overdrive questions ?

[flyinlow]

I was thinking about putting a 518 trans. in a 3rd gen 440 car. I found a 3 wire 518 out of a 94 pick-up (360 engine) in a junk yard.

The first 3 gears appear to be the same as the 727 trans. Can a 518 handle 500 ft lbs. of torque in the first 3 gears?

Normally would just be cruising in o.d.

Can the lock-up converters handle big block torque?

If you don't care about the lock-up feature can you not use it and run 727 converters?

I was thinking about using an Ultrabell (cut off stock bellhousing) to make it fit. Does this work well?

[caddman]

I have made this conversion my self but with a 318 car.  you are going to have to build your own mount, they don't sell one as far as i know.  i am still looking for a speedo cable that will fit, so if you find one let me know.  from the info i have seen i don't think you should swap the converter like your talking.  i just disregarded the lock up and run the OD only.  like I said this is a 318 car, but if you build it right I've heard it will easily handle the big blocks.

[John_Kunkel]

As noted, the front of the 518 trans is the same as a 727 and can easily handle 500 hp with minor mods, the weak link is the direct clutch in the OD unit. This clutch is engaged by a huge spring and the output of the trans must pass through it when the OD isn't engaged.

If the 518 is a lockup you can't use a non-lockup converter, the spline count on the input shaft is different. If you don't want the lockup feature it's best to choose a non-lockup trans. A 727 converter will work in a non-lockup 518. If a lockup trans and converter are chosen, the converter can be left unlocked at WOT so the clutch won't be carrying the high torque.

IMHO the Ultrabell is the best way to mate a 518 to a BB but I believe that bell limits the converter diameter to 11" or smaller. Isn't an issue with most installations.

[flyinlow]

Thank for the info.

Is a non lock up a 2 wire trans.  ?

not sure I understand the spring od .  If I took the car to the track I would be w.o.t. thru first,second and half way thru third (13.2/107).

Would this damage the Transmission?

[375instroke]

Three wire is lock-up, but the lock-up trans also has what looks like a little unsplined pilot sticking out the end of the input shaft, whereas a non-lockup has splines all the way to the end, with a small chamfer at the end.  This place has a stronger version of that big OD spring talked about earlier, along with tons of other fun trans parts.  Performance Automotive & Transmission Center.  The way it works is that the spring applies the pressure that hydraulic pressure normally applies the front and rear clutches.  Hydraulic pressure then overcomes  the spring pressure, releases the direct clutch, and applies the OD clutch, so a shift kit needs the bigger spring to apply more clutch holding force in first, second, and third gears.  More clutch discs can also be added to increase surface area, and therefore more friction.