k4vbb
Active Member
Let me tell you guys about my air suspension conversion saga, and hopefully it'll be a resource for someone who wants to try to do what I just did. Could be that someone here can answer a question for me, too.
Firstly, I didn't go the route that most take. I did a LOT of reading here, and elsewhere, and decided that I did not want to use a conversion kit. The kits that used to be everywhere are virtually non existent for a 24 year old truck, and the ones that are available seem to be somewhat lacking in quality. My goal was to have a simple, working, and easily maintainable suspension. My new-to-me truck had air suspension on all 4 corners.
I did a lot of reading on this forum, and others, about the way that these trucks came as it relates to the suspension. I knew before I started that the front torsion bars that came stock in my truck are a bit weak to take on the load of the truck without the air-ride shocks in front. To compensate for this, the front shocks would normally be replaced by coil-overs, where the extra spring would take up the extra load. I did not want this configuration on my truck if I could avoid it, as it would relegate me to buying coil-overs every time I replace front shocks. For reasons I won't go into here, I don't intend to keep this vehicle for more than about a year, and I didn't want the next owner to have to deal with it, either.
To that end I made a list of parts I needed: Front torsion bars from a non-air-ride equipped truck, coils springs for the back, and new shocks front and back. The torsion bars were an easy find at the junk yard, and even found a non-rusty set. Coil springs I bought from RockAuto.com (I got the Moog variable rate springs). Shocks, I bought front and rear, all KYB, as I had heard good things about them. Got them for a non-air-ride truck due to the fact that mine would not have air-ride for much longer.
Got to the Pick-and-pull in Colorado Springs to remove the torsion bars. Of course, it started raining as soon as I got there. Had to remove them while crawling around in the mud, soaking wet. I felt like I was back in the field (former USMC). I got lucky with the key removal--a quick strike with the hammer got the driver's side key off almost immediately, and a few more (to include one that crushed my left index finger) on the passenger side got that one, too. But the front of the torsion bars were stuck in the lower control arms. Stuck like chuck. I predicted this and brought with me a sawzall to cut them free, which I did. All in all it took about 2 hours to get them out. If someone decides to do this, be VERY careful NOT to cut into the torsion bar. Any cut, no matter how small, into something that takes this kind of load can eventually lead to a crack. We don't want cracks in the torsion bars.
Got home to start the disassembly. Since my truck was a tad bit more rusty than the one in the junk yard, and I predicted issues removing both the keys and the bars, I rented a large jack hammer. This worked GREAT in removing the keys -- mine were a bit more stuck than the ones at the yard. Since I planned on re-using my LCA's, I did not cut them. Instead I used the jack hammer to try and get the torsion bars free. Except it didn't work in the least. Those things were in there as if they were welded. I tried copious amounts of PB-Blaster, a 3-ton jack to try to press them out from behind, and even acetylene. All to no avail. These things weren't coming out willingly. My next bright idea was to cut one of them off close to the LCA, and to drill holes in it in order to weaken it. I figured if I could drill enough holes in the remaining slug, around its edge, it might break free. The problem was that these torsion bars are apparently made out of vibranium, and I didn't have a drill bit that would cut into it. With no other alternative, I ordered new LCAs for both sides.
About a day before they were to be delivered I decided to get ahead of the game and remove the passenger side LCA -- the one with the cut-off slug of a torsion bar stuck in it. When I chucked it on the bench, the slug damn near fell out on its own. Some persuasion with a ball peen hammer did the rest. Since this one came loose I decided to try and remove the driver's side torsion bar again. This time I used the cut torsion bar and butted up the cut end to the end of the one that was still stuck in the LCA. I used a jack stand to support it, and started hammering away. Lo and behold, this one started to come free as well. With about 5 minutes of pounding on it with a sledge, it was finally free of the control arm.
Because someone at some point had replaced the lower ball joints in the LCAs, and they were in excellent shape, I decided to go ahead and use the original LCAs on both sides, and try and get my money back from RockAuto for the ones that were coming in the mail. This would also get my truck back on the road a bit sooner. I re-assembled the passenger side LCA and cleaned up the hole (where the torsion bars fit). Still waiting on the shocks to be delivered, I decided to turn to the rear springs.
The rear went extremely well. Removing the old air bags was a cinch, and using a spring compressor made installing the new springs a cinch. No need to disassemble any of the rear suspension components. One thing I did notice was that there was no "insulator" (the rubber pad that normally fits between the top of the spring and the vehicle). I guess the air-shock design doesn't need it. I figured that it was going so well, and easy, that I'd add them later, and to just deal with any squeaks that may come of it. There are no squeaks, by the way.
No sooner than I get done with the assembly, the UPS guy shows up and hands me a box full of shocks. Since I was already at the back of the truck, I removed and replaced those first. Easy, except that on the driver's side the gas tank is in the way of the top bolt. Removing the spare tire made for plenty of room to get to it, though. Not long after, the rear of the vehicle is complete.
