brake thud

[pemarsh]

My problem was more related to the thud occuring when letting off the brake...worse if i was to accelerate quickly after doing to.

They lubed everything to death in my truck the previous two times. I also have the teflon coated....to no relief obviously.

I am just happy that they were able to resolve the problem by replacing the rear drive shaft. Its like driving a new car.

WHen the senior tech from lexus drove it the third time i took it in, his only words was "this is just horrible".

For those who have a similar problem, dont hesitate to get the rear drive shaft replaced. Question for everyone though----is this covered on lexus's top of the line extended warranty?????

 

[a990dna]

I am just happy that they were able to resolve the problem by replacing the rear drive shaft. Its like driving a new car.

Drive shafts typically don't wear out in two years... the only thing that can go bad are u-joints. Since you said the original shaft has Teflon coated splines… that implies your new drive shaft is the same PN as the original.

It's my understanding the Teflon coating was the change to remedy the situation.. apparently not.

Time will tell if your new shaft solves the longer-term problem. See if you start noticing a slight thunk at 3,500 miles.

 

[pemarsh]

i asked them to look at the u joints specifically...said it was normal

 

[a990dna]

I wonder if it is driveshaft flatulence? (As noted by others - momentary pressure buildup & release somewhere in the slip assembly, maybe a seal holds then releases pressure with a thud.)

I think what you said is more the problem ... and is compounded by the suspension settling & unweighting / and front to rear brake action due to proportion. Makes it a random event.

I chased this problem before on another vehicle with some success... it cost me $$$ in major driveline upgrades.

The good thing is LCs/LXs have a robust transfer case output right out of the box... so I don't know why the driveshaft is making these noises, probably poor design.

These guys make robust driveshafts... JE Reel Driveline

Been doing it for at least the last few years. Sounds kinda like the rear wheels strike a small pavement bump, immediately after starting to accelerate from a stop.
[snip]
My solution:

*Gentle* acceleration, from a stop. This prevents the thud altogether. (And also has the added benefit of helping to maximize life of the drivetrain.)

The only drawback to this solution is that the drivers behind me mistake this slow & gentle start as a sign that I am a weak, infirm, defective or somehow retarded individual, and they conclude that this makes it OK to tailgate me and generally drive like assh*les in passing me too closely.

This is what I do as well, the reaction is the same... only if the ass*les knew I raced Formula Ford in my 30s... and can lap 'em given the right circumstances.