RG wrote:
"NotNow" wrote in message
...
RG wrote:
The link didn't seem to work for me. But, I'm wondering why it would be
the driveshaft itself instead of the universals?
The drive shaft has a slip yoke that is supposed to slide smoothly fore
and aft. If it binds, you can get a latent clunk when it eventually
frees up, usually after a hard stop. I had the issue with my F250 and it
was solved with lubrication. I also had the issue with my Lexus GX 470,
and it was solved by replacing the driveshaft with a newer designed unit.
Like John said, it's a very common problem on the 4Runners and GX 470
(same drivetrain). Lexus has a TSB on it and when I took mine in for its
5000 mile service, the dealer performed the TSB at my request, with no
charge and no hassle. By 5000 miles, mine was just starting to show
signs of the clunk. No problem since the driveshaft was replaced.
So it's binding on the transmission output shaft splines? Interesting.
I've never had one do that, but then again, I've never owned a Toyota.

The slip yoke is a device unto itself with it's own set of splines, so it is
not binding at the output shaft of the trans. And it's not unique to
Toyota. Like I said, I had the same issue on a Ford F250. It's actually a
very common device in driveshaft designs. You can find them on all sorts of
vehicles, from Jeeps to Mustangs and Corvettes. The slip yoke allows the
rear suspension to flex freely without being bound by the drivetrain.


Commonly in small rear wheel drive vehicles, it's a one piece
driveshaft. Starting at the rear end, you have a universal, the
driveshaft, another universal, the yoke, which indeed does couple to the
transmission output shaft via splines. This is where the shaft is
allowed to move because of flex in the rear suspension.