Transmission Clunk TSB L-SB-0042-25 (2 Viewers)

[incognito.gx]

 

[pmajche1]

I saw this as well. Waiting to hear more confirmation. When you say TCM rest, does that involve anything more than disconnecting the battery? I disconnected mine for an hour last week and it seems to have helped with the rough downshifts.

 

[carlks]

I just dropped off my gx to the dealer for service. The service advisor didn't know about the TSB but the service manager knew. Show them the TSB.

 

[GMan93]

Made appointment for mine, I also called Lexus corporate and they verified the existence of the TSB and said that the dealer should be able to perform the update, if deemed it is necessary, when I bring it in Monday.

 

[SFLGX]

I just dropped off my gx to the dealer for service. The service advisor didn't know about the TSB but the service manager knew. Show them the TSB.

Thats an outdated TSB. I have access to the Toyota TIS and the version of that one on there says:

Attached below is the correct current one.

 

[munkeeboi]

The OP has posted the newest TSB showing the fix.

 

[NewSchool OldSchool]

this is super helpful...thanks

 

[AtomicEric]

I may call and make an apt to see. Have people had good luck with the recent TSB update? Very helpful indeed. So far the first yr production has required a few shop visits, but nothing to serious. Mostly annoyances. Hood flutter,PS seat massager, squeaky back up brake.

 

[GMan93]

I may call and make an apt to see. Have people had good luck with the recent TSB update? Very helpful indeed. So far the first yr production has required a few shop visits, but nothing to serious. Mostly annoyances. Hood flutter,PS seat massager, squeaky back up brake.

So still kind of felt my issue after getting the supposed update on the way home. Not sure what I have then because it did go away with the battery reset and isn't all the time anymore but something definitely still there. It's like a noticeable thud/low bass sound when slowing down but more so around 10mph. Is this just something these cars do or what? Letting it sit overnight but looks like will still be following up kind of disappointing :/

 

[AtomicEric]

I have an appointment but not for a few weeks. My issue is maybe less than you are experiencing. I notice a delay going from 2 to 1 coming to a stop or slowing to make a turn. Seems it holds second to long then is forced to go to first at a light throttle. This causes a noticable delay and makes a smooth acceleration difficult.

 

[cmfhsu]

I have an appointment but not for a few weeks. My issue is maybe less than you are experiencing. I notice a delay going from 2 to 1 coming to a stop or slowing to make a turn. Seems it holds second to long then is forced to go to first at a light throttle. This causes a noticable delay and makes a smooth acceleration difficult.

I have this problem, leading to accidentally pushing too much gas and shooting off the line. I kind of actually need a faster downshift to first gear - I wonder if this TCU calibration will actually make my symptoms worse.

I lubricated the driveshaft slip yoke the moment I received the car and there was nothing in there. It calmed my first gear thump and significantly improved the clunky dump truck feeling my car had on delivery. I suggest giving it a try.

Seems like maybe this vehicle needs some good lubrication in the slip yoke to be refined - much like the LX470.

 

[nartmot]

Can confirm the GX driveshaft only has assembly grease from the factory, just like all the other Toyota models rolling off the line in the past decade. Why they don't spend a few more dollars properly packing the u-joints and slip yoke with grease is beyond me. I knew this going in because of my Tacoma so I lubed my driveshaft at 500 miles with my first oil change. I created this basic guide: Anyone know if the GX550 Has Grease-able U-Joints

 

[cmfhsu]

I gave that gun like 10 pumps on the slip yoke and it didn't budge an inch. I don't see any splatter under the car either, so mine might have been even more bone dry than yours! Lmao

Haven't been able to grease the u joints yet because the grease nozzle on my gun is a little too large for those zerks. Need to get it up in the air to see if that changes things

 

[nartmot]

Thats crazy. Yeah, mine moved about 1-2mm with 3 pumps. I read that you really want to avoid overfilling it because it can damage the seals on the slip yoke.

Here is the grease gun I used: Amazon.com: Lincoln 1134 Pistol Grip Grease Gun with 18" Whip Flex Hose and Coupler, 6" Rigid Extension, 7,500 PSI, Premium Dual Lip Follower, Variable Stroke, Jam-proof Toggle, Filler Air Bleeder Combo : Automotive

 

[GMan93]

So still kind of felt my issue after getting the supposed update on the way home. Not sure what I have then because it did go away with the battery reset and isn't all the time anymore but something definitely still there. It's like a noticeable thud/low bass sound when slowing down but more so around 10mph. Is this just something these cars do or what? Letting it sit overnight but looks like will still be following up kind of disappointing :/

So I guess it's a bit "better" but not perfect. Maybe i'm expecting too much out of these 10 speeds. It'll occasionally feel like something is "disconnecting" with an audible low decibel sound when slowing down and shifting (never any other gear) but its occasional and not like a crazy jerk or anything. I think the update did improve on the low end clunkiness but what I was personally experiencing before is still there. I had driven manual exclusively for almost 20yrs before this car so maybe i'm not up to date on 10spd automatic transmission body on frame truck feels and this is normal.

update: So It has gotten smoother as i've driven it more...It will still randomly do the noticeable disconnect when going 2-1 but it's becoming rarer and since the update it has been less noticeable when it does do it. I guess maybe it's needing to "learn" a bit again since I think they did reset the ECU as part of the reflash (all my seat configurations were wiped). It is for sure an improvement over what it was and almost perfect but not quite in every situation, although i'm not sure if this is just something normal with the torque converter on these trucks or not. I haven't driven another one to really see as they don't exactly have them sitting on the lot.

 

[Roman]

Just reading from the repair procedure, it seems like a typical battery disconnect which I had my dealer do several months ago. I got better but still occurs depending on the driving style and conditions...
Will this TSB include an actual ECU/TCM update?

 

[pmajche1]

I have an appointment but not for a few weeks. My issue is maybe less than you are experiencing. I notice a delay going from 2 to 1 coming to a stop or slowing to make a turn. Seems it holds second to long then is forced to go to first at a light throttle. This causes a noticable delay and makes a smooth acceleration difficult.

Same here. This to me is more of an issue than the rough downshift.

When you come to a crawl and attempt to re-accelerate, the transmission is in 2nd and there is noticeable hesitation before it downshifts, forcing you to apply excessive throttle.

Not sure if the TSB update will do anything to correct this.

 

[incognito.gx]

Just reading from the repair procedure, it seems like a typical battery disconnect which I had my dealer do several months ago. I got better but still occurs depending on the driving style and conditions...
Will this TSB include an actual ECU/TCM update?

TSB says its a ECM update/reset

 

[Roman]

TSB says its a ECM update/reset

Well this is my concern as it is not clear. A reset can be achieved with a battery disconnect but for the update, they actually need to have a software update to reprogram the ECM/TCM... Does anyone have more info on this?

 

[jeffhardee]

I saw this as well. Waiting to hear more confirmation. When you say TCM rest, does that involve anything more than disconnecting the battery? I disconnected mine for an hour last week and it seems to have helped with the rough downshifts.

Sounds like a software flash.