1998 GMC S15 jimmy 4wd build *TONS OF PICS*
hello, new guy here but my brother and i have been working on this project for the last few months and figured it kind of fits in with this forum so wanted to share...
this is my brothers truck. has had it for a few years and since its no longer a daily driver, it gets used for trail exploring. it had a 2" rough country lift on it before which consisted of upper control arms and torsion keys at the front and lift shackles out back with 30" tires. this lift really makes the poor factory design of the front suspension and steering very clear. after destroying multiple idler arms, a beefy custom unit was fabricated. this worked for a while but while climbing a hill in the imperial valley over the past thanksgiving wknd, the center link twisted causing all sorts of alignment issues. that was it, time for a change....
couple before shots, it actually did quite well off road considering its shortcomings. traveled thru the dunes quite well, tho HP was lacking thanks to the 3.42 gears
Last edited by ElCaminoManT; 04-30-2012 at 08:15 AM.
started tear down in the beginning of january
removed the problem causing parts....
rear came out too...
a high pinion D30 from a 95 cherokee was selected for the axle shaft spline count that works with the GM unit bearings so we can keep the ABS happy and the ZQ8 wheels we have for the truck. for suspension, it was decided to go with Off Road Direct's new radius arm system for the non ZR2 S10 trucks and SUVs. 6.5" XJ coil springs from clayton for the front and a spring-over kit from ORD for the rear. the project was delayed for 2 months as ORD was apparently not ready to ship product tho it was made for sale. anyway, thats the past, this is now i will say that the components of this system are quite beefy
chose to go with 33" nitto terra grappler a/t tires (285/75r16) on the ZQ8 wheels
the NP233C transfer case needed to be retrofitted with a fixed output yoke from a N231 so we could run a real front drive shaft
time to tack and hang some parts in place
with everything tacked in place front and rear, it was time to push it out of the garage to have a look. it was quickly realized we have some serious cali-rake going on. hoping the coils will settle some otherwise we will prolly have to put some small blocks or add-a-leafs out back to adjust the attitude a bit. we also sourced some 10" travel bilstein 5100 shocks from my brothers friend. we are trying to figure out what valving to run and since these have 255/70, we can at least give them a try. if they are too stiff, then we go to the 170/50 valving
swapped in an XJ pitman arm and quickly realized it wouldnt clear the track arm bracket. we tried a WJ arm which has more drop but that just hit the crossmember under the steering box. we ended up moving the track arm bar back a little bit
just as a note, the D30 and the rear 7.625 axles have been fitted with 4.56 gears. the rear is using the stock locking diff unit and the front is being left open to cut down on the likely hood of broken parts while cruising around in BFE. the truck is not being built with the intent as a hard core wheeler, but to be kind of a good all-around, go most places safely vehicle and have nice highway manners for those long drives to wherever we plan to go exploring. hence the lack of 44" boggers on a D60/14bolt combo
so far the truck looks like itll have some good flex ability
we have noticed a bit of a downfall with running this system in this little truck with this much travel. the side to side movement while the axle moves from droop to bump is a bit noticeable and the right radius arm upright mount hits the frame at bump and the bump stops kind of dont line up either. i dont think this will really be a major problem in normal daily operation and as long as the track bar and steering drag link stay in the same plane, the bump steer will be minimal and nothing abnormal will be noticed while driving. now if we were running this thing baja style off road, that may be a different story but then we would have gone with a true 4-link or something
needed to make a little clearance for the tires at the front bumper and at the rear fender/bumper caps
then needed to build some hub adaptors to be able to run the S10 unit bearings in the jeep knuckles as we want the ABS to remain functional and keep the GM 5/4.75 bolt pattern. the 3 bolt pattern to the knuckle is the same as jeep but the GM bearing is smaller overall and needs to be spaced out a bit so that the axle wont bind as well as keep the brake rotors where they need to be in the calipers. no one makes these yet, my brother built them by adding a ring to a WJ spacer from JKS that he milled from a piece of large pipe
had custom length braided stainless lines built and re-routed the factory hard lines on the rear axle so they are better protected from possible damage. since the original lower shock mounting was part of the u-bolt retaining plate, we had to weld in new mount tabs from trail gear. a new rear driveshaft was had by finding the rear most section of a 2 piece shaft from an ex cab S10 pickup and swapping the blazer front yoke to the pickup shaft. the pickup shaft is 1" longer so this makes up for the driveshaft being pulled out from the spring-over lift out back. new u-joints were installed for obvious reasons....
the front upper spring pad/bump stop mounting really left a LOT to be desired as the spring was essentially resting on the 2 bolt heads that locate the bump stop. not cool, so this had to be addressed. good thing for friends with plasma cutting tables! converted the thru bolt design to stud mount. now the spring and pad rest nice and even in the spring bucket
the factory jeep steering would not work for our application not to mention its pretty weak. rugged ridge seemed to have the best system for our needs. its not perfect, but it should work out just fine. the right side sway bar bracket had to be cut off for clearance. we will address this soon as we also need to move the sway bar mounting on the frame forward for it to work as the ends currently end in the coils...