Rear suspension sag

[94fordguy]

Hey 94fordguy,
I looked at my setup and was not able to see how you moved the lower arm back. Mine is maxed and will not move any further back ( I would also have to drill holes). How did you do yours? Also, thanks polaris_1334 for the pics. I don't have a solution--except mine does the same thing, just not as bad--but your pic confirmed that my rail wasn't bent: your's has the same curve after the lower arm mounting point!

If you only need a little bit of pick-up (stiffening) you can simply drill a new hole right behind the existing hole, remove the bolt, and push the arm back with a set of clamps. As I stated mine was sagging pretty bad after all the snow and ice got caked on it, and moving the arm back about 3/4 of an inch did wonders for it.

Once again, be extremely careful, there is a very high amount of pressure on the springs and you need to be paying attention so that nothing slips, I was extremely amazed at how hard it was to push those springs back even with heavy duty clamps.

Remember, a small movement will give you a LOT more pressure

 

[dieselred]

Thanks. It felt like a lot of pressure when I pulled the bolt, so wasn't sure I could do it. But the clamps explain everything.

 

[dieselred]

Here are some thoughts...Rob. It's not a good idea to change the location of the rear arm like 94 did. It will also change the function of the shock & the length of travel. Must not be too bad if 94 has already been doing it. Shocks have a max travel limit & if you make a change to the distance of the swing you run the risk of bottoming the shock on a big hit-that could destroy the shock. Or the shock may lose some effectiveness because you have changed the movement points.

The shock does not control sag, only the springs. I assume that the suspension is all "flat" on a floor-if any part is on a block or rise it changes sag in the rear, makes it worse if the front suspension is collapsed. Can't tell in the pictures if the sag is with or without rider-assume rider is on the sled in pic 2. Will also assume that Rob isn't a big boy, 250 or more. If rider is on the sled & Rob is not a big guy then the springs are toast. (Or you have a broken suspension component) All springs take a set & some lose temper-then time for new springs. Going too heavy on rear springs has a negative effect on sled handling & weight transfer. Since the front track shock acts as a fulcrum, jacking up the rear puts the nose down. On the Edge chassis this is not so bad since they needed more ski pressure. But on The IQ, rider foreward sled, it can make the sled ill handling & nose heavy. When you pin the throttle you need some weight transfer to get the nose up, especially in the powder. Another thing on the IQ you are sitting/standing more over the front axle so the riders weight is much less on the rear suspension than on the edge.
The Polaris sleds are designed with sag. The most uniform method is to measure sag at the rear mounting bolt. (Measuring on the bumper is different because as a sled gets longer the rear drop at the bumper is greater.) First-measuring the distance to the floor without a rider, lift the rear of the sled & then let it sag to measure #1. Then get on the sled & jump up and down a few times, then sit in normal riding position & measure again. Polaris says the distance at the rear bumper should be about 5". I go for 4.5" to 5" at the rear suspension bolt.
As a practical matter I run my rear spring in the loose postion until hill climbing (in set up snow)& then crank it all the way up for less weight transfer. That way you have good weight transfer in the powder but no wheelies climbing. On hardpack this can lead to washing out in corners so you may need more rear spring tension, hasn't been an issue with mine. But if you get my drift, I use the rear springs as a suspension tuning tool.

If you determine that you need new springs, I have some. I put a Holz in my 09 so have all front & rear arms, springs, & a bunch of parts. Rear suspension parts retro back to 03 & are lighter on the 08/09 Dragons. I'll sell everything for $100 + $15 shipping, less than the cost of new springs. Picture of parts available.

Good luck,
Ron

Which springs are they .045,.054,.075s?

 

[Ron]

Thanks. It felt like a lot of pressure when I pulled the bolt, so wasn't sure I could do it. But the clamps explain everything.

Release the pressure on the rear springs, fold them back past the track & you should have very minimal pressure if any on the bolt.

 

[Ron]

Which springs are they .045,.054,.075s?

Different designations now?...Newer, better?, don't know...per Polaris parts on line:
PN 7041629-067 & 7041630-067. These are the Mid diameter listed at .359/77 with optional of lighter .347/77 & heavier .375/77. Mine is a 163" track but the same springs are used on the 155".
These are the same PN's listed on the 2006 600 RMK.
As I recall diameter of springs changed when Polaris changed from round springs to square ones. The new springs are square & perform better-less diameter, less weight.

 

[Rob1334]

Here are some thoughts...Rob. It's not a good idea to change the location of the rear arm like 94 did. It will also change the function of the shock & the length of travel. Must not be too bad if 94 has already been doing it. Shocks have a max travel limit & if you make a change to the distance of the swing you run the risk of bottoming the shock on a big hit-that could destroy the shock. Or the shock may lose some effectiveness because you have changed the movement points.

