I am thinking of buying a new aw4 with an upgrade. a little more beefy and a bigger oil pump. I am told that the shifting will not be as smooth as stock (I love how it shifts) .My question is, has anyone ever had the upgraded AW4 and how ruff was the shifting?
thanks

 

The AW4 is the same transmission as the Toyota A340. The Lexus transmissions (the A650) use a larger, higher volume oil pump. I didn't use that pump when I built mine, but the engine was stock so I didn't worry. I did use a Transgo HD2 kit for the valve body though, and that made amazing improvements in the shift quality. I wouldn't overdo it with the race settings unless you're not driving it on the street.

 

What's the advantage to a larger oil pump?

 

More inherently means better, right?

I honestly don't know if it would do any good on an AW4. I know on engines when people install high volume oil pumps, they'll sometimes experience distributor gear and oil pump driveshaft failures from the added (unnecessary) load. I'd just stick with a fresh AW4 with a valve body kit and a big honkin cooler.

 

the AW4 has always had problems with over heating. some of that is because of the exhaust pipe runs so close to the AW4. Jeep put in a weaker oil pump to get the smooth shifting that these jeeps have. Problem there is not enough volume to take the heat away. there are upgraded AW4s out there that has as a part of the upgrade is a bigger oil pump to help with the heating problems but the draw back is a firmer shifting transmission. so the question is, is it worth living with firmer (I don't know how firm ) shifting. I am willing to except some firmness but I don't want to feel like my head is going to snap off every time it shifts.
by the way I would not want to put a larger oil pump on a stock motor. I would add it to a rebuild.
thanks

 

303kmiles on my original AW4 tranny, still running fine.
When I bought jeep I found prior owner placed a tranny cooler on it. An auxiliary cooler is oft a good idea if heat is a problem. Maybe the cooler, plus sensible driving, and regular, frequent fluid changes have helped in getting 303K miles on an original tranny?

 

sorry about the 2 reply's. not sure how that happened. I'm new here

 

It's not the AW4, it's automatic transmissions in general. Heat is the #1 killer of automatics. Next is lack of maintenance (which can often cause #1). The AW4 is a stout transmission for its purpose. If you're doing things with it outside of that then you should put on a large oil cooler and change the fluid more often. Firming the shifts up will help keep clutch wear down. Again, don't go ridiculous with it. The HD2 kit in "truck mode" made it shift like I think it should have from the factory. I've been in one that was done with "race mode" and it was just nuts. Trail or track only with that thing. You'd be changing out engine mounts weekly.