|November 17th, 2011, 08:04 PM||#41|
Join Date: 11-17-11
Location: San Diego
First off I know this thread is old but I thought I would post this info for anyone who might be looking it up online.
You definately do not want to crank the bars "all the way" up. You should leave approx. 1/16"-1/8" between the upper control arm and the steel top out pad on both sides. You will have a very harsh ride if you don't leave a small gap at the top, you will need to get down low to see this gap.
The stock length shocks most likely will top out before you reach the top out pads making the ride very harsh "yes even bilsteins", unless you extend the lower shock mounts about .6" inches. I used a big flange nut as a spacer for this then went to longer grade 8 bolts for the lower shock mounts. This will allow you to have full travel without the shocks topping out which is what makes the ride harsh. This may not be true on every truck but it was certainly true on my 96 3/4 ton "8 lug" 4 by 4 Silverado.
If your not running bilsteins you need to be using them for this application because they will keep the upper control arms away from the top out pads. I never hear them hit on my truck at all, no harshness to the ride what so ever and the alignment is fine, I even managed to get the truck to NOT pull right which they seem to be famous for. The factory alignment was non existant, it was so far off it should have been a crime to sell me the truck.
I also needed to upgrade to 1/2" diameter bolts for the upper shock mounts. The factory installs 7/16" bolts for some reason and they create a major amount of play in the upper shock mount which you do not want. I think I needed to slightly ream the upper shock mounting holes "the ones on the truck" for the 1/2" bolts to fit, the shocks are made for 1/2" bolts already. If you don't do this it will increase the harshness of the ride considerably.
This will get you about 1 1/2"-1 3/4" lift in the front, I ended up with 1 3/4" lift in the front but the drivers side is heavier so it requires more turns to get the suspension even on both sides. I didn't need any of those so called special after market "keys" to get max height on my truck. This will put you well within specs on the camber adjustments. Mine was no problem to align at all, the camber adjustments were right in the middle of the settings.
To get the camber to adjust correctly you will most likely need to remove the "knock outs" from the bolt/frame area under the camber adjustment bolts/washers. You will need to remove the upper control arm bolts, washers and camber adjustment "cam washers" to see this "knock out" portion of the frame. The factory does not do this for you! You need to look closely and you will see that the steel frame part where the camber adjustment bolts go through is punched but NOT "knocked out" which prevents you from adjusting the camber on these trucks. You will need to pry and or pound them out using a hammer and punch or large screw driver which is what I used, there are 4 of them on each side that need to be knocked out. At that point you can adjust the camber to specs. It only took me about ten minutes per side to knock out and remove the metal from the bolt area.
As for getting the rear of the truck level with the front. It's best to go with leaf springs that have more arch to them for this rather than using blocks as you will only need to go up a couple inches. the stock shackles can handle this extra travel. Blocks work ok but allow for more movement of the pinion angle under load unless your using ladder bars. The after market leaf springs allow for much smoother travel and work better with the bilsteins.
The Pro Comp leaf springs part # 13211, and they work pretty darn well for me, they also have overload springs like the stock springs. They use one less spring in the pack, 4 springs + the overload instead of 5 plus the overload which is how the 3/4 ton trucks are set up. This allows for much smoother movement of the rear suspension using the bilstein 5100's. I used the 5100's with a bit of extra length over stock ones to make up for the longer downward movement of the new leaf spring.
According to Pro Comp, these springs are rated for 3" increased ride height but on my 3/4 ton 8 lug 4 by4 they only gave me 1 3/4" more lift which happened to be exactly what I ended up with in the front so my truck ended up nearly dead level. You will definately require an alignment after raising the front end, be sure and get it level at the correct ride height before you do the alignment. The camber adjustment is critical on these trucks, it has to be just right. The right side may need a bit of extra camber to keep your truck from pulling right, it's a very fine adjustment.
One problem I have with the Pro Comp springs is that the overload spring tends to walk out of alignment, both overload springs swinging outwards in the rear no matter how tight I get the U bolts. I fixed this by using some 14 guage shims between the U bolts and the springs. I can hit dips at 40 MPH now and it just flys through them smooth as can be.
The Tuff Country rear springs part # 19390, rated for 3" lift do cost more but have the extra leaf "5" leafs plus the overload spring so if your hauling much weight they would be better. You could also go with Deaver springs for better movement but they don't show a part number for these OBS Silverado's and they also don't have an overload spring.
I spent a lot of time figuring all this stuff out and I'm very happy with the results. None of the forums had very accurate information on this subject. It was all very general and vague to say the least. Hopefully these details will help some of you guys out. Some of the lift kits on the market are pretty scary and I would rather do this than run any type of lift kit. My truck is plenty high as is, the top of the bed comes up to my chest and I have to tip toe just to get into the front seat and I'm 6"5'. Ground clearance was not a problem on my last desert trip which was through the bad lands of burrego.
I'm running 285's 75 16x8 centerlines with T/A radials. This size tire required minor trimming in the front for those to fit without any rubbing at all. The 285's on my truck are just about worn out so I'm going with new 295's for a bit more traction and ride height. I hope this helps you guys out. I wish this info was available before I tried raising my truck. I had to figure out all this stuff out as I went along which took considerable time.
Last edited by chevell; November 18th, 2011 at 11:27 AM.
|November 18th, 2011, 03:04 PM||#42|
I'll Direc your TV
Join Date: 01-20-09
Location: Big Rapids, MI
thanks for the info, a little late though lol
FYI, I ended up not putting the keys in. Surprisingly I ended up putting a body lift in. Figured out with 35s it looks great, it's putting 33s on a Chevy/GMC with a 3" body that makes it look shitty.