kermit5327

what is the point in it??? I just dont understand it.

I seen it here in the write up section
https://www.cherokeeforum.com/f51/manually-lock-your-torque-converter-tc-14114/

and im just trying to figure out the use for it

4.3L XJ

There are more reasons to have one than not. First is better gas milage in high gear. Second is less transmission heat. Third, acts like a standard tranny going down hill. Fourth, it gives us something to yak about on the net.

kermit5327

ok so what would the benifits be for a DD

5-90

A "locking" torque converter differs from the previous type by having a mechanical clutch inside of it (usually actuated hydraulically,) that turns the torque converter into an effective 1:1 coupling. This circuit is typically activated in steady-state cruising in third gear or higher.

The primary benefits of a locking (corr: "lockup") torque converter are twofold: 1) By shifting to a mechanical coupling (vice hydraulic,) fluid shear is drastically reduced - thereby reducing operating temperature of the coupling and the transmission as a whole. This contributed significantly to transmission unit longevity. 2) By changing from a "slip-prone" fluid coupling to a 1:1 mechanical coupling (akin to the clutch in front of a manual transmission,) the cruis crankshaft speed can be made more consistent, and planning for more efficient cruise RPM - and therefore better fuel economy.

So there are two principal economic benefits to the lockup torque converter, as stated above. The ability to override the lockup circuit (and to turn it on in any gear range at steady-state) can also be useful, but this should be used judiciously. I'd probably find such ability most useful with low-speed hauling and towing (like in a "yard truck") more than anything else - but I'd probably use a four- or five-speed with a gear splitter for that instead, given the opportunity.

Does this make any more sense to you? I hope I didn't get overly detailed...

kermit5327

lol yes that does help im just wondering if its worth doing or not

bishop letov

If you have a cherokee and you have an auto tranny then you already have a lockup converter... It was necessary in order to achieve higher MPG during highway travel. Its one of the reasons whyyou get better mpg highway then city.

5-90

That, and not being in "stop and stop" traffic all the time - unless you're commuting out here (LA is more like 90mph bumper-to-bumper. In some ways, even more nerve-wracking than driving around up here!)

If you have the AW4 auto behind the 242ci six, you have a lockup torque converter, and it should feel like a "soft shift" from third or fourth when you hit a steady-state cruise.

The "Baby 904" used behind the 1984-1986 w/2.8L V6, I think, didn't have a TCC. I'm not sure about the slushbox used behind the earlier fours, either (later fours ended up getting the AW4, I believe, after the bellhousing pattern was changed from the GM V6-60 to the AMC I6/V8.)