About to Start a Highly Ambitious Project - 91 Suburban
Well, today I went on another successful trip to the junkyard, or at least mostly successful. I scored a GM Corporate 10-bolt front axle, leaf springs, transfer case crossmember and skid plate. It all came off a 1982 Chevy Blazer. Unfortunately, I didnít get the spring hangers because they were riveted to the frame and I didnít have anything to knock the rivets off with. I also didnít get the engine crossmember because of the rivets. I also didnít get a transmission or transfer case out of it because they werenít there.
For those of you that donít know, 4x4 vehicles are very rare down in my neck of the woods. So, Iím trying to turn my half-ton 1991 2WD Suburban into a 4x4 ĺ ton truck so I can pull my 9000 pound camper. I donít need 4WD on the Suburban, but I figured since I was swapping out the rear axle for a GM Corporate 14-bolt to help get my weight capacity up, I might as well work on the front end and make it into a 4x4.
I have both axles. For the rear, I have a 14-bolt with 4.10 gears. I got it off a 1999 Chevy 1-ton SRW truck. Iím going to rebuild it fully, and will probably drop a Detroit locker in there while Iím at it. I think it has a 65Ē WMS to WMS width, which I think is the right width for the Suburban. For the front, I got a 10-bolt with currently unknown gears, but Iím sure itís not 4.10sÖ that would be too easy. So, while I re-gear it, Iíll possibly add a traction-adder in, might as well. I still have not measured the width very accurately on this axle, but Iím hoping itís the same as the 14-bolt. I think the Blazer and Suburban have the same track width.
From what I understand, the older Blazers are essentially the same thing as a Suburban up until the B-pillar, so I figured the front end should just bolt up. Well, Iíve done some preliminary measuring and it does look like it will indeed bolt up to the front, but I will have to drill all my mounting bolt holes. The 80s Blazer and Suburban both use a solid front axle with leaf springs, and also appear to both use a 2-leaf spring pack. I thought that was a bit weird, and I may move up to a higher count leaf pack in the front to compensate for the perceived lack of weight capacity.
I also need a transmission and transfer case still. I am going to go with a TH700R4 because itís what I already have, but I need one with a short tailshaft to mate with the transfer case. I think Iím supposed to have either a NP241 or a NP208 transfer case, though Iím not sure which. Iím currently leaning towards that Iím supposed to have a NP241, though I may go with a NP208 since I already have one in the Bronco, and parts should at least partially work in both.
Mounts. I will definitely need a new engine cross member because the 2WD cross member hangs down too low and would interfere with the axle and spring pack. I was hoping that I wouldnít need it, but I donít think Iím going to get away with this. Going to have to source this one out. I have the transfer case cross member, but I will have to drill holes for it on the frame rail. I also need to source the spring mounts. LMC has them, so that shouldnít be a huge issue, but like all my other mounts, Iíll need to drill for them all.
Steering is one thing thatís troubling me some. From what I can tell, there are 2 different steering boxes, one for 2WD, one for 4WD. However, Iím not sure what the difference is. I do know that this 10-bolt front axle uses a weird curved steering arm that converts forward and backward motion into left and right steering. Weird. Iím not sure why I canít just rotate the center resting position of my current pitman arm 90 degrees and hook the linkage up, but from what Iíve read so far, I canít. Anyone know anything about this?
So, thatís where I am with this highly ambitious project and will be the biggest thing Iíve ever done on a scale of several magnitudes. Any comments or ideas are incredibly welcomed. Any help that can be locally provided is also greatly appreciated. I love this Suburban, and I hope to make it even better than it already is!