testing for transmission slip
 

I read in the manual form my Gryphon that if OSS=TSS there is no slippage. I assume this means only in 3rd? Mine are extremely close (within 3) in 3rd gear, but not in others. This is normal, right?

3rd gear with the TC locked, they'll be very close. In other gears they will not match up. An easy way to test is to press the O/D Off button and set cruise control to 60. The two numbers should read almost identical.

Yep. that's what I did, but at about 50. I've got some kind of "chunk" when starting off. U joints seem fine. Maybe clutch packs in differential?

Is your truck lifted? I've heard that often times the drive shaft will make a clunk as angles change under load.

Do you also have anything loose in the cab, toolbox or bed? My truck makes a clunk when I accelerate but it is from a bicycle seat post rolling into the tailgate. :hehe:

Nah. It's completely stock other than Gotts mod and some cosmetic stuff (rims, chrome).

Nothing at all in bed. It almost feels like my rear calipers are hanging up, but they don't seem to be wearing prematurely. Wonder if it would help to take the caliper pins out and lube them. I've already replaced the front calipers (early model '04) but I don't think there was a design flaw with the rears. I didn't see a TSB about them.