sierra trail boss transmission adjustment

[mystery52001]

was driving the t boss and the drivers side transmision wont go forwad no more it doesnt feel right like when i engage it it feels like somethingin the tranny isnt engagine and maybe thats the problem feels like its hitting something solid instead of that spongey feeling it had before. any thoughts would be greatfull. also can i get bands still for the seirra trail boss?

[Jeff t-boss]

It sounds like the friction material on the band may have come off, or the band itself snapped. I believe youu left me a phone message and i'll try to call you back later and explain better. Have you ever gone through the adjusting proceedure for your bands? Yes bands are still available, but you have to there are 2 styles, and you have to get them on an exchange basis.

[splitman]

Hi,Im new to this forum and 6x6's,I Live in New Zealand and have just bought a Sierra Trail Boss,its very tidy and i now have the original motor running sweetly,My problem is the previous owner fiddled with the adjustments on the transmissions and it has no drive?.If its up on blocks the wheels all turn,but on the ground ,pushing or pulling the levers achieves nothing.Im a VW mechanic,so used to tinkering with unusual things,but as I cant seem to find any info on these transmissions I dont know where to start ?.Any help would be appreciated !!,Many thanks !

[Jeff t-boss]

I'll try this again; First off, the cllutches on the engine and trans shaft will not engage until you raise the RPMS. These things are set up to run at 1/2-3/4 constant throttle. If you are doing that and it still don't move, then the trannys need to be adjusted. The Trail Boss has 2 transmissions, one (Obviousely) for each side. And each tranny has 2 bands in it to control steering and direction. You will see a threaded rod sticking out of the front and back of the trannys. (As you look at them standing behind the vehicle) These are what you work with to adjust your steering/movement. The one that sticks out the back adjusts the FORWARD band, and the one that sticks out the front adjusts the REVERSE band. What you may need to do is adjust these bands. If they are adjusted correctly, your sticks/laterals shouldn't move much more than 3-4 inches from full forward to full reverse positions. There is an arm on the shaft that the sticks/laterals control. That arm shouldn't move much more than 5 degrees forward or back when you work the sticks. If it moves more than that, then you definately either have to adjust the bands, or your bands are shot. If it turns out that you just need to adjust, let me know and I'll send a seperate post. First try the RPM thing. And check the travel of the sticks and control arm.

[splitman]

Hi Thanks for that !!,I tried giving it more revs and did get a little forward motion,but very slow and seemed to be driving only on one side.There is about 4" movement in the sticks,but they feel like they arent doing alot?.The adjustment bolt locknuts were all loose and I suspect theyre the problem.I was hoping someone could tell me what is happening inside when I tighten or loosen the adjuster bolts?.I also would like to know what type of oil to run and if the wrong oil could affect the way these work..I think I need to rekit the fuel pump too as the fuel drains back into the tank making it hard to start ,am I on the right track there ?
Many thanks [in advance ]

[Jeff t-boss]

It sounds like someone might have already tried to adjust the trannies and either didn't know what they were getting into and gave up, or quit when once they discovered the bands were shot. Either way, I'll try to walk you through it. Disconnect the control linkages from the arm on the trannies. Make sure the arm on the tranny is pointing straight up or down and turn both adjusting screws all the way IN until you have alittle tension on them. At this point try to move the arm. It should NOT move. Now back each one OUT 1/2 turn and move arm again. arm should not move more than 5 degrees either way. repeat until you get your 5 degrees travel in both directions. If you go too far, start all over from step 1. Once you get the arm to move no more than 5 degrees either way, (it isnt much) hold the adjusting screw and tighten the jam nuts against the tranny housing. Repeat for the other tranny if needed. As far as oil goes, 90W, AT,F and 30W have all come up in different discussions. I've tried all three with the best results from the ATF. (Dextron II) I'm in Wisconsin, so 90w proved to be too thick for use in our cold winter temps. 30W works, but takes awhile to thin and I don't wanna chance bearing loss because of it. There is a fill plug on the inboard side of both trannys. pull it and see if anything trickles out. If so, what does it look like? Is it real dark, milky, metallic? If nothing comes out add ATF for now to bring to level. The reason I am going with the ATF is that while it lubricates bearings and bushings (These trannies have large bushing-type bearings for the forward and reverse drums.) it is thin enough to quickly wash from the drums and let the bands grab so you can steer. And it allows the trannies to run alittle warmer in winter. In warm months I switch over to 30W. (Original manuals recommended 90W or 30W depending on wether you had new or old style trannys. {no need to get into that right now} I have pictures of disassembled trannies in my photo gallery, but don't know how to post a link, so you'll have to check my profile and go from there. As far as what goes on inside when you steer. That's tough to briefly state. The best I can describe is that there are the two drums I mentioned earlier and a cluster of planetary gears. When you drive forward, you are releasing the band from the forward drum while applying the band to the reverse drum. And visa-versa to go backward. Steering is a mix between the two, BUT BETWEEN transmissions. So to turn left, you are actually making the left transmission go into revese (to a degree) and the right tranny going forward. Same applies to turning right respectively. All the while, the engine RPM's should be at a constant 1/2-3/4 throttle as I mentioned. And you feather the sticks and don't yank or jerk them. See if this helps at all. Hope so.

[splitman]

Thanks a lot Jeff,I'll have a go and let you know how I get on!