I took my 2004 Yamaha Big Bear 400 4WD to the woods this weekend and because of recent heavy rains had to ride thru some deep water (knee deep or so) in several places to get back to my hunting spots. After the weekend and when loading the scooter up to go home I noticed that the large clamp that holds the drive shaft boot onto the engine case had somehow come off. I pried the bottom of the boot open with my finger and a small amount of water ran out.

I have no idea how this clamp could have come off if it was positioned and securely tightened as it should have been. There is no telling how much water had been inside that area as it could have leaked out before I noticed the problem.

My question now is if water had leaked in behind the boot, where would the water go to and/or what kind of damage is possible?

I got home late last night but intend to check the rear end differential oil and crankcase engine oil tonight and see if I can see any signs of moisture. If I can, I may try to peel the boot back and dry/clean in there the best I can and/or leave it open so it can dry out.

Anyone have any knowledge and experience with this situation and can provide feedback as to what I need to do to prevent damage, rust, corrosion, etc.?

Thanks, Dave
davisalf@aol.com

 

This Really isn't a Big deal since you caught it in time. just clean out the knuckle (inside the Boot) and pack it with Grease not Completely Full. Then either get a new clamp or a regular hose clamp and tighten it back in Place. Should have no Problems.

 

NAAA no worries just clean it up and if it was me i would use marine lube its watter proof and lubes great got to walmart they will have it . AND BY THE WAY WELCOME TO THE FORMS~~JEREMY

 

Here's what I did and found last night. Removed the large boot clamp and peeled the rubber boot back best I could. The space is very tight so I could not get the boot peeled back but just a half inch or so and barely enough room to look inside that area. Inside there you can see the shaft coming out of the engine and the u-joint knuckle.

I found a little water in the bottom of the boot and some sand that had accumalated in the ripples or creases inside the lower section of the boot. Because the drive shaft tube is angled down and thinking there may be water down in there I tilted the rear of the scooter way up so any water that was in the lower end of the shaft tube hopefully would run out. None came out so I don't know if there could be any trapped back in there or not. I drained the rear end gear lube and found no water in there.

I cleaned the boot and the immediate area inside of the boot best I could. It was tight so I couldn't get in there very well but removed the little bit of sand that had accumalated there, wiped dry all I could get to, then folded up some paper towels and used them as spacers to hold the rubber boot away from the case to allow the inside to air dry. It is now all cleaned up and sitting inside my garage "drying out". It gets fairly warm inside the garage so it should dry out well in a day or two, then I will reassemble the boot and clamp.

On the bottom of the boot sealing surface I noticed a gouge that could be the result of a heavy stick or something flying up and getting caught under there. Not sure, but that may have been the cause of the clamp coming off. Because I drive down thru the woods and swamps and have got sticks caught under there before, I am wondering if I shouldn't buy and install a skid plate to try and prevent any future damage.

Anyone have a reccomendation for a good skip plate protector for this ATV? Are there any drawbacks or problems with adding a skid plate.

Hopefully there won't be any after effects or problems later but I am worried about possible seal or bearing damage that could have been caused by the water and/or sand that got in there. Guess I will just have to wait and see.

BTW, unless I am missing something, I didn't see anything to grease in there behind the boot. I didn't notice a grease fitting on the u-joint. Hopefully the drive shaft bearings and u-joint caps are sealed and not open type bearings.

Thanks, Dave

 

Yea if I was you i would invest in some a-arm guards and a skid there worth every cent my unk has a 03 big bear 400 he has had 2 cv boots ripped from stick's he put some arm guards on it and its been a year now with no problems go to www.rockymountainatv.com and put in the make - model and year of your atv they will give you a list of parts for your atv good luck and good rideing to you.- JEREMY

 

I checked out the skid plate on the Rocky Mtn site. They are made by Richocet, are .160 thick aluminum, etc. Has anyone bought these, had any experience with this particular brand, and can provide any feedback about them?

Are there any other brands available that may be better or cheaper?

There are several skid plates listed on the Rocky Mtn site for my 04 Yam Big Bear 400. Front swing arm plates, rear swing arm plates, engine skid plate, etc. I was thinking or hoping I could buy one plate that would cover all. Is it necessary to buy all of the plates listed to get as much protection as is needed?

Thanks, Dave

 

It's a matter of personal preference in which brand or metal type of skid plates or CV boot guards you want to go with. I personally preferred to get the aluminum type because they're lighter and won't rust. But some people prefer those made of steel because they're steel, probably a tad bit tougher. But if something were to bust through the aluminum ones I have, I'll have more problems than just a torn CV boot because the aluminum plates seem pretty tough to me.

Ricochet guards are pretty nice from what I hear. Oxlite and Savant Mfg. are other makers of plates and CV guards, steel I believe. Highlifter makes them too (aluminum), and they look pretty solid. There's several manufactureres, so just do a search in this forum or on google for "CV boot guards", "CV boot protectors", "stick stoppers", etc. You'll find a set you like eventually.

I don't believe there's a single belly plate for the Big Bear, you have to either buy individual plates/guards you want or purchase them as a package, which comes with all the separate plates in one package.

If you go by the old adage that, "an ounce of prevention is worth a pound of cure", you'll be able to decide just how much armor you're willing to invest in.

 

I have never had to replace a torn boot on one of these machines but from what I can see that would be quite a job and a very expensive job if you took it to a dealer to have done. To replace either the front end or rear end drive shaft boots would require near complete disassembly of that section.

I run in some nasty stuff where the hurricanes of last year has broken down many limbs and trees. I am always getting sticks caught up under there. I probably should invest in some form of under frame protection.

Wonder if Yamaha sells skid plates for these things??? If so, they would likely be very expensive.

Dave

 

Yea i went to the yamaha web site they sell skids and cv GUARDS the cv guards are 74 bucks and made of para fiber or somthing never heard of it jus go to the site www.yamaha-motor.com then go to outdoors and click big bear on the list on the left side of the screen and go to accessories and there you will see.