Hey Vortec Guys! / Sierra pickup / Suburban / Yukon etc - Finally has Index!

[rho]

@rho and oh hey, if you are going the torsion key route on that 2wd pickup, I have my stock Sub Z71 keys sitting around in the box my Rancho lift keys cam in. I've read before that the stock 4wd/Z71 keys are supposed to provide a similar amount of lift over the stock pickup keys. I don't have that reference bookmarked, but have seen people mention it. They're yours for a reasonable low price, not much more than the cost of shipping those heavy things. I have a pic somewhere of the old keys on top of the new (or vice versa) to illustrate how much the hex-shaped hole is rotate in the key. I could take a pic of my stock key and maybe you can compare it to yours to get a good idea if they'll provide you with enough difference from your factory keys.

found the old pics, the Rancho lift key is on the bottom. If you print that pic out life-size and lay it on your factory key you ought to get a similar rotational offset, IIRC. It was a posting one of the GM truck / SUV boards that had the details, don't think it was Pirate4x4.

eta weirdness, that part number comes up listed as both an OEM part for all manner of GM trucks and SUVS spanning GMT400, 800 and later, but it also is presented as a 'leveling kit' to take out the factory nose-down attitude.


I will say I got almost as much height cranking on the stock keys as I did the aftermarket 'leveling' keys. The only difference seemed to be that stock the adjusting bolt only had a couple threads left before it bottomed out - AND more importantly the bolt heads were nestled down in the crossmember vs the aftermarket keys leave the bolt 8-9 threads clear and the bolt heads hang out the bottom of the crossmember. Not good if you are going to grind the frame rails over something.
The rotational angle of the lower control arms and CVs is the same with either key, the aftermarket key will just let you drive things far enough to bottom the upper control arm against the movement stop, which is a Bad Idea.
So I might suggest noting where your torsion adjuster bolt is right now, how many threads between the bolt head and the crosskey and put some turns on them and see what a good ride height is for you, using the factory keys. You may not need to spend any money on keys, aftermarket or mine. It's an 18mm bolt and unless it's rusty as hell you can turn them readily enough with a breaker bar with the vehicle sitting on the ground. Just shoot them first with penetrating oil. Easier if you jack the front wheels off the ground. Measure the height of your wheel well opening over the front hubs as a reference point before you start and as you finish. And you will almost certainly find the vehicle is sitting unevenly before you even begin as the driver side typically sags from always having the driver weight in the vehicle.

Right on, that is some stuff I'll keep in mind... Sounds like I need to make a pick n pull trip sometime to see if I can scare up a torsion bar mount crossmember and a couple torsion bars and maybe see what other differences there are besides the obvious ones like LCAs, shocks, etc. So far this is a lot easier than a ax15/NP242 swap i did on an XJ years ago.
I do need to start asking people around here if I can take measurements off all of this stuff on their truck, hah.


I think this weekend, weather permitting... I'll tackle the coil spring spacers in the front and the additional leaf in the rear and also get the last of the bushings that I should have replaced but didn't the last time I had it apart because I'm an idiot.

I'm toying with the idea of putting in my home-made torsion bushings either tomorrow or Wednesday. Right now I have both days mostly free. And the torsion bar unloading tool is 'free'. Don't have my lower control arms yet, but it is quick work to dismantle the torsion setup especially with air tools. I don't really want to wait for a month+ to find out how they'll fit and work. And if I put them in now I can be learning that now and in the coming weeks, while I maybe get the polyurethane bushings to modify. and I have to get under there again anyway, something is STILL knocking around on stops and starts as the vehicle body weight shifts fore-aft. Got to find out what that is before something breaks at an inopportune time.

I hope the install goes well! Air tools or a good electric impact really make working on this stuff so much easier. I already know I can't get the control arm bolts out without power tools, which is frustrating but it is what it is. I'm curious how the bushing experiment goes, I haven't heard of a lot of people making their own from hocky pucks. Would making something out of polyurathane or delrin or something work in case the rubber doesn't work out?

We're chasing a similar fore/aft loading/unloading knock somewhere on our truck. That kind of stuff drives me NUTS and its such a huge pain playing find-the-clunk. Hoping yours isn't too bad to find and fix!

 

[rayra]

I'd seen the puck trick used on some very old vehicle where rubber parts weren't available. And elsewhere as vibration dampners / isolators for air compressors and other motorized equipment in shop environments, so the idea came to mind. I have some question on how they'll hold up to the chewing the torsion mount design seems to impart. The original design seems to be made with that motion in mind. But that room for movement is also what eventually makes the rubber core fail.
My designing the replacement bushes like a control arm's bushing, with a thick flange AND doing that on both sides effectively filling up the crossmember and restricting any fore-aft movement of the crossmember on the mount might help or it might cause harm somewhere else. Maybe force the metal of the crossmember to torque and develop stress fractures. (shrug) don't know. We'll see. But I'm not taxing the vehicle hard nor driving it more than 5-6k mi / year so I might never see any problem from changing the mount design.

