I have a 99 EB expy that I lifted with the coil spacers and a torsion bar crank. I love the way it looks but now I have a nice driveline vibration. I knew there was a chance for it but figured it was worth a shot. Im wondering if there is a way to get rid of it? Its the auto awd model and it does it all the time, with or without the 4x4 locked in. It does it most on accel but will continue to hum even while coasting, its not as noticable under steady driving but its still there. Im guessing that I either have to bring it back down or have my blocks machined smaller. I went with the 3 inch ones which again I know are the biggest ones and the ones most likely to cause the noise, but I figured it wouldnt cost me much to have a machine shop turn em down a bit on a lathe. Whats the max people have gone without the vibration?

Also where do the blocks go, top of the spring or the bottom. If the top does the rubber pad go above the block in between the body and the block or between the block and the spring?

Also, might be related or might not, I havnt changed the shocks yet. It feels to me like they reach the end of their travel over the smallest drop off, like any downward movement of the axle at all is to much. If they are at the complete end of their travel could they be transmitting vibration to the fame/body that they normally wouldnt? While looking for shocks I have found rough countrys and procomps and bilstens that all say for 2-4 inches of lift but when I check the actual measurements of the shock on the rough countrys they are to long at fully compressed. I dont have the measurements handy but for example the stock shock compressed is 10 inches and the one for 2-4 inches of lift is 14. Doesnt that mean that at full compression of the suspension the shock will bottom out?

Need to get the shocks changed asap but dont want to get the 2-4 inch lift shocks only to have to drop the expy back down to get rid of the driveline hum and have the wrong shocks.

 

No one ever lift a 150 or an expy 3 inches? no one know the right shock measurements? Come on someones gotta be able to help.

 

try posting this in the 1997 to 2003 F150 section that's will get more traffic than the this section of the site. i had a 99 expy XLT exactly like yours but i ended up trading it in instead of lifting it i miss that truck. i wish i could help you out man. but try posting it in the other section.

 

K man thank you for the tip. I love my expy, I haul my wife and 3 kids, a forklift for work, a flat bed trailer full of quads and groceries anytime I need. I dont care what people say about minivans and fuel mileage I wouldnt give the expy up for anything else.

 

Hey Matt!! Good call on the shocks...most people would have overlooked the compressed length. You're correct, they would be too long. I'm assuming we're talking about the front shocks.....because this is common with the torsion bar crank. It's not what's causing the vibration, but it IS killing your ride. Are the front shocks bad?? Or are you only replacing them because they are too short?? There are ways to extend them......

You vibration is most likely from the rear drive-shaft. Your pinion angle needs to be adjusted.....and I have no idea how to do that on an EXP. Do any of the rear control arms have alignment cams??

The noise could also be coming from the front CV's. But unless one of the CV's is damaged, that's unlikely. But, with the AWD, it is a possibility. However, I had my torsion bars cranked up on my 99. I eliminated the disconnect system so that my front axle was always engaged. I never had any problems with the CV's.

Did you use aftermarket keys on the torsion bars?

 

isnt 3" to much. i thought the 97-03 f150's and the expeditions that matched them, were limited to about 1 1/2"s

 

A lot of people have lifted F-150's by cranking up the torsion bars and installing a lift block out back, but the Expy has coilsprings out back. Everything up front is the same and you will need oem length shocks up front. However, with the rear suspension being different, I'm not sure about what length rear shocks you will need.
If you are really unhappy with the ride, I'd install a body lift and back off the torsion bar's preload.

 

The back shocks are at the end of their travel, they are all the way out all the time. The coils on the back are no different than blocking leafs, it was simple, unhook shocks and sway bars, jack up body, stuff in blocks under the coils. Then of course bolt it back up.

I did use the stock keys and just cranked the bolts, I dont mind the stiffer ride, it always felt a little to much like a luxury car rather than a truck to me before.

I never had a vibration before but I saw someone say there are aftermarket half shafts for the front end to help clear it up on bigger lifts, I believe it was for a 6inch rough country kit. That bieng said it still sounds/feels like its coming from the back end. Ill look into the pinion angle to see if there is an adjustment somewhere.

The shocks are amazingly stiff for bieng original shocks with 200k miles on them but the expy has a tendency to porpise and did even before the lift so I want to replace them. I believe I will need longer shocks in the front as well, the truck no longer sits at the same height it did before, most of its travel will be up at the top of the shocks limit, bottoming out a shock isnt good for it correct? Even if its bottoming in the extend direction.

 

Oh, and there is absolutely no chane of a body lift ever ever ever ever ever going on any vehicle I own, ever. Unsafe and ugly. And no Im not just saying that because of something I heard or saw online somewhere. I had 1 truck with a 3 inch body lift, and it will be the last. broken blocks, broken bolts, repeatedly.

 

sorry man but until i see pictures of broken blocks then i cant believe this.

Ive been called to accidents where trucks with body lifts have hit solid walls and not crack a block or sheer a bolt.

Performance Accessories makes the best Body Lift on the market.

IMO if you hit something hard enough to break a block or shear a bolt your dead anyway so whats it matter.

NOW all this is being said means nill if the lift wasnt installed properly.

Sorry to do this in your thread but something had to be said about this.

 

I put the lift on myself, I know it was done right. It was on a 91 s-10 extended cab 4x4 with the manual and z generation of the vortec. It was a JC Whitney special body lift, the truck is long gone, like 10 years gone but I can assure you I broke blocks on it. The one under the drivers foot broke once and the ones up at the very front of the body broke twice. Both times it was after abusing the truck extremely badly, airborne several times and pushing small trees out of the way. Not sure what broke em but they broke.

Not sure why something had to be said about it but its cool, everyone has their own opinion. You are entitled to yours as much as I am mine. I had bad luck with the only one I have ever used, therefore I wont use one again.


But thanks for your help with the questions in the original post.....