Have a '99 GV with new vacuum motor and rebuilt front differential.  It has always been hard to shift into 4-h while driving.  With winter, it is nearly impossible to engage the the system while moving.  If stopped, it engages easily.  Once engaged, it shifts easily out of 4-h.  It can be shifted back into 4-h very easily while moving, for a shore time (29 seconds or so), then becomes hard again.  Anyone with similar problems, that had a resolution, or know of a fix?  Local dealers are nearly worthless!

Are all your tires equally worn and equally inflated?

This is probably the synchro in the transfer case (yes, Gen2 has a synchro).  Some oils are just too slippery for the synchro cone to grip.  I would try a good quality synthetic GL4 oil - maybe Royal Purple?

I agree about the worn synchros.  Not too much you can really do about it.  Do you at least have synthetic oil in there?  That would help a little with the cold weather.

Seeing how you just rebuilt the front diff and replaced the pump you probably would like to get some use out of them.  However, if you converted to the old style diff and put on manual hubs you could shift on the fly easily again.  If you lock the hubs and shift while driving it will go in and out of 4WD VERY smoothly - no need for synchros because the t-case and front driveshaft will already be spinning at the same rpm.

Thanks for the replies.  I have had Mobil 1 Synthetic in the unit for the last two years.  I was hoping that a speed sensor or some adjustment was possible.  Even with the system warm and running in 4-h there is no change in the shift-ability. It  comes out of 4-wheel easily, but does not go back in easily after only a few hundred feet.  If I come to a complete stop it is easy to shift. There is no grinding either in or out.

I use the unit as a toad behind my motor home for most of the year. It is excellent for that application. Bike rack off of the hitch bracket, canoe on the top.  Go anywhere and have all of the toys. I guess I'll have to put up with the small inconvenience of changing ranges from a stop.

Thanks again. Just joined. I've been trying to catch up on past threads. Some great stuff!

Tom

When i used to use junk GL4 fluid i use to get this prob. I use 75w90 royal and never a prob.

Also make sure you let off the gas when shifting in 4wd and all tires are same size

I agree, the best way to shift is to let off pressure on the throttle.  but at the same time don't back all the way off either, just hold the gas pedal to have no pressure, then shift, should work better.

Exactly. This is a true lock 4x4. so when you are on decel the rear tires will tend to want to turn slower then the front and on accell they want to turn faster then the front. So best way is at a slow speed. put it in N or stay steady on the gas.