New TSB L-SB-0048-25 for transmission downshift clunk
 

Just saw someone posted this over at reddit. If someone had it done already, any issues afterwards?

The description sounds like what I'm experiencing when slowing/coasting to a stop for 5-4 or 5-3 downshifts although its less noticable after 10-15 minutes of warmup.

^^^ I googled that TSB and it appears to be for the GX 550 and a hood flutter issue. Correct me, if I'm wrong.

Just released yesterday apparently so probably why nothing shows up on google. Post with screenshot of the TSB: https://www.reddit.com/r/Lexus/comme...wnshift_clunk/

Amazing news. I always had a bad feeling about that noise.

I was wondering when this TSB would come out and I it is reassuring to know others are hearing/feeling this same issue.


For those that have reflashed ECUs, do you think this will erase your existing tune?

This is just an excuse for service techs to drive the car.

On a related note, if they can do this, why not reprogram the transmission altogether to make it more zippy?

Dumb answer? Cause they hate fun.

Serious answer? Wear management strategy.

So it looks like if you don't have this happening, there is no reason to take it in for service, correct?

You don't have it? Lucky. :D

I guess not. I wouldn't bother unless it's an issue for you. If nothing else, it seems like this issue doesn't grenade the transmission after a few thousand miles (if mine is anything to go by). Mine has done it since day 1, over 2.5 years and 23,000 miles ago.

I would argue a well-tuned transmission would cause less wear because when you mash the pedal everything is just smoother - I could be wrong though.

Toyota/Lexus is such a mess. Their inconsistency when it comes to listening to customers is absolutely infuriating. Follow my logic:

(+) they come out with the IS500 (V8)
(-) they keep a 10 year old interior and transmission
(+) they extend the life of the IS in 2026
(-) they make the exterior worse
(+) they update the interior
(-) they drop the V8 from the next IS
(+) they release a TSB for the IS500 transmission

That's just the IS lineup in a nutshell. Don't even get me started on their boneheaded decisions regarding the ES, RC, LS, and GS.

Keep in mind the TSB says something specifically about the "fuel cut logic", so I don't know whether that would have anything to do with the overall performance of the transmission.

edit: OK I reread it, and it also mentions the transmission control unit. Hmm.

I am not sure I understand what you guys are experiencing/describing - It is likely a sign that I don't have it or that I just assume it is part of how this thing is :)

There is a simple fix for this - drive it in sports plus mode and drive it like a V8. :) I am averaging 16mpg and I rarely run into this.

I remember they came out with something like this for one of my Minis and after the update the car felt lazy as hell! It was a completely different car afterwards and just plain sucked. I'd be careful with this TSB :eek1:.

This crossed my mind too since they botched the front apron separation TSB. I think I'll wait for the reports from others before going myself.

Sad you can't trust Lexus anymore.