Operation in 4 Wheel Drive?

dieseln · Dec 25, 2004

Hi - happy owner of a JM284 here, correct me if I'm wrong but on my 2004 model 284 there is no 4 wheel drive "lock position" like on a traditional 4x4 jeep or pickup(and earlier Jimnas). Therefore I leave mine in 4 wheel all the time - pavement included - because both diffs slip so no harm done, right? It does have rear wheel lock but I've never needed it, yet.

Harrygoodwrench · Dec 25, 2004

Hi, I'm a little confused with your post. You said your 284 does not have a 4WD lever but you leave it in 4WD always????????????
It really is not a good idea to operate a 4WD on hard surfaces like asphault or concrete.

dieseln · Dec 25, 2004

It does have the 2wd/4wd lever. It does not have a 4 wheel "LOCK" feature. So it operates more like an all wheel drive veh (front and rear diffs slip). I was under the impression that previous Jinmas had a 4 wheel Locking mechanism (like the rear wheel diff lock). I had a heck of a time getting it into 4wd initially. Broke the lever off. Dealer suggested I just leave it in 4wd.

I will give a complete "new owner report" soon.

Harrygoodwrench · Dec 25, 2004

Okay, now I understand. There is no "lock" position. Its either engaged or disengaged.
I do question your dealers comment "if true" to just leave in 4WD as that would be a BS statement. There is no "center differential" to permit different speeds between the differentials thus thats why operation on hard surfaces will not be good.
Its your tractor and do as you like/choose but I would not continue operating in 4WD on hard surfaces.
Just my opine and only mine.

greg_g · Dec 25, 2004

( It does have the 2wd/4wd lever. It does not have a 4 wheel "LOCK" feature. So it operates more like an all wheel drive veh (front and rear diffs slip). I was under the impression that previous Jinmas had a 4 wheel Locking mechanism (like the rear wheel diff lock). I had a heck of a time getting it into 4wd initially. Broke the lever off. Dealer suggested I just leave it in 4wd.)

Sounds as if that dealer may have been just tellin' you what he thought you wanted to hear. I personally have never seen a Jinma with anything that resembles a "LOCK" feature like you describe. Difficulty in moving the lever between 2WD and 4WD is an entirely unrelated issue.

Easy way to prove to yourself one way or the other, is to put the front axle up on jackstands so that both tires are off the ground. Ensure the lever is engaged in the 4WD position that and transmission is in Neutral. Then rotate one wheel. If the other turns at the same speed in the same direction, don't drive on hard surfaces with 4wd engaged.

//greg//

Ronbo · Dec 25, 2004

See my post about 4 wheel drive wont. I sent the file to John so it will be posted on Johns Tractors showing the rebuild. Parts were $500 worth. No charge to me. I don't run 4wd unless I can't do without it.

Ron

bluechip · Dec 25, 2004

Merry Christmas!
don't run in 4wd on hard surface. While the front and rear differntials are "open" meaning the wheels can turn at different speeds to facilitate turning, As Harry says, the transfer case contains NO differntial so there is no allowance for variance of speed between the one driven front wheel and the one driven rear wheel other than a tire slipping a little in the dirt. this is why in 4wd the lawn will get damaged when you turn.

Diff lock give you a solid 3 wheel drive, allowing the wheel with the least traction in the front to be driven.

Hope this makes some sense. I have replaced twised off front drive axles that I suspect may ahve been damaged by driving in 4wd down the hwy. (that or popping the clutch with a heavy load in the loader).

greg_g · Dec 25, 2004

( Diff lock give you a solid 3 wheel drive, allowing the wheel with the least traction in the front  to be driven.)

Now I'm confused.....my tractors seldom travel on hardpan, so 4wd is engaged probably 90% of the time. I've never once seen either of the Jinmas or the KAMA front tires turn independently. They're always "clawing" in tandem, all of the time. And - other than toeing a straight line when it's engaged - I don't understand how rear diff lock is relative to front drive operation

//greg//

yugo · Dec 25, 2004

Mike 1,
Since you brought up the question of using the 4WD, I would like to ask for information (if anyone has it) on CV joints. Has any one tried to re-pack the cv joints between the transmission and the front axle on the jinma 2425 model? They seem to be a little shy of grease in the joints themselves and where the joints go on the shafts seems to be a very poor design, so by pulling back the outer tube, and pulling back the rubber boot, and putting fresh grease in, I ended up removing the cv joint, so I could grease the shafts. I put grease serts in the outer protective tube at both ends, so I could grease it from the sert and hope it gets to the cv joint. Any comment would be appreciated. Thanks, Yugo

bluechip · Dec 25, 2004

With an open differntial, the wheel with the least traction will get the power. If they are the same they will both be driven equally. diff lock is only effective on the rear, hence the two rear are locked and the one front will continue to be driven, but only if one wheel has less traction than the other. the open differential is pretty effective because If one wheel breaks traction, the differntial will drive it twice as fast as when both wheels are turning, this helps it find some traction and then makes power available to the firmly planted wheel, so when both wheels are in similar traction circumstances, both will pull, but I think they tend to take turns, sort of like crawling, rather than turn exactly together as they would if it was a locking differential.

If this does not make sence, I'll blame in on too much Christmas Baking, probably have syrup in my veins by now!