A friend of mine has an 03 Grizzly with 1500 miles on it. He has replaced the rear differential internal parts closest to the rear wheels three times in the last year. I have heard this is due to shabby seel being used in the internals. Does anyone know if my 05 Grizzly uses the same grade of steel on the rear axles or has Yamaha figured it out and fixed the problem? Also what is a good fix for my friend's problem? Thanks for any input on this.

 

Are you talking the actual differential or the axles? I have had my fair share of axle probs but no diff probs. 03 was bad for the axles.

 

Yes the differentials. The parts inside keep going bad. I have not had one of these apart to see inside but he tells me they keep blowing apart

 

This may seem like a silly question, but is your friend installing the ring gears, Ring gear shim(s) Bearing housing, Thrust washer, ect ? If so these parts need to be Blue Printed, or Blued for short. Many measurements need to be taken. The measurements are as fine as a few thousandths of an inch. This is not a job for most home mechanics. This is a specialty job for a professional. If any tolerance measurement is not to spec, the result will be total failure- a blown rear end. I do not know the ability of the mechanic here, but it is odd that the machine has had the same failure three times.

 

Thanks I will talk to my friend and recommend that he take it to a professional. The only problem with that is the $75.00 an hour they charge just to look at a quad.

 

I dreadfully understand the cost of a competent mechanic. The first problem would be to find one, and the second one would be to afford him. The upshot of using a professional mechanic to diagnose the problem and then make a qualified repair is that the shop would be responsible for the diagnosis and the repair. Among other things to consider at this point may be how much was spent to purchase the parts the previous two times, and would another replacement guarantee the appropriate repair?