Sam1234

New to the forum and just purchased a used a Lexus GX470. The transmission seems to do something fairly consistently that seemed unusual to us, but we are new to this car so I'm not sure if it is normal, abnormal, or a sign of something big to come.

When starting from a complete stop, upon removing your foot from the brake, there is a noticeable mini-surge in the engine as the transmission engages, and the sensation seems to repeat when the transmission is disengaging as you brake to stop.

Does this sound normal?

From searching on google, I have read that there are issues with "hard shifting" but this does not seem to happen with shifting...just when the transmission engages or disengages, and it isn't a big 'bump' as much as a mini-surge. I have also read where it could be related to something electrical such as the air conditioner.

The car is under warranty, but the service department notes no error codes when they scanned the engine.

Ryan37

It sounds like it may be the driveshaft "clunk" that many GX owners (including myself) has experienced. Read the top thread in the GX forum and that may be your issue.

Kermee

iTrader: (1)

+1

Sam1234,

You say you notice it when the transmission either engages or disengages from either stop or go from stop. Read the top thread.

What year is your GX?
Is it CPO or do you have access to the Service Records to see if the TSB for the 'Clunk' has been done?

Cheers,
Kermee

Sam1234

2005, around 70k miles.

It didn't sound like the drive shaft thread but I didn't read the entire 700 pages :-/

snhrph

+1 in favor of a driveshaft.

Also, make sure its properly greased after replacement.

mattbeeezy

iTrader: (26)

I had the same problem. I bought the drive shaft from sewell parts online... and I fixed it today. Problem solved.

pgsandiego

I had the same "surge" on my 2005. Checked with the dealer and found the driveshaft had not been replaced. Dealer replaced it for free (part of the TSB I assume) and, no more surge!

If your driveshaft hasn't been replaced, start there.

snhrph

Definitely a TSB. https://www.clublexus.com/forums/gx-...h-new-tsb.html

Sam1234

Lexus says "there are no recalls for this VIN" and the local dealer confirmed that the Driveshaft has not been replaced.

No one is volunteering to replace it.

We bought the car from Carmax and it is under warranty with them (but getting them to do it may take an act of God).

Kermee

iTrader: (1)

They're technically correct. It wasn't actually a 'Recall' but a TSB to guide service departments on how to resolve the issue. Most people had it done and covered under factory warranty when the issue arose.

Cheers,
Kermee

P.S. If out-of-pocket, the cost should be between $500-$600 at most places to have them replace the driveshaft.

ALAN553

Try lubing the driveshaft, i had the drive line clunk for years, did not know about TSB, passed the warranty...took matters into my own hands, got a grease gun, some royal purple synthetic grease, greased all 6 zerk fittings, back gets done every 5000 miles or so, front 10,000...it has now been about 50,000 miles of my own service, 130,000 on the odometer, have not had a clunk since then...not sure what lexus was doing all those years when i asked them to lube the shaft but whatever....its only grease and it works...

mann777

The Clunk TSB is effective for models from 2003 - 2008, you should not have a problem replacing that from the dealer. The TSB applies to vehicles produced before the production change effective VIN - JTJBT20X*80170241.
The TSB was superceded with L-SB--116-08 issued on Sept 16th 2008. The Copy on the TSB is already posted on the Clunk / Propeller //Drivehaft issues. My 2004 was replaced, and since yours is a 2005 I see no reason why they cant.

Familylex

We had our replaced as well.
Take the paper with you to the dealer.

My dealer acted like they had never heard of it when I mentioned it, but when I pulled out paper, they fixed it on the spot......

It's a shame it has to be this way, but it does...
They know they had a problem, because they had the new drive shaft in stock......

Hope it goes well for you.

tzh2231

Hi Alan,

Would you mind share a photo of the 6 zerk locations? Do you need to remove any skid plate to access them? I am about to try doing this myself as I am noticing occasional 'surge' on a full stop from higher speed on my 06 GX470, sounds like this infamous issue.

Do I need a flexible grease gun tube/extension for this or just normal straight fitting would work?

snhrph

There is 1 fitting on every U-joint and 1 fitting on each spline joint. You will need a grease gun with flex-tube and you don't need to remove the skid plates.

Be careful when greasing the U-joints - you don't want to damage the seals.

Splines will take a LOT of grease.

Repeat with every oil change.