i drove my truck around in fwd for a while when i was getting my driveshaft balanced and it was hell lol. especially since i have lockers, turning was almost impossible unless i took it of gear, if i didn't it would make this awful clunking sound. the truck would pull really hard if i accelerated also. i know the locker had a lot to do w/ this(along w/ minute differences in tire size), but i was wondering if it was b/c the cv axles are of different lengths.

*edit- i just noticed that you said your buddy already suggested this. i know that torque steer is a problem under hard acceleration on honda civics b/c the cv axles are of different lengths, but i'm still not sure if this is the cause of pulling in fwd on our trucks.

as for your question, i'm not sure if my advice is still relevant since i have lockers. but when i jack the front end up and spin one tire w/ both hubs locked, occasionally neither the opposing wheel nor the driveshaft will spin unless i turn the driveshaft a little bit clockwise to engage the other wheel. after that, both my tires will spin in the same direction. thats in 4wd of course.

The A340H's 4WD is hydralically controlled with a clutch pack, actuated by the tranny's pump and the parking pawl is on the output shaft of the tcase. When it is running, the front wheel will be in 'park'. Once you shut it off, the hydraulic system relieves and you will loose front driveline connection.

It is analogus to not being able to push start an auto.

No, i think i have the reason why it doesnt work.
Your truck has ADD (not manual locking hubs)
when you turn your engine off, the vacuum is now gone and your 4wd will not be engaged (ADD runs on engine vaccum) therefore only 1 half of the differential will be connected to the t-case, allowing it to spin.

None of this hydraulic mumbo-jumbo, it's all in the pneumatics <img src="/forums/images/graemlins/smile.gif" alt="" />

The ADD actuator stays in whatever position it was last in when vacuum is lost. It is not spring loaded and must be pulled one way (by vacuum) to engage and be pulled the other way to disengage:

http://toyota.off-road.com/toyota/article/articleDetail.jsp?id=399612

sh!at. i thought i had something.

Yeah.... especially since I do not have an ADD system and have manual hubs, as suggested when I said "hubs locked" ('89 4Runner).

My front diff is in fact from a '93 and has the ADD cylinder, but it has been permanently locked by slipping a hose clamp over the cylinder. I know that it is indeed locked b/c if I turn that (driver's) ide wheel, the other axle turns opposite (well, briefly until the DS moves a I mentioned above).