I put the front diff yoke back on the front diff, tightened nut, and at the other end is just a yoke with splines that recieve the driveshaft, but like I said there's nothing attached to that yoke now cause I took out the driveshaft. So I started it up and pressed throttle and no forward movement. That back yoke (underneath the transfer box) just turns on its own when I put it in gear, at idle it stays still.

 

Not sure what you are referring to when you say "just a yoke with splines", you remove half of that yolk and the spider so it doesn't flail round, like you have at the front. Leaving only the back half yolk, held into the transfer box by a nut.

If the bike doesn't move forwards when in gear, your rear drive has broken as well. Either the splines on the rear axle are worn away, (a very common problem) or the diff, or the rear prop shaft has broken.

 

Shouldn't I know if it goes forward or not now the way I have it now, with everything being free. What would make a difference if I take out that back half yoke now.

 

Of course I'm gonna take out that flailing yoke, but only if I ever get the bike to move forward. As far as the propshafts go, I only see one front propshaft. I had to tip my bike sideways and tear, (well open) up the skidplate to get at my first yoke.

 

If that flailing yoke hits some part of the engine it is going to do damage. That is why it has to go before you engage gear. The rear propshaft is in the tube between the transfer box and rear diff.

 

I know what u mean, but I already engaged gear, it just flails about. when I put it in first gear, I don't go forward, nothing happens, it just flails about. Like, it's not (the flailing yoke) that stuck where I can't check if the bike moves at all, when I put it in first gear and press the throttle. Now, if I ever get it to start going forward in first gear then I'll take off that flailibng yoke so nothing won't break. Ya, that same yoke that flails about, that's the one that receives the dtriveshaft. I guess I should tell u how the problem started anyways,- the yokes that broke (in the front), they started hitting the cover above it, I noticed. I know u said something in the rear end might be broken, but geez, I'm an easy rider. It just doesn't move, even with that yoke not hindering it.

 

What often happens is a back axle bearing gets worn, this loosens the fit on the rear axle to diff splines, which wear out, so you loose drive to the rear axle. This puts all the strain of moving the machine on the front axle, and the front prop shaft splines or UJ spiders let go.

You asked me how to convert it to 2WD, you remove both front drive UJ spiders and the parts in between. Sorting out a rear end drive problem is a different thing altogether. Here in the UK, a new rear axle for a Big Bear is very expensive and, unlike Honda 300s and 420s that also suffer from the worn spline problems, you can't get "pattern" axles for Big Bears. We get them built up with weld and the splines machined back on, also expensive. The splines in the crown wheel can wear too, so dismantle and check the rear axle to find out what you need.

 

I think what I will do is just buy the front assembly, put it on and see what happens, before I tear apart the back end or anything else. I'm gonna need them parts anyways. I already deposited $200 towards the $485 total. Probably let uu know in a couple weeks.

 

Merryman, Hello. I forget what my codename is. The Big- Bear 350 u-joint. I installed the u- joint assembly and ran it around for a while. Everything was great. Now, when I checked it over again, to make sure it was still solid, (after the ride), it seems like the driveshaft has a lot of play in it (back and forth). When I push it all the way forward, the back splines come out about 1/2 inch (out of the yoke underneath the transfer case). When I push it all the way back, the splines come out of the middle yoke about 3/16 inch. I understand a little play, but this seems like it's too much.

 

I think I mentioned somewhere in this thread that it is years since I did a propshaft on a Big Bear, so can't remember how much end float there is. I have a feeling there was a circlip or two on the shaft, to stop it sliding out, but may be mixing it up with Kawasaki 300s which have a similar set up.