Suspension Swaps by WWW.JBShocks.com
I am often asked if X suspension will fit in Y sled. The answer is almost always that it can but it depends on your skills and confidence turning your tunnel into swiss cheese. Before reading further understand that I take no responsibility for your decision to move forward with a suspension swap. The dimensions on my site are posted there for your convenience and it is up to you to decide if they are right for you. What I can tell you is that I have used the specs myself for swaps and probably hundreds of other people have used them with excellent results.
What is a good swap to consider?
You want to make sure that the balance of the machine is still good. In my opinion this means not jumping more than 1 generation backward. So if a sled has a wide stance/long travel front end such as most 97 – 2001 Polaris sleds (older extra 12 equipped sleds as well) an Edge, ProX or M-10 could make a good choice. If you try to install an edge in an older sled it can fit but the sled will be very tippy and possibly difficult to control. If you must improve the suspension on a 91 then you need to think about a front end as well and that is a subject of its own.
All is not lost for the earlier sleds. If you have one of the older indy sleds an extra 10 can almost always be made to work. The wider the front end the better. Years ago when I installed an extra 10 in a 91 indy I ultimately installed longer radius rods and longer shocks to balance the sled better.
Many people have done Polaris suspension swaps into other brands of sleds as well. But there are other things to consider so be careful. Personally , I have installed an edge suspension in a 97 SkiDoo 500 Deluxe and it was by far the easiest swap I have ever done because no support plates needed moving. I simply drilled 4 new holes. Many others have done Edge into Yamaha.
Forget the extra 12 that you bought, got free, found on the side of the road etc. It is the most difficult to swap and probably the least desirable. People have swapped them in but I wouldn't and don't have the specs. If the sled you are planning to put an X-12 has the right balance with the front which it probably doesn't, you would be better putting an edge in it.
What do I need to do for a successful swap?
Lets get the easy one out of the way. If you are installing an M-10 call fast and buy the mounting kit. They will need to know if it is a polaris M-10 or a Fast M-10. The other 3 you basically deal with in the same way which is to put 4 new mounting holes in your tunnel. This sounds easy enough but it is a little more difficult than that. The original holes are almost never in the correct location and the mounting holes must be supported by steel support plates which are almost always in the wrong location for the new skid. You have 3 choices which will need to be decided on a case by case basis. I have purposely not provided model specific information because you need to determine mounting locations for your sled and determine if there are things that need to be dealt with. It is never appropriate to move mounting holes based on the existing holes. The first thing that you need to do is determine where the new mounting holes are to be located. Specs for various suspensions are located on my web site at www.jbshocks.com/tech.html. Be careful locating the mounting holes. Mark all 4 holes and verify the locations. Then compare side to side. This mount points are critical. The specs on my site are based on turning the drive shaft so the rear most portion of the drive shaft has a vertical flat.
Now that you know where the holes are located you can decide what is the best approach to dealing with the support plates and any obstacles in your way. If you are lucky the new holes will fall all the older steel support plates. If you need to move your plates there are 3 approaches that you can take listed below.
Move the original support plates (this is what I usually do). When I do this I drill the original rivets from the inside of the tunnel just enough to pry the support plate loose so that the original rivets can stay in the tunnel and reduce the number of holes. You will then want to hold a body dolly or large hammer on the head of the rivet on the outside of the tunnel and peen over the remaining rivet on the inside of the tunnel. Now move the support plate to the new location per the specs for your skid. I prefer to use the original cross shaft hole but this is not always possible. Once you drill the mounting hole put a bolt through the mounting hole to mount it to the tunnel and now drill the rivet holes.
Buy the OEM mounting plates for an extra 10 and mount them in the proper location. I did this on a 91 Indy 400 and it worked out very nicely. The older indy's did not have tunnel braces like they did after going to 10 gallon fuel tanks so I had wanted them as well. I ordered rear support and tunnel braces from a 97 Ultra SPX and quickly discovered that many of the rivet holes and bumper mounting holes had not moved between models. Everything just fell in place perfectly. I validated the measurements and everything was perfect. I don't recall how I dealt with the front plates.
Make your own plates. Just make sure you use appropriate materials.
How to attach support plates?
I have used 3/16 and ¼ inch stainless pop rivets. I have never used the factory polaris rivets but some people do. If you are using ¼ inch rivets you can use the original rivet holes otherwise you need new holes in order to get a tight fit. These rivets are very heavy duty and it is easiest to use a long arm riveter or a pneumatic rivet gun. I have heard of some people using small bolts and nylock nuts but this is not how I would do it.
You need to be able to get the suspension in and out so be careful that rivet locations don't get in your way.
Tunnel coolers can interfere with the rear mounting location. I cut the cooler mounting flange just enough to slide the support plate under the cooler. Just don't cut into the cooler itself. You will also have to skip one of the bottom rivets when doing this. I also like to dent the inboard rear cooling fin on each side so that if the TSL ever hit it would just ramp up. After thousands of miles on a couple of these swaps I have seen no witness marks showing contact. It is really a tight fit though.
There are other issues that you could run into but nothing that can't be solved. I have never heard of anyone having to move a cooler or anything like that so before you get radical on your mods post to one of the boards and see how others have solved it.
Finally, before taking the sled out for the first time get the shocks rebuilt either by www.JBShocks.com or someone else. If you don't know the history on the shocks it could ride worse than it did with the old suspension until rebuilding.
Which suspensions should I get?
This is easier to answer by which shouldn't you get and they are as follows:
1. Extra 12 – don't waste your time
2. 2001 Pro X – There are many updates needed to the shocks to get a good ride. I can help you with this but it can get expensive. If you got the skid cheap it could be worth the shock updates.
3. 1999 -2000 Edge These are 1 off suspensions and had plenty of issues.
4. Almost any race sled suspension should be avoided unless you know what you are looking for. The shock packages are really stiff and Some years are one off suspensions.