Moving on to the front, I removed both air shocks. However, when I went to install the NEW shocks I noticed that they were about 4 inches too short. Back to google. I found out that the stock non-air-ride suspension uses a shock with an extended length of about 14 inches. The air shocks have an extended length of 18 inches. It appears that the air-ride equipped Expeditions have a shock mount that is in a different position than the rest of them. Problem. I tried searching for a replacement shock that would fit, but none of the non-air-ride suspension trucks use shocks of this length. I toyed with the idea of welding in an upper support for the shock, 4 inches lower than the one that was on the truck. But I came across a post where someone mentioned shocks for a lifted truck. I found a couple of them on the market, and eventually settled for the KYB MonoMax 565088. It had the dimensions I was looking for, and I promptly ordered a couple from Autozone, who was able to get them in the next day. Man, are these things stiff. It was a challenge to prime them -- took all my weight to compress them. Once primed, it was a challenge getting them in there, too. I had to use a pickle fork as a pry bar to squash them down and maneuver them into place, but I finally did it.
Challenge accepted, challenge overcome. Re-assembly was easy after that, except that I had already bolted the rear cross member (the ones that hold the keys) back into place. With it in place, there is no way to feed the torsion bar back into the LCA, so it had to come back out. Things to note: 1) thrououghly clean the ends of the torsion bars, the inside of the keys, and the inside of the LCAs, and use copious amounts of Anti-Seize in case you ever have to take it apart again. 2) The torsion bars come in left-hand twist and right-hand twist. They have a front and a back. When installing them, make sure they go in the correct place AND orientation. Any deviation could result in a torsion bar that twists the opposite way it was originally designed to. The front end of the torsion bar is marked with a small arrow to show the direction of twist.
Once the cross member is out, the torsion bars can be slid into the LCAs further than the would normally go, and the crossmember can be re-attached. Then, the torsion bars can be slid back into that crossmember, making sure that the keys are indexed correctly.
After all of that, I put the "keepers" back into place and cranked down the leveling bolts to roughly the same position they were in before I took everything apart. Putting the truck back on all 4's I could tell that the keys were cranked WAY to tight. The truck looked like one of those "carolina squat" trucks, where it looks like a dog dragging is rear end across the carpet. I'm not having any of that, so after about 6 adjustments later I finally got it looking right. I wound up backing both bolts all the way out, and then cranking them in just enough to take on the weight of the keys. The thicker torsion bars don't need to be cranked anywhere near as far as the thinner air-ride torsion bars. I imagine that I'll have to re-adjust them again in a few days after everything settles in.
The truck rides nice, but with those KYB monotube shocks up front it's a bit stiff. This too may work itself out in a few days.
With all that said and done, has anyone else done the conversion this way? If you have, what was your solution to the front shock situation?
Firstly, I didn't go the route that most take. I did a LOT of reading here, and elsewhere, and decided that I did not want to use a conversion kit. The kits that used to be everywhere are virtually non existent for a 24 year old truck, and the ones that are available seem to be somewhat lacking in quality. My goal was to have a simple, working, and easily maintainable suspension. My new-to-me truck had air suspension on all 4 corners.
I did a lot of reading on this forum, and others, about the way that these trucks came as it relates to the suspension. I knew before I started that the front torsion bars that came stock in my truck are a bit weak to take on the load of the truck without the air-ride shocks in front. To compensate for this, the front shocks would normally be replaced by coil-overs, where the extra spring would take up the extra load. I did not want this configuration on my truck if I could avoid it, as it would relegate me to buying coil-overs every time I replace front shocks. For reasons I won't go into here, I don't intend to keep this vehicle for more than about a year, and I didn't want the next owner to have to deal with it, either.
To that end I made a list of parts I needed: Front torsion bars from a non-air-ride equipped truck, coils springs for the back, and new shocks front and back. The torsion bars were an easy find at the junk yard, and even found a non-rusty set. Coil springs I bought from RockAuto.com (I got the Moog variable rate springs). Shocks, I bought front and rear, all KYB, as I had heard good things about them. Got them for a non-air-ride truck due to the fact that mine would not have air-ride for much longer.
Got to the Pick-and-pull in Colorado Springs to remove the torsion bars. Of course, it started raining as soon as I got there. Had to remove them while crawling around in the mud, soaking wet. I felt like I was back in the field (former USMC). I got lucky with the key removal--a quick strike with the hammer got the driver's side key off almost immediately, and a few more (to include one that crushed my left index finger) on the passenger side got that one, too. But the front of the torsion bars were stuck in the lower control arms. Stuck like chuck. I predicted this and brought with me a sawzall to cut them free, which I did. All in all it took about 2 hours to get them out. If someone decides to do this, be VERY careful NOT to cut into the torsion bar. Any cut, no matter how small, into something that takes this kind of load can eventually lead to a crack. We don't want cracks in the torsion bars.
