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Hey, this is my first posting. My name is James and I am into about motorized and like to work on stuff. Well I like riding and driving better but you know...
I currently own a 1997 Polaris Xplorer 300 AWD that was in bad shape when I got it but got pretty much everything sorted out and is trail worthy. About the only thing left is the rear shock bushings and change out the belt (just in case).
I've got a 97 Polaris Magmum I bought off a co-worker. You know some stuff broke, neglected and was parked in a barn so it needs allot of work to get it going (brakes, carburetor, etc). So that's going to take some time.
My co-worker is wanting to sell me a 2005 Yamaha 350 Bruin 4X4 for $500. I actually worked on this thing a year ago. It tumbled down a hill and did some damage to the front end. I fixed all that, cleaned the carburetor, and got it running pretty good. While I had it, I tried to adjust the rear brakes and got them to where they worked some what. He said he had someone "fix" the rear brakes but afterwards they locked up so he just backed the adjustments off. I think new cables would have fixed it.
Well back in the summer he said it started making an awful racket from the rear axle. He said he took the rear drum and shoes off and it was fine for awhile. Now he says either the differential or rear axle is slinging oil and making an awful racket.
My guess is the axle bearings are shot which explained why removing the rear brake assembly "fixed the problem" temporarily and is now signing oil and making an awful sound. I asked him if the rear end was slipping or binding and he said no, just an awful racket.
I did find a breakdown of the rear axle. Just curious if this sound typical of this model. And what I might be up against.
I've changed out bearings and seals before so I think I am up to the challenge. I just haven't had any experience taking differentials apart.
He initially wanted $900 for it and I passed but has dropped the price down to $500. Since it runs I think $500 wouldn't be a bad price. I think I could flip it and make some money on it.
Hate to sound cheap but doesn't anybody know where I can download a "free" shop manual for this thing in .pdf format?
Don't know about manuals, but the rear axle splines are a bit suspect on Yamahas. Not entirely Yam's fault as they put a bearing on the shaft outboard of the diff bearings, but owners neglect to change it when it gets play in it. So, the weight of the bike is transferred onto the crown wheel via the axle, and the splines between them start to fret. Stripping the diff is not difficult, but you need special tools. The peg spanner can be made from a piece of suitably sized tube.
I sent him a text and he says it's the differential that is slinging oil. So I suspect the bearing is worn so bad, it's messed the seal up.
When you say special tools, like what ? I've got lots of tools. I also have access to a large bearing press at work. Do you mean to dismantle the diff or to set the preload adjustment on the differential?
Im looking into buying a used differential. I hate to take the differential to the Yamaha dealership. Shops usually charge a fortune. That's why I like doing stuff myself.
I'm going to have to get the bike over here to get a better look at it. I'm trying to remember how the differential and axle carrier are connected to one another. If you look at the axle carrier tube below, it looks as if the differential bolts to the right hand side of the tube.
Replacing the bearings and seal in the axle tube should be straight forward (just one bearing and seal on the left side?). Just knock the bearings out from the inside of the tube with a rod and hammer, press the new bearing and seal in from the opposite side. Or at least that's how I've replaced bearings in the past on various things like my daughter's 110cc ATV and the front wheel bearings on my Trabant 601.
It may be better to take the differential to someone who knows what they are doing.
Why would the axle wooble go away after removing the rear brake assembly? Unless the axle bearings are bad as well.
The other question is, what kind of shape are the spines on everything? I may be in for more than I bargained for.
There is supposed to be an ATV junkyard near Knoxville TN. About 100 miles drive south. I may call this guy if I can find his number and see if he has a whole deal I can just swap out.
Check those bearings for play before assuming the diff is shot, it may just need an oil seal. There is nothing difficult in quad diffs, setting up car ones up requires skill, but on quads I always go for putting the shims back in the same place as they came from, with new seals and bearings, and the diff works fine. The peg spanner is needed for the threaded ring shown on the modified picture, though you may get away with a hammer and drift instead. You can get full bearing kits from firms like "all *****", but you also need the separate one that fits on the axle shaft and causes the problems in the first place. Check the bearings in the centre of the brake backplate for play too.
Thanks for the reply. I've actually had to remove something similar to this on front wheel drive wheel bearings using a punch and hammer instead of the factory tool.
I'm pretty sure the differential bearing is bad simply because my friend said it's making an ungodly noise. Just based on experience, even a slightly worn bearing can transmit vibrations and noise 10Xs fold on the device. Input shaft and wheel bearings in particular.
The good news is he says the rear end is not slipping or making a clunk when moving so that is a good sign maybe nothing inside is stripped.
So once this collar is removed, what's next? Is it pretty straight forward from there? Just a matter of removing all the external bolts and everything just falls out?
One trick someone taught me on ring and pinion differential when replacing the pinion seal is to paint a reference mark on the nut and housing and count the # of turns it takes to remove the nut. The pull the seal out, pop a new one in and install the nut the same # of turns and align the reference marks. This may not be the same as setting the pre-load adjustment but get's it back to where it was.
Quad diffs use mostly ball races so pre-load isn't a problem as a rule. Haven't done many Yam diffs, they are less prone to problems than Honda 300s and 420s, but the threaded ring is often tight and you have to be sure it is right down when re-fitting. "Horrible noises" can come from many places, so do not assume it is the diff. If there is no play in the bearings, and they don't bind or chatter when spun, they are OK. Check crown wheel and pinion for broken teeth.
03-24-2018, 05:55 PM
2005 Yamaha Bruin 350 4X4 axle questions
