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General => Tech Corner => Topic started by: pkeeney on December 17, 2006, 11:23:30 AM



Title: can't remove big bear rear diff
Post by: pkeeney on December 17, 2006, 11:23:30 AM
'95 big bear 350 4x4
I have something wrong in the rearend.  I'm trying to remove the rear axle and diff casing without removing the swingarm (which wouldn't make a difference anyway, if the swingarm was removed).

The service manual says to hammer the axle out from the right side.  I've hammered and hammered, but it hasn't budged a bit.  What am I doing wrong?


Title: Re: can't remove big bear rear diff
Post by: Mars on December 17, 2006, 08:42:09 PM
Try the other right. Also check for snap-ring holding the axle bearng.


Title: Re: can't remove big bear rear diff
Post by: pkeeney on December 18, 2006, 08:12:52 AM
I actually meant from the left side, but it doesn't matter, I hammered from both sides.

I could only find a rubber seal on one side, and didn't see a snap ring on the other either.

After looking at some pictures, it looks like the axle is just supposed to have spline teeth (or whatever you want to call it) on the middle there, and it should slide right out from the rear casing.  The damage may be to those teeth, which may also keep it from sliding out.  I dunno, I just guessing.


Title: Re: can't remove big bear rear diff
Post by: cutngrs on December 18, 2006, 08:29:58 AM
heat  it up a little bit  and  use a  block of wood  on the end  of the axle and hit it with a big hammer  and hit hard real hard   


Title: Re: can't remove big bear rear diff
Post by: pkeeney on December 18, 2006, 08:32:44 AM
Think a propane torch would be good enough?


Title: Re: can't remove big bear rear diff
Post by: Mars on December 18, 2006, 09:30:23 AM
I actually meant from the left side, but it doesn't matter, I hammered from both sides.

I could only find a rubber seal on one side, and didn't see a snap ring on the other either.

After looking at some pictures, it looks like the axle is just supposed to have spline teeth (or whatever you want to call it) on the middle there, and it should slide right out from the rear casing.  The damage may be to those teeth, which may also keep it from sliding out.  I dunno, I just guessing.

Very possible, if the splines have twisted it's going to take alot of effort and a new axle.


Title: Re: can't remove big bear rear diff
Post by: pkeeney on December 18, 2006, 09:43:49 AM
Oh, and I don't think I'm going to heat it up.  Just thought about it, it's an aluminum case filled (or coated, if I drain it) with oil.  What exactly am I supposed to heat up?

I'm leaning towards borrowing a sledge hammer from somebody.


Title: Re: can't remove big bear rear diff
Post by: yunt2ride on December 18, 2006, 02:40:36 PM
You need to look at some schematics. I would almost say there has to be a clip ring at on end keeping it from sliding or it would slide off while you were riding it.


Title: Re: can't remove big bear rear diff
Post by: pkeeney on December 18, 2006, 02:44:40 PM
I thought the brake assembly was holding it in place, but I'll definitely look over it some more before trying anything drastic.


Title: Re: can't remove big bear rear diff
Post by: yunt2ride on December 18, 2006, 08:19:08 PM
I don't think the brake assembly would be holding it together. If that was the case your brake pads would be wore out in no time because it would move over to the pads.


Title: Re: can't remove big bear rear diff
Post by: dnigels on December 18, 2006, 09:23:59 PM
'95 big bear 350 4x4
I have something wrong in the rearend.  I've hammered and hammered, but it hasn't budged a bit. 
Might I suggest a proctologist.


Title: Re: can't remove big bear rear diff
Post by: pkeeney on February 26, 2007, 11:04:39 AM
Update, still no good.  I removed the bearing on the brake side, and dug at the rubber seal on the left side, still no signs of a snap ring, collar, nut, or anything holding it in place.  I'm thinking the splines are twisted somehow.  I still don't know how to get it out though, even if I do drop the $1,000 for a new axle and diff.  I'm guessing I'd have to cut the axle somewhere.

What a bummer, I only paid $2,000 for this thing.  I've been looking at e-bay every day for spare parts, to no avail.


Title: Re: can't remove big bear rear diff
Post by: Joedirt on February 26, 2007, 11:17:59 AM
Here is the Micro Fiche of the rear Wheel and Axle




[attachment deleted by admin]


Title: Re: can't remove big bear rear diff
Post by: pkeeney on February 26, 2007, 11:23:53 AM
Thanks, but it's actually like this:
(http://houseofmotorcycles.bikebandit.com/partsbandit/assets/schematics/Yamaha/4892_51.gif)


Title: Re: can't remove big bear rear diff
Post by: MedicMudder on February 26, 2007, 11:41:27 AM
Try pm-ing Tony Pitts he is good at working on atvs.


Title: Re: can't remove big bear rear diff
Post by: lugnuts on February 26, 2007, 08:59:03 PM
that axle look's like it removes to the left so you would hit it in the right side but I have done several yamaha champ and bager rear axles and the ring gear has a snap ring and thrust washer attaching it to the axle and must first be removed befor the axle will "just pull out" and by the picture the big bear rear looks the same and probley suffered the same fate stripped ring and pinion gear's

steve


Title: Re: can't remove big bear rear diff
Post by: pkeeney on February 27, 2007, 08:06:53 AM
that axle look's like it removes to the left so you would hit it in the right side but I have done several yamaha champ and bager rear axles and the ring gear has a snap ring and thrust washer attaching it to the axle and must first be removed befor the axle will "just pull out" and by the picture the big bear rear looks the same and probley suffered the same fate stripped ring and pinion gear's

steve
Which side would the snap ring and thrust washer be?  I don't see it on the diagram, and I don't see it on the axle itself. 


Title: Re: can't remove big bear rear diff
Post by: lugnuts on February 27, 2007, 09:55:55 PM
pull the complete rear from the swing arm pull out the ring gear and take all the bolts from the housing split the housing open it should "fall apart" from there


Title: Re: can't remove big bear rear diff
Post by: pkeeney on February 28, 2007, 08:12:57 AM
I cannot remove the rear from the swingarm, I've already tried.  To remove the rear carrier from the driveshaft, it has to slide to the rear; the rear axle prevents it from moving to the rear.

I suppose I could remove the entire rear swingarm, pull the driveshaft out, then cut off the studs that hold the rear carrier to the rear swingarm.  That would allow me to crack it open and pull it apart, with the axle still in place.  ???


Title: Re: can't remove big bear rear diff
Post by: Tim Ross on October 19, 2017, 08:47:20 PM
10 years later I am in the same predicament with a Big Bear 350. I have pulled off everything except the rear differential and when I pound on either end of the axle it doesn't budge. One thing I did not see you mention in your posts are the two big ring nuts that I have on my axle that seem to be seized. They are on the left side of the diff. I thought I could skip taking those ring nuts off and just slide the axle to the left but nope, it won't go. Did you eventually get the axle out? How? Did you have to disconnect the entire swing arm and pull the axle off with the diff still attached? Any advice would be great.


Title: Re: can't remove big bear rear diff
Post by: pkeeney on October 19, 2017, 09:01:17 PM
I never got it off, I sold it in that state of disrepair. If I had seen those ring nuts though, I would have tried to get those off. Soak it in PB Blaster every day for a week.



Title: Re: can't remove big bear rear diff
Post by: Tim Ross on October 19, 2017, 09:32:17 PM
Thanks for answering so quickly. I was hoping to hear a story of triumph but alas it sounds like the bear won the battle. I will try the PB Blaster, and when my friend shows up we will take a 20 lb sledge hammer to the bloody axle (fingers crossed).