mljohnson2

So I've had a reoccurring issue of vibration down below that happens between 40-50 mph and only when accelerating. It doesn't happen all the time, just occasionally and stops immediately upon letting off the gas. I was thinking it was something with the driveshaft and I had in dealer today for a look at it along with oil change. He just called to tell me that it's something with the transmission ("clutch pack going out?"). He proceeded to tell me that they don't do transmission repairs and would just put one in new from Lexus for $4,200.00

Has anyone ever heard of this or had experience with this? I can find almost no information on a GX transmission going out this soon.

I'm obviously not spending that without a second opinion and told him that. He is going to check with another tech and see if doing a transmission flush might help it or prolong the issue.

Any advice would be helpful as I've owned the truck about 5 months and just spent $1,000 on timing belt 2 months ago.

2009 Lexus GX470 126,000 miles

mljohnson2

Update:

They are going to keep it overnight to drop the pan, flush trans, change filter, new fluid and check for metal flakes. Hopefully everything looks good and I've just spent $500 to prolong the life of the transmission.

"crossing fingers"

chiph9

Vibration on acceleration around 40-50 mph? That's not driveshaft clunk.
Normally I'd say to avoid a "flush" because the pressures can damage the internal filter, but since they're going to be replacing it -- go for it.

Chip H.

mljohnson2

Yea he said they would have a look and if nothing was amiss they would just change fluid but if they needed to do a flush they would change filter.

sheikhmax

I was having the same issue during Summer. That is Transmission Shuddder... For me it used to happen when i was between 20-35 MPH and transmission tried to downshift but shuddered. I use to let my foot of accelerator and it downshifted and use to smooth out.

Have the Transmission Fluid Fluid Flush and It should go away... Refer to this thread below:

https://www.clublexus.com/forums/gx-...-too-long.html

mljohnson2

Thanks @sheikhmax

I am hoping that solves the issue atleast for the time being. I read somewhere else about some LX's having these issues as well that were remedied but came back about every 40,000 miles. It was apparently a TSB at one time that had something to do with a transmission breather skirt allowing water into the transmission.

Someone suggested that a synthetic fluid with anti-shudder additive solved there's but I'll let that be a last resort.

DiabloX22

mljohnson2 what did you do to spend $500 to prolong the life of the transmission?

DiabloX22

Do you know if the transmission was serviced on time? Did you look at the color of the fluid, did it look or appear burnt? I worked at a trans shop and yes clutch packs can burn out. Socan many other components in the trans and or valve body. Did they hook up the computer to see if there were any stored trans codes? 45 to 50 mph could have something to do with the torque converter locking up. It really all depends on how well the trans was serviced. If you have any questions, feel free to contact me.

chiph9

The owner's manual says the transmission fluid is good for the life of the car. So there's no dipstick or service interval for it.

There are probably lots of 100k+ GXes out there running on the factory fill.

Chip H.

mljohnson2

DiabloX22, it's hard for me to answer many of those questions as the service is being done currently at my local Lexus dealer. He initially said something about the clutch pack but then said something about torque converter. I got the feeling they really didn't know without dropping the pan and getting in there. I gave them the go ahead to do that which will probably lead to the flush/new filter. I'll update what I hear from them today as they kept it overnight.

Chiph9, I understand they throw around the term "lifetime" with these trans/fluids. I just can't help but be of the camp that believes "lifetime" to them really means the life of the warranty. I've seen where many have suggested fluid changes around 90-100,000 miles. This known issue with LX transmissions seems to lend more credence to that because it is allowing water into the trans. This to me would explain the issue I have getting worse and worse over time.

In the meantime, I'll enjoy the 2017 ES 350 they gave me.

mljohnson2

UPDATE:

Just heard from the Dealer. They dropped the pan and he said they found a few "bits of brass". He said the "transmission is eating itself up" and he suggested replacement. I told him about all the things I had found regarding trans flush helping etc and he said he is happy to try that to extend the life but can't make any guarantee. I just get the feeling this guy wants to sell me a new transmission.

I told him to flush it, install new filter and fluids. We shall see..

Booyah

Did you tell him to save the brass or whatever they found, I would definitely want to see what they are talking about and not BS you!

co4wheel

Yeah, just flush it and move on. If it's actually going bad it will eventually fail to go in a gear for 2-6 secs. Something like that. If that starts happening you need a new transmission.

mljohnson2

Yea it's strange though because I don't think it actually fails to go into gear. It's between 40-50mph every once in awhile (some days not at all) you'll start to get a shudder. I've actually gotten quite good at immediately letting off the accelerator just enough for it to stop but not lose headway.

It's never happened outside of that speed range so I'm thinking near 5th gear or torque converter lockup.

chiph9

I agree with the others. Do the full fluid change, put a new filter in it, and drive it until it fails. Or doesn't fail (crosses fingers).

In the meantime, start saving money, either for a new/rebuilt transmission or a new vehicle.

Chip H.