I installed them this afternoon. I still have some movement / clunk / creak going on, but I presume it is in my worn lower bushings and ball joints. If I still have those signs after changing the lowers I'll start crawling around under there again. Done that several times, can't find anything loose, cant find any rub marks or shiny spots form things shifting around. I might also change the engine and trans mounts just on general principles. 17yrs, 140k mi.

-

Went ahead today and installed my home-brew replacement bushings for the torsion bar adjuster crossmember mounts. Took a bunch of different implements to drill / carve / cut / drum sand the old rubber out of the mounting rings.
Quick enough to break things down with an air impact and the proper torsion 'unloading' tool. Then the messy tedium of carving the old bushings out. Cleaned up the metal bolt sleeves from their chewy centers using my big disc sander. Once the mounting ring was cleared out I took some time test fitting my cut-down hockey pucks, to the point of pulling the crossmember down onto the new bushings to make sure things fit, before greasing up everything.
Started with the driver side.

When I did the passenger side I tried a different technique for drilling out the old bushing. On the driver side I went with the largest drill bit that I could angle in there, ~3/8" thinking to hog out as much rubber as I could, but that left a lot of rubber still attacked to the mount ring after the core came out. On the passenger side I elected to first drill a lot of much smaller holes all the way around up against the mount ring. Then stepped up thru 3-4 sizes of bit, each time taking more of the rubber nearer the outer ring. That worked a good bit better, the core was freed more readily and there was a lot less rubber that remained. Still took a hand rasp, a dremel wand with a wood carving bit, a drum sanding bit in the drill, and some carpet knife shaving to get most of the remainder out. Enough so that the new bushings would properly seat.
After that I shimmed the bolt sleeves a bit with a few wrappings of electrical tape - note for 'next time', don't bother taking ALL the old rubber off the sleeve, it leaves things a little loose - and found out I was out of silicone grease. Wound up using some super gooey bearing grease to hand-smear the new bushings on all their surfaces and put them in place in the mount rings. Once I got the cross member up in place above the bushings I was able to work the passenger side into place and set the bolt but then that loss of play made it tough to get the driver side in place. I wound up using a thin narrow putty knife between the mount and bushing to get teh bushing edge to tuck in. After that the crossmember pulled down just fine.

Came out to a nice snug fit. Whether that's a good thing in the long run, I don't know. But it looks fine right now. And it feels fine on the road.

Reassembly was quick and easy and rushed so I could return the loaner tool before the evening rush hour traffic went to hell. I'll fine tune the ride height tomorrow, today I just eyeballed the adjuster bolt depth.
My workbench and garage is a disaster, I just threw everything in / down and took off for the Vatozone. Later when I clean things up I'll take some detail pics of the reinforced rubber washer I put in there. The driver side was getting pinched already, but didn't look cut yet.

 

[rayra]

And I probably will go ahead and re-size the closest polyurethane bushing set I can find, both as an exercise and in case I decide to change these out when I do the lowers. Have to unship the torsion bars yet again for that install anyway. And I wasn't happy about using petroleum-based grease on the rubber bushings, anyway. Did it for expediency's sake. But the two aren't really supposed to go together, that's a big part of why ball joint boots don't last. That and overfilling them.

 

[Overlandtowater]

rayra that looks great!

 

[4bytruckin]

This probably the best place for this question. I have a lifted 2000 Tahoe. GMT400. Old body style. I am going a different route than normal. Its 4wd and I'm contemplating going Long travel and 2wd. Can I use 2wd control arms on a 4wd. If so will a 2wd lift spindle fit?

 

[Martinjmpr]

Question for the GMT800 Suburban Mafia: If I'm replacing ball joints, would it make sense to just go ahead and get new/improved lower and/or upper control arms as well?

And if so, which LCAs / UCAs are recommended? Not intending to go over my current ~ 2.5" lift but wouldn't mind beefier components up front.

And are there any other wear components on the front axle/steering that I need to think about replacing on a 182,000 mile truck that sees heavy towing?

 

[Pacific Northwest yetti]

It was more expensive, but i did the ball joints, and LCA's/ LCA's all in one sweep. I ended up going with OE lower,s and ICON Stage two uppers. lots of towing hauling on my 2004 2500, has 250k miles now.

Those with the diesels beef their front ends up, as the diesel is so much heaver.

