Arctic Cat Forum banner

1 - 15 of 15 Posts

·
Registered
Joined
·
102 Posts
Discussion Starter #1
I've managed to acquire a set of cases, a crank and a balance shaft for my 98 T-cat. I'm in the process of the re-build. I am going to change the balance shaft bearings. I have never had one of these triples apart so forgive my lack of knowledge. I assume that the balance shaft is pressed together but is it also keyed to keep the lobes in the proper sync?
 

·
Registered
Joined
·
9,747 Posts
Yes, that is correct. It is keyed. Very easy to do. But,....be sure to get the C4 bearings. They are a high speed bearing. The others WILL NOT last.
 

·
Registered
Joined
·
1,631 Posts
Just to add. Bearings are mark in class's. From C3 to C7. A C3 bearing is a farm bearing made for low rpm and in dirt. A C7 is a precision machine spindle bearing with zero play in the bearing and is designed to be in a oil bath ran through a oil cooler to maintain at certain temp. A C3 will have approx .0004" play.

So you can see there is a difference in both clearance and there is a difference in speed rating. These difference's is why you must use a C4 bearing on it.
 

·
Registered
Joined
·
102 Posts
Discussion Starter #4
Thank you both for the insights. I will be sure to use C4's. Do either of you have any idea how much interference there is in the fit for the lobes? I'm just curious as to how hard the might come apart.
 

·
Registered
Joined
·
9,747 Posts
Al may know but I have always had the local speed shop do it in there press as I don't have one. I think they charged around 20 buck to press apart and install all the bearings. To me, it was worth it.
 

·
Registered
Joined
·
727 Posts
I have rebuilt 2 balance shafts so far. The shaft and lobes are keyed. Make sure you mark them so you get them back in the same place. The center lobe can go either way. See the pictures of how I tooled up my press to push it apart.
IMG_3499.JPG IMG_3502.JPG

You pull the water pump shaft with a deep socket and washers with a hard puller bolt. Don't let the bolt bottom in the hole and twist it off and don't let the shaft bottom in the socket. Make sure you measure how much shaft sticks out and put the new one to the same depth or the impeller will drag on the housing. Pull the bearings.
IMG_3505.JPG IMG_3507.JPG

I put the shaft sections in the deep freeze to shrink them and warmed the bearings and center lobe in a toaster oven to 200 deg F. Don't go too hot or you will wreck the bearings. Press it back together and don't press on the outer race of the bearings. That will wreck them. Due to the temp difference, they almost fall back together.
IMG_3511.JPG

I actually taught a Cat Master mechanic to do his own balance shaft last Christmas. His boss told him he couldn't do it and had to send it out to a shop. If you learn, there will be one more out there that knows the magic. I have more pictures if you need more help but I can only upload 5 on this post.

BP
 

Attachments

·
Registered
Joined
·
1,631 Posts
I have rebuilt 2 balance shafts so far. The shaft and lobes are keyed. Make sure you mark them so you get them back in the same place. The center lobe can go either way. See the pictures of how I tooled up my press to push it apart.
IMG_3499.JPG IMG_3502.JPG

You pull the water pump shaft with a deep socket and washers with a hard puller bolt. Don't let the bolt bottom in the hole and twist it off and don't let the shaft bottom in the socket. Make sure you measure how much shaft sticks out and put the new one to the same depth or the impeller will drag on the housing. Pull the bearings.
IMG_3505.JPG IMG_3507.JPG

I put the shaft sections in the deep freeze to shrink them and warmed the bearings and center lobe in a toaster oven to 200 deg F. Don't go too hot or you will wreck the bearings. Press it back together and don't press on the outer race of the bearings. That will wreck them. Due to the temp difference, they almost fall back together.
IMG_3511.JPG

I actually taught a Cat Master mechanic to do his own balance shaft last Christmas. His boss told him he couldn't do it and had to send it out to a shop. If you learn, there will be one more out there that knows the magic. I have more pictures if you need more help but I can only upload 5 on this post.

BP
Thanks For the pics. I was just trying to remember how I did my last one. Its been 10 years or better. lol. As soon as I seen the bearing separator it all came back.:chug:
 

·
Registered
Joined
·
102 Posts
Discussion Starter #9
Thank you a ton for the pics. This is kinda what I figured but it's always better to ask those that have done it.
 

·
Registered
Joined
·
727 Posts

Attachments

·
Registered
Joined
·
727 Posts
More pictures.
I used moly past on the bearing surface to lube the inner race going on the counterweights so they did not gall and chilled the weight and heated the bearing.

IMG_3508.JPG IMG_3509.JPG IMG_3510.JPG IMG_3512.JPG IMG_3514.JPG

The finished product looks like new. I bead blasted the counterweights to remove and rust.

BP
 

Attachments

·
Registered
Joined
·
1,631 Posts
Thanks BP for all the pic's.

Guys take Note on Post #10, Pic #1 the location/direction of the Snap ring groove in the bearing on the water pump side. You Don't want to put that one on Backwards!!!
 

·
Registered
Joined
·
1,631 Posts
Being BP showed how to do this and he Jarred my memory I had to go out and try it again on a CB that was under water for a while. If you look you can see the water line on the gear. I had success on taking it apart so now its off to the bead blaster to be cleaned up.
 

Attachments

·
Registered
Joined
·
1,631 Posts

Attachments

·
Registered
Joined
·
9,747 Posts
That 1/4" drive socket marked in the pic should of said 3/8" drive socket instead. Won't fit over the shaft. Oops. I dunno
 
1 - 15 of 15 Posts
About this Discussion
14 Replies
4 Participants
tcat446
Arctic Cat Forum
Arctic Cat forum is a community to discuss Arctic Cat 400, 440, 500, 650, snowmobiles, sleds, ATV's and more. Join the fun!
Full Forum Listing
Top