torque convertors

[winston]

Hey there guys (gals),
Just have A question(s). On torque Convertors? What is a "non" lockup and a lockup what are the "pros" and "cons" ? Were application are they reccomended for?

Thanks for debating here Red face

Oh I may have more questions on this and so forth.

Winston

[dodger1]

Simple answer - a "lock-up" converter, as the term suggests, will lock, that is, will not have any slippage inherent in any non-lock-up converter. It has a mechanical clutch inside the converter that is engaged or dis-engaged by hydraulic pressure supplied from the trans at a pre-determined speed, in the case of non-electronicTorqueflites anyway. They were developed to improve fuel economy. If (heaven forbid) you've ridden a transit bus, what you thought was an upshift to 2nd was usually the converter locking up, and then progressing through the rest of the gears. Torqueflites only lock up in 3rd, usually after 40 MPH. I think all 904's went lock-up in the late 70's, but some truck 727's remained non-lock-up right through the O/D 518's. You can't mix and match converters and trannies. If you have a lock-up tranny you must use a lock-up converter, and vice-versa. That said, a lot of folks are afraid of lock-up converters for performance work but there are some shops doing street performance upgrades to them so depending on the end use they might work for you. I've had no probs with my 998 lock-up rebuilt to cop-car specs with a bolt-in sprag and some Kevlar clutches behind a mild 360 and in front of a 2.94 rear. But I expect we'll get lots more comment here