Hi all,

I'm new here in this forum and have a question to ask.

I've got an Isuzu Trooper '88, 2.8td, diesel engine 4JB1T, 5 speed manual transmission, manual front free wheeling hubs, 310000km.

Lately I've experienced problems to shift gear from 4H back to 2H. It takes sometimes 500-1000m of driving after having shifted to 2H until the transfer case finally disengages with a terrible noise and a bump that you can feel in your back. I guess I should not do that too many times otherwise something might break inside the gear box. I did already change the transfer case fluid (5W30). Shift lever can be engaged as usual so IÆm never entirely sure what transmission mode I have selected. Of course if I make a turn I realize whether it 4H or 2H is engaged. The 5 speed transmission itself works properly.

I donÆt want to think of the worst already (worn shift fork/sleeve/gear/hub) and wonder whether someone here does have a clue what I could try.

Regards

MfA

So if I read this right, you are able to move the shift lever to 2H but it doesn't actually drop out of 4H for a while?

Hi BigSwede,
I know it sounds strange but exactly that seems to be the case.
Disengagement of 4wd - as it finally occurs - is not soft and quiet as it should be. The corresponding sleeve in the transfer case seems to get slightly stuck or does not perfectly well and immediately move back to its original 2H position when disengaged.

Do you or anybody else here in this Forum have experienced something similar or at least heard of it <img src="/forums/images/graemlins/confused.gif" alt="" />?

Regards
Mike

I'm not sure what's wrong with the t-case but I would make sure to have the hubs unlocked if you don't need the 4wd otherwise you are putting a lot of stress on the drivetrain.

I don't even know if you have the same t-case as I do, but based on my t-case there isn't a lot of flex available for that kind of binding to happen in the 2hi-4hi shifter. The shift fork can flex a little, but I can't really envision how you could move the lever all the way to 2hi position and not actually achieve the shift.

What you are describing kind of reminds me of shifting a pushbutton shift-on-the-fly system out of 4wd while the driveline is binding...it will hang in 4wd due to the binding, but as soon as a turn or loose surface allows the driveline to unbind the shift will occur with a bang. But that is a function of the actuator at the diff, not the t-case, and an 88 doesn't have a SOTF actuator at all. So I'm not sure where to go from here... <img src="/forums/images/graemlins/confused.gif" alt="" />

you try backing up a little bit after disengaging

Shouldn't matter with manual hubs, but it can't hurt to try, might relieve some sort of binding...

I suspect that your hubs are not unlocking - My 92 Amigo with Asian autolock hubs sticks in the lock mode when it is VERY cold outside (-5 C or colder) and the vehicle has been parked and then I shift back into 2WD when taking off in the cold vehicle. On my vehicle I suspect that it is a grease in the hubs(too stiff when cold) problem. I have learned to shift back into 2WD (and changing direction to unlock the hubs) prior to parking the vehicle. If I forget to do so, on occasion I get the grinding noise followed by a bang that definitely can be felt thru the seatback. The bang usually happens within about 100 m / yds. I never have a probem with the hubs not going into lock mode from 2WD to 4WD.

I have the same problem on my 95.5 Rodeo (3.2L V6, Manual Tranny with Superwinch manual hubs). Shift from 4H to 2H, and it stays in 4WD.

Its like this: If I stop and back up, the transfer case unlocks and stops turning the front propeller shaft. In the snow, if I shift from 4H to 2H, it will stay locked unless I get on the gas hard and spin the wheels. The rear wheels break free and the transfer case is no longer locked.

Its a real pain in the ass that I'm going to have to fix sometime soon whenever I can find the time. Don't drive it for any distance in this condition in 2H. Just stop and back up. I'm thinking that your Trooper has manual hubs?

I think that the problem is with a synchro gear in the transfer case.... I haven't spent any time researching it yet.