700R4 - "Torque Drive" upgrades

[CleviteKid]

[b]Notice concerning the use of

[CleviteKid]

The information above has been added to PERFORMANCE 700R4 PART II (http://www.thedieselpage.com/reviews/lee700r4-2.htm), so if you save articles via download, you may want to click on the link and download the revised version.

Dr. Lee :cool:

[Subzilla]

Greetings,
If you recall from a couple of months ago, I had the exact symptoms as you described but had a much more difficult time getting my local shop to diagnose it. With the help of others, including a response from you, I concluded that the TC itself was fried and replaced it with success. Just curious, what did your shop do to diagnose and come to the conclusion that it was something other than the TC? Did he test it or did he tear it down first? Just trying to further my knowledge, you know?!?

[CleviteKid]

The behavior was a mystery with the tranny in the truck. When we got it out, Don grabbed the input shaft, and wiggled around way too much, so he knew the front pump bushing was trashed. When he took it apart, he found that the rear pump bushing was worn also. So this was found the hard way, tranny out of the truck, and in pieces on the bench.

I had contacted the AUTOMATIC TRANSMISSION SERVICE GROUP (http://atsg.biz/) that offers free tech advice to non-members when their staff has free time. I emailed them:

After about 10 months and only 6000 miles I took this truck out of flat Miami and going up hills in locked-up 4th, on cruise control, the rpms drifted upward 100 to 200 rpm. Turning off the power to the TCC solenoid, the rpm went up another 100 or so rpm. What should we look for on the teardown of the old tranny to explain this weird behavior? and a couple days later got a reply:

Try the Sonnax lock up valve that goes in the pump with the teflon sealing ring. Make sure the two bushings in the pump stator are not worn.
Mike S. ATSG/Miami Good work, Mike, you nailed it with the comments about the bushings.

Dr. Lee :cool: