Big Bear Middle Drive Gear Seal Replacement

Hey there guys and welcome back to another video at TopTier Garage. Today I will be showing you a step by step process on how to replace the seals on a middle drive gear. This is on a 1989 Yamaha Big Bear but will work with many other generations of the big bear. This will stop your engine from leaking out oil to the front and rear driveshaft seals.

[@toptiergarage7378]

Any questions about the process feel free to drop them down in the comments.

[@donaldpigeon]

Man my big bear give me a hard time, I was out the country for 2 years and left it behind to 2 friends that was less mechanically incline that I thought. What I thought was going to be a simple timing chain and exaust valve job turned out to be a absolute complete overhaul, and I cant find a manual for my bigbear because it is a special edition release only in canada in 2000. You just saved my day.

[@derikblake8795]

Hey I know this is an older video, but having a problem with excess oil getting into my middle gear drive. When I remove the fill cap to the middle gear box, oil just starts poring out. When I change the oil, I put the right amount in the middle gear drive the manual calls for, and it is fine. I run the atv for a minute then shut it off and let it sit for a couple of minutes. Then When I open the fill cap, oil starts gushing out. l I am assuming there is a seal or O-ring that is worn between the crankcase and the middle gear drive that is letting more oil overfill it. Any ideas where this seal is or how to get to it? Thanks

[@wrdturkey]

Mine does the same thing. I'm sure the oil that's in the middle drive gear housing mixes with the crankcase oil. The fill plug that you refer to, is a plug used to initially fill the middle drive after an oil change. It should take about a half a court. After you put the initial oil in the drive you shouldn't have to worry about it again. The oil is mixed with the crankcase oil and is checked at your engine dipstick. I hope I'm right. I hope that helps.

[@maxwelltwito9524]

do you need a gasket in between the two halfs of the drive gear?

[@connersnow298]

Awesome video

[@colt0864]

Any idea where to order that seal? I’ve got the same problem .. is it called a drive gear seal?

[@paulkelsey6411]

Was yours leaking into the boot that covers the u joint? Mine is leaking somewhere and it fills the front of the protective boot around the u joint. I jacked the quad up and put it in gear and let it run in gear and I pulled back the boot and it wasn’t leaking out of there. It actually looks like it’s leaking from the cover that bolts onto the jug. Can that cover that bolts onto the jug be removed with out doing all this? Like the seal around the cover is bad

[@przepieron8684]

Thanks!!!!

[@chriscummings6724]

How difficult was it to remove the u joint? Mine is leaking here....I'm debating removing the front U joint and trying to tighten the nut that way first.

[@toptiergarage7378]

It's alot easier to try that first. Should only take about an hour. Depending if you have ever done it before.

[@bskinner1969]

Is the rear yoke nut right handed or left-handed threads

[@Cataklixxx]

Man where do you get parts for it i cant find parts for my big bear

[@josemendoza6297]

I'm having trouble finding these middle drive gear replacement seals - 1996 big bear 4x4 - where did you get yours? Could you drop a link? Thanks! nice video

[@toptiergarage7378]

I normally use Partzilla to get the OEM part number then copy that into Rocky Mountain ATV or my local dealership. Don't cheap out on seals. 😃

[@przepieron8684]

what is the size of the sealants ??

[@emily-influencer2245]

I- how you so friggin fabulous ✪ ω ✪