2004 Sportsman 700 Tranny explosion

[98mkiv]

The final drive chain inside my 700 tranny is now sticking thru the bottom of the case. I have not diassembled it yet, but I can see it sticking thru a hole it punched in the case on it's way to death.

This would be the chain between the front and rear driveshaft outputs.

I looked at some options, a new tranny $800-$1400 depending which dealer you go to. I located a good used 04 sportsman 600 tranny. I only need the main housing (cheapest is $365 by the way). They are the same so I am swapping the 700 guts into the 600 case and will sell off the good parts of the 700 case to recoup some of my money....

Has this happened to anyone else? I've never disassembled the sportsman before. I have an 05 700 as well and I do all the main (fluid changes on diffs, tranny, engine, coolant, grease zerks) and find them very serviceable.

Day one, disassembly: (approx 1.5 hours)
bitch seat
seat
rack
rear cab
both footwells (left attached to rear cab)
clutch cover
secondary clutch
belt
battery cable
battery box
air box
tranny bolts
rear driveshaft

Observations: Came apart pretty easily, except for the roll pin. I farted around with a punch and a hammer, but got no where. A kiss with my air chisel and it was out in one second. Sec. clutch came off super easy, was a surprize. leaving the footwells attached to the rear cab made that a little faster. Also noticed that my frame is cracked, so I will weld on a small patch and paint it. Better than new


Day 2: (planned)

remove tranny without removing primary clutch? Is this possible? I hope so because I don't have the special tool required to jack it off the crank..... (edit: just found a thread suggesting using a 3/4 fine pitch thread (on a trailer ball, which I have) and a socket to jack it off the crankshaft, I'll let you know how this works!) I'd rather leave it on if I can of course!

once it's out I'll post some pics of the grenaded case and internals when I get there.

[Bruce!]

Sounds like FUN!

[98mkiv]

OK, days for me don't happen consecutively, I usually get tuesday or thursday nights to work on stuff. So here is day 1&2 - tranny out and apart. I'll weld the case and sell off the good parts (the top half of the drive is OK, the lower half is toast as you can see). The bad parts will go in the pile of mangled pistons and rods that I've amassed in 38 years. I'm not sure how many pistons I've owned, probably several hundred by this point!

Turns out I did not need to remove the primary to make space to remove the tranny from the right side, I just wedged it out on the left side. Might not be so easy going in because I need to line up the front driveshaft and rear driveshafts, but I really want to avoid removing the primary clutch so I will letcha know on that one.

Here you go (don't blame me if you have a weak stomach and toss your cookies looking at the carnage)

[98mkiv]

and more....

[98mkiv]

and still more.....

[98mkiv]

It's not obvious what caused the failure. As you can see she has a plow, so perhaps it was just too much loading.

Not sure what part failed first? Silent Chain? input/output shaft chain teeth? Ring and pinion drive? If I had to bet I'd say that one of the teeth on the input/output shafts came apart, then as it bounced around the tranny just started causing carnage. The teeth actually came off whole, like you could just hotmelt glue them back on

[stickem]

wow....

[juicedcummins]

My 07 800 was wore halfway into the case in 1400miles. It never towed or plowed. I told dealer and he told me I was nuts, that does not happen.
1 month later traded bike to same dealer on an 08 800. Now this 800 is wearing into the drain plug right from 120miles. It now has 400 on it and has had 4 tranny oil changes.
The 07 tranny oil was like metal flake paint and you could not rinse out the filings and the oil was changed 6 times with Polaris oil in 1400 miles. It also became hard to shift except after a fresh oil change.
The 08 gets the tranny changed the same time as the engine no matter what, and more if I am looking for water. Never had any in either bike.

Anybody that owns a Polaris should keep an eye on the condition of tranny oil.

Based on my exp my next machine will not be a Polaris.

[98mkiv]

I have another sportsman and it has no issues. This was clearly a single part failed and took out the rest of the unit. I welded the case up and its good as new. I may keep it for a spare in case I lose the top end on either of my 700's. I don't see this as a problem, I think its probably a rare failure and not related to maintenance or use, just a fluke. Perhaps a better oil might have prevented it, not sure. I use the polaris oil, but I personally don't think it's the best choice. It does not have any sulfur in it and where this particular tranny has a hypoid gear, I think it should have some diff oil in it, for the sliding friction. It is called an angle drive after all, and I am using angle drive lube. Guess I am wanting something a little heavier with the sulfur for wear....