Seeing that its not an enclosed straight axle, I wondered if this works just the same as a limited slip front end? Anyone know?

 

Andy, to the best of my knowledge none of the new model quads have a rear differential. They are final drive units. A differential transfers the power from the driveshaft and pinion gear to the ring gear, and from the ring gear (which is the big gear) 90 degrees to the spider gears and side gears which are splined to the inner ends of the axles. You need all of these gears so that one wheel can turn faster than the other in a turn (then they add springs and clutch discs or other designs to make limited slip designs). Anyway, a final drive just changes the power 90 degrees with the same solid connection to both wheels. It has a pinion gear on the end of the driveshaft which turns the big ring gear (the difference in the number of teeth of these gears gives you your rear end ratio) the same as a differential, but the inside of the ring gear has a spline in it which mates with a spline on the rear axle. If it has independant suspension, the final drive is attached to the quad's body and the axle has constant velocity "u" joints where it comes out of the final drive, and at each wheel. I hope this helps.
One of the old Kawasaki's have a locking differential in the rear ( I don't remember which one). I wish my quad did so that I could unlock it and drive around on the grass without chewing it up.

 

I'm talking about the IRS 660. It doesn't have a straight axle with a gear case, its totally different. I just wondered if it was set up the same way or not. It looks similar to what you would see on the front, but I would have figured it would not be set up for slip like a front differential because the rear wheels don't turn obviously. Am I right here?

 

I'm talking about your IRS rear end on the 660 Grizzly. Its hard to describe without showing you pictures, but if you read my last post carefully, you may understand what I am saying. I tryed to explain the difference between a differential and a final drive. The name differential indicates that one wheel can turn at a different speed than the other one. A final drive powers both wheels the same. Your rear end is a final drive unit, but instead of having a solid axle through it going all the way to each wheel, yours has a universal joint in the axle as soon as it comes out of the final drive (or gear case), then a solid axle to another universal joint at the wheel so that each wheel can move up and down independant of the other one. With IRS, it has an "A" arm arrangement to support the wheel, where on a solid axle arrangement, the axle itself (or the housing around it in some cases) supports the wheel. I hope I've made it a bit clearer---better yet (and maybe this is what you meant), picture the rear end (IRS) as the same as the front end (FIS) when it is locked. Thats how it works, but because it is a final drive, it is much simpler than a differential in actual design.

 

Thats what I wanted to know. If it was a differential or a final drive. Basically if whatever was in the rear would allow both tires traction at all times. I just didn't know how to word it.

 

You're welcome.