 

[rho]

I just finished with my partners truck... new stock-ish LCA's with ball joints, new upper ball joints, new coil springs, shocks, isolators, 2" lift spacers, sway bar links, tie rod ends. Our pickup has the rack and pinion steering so we had a little less steering stuff to do, but not much.
We also added a leaf in the rear spring packs and flipped the overload leafs over as well as added new shocks. I ordered the wrong rear bumpstops so those are going to go in when the new ones come in.

Its a little bit stiffer, sure, but it doesn't ride on the bumps anymore and it doesn't wallow or float or roll or generally feel like a boat. It drives, tracks and handles a lot better and its much more comfortable imo as its not floating or slamming into the bump stops over speed bumps or bumps in the road anymore. We're planning on keeping this truck for a while which is why we started putting some money into it, so a few years down the road it'll probilly get 2wd mid-travel setup in the front and better leafs in the rear and much better 2.5" shocks for grins.

 

[rayra]

Martin almost certainly the idler arm and maybe its support, they rarely get greased as often as the rest. Tie rod inners and outers are inexpensive and tightening all that will help reduce bump steer and wandering, which in turn should help with keeping the trailer steady.
I haven't researched heavier duty control arm$ and joints$. But for a basic refresh having replacement bushings and ball joints pressed into your old arms plus the parts costs about the same (within $20) as buying some of the aftermarket complete arms. To me it was worth it to just get the whole arm set and swap it in, instead of having to mess with taking it apart, taking the parts to a shop to have things pressed out and in, etc.

4bytruckin, the pickups are coil vs torsion, I think you'd have to weld in the coil mounts. I would suppose that the control arm mount locations are the same, the way GM does things. But I am not sure.

 

[rayra]

well I've put about 400mi on the Sub since that slightly botched CV axle replacement. The boot whose metal band strap clamp I undid to put the CV joint back together and then re-clamped as best I could with the original band is not yet spewing grease everywhere. We'll see what happens this summer. I didn't get the metal band as tight as it was originally, maybe about 1/8" shy of where it was previously folded back on itself. So I'm keeping an eye on it.

Still got a weight-shifting sort of clunk going on when I let off the brakes and apply any gas. Still can't find it but I figure it's my lower arms / ball joints. Tried to tighten the lower ball joint nuts just in case, barely budged and made no difference. Another visual inspection failed to find any indications of loose things or wear / rubbing. Going to get a trusted neighbor to ease the vehicle back adn forth on and off brakes and fuel while I observe things from as close as I dare get and see what my eyes and ears tell me.

 

[jonb8]

That sounds like control arm bushings.. Or lower arm bushings...

 

[rho]

well I've put about 400mi on the Sub since that slightly botched CV axle replacement. The boot whose metal band strap clamp I undid to put the CV joint back together and then re-clamped as best I could with the original band is not yet spewing grease everywhere. We'll see what happens this summer. I didn't get the metal band as tight as it was originally, maybe about 1/8" shy of where it was previously folded back on itself. So I'm keeping an eye on it.

Still got a weight-shifting sort of clunk going on when I let off the brakes and apply any gas. Still can't find it but I figure it's my lower arms / ball joints. Tried to tighten the lower ball joint nuts just in case, barely budged and made no difference. Another visual inspection failed to find any indications of loose things or wear / rubbing. Going to get a trusted neighbor to ease the vehicle back adn forth on and off brakes and fuel while I observe things from as close as I dare get and see what my eyes and ears tell me.

I'm still chasing a sound like that in our truck... I'm going to start looking real close at the motor/trans mounts, some of the control arm frame supports and stuff like that.

 

[XJLI]

The weight shift clunk I had went away when I did my torsion bar crossmember bushings. There is still a pop/clunk every now and then from the G80 though, but that’s normal.

 

[rayra]

This is pretty pronounced, as I take my foot off the brake and apply gas. I'm starting to think maybe motor mounts. Trans mount looks ok. I do occasionally really romp on it on the road / highway, 17yrs, 140k mi, it could easily be a torn mount. Going to do the test thing with my neighbor this week and replace the lower control arms in a couple weeks. If it persists after that I'm going to step up the search. As noticeable as it is, something's gonna break soon, in a 'there's your problem right there!' sort of way.

 

[NevadaLover]

This is pretty pronounced, as I take my foot off the brake and apply gas. I'm starting to think maybe motor mounts. Trans mount looks ok. I do occasionally really romp on it on the road / highway, 17yrs, 140k mi, it could easily be a torn mount. Going to do the test thing with my neighbor this week and replace the lower control arms in a couple weeks. If it persists after that I'm going to step up the search. As noticeable as it is, something's gonna break soon, in a 'there's your problem right there!' sort of way.

Easy way to see if the motor mounts are bad, open the hood, start the engine and put it in drive, step on the brakes hard and quickly give it some throttle then let off, if the mounts are bad you will see the engine move quite a ways, if the mounts are good it will barely move!