Got home to start the disassembly. Since my truck was a tad bit more rusty than the one in the junk yard, and I predicted issues removing both the keys and the bars, I rented a large jack hammer. This worked GREAT in removing the keys -- mine were a bit more stuck than the ones at the yard. Since I planned on re-using my LCA's, I did not cut them. Instead I used the jack hammer to try and get the torsion bars free. Except it didn't work in the least. Those things were in there as if they were welded. I tried copious amounts of PB-Blaster, a 3-ton jack to try to press them out from behind, and even acetylene. All to no avail. These things weren't coming out willingly. My next bright idea was to cut one of them off close to the LCA, and to drill holes in it in order to weaken it. I figured if I could drill enough holes in the remaining slug, around its edge, it might break free. The problem was that these torsion bars are apparently made out of vibranium, and I didn't have a drill bit that would cut into it. With no other alternative, I ordered new LCAs for both sides.
About a day before they were to be delivered I decided to get ahead of the game and remove the passenger side LCA -- the one with the cut-off slug of a torsion bar stuck in it. When I chucked it on the bench, the slug damn near fell out on its own. Some persuasion with a ball peen hammer did the rest. Since this one came loose I decided to try and remove the driver's side torsion bar again. This time I used the cut torsion bar and butted up the cut end to the end of the one that was still stuck in the LCA. I used a jack stand to support it, and started hammering away. Lo and behold, this one started to come free as well. With about 5 minutes of pounding on it with a sledge, it was finally free of the control arm.
Because someone at some point had replaced the lower ball joints in the LCAs, and they were in excellent shape, I decided to go ahead and use the original LCAs on both sides, and try and get my money back from RockAuto for the ones that were coming in the mail. This would also get my truck back on the road a bit sooner. I re-assembled the passenger side LCA and cleaned up the hole (where the torsion bars fit). Still waiting on the shocks to be delivered, I decided to turn to the rear springs.
The rear went extremely well. Removing the old air bags was a cinch, and using a spring compressor made installing the new springs a cinch. No need to disassemble any of the rear suspension components. One thing I did notice was that there was no "insulator" (the rubber pad that normally fits between the top of the spring and the vehicle). I guess the air-shock design doesn't need it. I figured that it was going so well, and easy, that I'd add them later, and to just deal with any squeaks that may come of it. There are no squeaks, by the way.
No sooner than I get done with the assembly, the UPS guy shows up and hands me a box full of shocks. Since I was already at the back of the truck, I removed and replaced those first. Easy, except that on the driver's side the gas tank is in the way of the top bolt. Removing the spare tire made for plenty of room to get to it, though. Not long after, the rear of the vehicle is complete.
Moving on to the front, I removed both air shocks. However, when I went to install the NEW shocks I noticed that they were about 4 inches too short. Back to google. I found out that the stock non-air-ride suspension uses a shock with an extended length of about 14 inches. The air shocks have an extended length of 18 inches. It appears that the air-ride equipped Expeditions have a shock mount that is in a different position than the rest of them. Problem. I tried searching for a replacement shock that would fit, but none of the non-air-ride suspension trucks use shocks of this length. I toyed with the idea of welding in an upper support for the shock, 4 inches lower than the one that was on the truck. But I came across a post where someone mentioned shocks for a lifted truck. I found a couple of them on the market, and eventually settled for the KYB MonoMax 565088. It had the dimensions I was looking for, and I promptly ordered a couple from Autozone, who was able to get them in the next day. Man, are these things stiff. It was a challenge to prime them -- took all my weight to compress them. Once primed, it was a challenge getting them in there, too. I had to use a pickle fork as a pry bar to squash them down and maneuver them into place, but I finally did it.
Challenge accepted, challenge overcome. Re-assembly was easy after that, except that I had already bolted the rear cross member (the ones that hold the keys) back into place. With it in place, there is no way to feed the torsion bar back into the LCA, so it had to come back out. Things to note: 1) thrououghly clean the ends of the torsion bars, the inside of the keys, and the inside of the LCAs, and use copious amounts of Anti-Seize in case you ever have to take it apart again. 2) The torsion bars come in left-hand twist and right-hand twist. They have a front and a back. When installing them, make sure they go in the correct place AND orientation. Any deviation could result in a torsion bar that twists the opposite way it was originally designed to. The front end of the torsion bar is marked with a small arrow to show the direction of twist.
Once the cross member is out, the torsion bars can be slid into the LCAs further than the would normally go, and the crossmember can be re-attached. Then, the torsion bars can be slid back into that crossmember, making sure that the keys are indexed correctly.
After all of that, I put the "keepers" back into place and cranked down the leveling bolts to roughly the same position they were in before I took everything apart. Putting the truck back on all 4's I could tell that the keys were cranked WAY to tight. The truck looked like one of those "carolina squat" trucks, where it looks like a dog dragging is rear end across the carpet. I'm not having any of that, so after about 6 adjustments later I finally got it looking right. I wound up backing both bolts all the way out, and then cranking them in just enough to take on the weight of the keys. The thicker torsion bars don't need to be cranked anywhere near as far as the thinner air-ride torsion bars. I imagine that I'll have to re-adjust them again in a few days after everything settles in.
The truck rides nice, but with those KYB monotube shocks up front it's a bit stiff. This too may work itself out in a few days.
With all that said and done, has anyone else done the conversion this way? If you have, what was your solution to the front shock situation?
