it to start doing it again 9k miles later. If I had kept the car I planned on adding a transmission cooler. I ended up selling it because it started having more issues than I cared to fix. The guy I sold it to replaced the ATF and has been driving it around fine as far as I know.

If I were you and the ATF is burnt, I'd change it out and add a transmission cooler. If the ATF isn't burnt then I'd add the Lube Guard shudder "fix". Then one more if that doesn't help. If I still had issues then I'd go the route you suggested but add in a transmission cooler.

See thats the thing, my fluid is perfect. Not burnt, nice and red, correct level. I may drop the pan and look for metal. But I think its the torque converter clutch locking up when it shouldnt. And it only did the ruble strip effect that once with the trailer. But when slowing down abruptly for a short red light, sometimes i notice the rpms will jump for a second. Like its locking up when it shouldnt on stopping. I just watched a SUPER informative video on how the torque converter works and I think I have a better idea of what could be going wrong. No gear problems, no slipping, no hunting for gears or hard shifts. Theres a trans shop by the house that specializes in custom cummins and allison match-ups. I think im gonna stop by there and ask them if they know anything based on my descriptions of the symptoms.

 

[gpracer1]

This might help.....

TransGo - 6L8 CS-TCC - Clutch Select Valve and TCC Regulator Valve Kit

2006 and later General Motors and BMW vehicles equipped with 6L45, 6L50, 6L80 and 6L90 automatic transmissions often come in with complaints of lock-up

transgo.com

 

[olliec420]

This might help.....

TransGo - 6L8 CS-TCC - Clutch Select Valve and TCC Regulator Valve Kit

2006 and later General Motors and BMW vehicles equipped with 6L45, 6L50, 6L80 and 6L90 automatic transmissions often come in with complaints of lock-up

transgo.com

OK so this looks interesting. And for $40 that seems like a deal! Obviously Im just learning about transmissions right now. Would it make sense to, while the trans is open but not out, drop the valve body (I think im using the right terms) and replace solenoids or anything else while in there?

 

[robgreg75]

OK so this looks interesting. And for $40 that seems like a deal! Obviously Im just learning about transmissions right now. Would it make sense to, while the trans is open but not out, drop the valve body (I think im using the right terms) and replace solenoids or anything else while in there?

When I rebuilt my 6L80 I used one of the Sonnax Zip Kits it had a lot of good pieces that address common issues of the valves.

 

[Meccanoble]

Two bottles of the lube guard fixed my torque converter shudder in my Escalade, but my transmission still lost all forward gears eventually. All my problems started because the radiator sprung an internal leak and put coolant into my transmission. I was able to band-aid that transmission for awhile before it finally bit the dust.

I had a 2008 Pontiac G8 V6 where the torque converter started unlocking/locking all the time between 45~55mph. I replaced the torque converter only for it to start doing it again 9k miles later. If I had kept the car I planned on adding a transmission cooler. I ended up selling it because it started having more issues than I cared to fix. The guy I sold it to replaced the ATF and has been driving it around fine as far as I know.

If I were you and the ATF is burnt, I'd change it out and add a transmission cooler. If the ATF isn't burnt then I'd add the Lube Guard shudder "fix". Then one more if that doesn't help. If I still had issues then I'd go the route you suggested but add in a transmission cooler.

My shutter issue was greatly improved after using Lubegaurd transmission fluid at my last change at 200k miles. Currently at 245k miles.

 

[olliec420]

Im back! Today leaving someones house I felt it just a little, no trailer but I had picked up several boxes of books and paper work to take else where. Maybe 6x 50lbs boxes, at least 300 extra lbs, dont know if that matters or not. Felt it a couple times on the way home. Going to give it a drive again tomorrow and see. I have 1500 miles ago I did fluid and filter just to see if that helped. Had not had any strange behavior, just the usual "unwillingness to downshift" as another user had described here. Im thinking to have my friend's shop (not trans specialists) do a new TC and rear main and oil pan gasket. If the problem goes away good, if more trans problems come, at that point I may just buy another and do the transmission swap myself and use the new TC with it. Anyone with experience see a flaw in that plan? I plan on keeping this Yukon for a long time and eventually turning up the power.

 

[Geotrash]

Im back! Today leaving someones house I felt it just a little, no trailer but I had picked up several boxes of books and paper work to take else where. Maybe 6x 50lbs boxes, at least 300 extra lbs, dont know if that matters or not. Felt it a couple times on the way home. Going to give it a drive again tomorrow and see. I have 1500 miles ago I did fluid and filter just to see if that helped. Had not had any strange behavior, just the usual "unwillingness to downshift" as another user had described here. Im thinking to have my friend's shop (not trans specialists) do a new TC and rear main and oil pan gasket. If the problem goes away good, if more trans problems come, at that point I may just buy another and do the transmission swap myself and use the new TC with it. Anyone with experience see a flaw in that plan? I plan on keeping this Yukon for a long time and eventually turning up the power.

Nope. Solid plan. Best to do it before that converter lets loose.

 

[olliec420]

Nope. Solid plan. Best to do it before that converter lets loose.

Can you (or anyone else) recommend a TC that would be better for potentially turning up some horsepower later on?

 

[Geotrash]

Can you (or anyone else) recommend a TC that would be better for potentially turning up some horsepower later on?

I installed a CVC brand, model BU60FHD on the advice of my local Indy transmission shop. It is a remanufactured factory unit upgraded with a billet housing, a stronger lockup clutch and a few other improvements designed for heavy towing duty. It’s the factory stall rating and it’s been great for me - great peace of mind when towing our 7500 lb camper.