I am right in the middle of a 1996 xplorer 400 total rebuild. I was looking at the gasket kit I got and was wondering what the o-ring was for. Its way too big to be one of the little crank orings and there is only the one. Its about one to one and a quarter inch diameter and about 1/16 of an inch thick.

 

there are two orings in that motor. One between the seal sleeve (that goes between the crank bearing and the counter balance drive gear) and the crank bearing. the other oring goes after the washer that sits against the counterbalance drive gear then the oring goes then the seal sleeve/spacer. at this point don't put the nut on yet. wait till after the side cover is on as you can't get through the seal with it on there.

You can see that the seal sleeves have a chamfer on the inside on one side this you would put against the oring

also make sure you put the water pump seal in the water side and the oil seal in the other. If you have polaris parts otherwise they might look the same. get some emery and polish up the shaft they sit on as well.

If you are concerned about the counterbalance bearings, the gear can be pressed off very easily and a new bearing put on. polaris will tell you that this can't be done so just buy a new counterbalance shaft that has one on there. this is not true. If you do change this bearing make sure the center punch marks are lined up when pushing the gear back on as this times the shaft. there is also marks on the both gears to mesh them in the right place.

the bearing on the other end of the shaft might have stayed in the housing it is cheap to replace also but might needed to be welded on and slide hammed out.

the inner crankbearing on the pto side you have to purchase from polaris or erlandson.Because it has a big chamfer to clear a radius on the crank. the other too you can get at a bearing store ie. bc bearing or bearing and transmission. that goes for the rest of the bearings as well. If they don't have them on the shelf they can order them.

the crank bearings are ntn 32/62 c3
the small bearing that is in the right side cover is a ntn 16008
the bearing under the gear on the counter balance shaft is a 16006
the bearing on the other end of it is a 6004 check that one the should be stamped into the bearing race.

when assembling loctite the crank bearings on with 609 loctite as they are sometimes loose on the crank.
then clamp the crank in a vice using aluminum soft jaws. heat the housing to 200-250 degrees f
and they should just slip on. once you've got one side on turn the crank around and clamp the other side.
at this time let it cool then put on your crankcase sealant. use three bond 1104 or locitite 618 do not use rtv slicone as it is not recommended for parts in conact with gasoline.

once you have your sealant on, get the bolts ready and a torque wench. heat the other crankcase half and slip it on.
then torque in the sequence layed out in the manual and the torque specs specified.

next you have to put the balance shaft in. as it easier to do the previous with it out it in. again we will use a little bit of heat. make sure the retainer plate is resting between the bearing and gear as you can't get in after . the shaft should slip in quite easy. tighten retainer plate.

well that's enough for now, if you have anymore questions post reply.

a good tool is the online polaris parts manual. you can look at parts break downs of every quad or three wheeler they ever made

 

Thanks for the reply, but the oring that came in the gasket kit is smaller in diameter but way thicker than the two orings on the crank. It is probably twice as thick or thicker.

I got all of my bearings from Kaman bearing including the chamfered crank bearing part # 62/32x6c3

 

karman bearing who is that and what did it cost for that one? was that a winderosa gasket set. I remember now a strange oring that came in the same bag as the water pump ones and wondering whats that for. but ignored it cause i've seen the insides a couple of times.

400 polaris's rock i just beat a 800 sportsman in a drag race yesterday

 

oh and the ones on the crank are a 1/16" i'm pretty sure. or maybe a metric equivalent.

 

Sorry meant to say Kaman Bearing. All three of the crank bearings were somewhere around $25. The chamfered one might have been a couple dollars more, but still under thirty( compared to closer to fifty from polaris). The only bearing I got from polaris was the outer skinny crank bearing (6008 c3 I think) and that was only cause it was going to take five weeks from Kaman. Kaman's price was around $17 I think and it cost almost fifty from polaris. Funny thing is that it was the EXACT NTN bearing. I just couldnt wait for it. I think the o-ring might be for the oil pump but I haven't checked yet.

 

yes that's what it is for. good thinking. was that chamfered one a c3 or c4. did it have a snap ring around it when you got it? because i got one of those once. but didn't want to uce it because of the greater clearance spec of a c4.
i got that 16008 through bc bearing in like three days. one good thing about a polaris is the use of off the shelf common bearings it makes them way cheaper to fix. front hub and strut bearings you can save lots of money over buying them from polaris

 

Bearing was a C3 with no snap ring