jrmckinley

Took the LX on a roadtrip last week and noticed several times some pretty harsh downshifting when letting the truck slow itself down (meaning no foot on brake) from 45mph down to about 35mph. Not sure what gears- maybe from 4th to 3rd. Honestly would describe it somewhat as feeling like it was 'slipping' into gear. I have felt this a few times in the 2 1/2 years we've owned it but never quite this harsh. Was somewhat low on gas and filled up (Shell 93) and problem seemed to go away. I always use high caliber fuel - and always 93 octane- 99% of the time we get Shell because it's the closest station to our house. I can't imagine this was gas related but have no idea.

I'm due for my 90k service in a few weeks - any ideas of what this could be and what to tell the Techs? Anyone else feel this sensation?

hankinid

When was the last transmission fluid change??

jrmckinley

I bought it at 60k - currently at 90k and I have never done it. I don't recall seeing it on the service history when I bought the truck- but I did get Lexus to do the entire 60k service "free" as part of my final negotiation to buy it. I'm seeing my service guy today for oil change on my LS and will ask him if that's included in the 90k recommended service for the LX. If not, sounds like I should do it. I can research the forum, but is it a sealed transmission like the older LS that requires a bit more attention to the technique? With my LS they have to have the car for a full day to allow it to cool down, use some type of machine to extract the fluid, etc. I take my LS and LX to Toyota for all service. They have a former Lexus tech there but I always like to bounce things off of the crew here as well to make sure things get done correctly.

jrmckinley

Update: Got the 90k service done today- my dealer typically does transmission fluid service at 100k but I had them do it today due to my harsh downshifting I experienced. My service advisor (Toyota dealer) advised me that he would also check the "grease level at the U Joint" - I think that's of the drive shaft (???) He said what I was describing sounded like that U Joint was losing it's lubrication - also recommended we do that once or twice per year. I don't know if it was having the transmission fluid changed or greasing the U-joint, or both, but it's driving silky smooth now. Wanted to pass along the info in case anyone else experiences it- I honestly don't even know if he charged me for that portion.

hankinid

He's talking about both front & rear driveshafts. He's talking about lubing the u-joints on both ends of the shafts. The drive shafts may also have a grease fitting that lubes the splined inner and outer sliding joints of the shaft. Lack of grease has found to be a cause of clunking sounds, usually starting out from a stop. I lube all fittings on both shafts at oil change time...around twice a year.

jrmckinley

Yep, that's exactly it. We probably do about 4 oil changes/year on the LX- just as you are saying he recommended we attempt to lube everything 2x/year. Again, not sure what contributed to smoothing out my shifting- it could have been both the tranny fluid change and the u-joint greasing, but all is good now. Appreciate the insight.

hankinid

From a ton of threads on mud, it seems to be less of a u-joint v. the sliding splines on the driveshafts. My front ds has never been an issue as 5-6 squeezes of the grease gun result in dirty then clean grease flowing out around the seal. But first time I tried greasing the rear, I saw no grease flow around the seal whatsoever. That resulted in my pulling the ds from the truck, pulling the shaft completely apart, and cleaning the internal and external splines...a PITA kind-of on the internal splines but a baby bottle brush or (if you're near a good surplus store) 25-30mm cannon cleaning brush works well. After cleaning, good grease flow out the seal.

hth

steve