Title:Slapper Bar Install

Common things you will probably need.

1 - Pair of SSM Lift bars for 83-92 S-Series Pickup
1 - 9/16 Deep socket
1 - 3/8 drive ratchet or pneumatic ratchet
1 - 9/16 open end wrench
Jack
Jack stands
Blue LocTite
Penetrating Oil
Wheel block or two

Other things you may need.

2 – 4" long ½" bolts and ½" nuts
4 – Washers for the bolts
4 – U bolts for leaf springs
Hacksaw
"Breaker" bar
pry bar
Tap and Die set
3/4" socket or wrench
11/16" socket or wrench
13/16" socket or wrench

*NOTE* SSM bars will not work with lowering blocks! If you are like me, and have (or had) lowering blocks in your rear suspension, and you still wish to keep it lowered after the install, I suggest that you either get your springs de-arched the amount of your drop or get new springs made to the specs that you want.

Theory of Operation – (lengthy)

This particular lift bar kit comes with 3 front snubber shims for tuning. It has an odd number, because you are supposed to have on more on the right (passenger) side then on the left to pre load the spring. I.E. If you use two shims on the right side, you would only use one on the left side or one on the right side and none on the left. The theory behind using one more shim on the right then the left is to help counteract the left front tire lift during acceleration. The left front tire upon instant acceleration, has the least amount of down force and tries to lift due to weight transferring from the front of the vehicle to the rear. The torque from the engine pulling up on the left side of the frame and pushing down one the right is what actually causes the tire to try and lift. All clockwise rotating engine powered vehicles suffer from this condition (CCW rotation engines will try and lift the right front tire and in those cases, you could put the extra shim in the left side, instead of the right) but it is not as noticeable in most stock vehicles because they do not have the necessary traction and torque to actually lift the tire off the ground. Even so, the added traction from traction aids like SSM Lift Bars can go a long way to adding the traction necessary to accomplish lift, but tries to prevent it from actually happening.

Newton (and I'm not talking about those fig things either) stated that for every action, there is an equal and opposite reaction. In this case when torque is applied to the ring and pinion it causes the tires to rotate. The equal and opposite reaction is that the housing wants to rotate in the opposite direction of the tires. Picture your truck as a lever with the fulcrum being the rear suspension and the load (the vehicles weight and other downforce) and force (the engine) being on the same side. Since the housing is "stationary" and severely limited in it's ability to turn because it is bolted to leaf springs, the leverage from the length of the vehicle in front of the housing with the weight of the vehicle acting as a load, keeps the vehicle from lifting and flipping over. If you have enough torque to overcome that down force and enough traction (the friction of the tire and the pavement) to keep the tires from spinning like some high end race cars and dragsters, then you can actually cause you vehicle to lift the front end totally off the ground and flip over on itself. You can prevent this from happening and change the "class" of lever your vehicle acts like by adding wheelie bars. That is a whole different issue though and doubtful that you can get that type of torque and traction in an 83-92 S-series pickup without paying seriously obscene amounts of money.

Anyway, when the housing tries to rotate it causes the portion of the leaf spring in front of it to arch upwards and the length behind it to flex down, the leaf spring binds into an "S" shape. Once the spring reaches the point where it's resistance to flex is greater then the force that is causing it to flex, it will try to "spring" back to its original shape. If the traction is good enough to keep the tires from spinning, and the force still being applied is great enough to bind the spring back up but not enough to lift the front end, then it can cause what is know as "wheel hop." "Wheel hop" means that the springs are binding up and forcing the tires to leave the pavement in order for the springs to un-bind and straiten out. This form of traction loss is not very common in trucks though, due to the overall weight distribution of a truck.

Newton's law of inertia states that an object at rest, will remain at rest, unless acted upon by another force. This is relevant to traction loss too, in the perspective that during instant acceleration, your vehicle (at least the body) wants to remain at rest. Since the engine is causing the tires to rotate, moving your vehicle's frame forward overcoming inertia, but the body wants to stay exactly where it is, it causes weight transfer from the front to the rear of the vehicle. When weight transfer occurs on an un-tuned suspension, it can cause the housing, and consequently the tires, to move up away from the pavement. When this occurs, the weight of the vehicle forcing down, in combination with the housing trying to move up reduces the amount of traction available. This is known as "squat" in automotive world. When this happens, the amount of traction is lessened somewhat simply because the ability for the tires to plant and transfer energy to the ground is reduced.

The geometry of the suspension changes with the install of lift bars and uses that same torque energy on the housing that would typically cause tire hop, spring bind and squat, and directs it down into the pavement. It does this by causing the front of the leaf spring to act a solid piece of metal that can pivot at the spring eye. This solid front "spring" now uses the torque of the housing to its advantage and instead of being able to bind up the front of the spring, it is forced to pivot at the spring eye causing the rear suspension to be forced down. This downward action "plants" the tires into the pavement and significantly increases your traction, and will also cause your vehicle to weight transfer more efficiently.

Installation Instructions

Before you jump head first into this install, you will want to crawl under the back of your truck and check rear lower shock mounts. What you are looking for is to see whether they are welded to the lower spring perch like mine were. If they are welded in place, you will need to buy bolt-on lower shock mounts. I went to my local AutoZone and bought 2 of the Help! Universal Shock bolt kits far about $10. They ended up being too big a diameter to fit inside the rear shock eyes, but I didn't find that out until all the parts houses were closed and I had pulled my shocks loose to try and fit them. I was able to find some ½" bolts that were long enough, nuts and a couple of washers instead, but I still recommend using designated shock bolts if they will fit your shocks.

