I might be needing a 4X4 ATV and I will only buy one with lockers front and rear.

Yamaha is the leading manufacturer with this diff lock feature. Almost all the models offered with this have the Ultramatic transmission. I'm not anti auto transmission, but I am curious about the pulling torque, or low speed high torque output.
The Yamaha has a 2WD/4WD and diff lock selection.

Actually my Rokon is an auto Transmission and has tons of torque but it's nice to hear from others if this ultramatic has good powerful low speed pulling power and torque.

I do not own an ultramatic, but know several that do. As far as belt driven auto's they seem to hold up real well. I think all of Yammi's that are auto are called ultramatics so you have a pretty wide range of power to choose from. If you were looking in the 400-450 class the Grizzly 450 has a low range and plenty of torque, however the the 400 does not.

If you don't want to go the auto route but like the Yammi, the Big Bear is a 400 with semi-auto shift and it has the diff lock feature. This machine is made to pull and is bullet proof to boot.

I just bought three 2007 450 kodiaks for work. The belts go forever IF you use low range when appropriate. I don;t recommend the 350 or 400 models because they only have a high range, though they are otherwise decent machines.

the Kawasaki also has a good front diff-lock on a lever that you can just grab when the front needs more traction. the yamaha you have to either lock up before entering the mud/hill, or else stop and engage.

the belt/drive system is essentially the same as in a 150 hp snowmachine, so there is no durability issue. in low range they will generate enough torque to break axles (i've seen it happen on frozen up machines)

The ultramatic tranny provides constant belt tension unlike the cvt used by polaris,which constantly flexs and wears,not to mention slips easier.. If the ultramatic design had hit the market first you wouldn't have all the bad press about belt drives. Polaris earned that deserved bad reputation for belts and cvt.

Arctic cat runs a very similar belt design to the ultramatic and has real good durability.

The ultramatic was introduced in 1997 on the grizzly. I bought my first grizzly in 1999 and the dealer had two 97 grizzlies in the shop. A rancher owned both and had them in for service. One had a little over 19000 miles and the other had 14000 miles. They took the covers off both trannies while I was standing there. Both belts were still like new and well within spec.And that was the first time the tranny covers had been removed. Durability isn't an issue. I've got access to two differant mechanics that work on yamahas not to mention they both ride the hell out of yamaha atv's. Both swear up and down that they don't even pull the cover on the tranny until the quad has 5000 miles on it and then its usually not a belt issue,its a lube issue

The ultramatic tranny is considerably differant then a sleds belt drive. I can burn up sled belts all day long. A sleds belt drive is alot like a polaris cvt drive which is why belts are easier to burn up on a polaris. Especially when you get into the 700 and 800 models that produce good power.


The breather vents on the current Yamaha's are really good. I've had creek water over the handlebars on both of my grizzlies and never slipped a belt or took on water. The trannies also have easy drains on them if you did swamp it. Which you'd have one hell of a time swamping one.


Get a grizzly if you're going to buy one. You won't regret it and you will use all the power,wether you believe it now or not. I put on 3000 plus miles on an atv every year and I get to test ride all the latest models and brands. Can Am or bombardier has a shitload of power,but durability isn't there. Polaris is a nice stable ride but will nickel and dime you to death,plus a junk tranny. AC has good tranny design,and good features,but durability is no where near what yamaha has. Honda has set on their nuts for too long. Good durability,but everything else is sub par.

You're on the right track with the locker. Its the only way to go.

Wow Mr. Sledder......Great post, I'll have to go get this little 4X4 this weekend. It's the IRS model with the 350 engine. Your post was a great help to me.

I'm tellin' ya get the 700 griz.

I cannot imagine anything I would need that big one for. I owned a Fortrax 300 for about 8 years and it did everything I ever asked of it, One of my best friends has it right now and he won't sell it back to me! If I were to move up in size the 400 would be as large as I would go. However if the Fortrax 300 did everything I ever needed with an open diff then this full locker with 50 more CC's should work out just right. Plus full independant suspension and that clever drive train sealed life time braking system.

Maybe if I were using it full time for farm work the 700 would be a good choice. However for that cost I would rather buy a small John Deer tractor!

JJ,

I rode a Griz 350 and a Griz 400 and I thought the 350 had a little more grunt on the low end. Maybe not but that is how it felt. I thought it was a better price than the 400 because there was not a lot of difference between the two. I think you'll like it.

The only tranny problems I had with one was a first-year model 600 Grizzly that I ran super hot (air-cooled) and then hit a deep water hole. I suppose the expansion and contraction of the metals allowed water to get in as the belts began to slip like crazy and we had to tow it back to the trailer. The dealership said the model has been experiencing these problems and that a new seal or case would be installed. Never had any tranny problems after that. I would really prefer a low range option on a mid-size bike with auto tranny just for the granny-low situations.

it sort of strikes me as bass-ackwards that the big bore quads have a sub-tranny with low range and the mid-small displacement machines do not.