The shock does not control sag, only the springs. I assume that the suspension is all "flat" on a floor-if any part is on a block or rise it changes sag in the rear, makes it worse if the front suspension is collapsed. Can't tell in the pictures if the sag is with or without rider-assume rider is on the sled in pic 2. Will also assume that Rob isn't a big boy, 250 or more. If rider is on the sled & Rob is not a big guy then the springs are toast. (Or you have a broken suspension component) All springs take a set & some lose temper-then time for new springs. Going too heavy on rear springs has a negative effect on sled handling & weight transfer. Since the front track shock acts as a fulcrum, jacking up the rear puts the nose down. On the Edge chassis this is not so bad since they needed more ski pressure. But on The IQ, rider foreward sled, it can make the sled ill handling & nose heavy. When you pin the throttle you need some weight transfer to get the nose up, especially in the powder. Another thing on the IQ you are sitting/standing more over the front axle so the riders weight is much less on the rear suspension than on the edge.
The Polaris sleds are designed with sag. The most uniform method is to measure sag at the rear mounting bolt. (Measuring on the bumper is different because as a sled gets longer the rear drop at the bumper is greater.) First-measuring the distance to the floor without a rider, lift the rear of the sled & then let it sag to measure #1. Then get on the sled & jump up and down a few times, then sit in normal riding position & measure again. Polaris says the distance at the rear bumper should be about 5". I go for 4.5" to 5" at the rear suspension bolt.
As a practical matter I run my rear spring in the loose postion until hill climbing (in set up snow)& then crank it all the way up for less weight transfer. That way you have good weight transfer in the powder but no wheelies climbing. On hardpack this can lead to washing out in corners so you may need more rear spring tension, hasn't been an issue with mine. But if you get my drift, I use the rear springs as a suspension tuning tool.

If you determine that you need new springs, I have some. I put a Holz in my 09 so have all front & rear arms, springs, & a bunch of parts. Rear suspension parts retro back to 03 & are lighter on the 08/09 Dragons. I'll sell everything for $100 + $15 shipping, less than the cost of new springs. Picture of parts available.

Good luck,
Ron

Thanks Ron, that helps a lot. What I think happend was that when the one shock wore out, it may have put added pressure on the springs. When the suspension was put back into order, it showed the springs were wore out.

The only other thing I can think of is that front mount on the rear shock. It seems like it camed forward when it installed, and was pushing the whole rear forward and the everything else stright down. Tonight I was messing with it and moved that bottom mount past the binding point to switch the shock from pushing forward on that pressure to going down more. What I noticed was that it "triangulated" the suspension more and seemed to be moving more correct, but it would roll down into the track when weight was added to it. I think I was getting closer by moving that, and that might be where it may be causing problems. which way should it be pushing the force on that spring? Hopefully clear enough on what i'm trying to say, haha, but if it should be binding above the bottom mount and push forward above the rear mount it is probably the springs. If it binds behind that lower shock mount and push down, I'm missing something.

And Ron, I weigh about 180 with gear on so ya, it shouldn't sag like that hahaha.

 

[Ron]

Thanks Ron, that helps a lot. What I think happend was that when the one shock wore out, it may have put added pressure on the springs. When the suspension was put back into order, it showed the springs were wore out.

The only other thing I can think of is that front mount on the rear shock. It seems like it camed forward when it installed, and was pushing the whole rear forward and the everything else stright down. Tonight I was messing with it and moved that bottom mount past the binding point to switch the shock from pushing forward on that pressure to going down more. What I noticed was that it "triangulated" the suspension more and seemed to be moving more correct, but it would roll down into the track when weight was added to it. I think I was getting closer by moving that, and that might be where it may be causing problems. which way should it be pushing the force on that spring? Hopefully clear enough on what i'm trying to say, haha, but if it should be binding above the bottom mount and push forward above the rear mount it is probably the springs. If it binds behind that lower shock mount and push down, I'm missing something.

And Ron, I weigh about 180 with gear on so ya, it shouldn't sag like that hahaha.

Not clear on what you are saying but here is a pic of the front & rear mounting on the rear torque arm. Both lower arms are close to vertical in normal mode-no rider. Different sled, differnt shock but same geometry!

Have to run so hope this helps..will check back in an hour or so.

 

[Ron]

Sorry forgot to reduce pic size, over & out.

 

[Rob1334]

Hmm, same way I had the when they were saging really bad. Looks like I need new springs, haha. Ya where that bottom shock is mounted I tested the shock binding in both directions of where it mounts to the rails. It gave a lot better pressure and seemed like it was right, but it would push down into the track and bottom out, so at least I know what that does haha.


So it looks like springs then I guess.... this was probably the most stressful thing to figure out haha...

 

[dieselred]

Oops, my bad I was looking at different part #s. I am looking for the .375s