Once you have determined whether or not you actually need the shock mount kits or weather they will actually work on your Truck or not, you will want to soak the nuts and threads of the u-bolts holding the shocks and the spring perch in place thoroughly. This will help to lessen the chance of breaking bolts, nuts, tools and fingers and make it easier to get them off. If your u-bolts bolting your springs to the spring perch and housing are too rusted or the threads are too messed up, you may choose to replace outright with new ones. You can get leaf spring u-bolt kits at your local parts house for a couple of bucks each. Worse case scenario, you will have to cut the u-bolts off the housing and replace them with new ones. Since I installed 2" lowering blocks on my truck just over a year ago, my u-bolts were still in pretty good condition, with the exception of built-up of road grime in the threads.

I started my lift bar install at 8:00 PM sharp, and began by gathering the tools and equipment that I would be using. With the Lift bars just out of the box, I installed the snubber shims onto the bars and removed the two 3/8" u-bolts to prepare for installation. I used 2 shims on the right (pass. side) and the last one on the left (drivers side). Next I blocked the front tire and jacked the rear end of my truck up. Placing the two jack stands on both sides of the frame just in front of the front spring eye (DO NOT PUT THEM UNDER THE AXLES!), I lowered the rear of the truck onto the jack stands, completely relaxing the rear suspension. I then used my 16" breaker and a 13/16" socket to loosen the lower shock retaining nuts and then backed them off using an air ratchet. After that I pulled the shocks loose from the spring perch using a small pry bar, I left them attached at the top so that they were hanging down waiting to be re insatlled. Next I used the 11/16" socket and breaker bar to loosen the eight nuts holding the u-bolts in place and tried to finished by backing them off with the air ratchet. After fighting for nearly an hour to get the nuts off of the u-bolts with a socket and a ratchet, (because the air ratchet didn't have enough torque to back the nuts completely off the u-bolts and because I also didn't want my neighbors to complain about the noise), I finally got them loose. Once I finally got them removed from the 4 u-bolts and the spring perch, I used the jack to lift the rear end enough to remove my lowering blocks then lowered the jack and re-positioned the housing so that the nipple on the top of each leaf spring seated into the small hole in the housings spring perch. Once I had finished doing that, I took my 4 u-bolts and 8 nuts into the garage and used a wire wheel to clean the u-bolts up a little. I then used a reciprocating saw with a metal cutting blade and a vise to cut some length off of the bolts. Since the u-bolts were for 2-4" lowering blocks (2" in my case) I had to cut off quite a bit of thread so that it wouldn't drag the ground. After I cut all four bolts, I used a die to clean up the threads of the bolts and a tap to clean the threads of the nuts so that they would thread easier. I spent nearly and hour and a half just working on the bolts and nuts, but unless you also have lowering blocks and have to cut the bolts, you shouldn't need to spend nearly this much time on them.

Now that I was finished messing around with cleaning up the u-bolts, it was time to actually bolt the lift bars to the springs and housing and that was exactly what I did. I then positioned the nipple sticking out the bottom of the springs into the hole in the center of the lift bar spring perch and then installed the four u-bolts. Using my air ratchet and the 11/16" socket, I tightened the nuts and washers down (or up, however you look at it). With the lift bars in place at the rear, I then positioned the jack under the front of each bar and jacked them up into position so that I could install the 3/8" u-bolts that attach the front of the bars to the springs. Once the snubbers were centered and within a ¼ - ½" of the spring eye I tightened the 3/8" u-bolts in place using both the upper and lower nuts and then lowered the jack. I repeated this process for the other side and was ready to attach the shocks to the lift bars with the ½" bolts and washers. Puting a washer between the shock and the lift bar and the shock and the nut on both sides of the vehicle so that it could rotate on the bolt without damaging the bar or loosening the nut, I then tightened the nuts down on the bolts. Since I use KYB Gas-A-Just shocks on my truck (a VERY stiff shock), it took me a while to get them compressed enough to get them onto the bolt, but once I got them tightened down it was time to jack her up and pull her off of the jack stands. Her tires touched down at 12:31 AM and it was only a matter of minuets before I had all the tools and equipment cleaned up and was in the shower cleaning up for bed.

I started the install at 8:00 PM and stopped for a ½ hour for dinner at 9:29 PM, resumed at 10:09 PM and was completely finished by 12:31 AM. I wasted more time working on my u-bolts, searching for bolts to install my shocks, and taking notes for this article, then it actually install took to install the bars. The Overall install was very easy and the rear suspension feels MUCH more solid now. I could tell the difference immediately that the bars were doing their job, and would do it over again if I had to.

It could have a quicker and simpler install if SSM had provided shock mounts with their bars and I called them and questioned them about this issue. When confronted with the question of "Why don't your bars come with lower shock bolts?" durring their brief technical support timeframe, their responce was this. "Use a couple of 1/2" bolt and some washers to attach the shocks. We used to include the proper sized shock studs for your particular application, but we can no longer get the parts." I would think that since they have the facilities to make the lift bars, they could make or could get them made but that is beside the point.

In my opinion, if you are looking for better traction and thinking about a suspension mod, this is the way to go.