On my 700, I wired it to go into lockup as soon as it goes into 4th. I also
ran a wire straight out that will lock it in 2, 3, or 4 when power is
applied. Both of these go to a switch on the dash. The connector has 4
pins, so it can be rigged many ways. The $100 lockup kits are not worth it.
The B&M (even more expensive) kit locks the convertor at speeds over 43 mph.
This is not necessarily the best way. The Painless and TCI kits lock it up
in 4th. Both kits give good diagrams and options for locking in other gears,
locking manually, etc. The lockup convertor was for mileage, and really
can't stand much abuse. The tranny's 4th gear is also not designed for
abuse. 4th gear, especially on stock units without pump passages enlarged,
starve the rear planets for lube when locked up. One purpose of the throttle
valve is to kick the tranny out of 4th at high speeds. The Corvette 3-4
shift valve and the B&M counterpart risk really screwing up a tranny by
keeping it locked in 4th at high speeds. The 700 is a great tranny, but
shoudn't be abused. Use 4th for mileage, and 3rd for fun. As has been
stated before, the TV cable has to be hooked up right, or the tranny is
toast. Also, the comment about a 400 with overdrive is not quite correct.
The 400 is much stronger than any 700. The 4L80E shares 3/4 of its parts
with the 400. The 4L60 (aka. TH700-R4) and 4L60E are not so fortunate.
Anybody that can afford the 4L80, have fun. I wish I had those resources.
Complete, it will run about $2500, but it is indestructible. It is also a
computer controlled trans.
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