CK5
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1989 GMC Suburban "Trail Boss" conversion

1989 suburban SLE conversion by Trailwagons
I put new leaf springs in the front and it still leans to the driver side, I added a zero rate and it still sits unlevel. The frame has to be tweaked but i cant see where.
I experienced a lean in the front that was actually due to a rear spring. It "looked" like the problem was in the front, but it still leaned with brand new springs. Evened out the back and then it sat level all around. It sounds less likely with a Suburban than a K5, but who knows.
 
I experienced a lean in the front that was actually due to a rear spring. It "looked" like the problem was in the front, but it still leaned with brand new springs. Evened out the back and then it sat level all around. It sounds less likely with a Suburban than a K5, but who knows.
I ran out and took some measurements, measurements are from the tire to the fender flare

FR 9.5
FL 8.5 (with a 1" block under the spring)
RR 9.25
RL 9

besides the front left, the other three are within half an inch

measurements from ground to flare (i know tire pressures can play into this and I did not check them but just for poops and laughs)

FR 40.75
FL 39
RR 39.5
RL 38.5
 
I ran out and took some measurements, measurements are from the tire to the fender flare

FR 9.5
FL 8.5 (with a 1" block under the spring)
RR 9.25
RL 9

besides the front left, the other three are within half an inch

measurements from ground to flare (i know tire pressures can play into this and I did not check them but just for poops and laughs)

FR 40.75
FL 39
RR 39.5
RL 38.5
If you want to rule out front vs rear springs:
  • Level the frame at the rear on jack stands and measure the front
  • Level the frame at the front on jack stands and measure the rear.
This will allow only one set of springs to work at a time.
 
think I figured out the running issue ( i hope), Its only getting 8PSI of fuel pressure at best. I picked up a fuel pressure testing kit from harbor freight with the GM adapter (man was that a pain in the a** to put in). fuel pressure ranged between 6-8psi and should be 10-13.

was going to cut an access hatch through the floor but someone has been here before
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picked up a new pump and strainer but it will have t wait till after Christmas.
 
swapped out the pump tonight, its running at 10 PSI. I want to remove the tester tomorrow before I drive it as the hard fuel line is pushed up against the bottom of the distributor with it in there.
 
spent most of my New Years Day pulling the axles from my stepside, tore the rear down, welded up the undercover fab diff cover, and started putting the rear back together.

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ive seen people put an axle shaft into a vise then put the carrier on it to torque the ring gear bolts, I gave it a try last night but it just wasnt working since the shaft is not the same thickness the whole way and it just kept trying to spin the shaft out of the vise. So it was back to the trusty way ive been doing it.

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I need to get some wheel bearings and seals for the axle so last night i went out and bounced from thing to thing. I could not get the wheel bearings removed with a slide hammer and the attachments I have, ended up destroying the driver side and just leaving the race in the tube. Looking around the shop I found a piece of thick wall exhaust tube that I am going to use to build the steering column for my samurai. It worked but it still took a ton of beating on it and mangled the ends of the exhaust tube.

pulled the pinion bearing off the old one to get the shim off. Both the new and old pinions have the same pinion depth number on the ends so setup should be fairly easy. My cheap harbor freight digital caliper i bought 15 years ago finally died so I need a new one.

Then I clearanced the old pinion bearing for a setup bearing with a small belt sander.

I "should" have the rear axle back together this weekend.
 
I was fed up with the stumbling issue after replacing almost all of the related components and ordered a new intake to accept a carb and all the associated bits. Being an OBD1 theres only so much testing I am capable of doing, I was recommended to get a bluetooth tester for it but thats even more money and a laptop or phone that I dont have and theres no guarantee it was going to "show me the light" lol since this thinig does not show any codes or CEL lights as is.

So i went out to start the change over to a carb (waiting for a fuel pressure regulator to show up), pulled the intake and the EGR ports are completely blocked

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Now I am wondering if i should just clean the ports, throw it all back together and test again... or just say forget it and go carb?

also (maybe unrelated) there is a bunch of what I am guessing is carbon buildup on the driver side of the engine in the valley, at first I thought it might be a shop towel it was clumped up that bad. Most of the bolts on clamps and brackets were all loose or half installed telling me someone was in here before.

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I would clean it up, seal it up and give 'er another shot before I reverted to a carb.
How did the intake gasket look? Maybe it was leaking too?
 
last couple of days ive been spending a couple minutes cleaning the engine valley till it gets dark then move into the shop and work on the rear axle. While the valley is not as clean as I would like (without tearing the engine apart), it is better than it was. I figure I will run some ATF in the oil for a couple of trips then do an oil change.

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I like to paint my diff covers, engines, and stuff like that grey or a lighter color, it makes finding oil leaks easier than black on black... but this aint it lol

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wife brought me aluminum color, the cap looked silver, in person it almost looks like spray paint chrome lol. thats gotta change. But i got the 4.56 gears and posi setup in it.
 
sometimes its the small things that irritate you the most.

I spent a good penny on this paint thinking it was going to be a better paint

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but after 5 coats of paint you could still see the marker underneath it

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and bare metal showing through

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quick trip to trusty Ace hardware

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and we have a painted diff

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I finally feel well enough to get back to work on this thing after dang near a month. Sunday I degreased and wire wheeled the majority of the housing and got it moved into the shop. Last night I started stripping it down.

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Its been almost 3 weeks since I have done anything on this thing besides going out and firing it up once a week. Between scouts, being sick, snow storms and cold temps, I have not wanted to go do anything with it. Well tonight with a torrential down pour I finally went back into the shop lol.

I drilled and tapped the hole for the Zip Locker
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I knew the breather was plugged and i cleaned it out as best I could with a pick and brake cleaner but wanted to clean it better, when trying to get it out of there the way it was bent over it was hitting the housing. So I spun it back around to try and bend the tube up and the whole thing just popped out. As you can see theres about half a thread in the housing it was threading into.

(after cleaning the hole a bit)
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Well now i can get a fitting with a pipe nipple and be better off
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I have seen people running ARB lockers and drilling a hole inside the housing and using a machine screw and P-clamp to secure the copper line to keep it from vibrating into the ring gear. I am wondering if anyone has done the same thing outside the housing to attach the air line and maybe the breather tube so theres less chance of them getting ripped off?

Im thinking in this flat spot where the yellow spot is
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If you want to rule out front vs rear springs:
  • Level the frame at the rear on jack stands and measure the front
  • Level the frame at the front on jack stands and measure the rear.
This will allow only one set of springs to work at a time.
Finally getting a moment and weather that is co-operating, I went out and put the suburban on level ground, crawled under it to see how off level it was to start. The frame rails are level as is, front and rear. Measured the from spring top to bottom of the frame rails and the rear was 11.75 even on both sides. The front was 7.5 on the driver side and 8.75 on the passenger.

Would putting the frame on jack stands still make a difference in measuring? Wouldn't it just be measuring unsprung distance? Or am I just not thinking correctly... Which happens a lot lol

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That is probably good enough to say your front springs are likely a problem, unless there is a small hole under one tire. I have 5 acres and cannot count on the ground being level anywhere but the concrete floor in the shop.
 
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