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

[rayra]

rho that picture you posted is clearly a full lift kit install, those are new brackets attached under the frame rails to relocate the torsion bar crossmember lower to keep the proper geometry in the torsion bar setup. You can see the original donut mount right above those new mount brackets, that's the mount I'm making bushing replacements for. The circled thru-hole in the next crossmember forward is where the torsion bar normally passes thru.
I think you are trying to make general statements about 2wd vs 4wd vs different year ranges for GMT800 pickups and SUVs and mixing things up a bit. What is it you are after? Trying to figure out?

I dug out my Haynes manual (24066) to see if it had anything definitive on the frames and section 10 talks about disassembly of various suspension components. 10.4 talks about torsion removal and even asserts the crossmember mounting bushings are replaceable, 'they must first be unstaked, then driven out towards the front of the vehicle.' Guess I'm heading back to my local GM dealer to see if such a thing as a replacement bushing is available. Can't find one online.

torsion bar crossmember bushings

www.gmfullsize.com

mentions a 'torsion bar support / insulator,
GM Part # 15001006 - INSULATOR, Front Spring Front

Part No.	15001006
Part Description	Insulator,Torsion Bar Support
Replaced By	20829013

But none of that crap looks anything like the donut I'm trying to replace. And I can't even find a pic of 15001006


digging around some more I find a similar replacement mount with bracket and now the 'unstaking' makes a little sense -

you can see that in this mount, the rubber is inside its own steel ring, set in the steel ring of the mount. And that bits of it are bent up, staked, so it can't move out of the mount ring. That might be a later-year mod. I don't see any of that on my mounts.

I'm looking right now at a set of pics I took when I had things apart, before I put the rubber washers in. I really can't see any staking. There's damage / shiny metal on the forward face where the crossmember was making contact with the mount and MAYBE the appearance of a separate ring given by a change in appearance of the gunk on the mount. The pic of the rear face seems to show two rings, but I took that to be a separation or movement of the rubber core out of the mount ring. I never blasted them clean or got a good look. And with the washers in now, I can't.

Guess I'm going to the Chevy dealer at lunchtime to see what I can find out.


Dorman Products - 905-507

clearly shows staking of an inner ring. I suppose that part could be bought and the core mount drive out and put in the vehicle mount. Sure to be a pain in the rear. And that's withOUT a lot of vehicle corrosion. I also note the same part is $60+ at Summit, $45 on amazon described as an Escalade part, $35 everywhere else. And I find other similar mounts for GM products and Hummers. The brackets are different, the core of the mount looks the same and I bet that the dimensions of the inner donut are identical, given GM's persistent 'economies of scale' design methods.

I've got to get ready for a conference call, once I'm free I'll head for the local GM dealer and see what's available.

 

[Burb One]

I think in this case the frames are different. All of the 4x4 examples i've been finding have had [ shaped frame rails and our truck has those as well.

View attachment 503410
I cropped this from some other site that was doing an install, but this is a nice clear photo... the areas in red are what look like the biggest differences between our 2wd and the pictured 4wd. The holes in the transmission crossmember are already there on our truck, as are the contact pads on the frame rails where the torsion bar could contact. The upper mounts are same across models and I suspect the lower mounts have the same interface to the frame...
There looked to be holes in the frame rails on our truck where the rivets would have been for the torsion bar crossmember mounts/bushings, but i'd have to crawl back under there to take more photos and to poke around more and i won't be able to do that till the weekend. I think this might be a viable project after all.

All in all i'm not sure this is ever something i'd do with this truck, but its kind of interesting to look at it from the perspective of badge engineering and where they saw the production line costs could be lowered with common products, I'd guess the 'burbs and burbs had different frames than the trucks because of their higher passenger count requiring a higher GVWR... Hmmm. Plus the general poor ride quality of torsion bars, but If it was something we chose to do it'd be less for ride quality and more for durability, lower maintenance and stronger factory LCA's. 2WD trucks bash through things off-road instead of slowing crawling over stuff so it is something on my mind (plus skids...).

Looking at this again in detail- Ryra is correct I think- It's all the same. The rearmost circle is just a torsion drop bracket from the lift kit. My truck has the middle circled holes (4wd).

I am 99% sure the only difference in the yukon/burb/silverado GMT800 1500 is the work truck 2wd coil models.

 

[Burb One]

rho that picture you posted is clearly a full lift kit install, those are new brackets attached under the frame rails to relocate the torsion bar crossmember lower to keep the proper geometry in the torsion bar setup. You can see the original donut mount right above those new mount brackets, that's the mount I'm making bushing replacements for. The circled thru-hole in the next crossmember forward is where the torsion bar normally passes thru.
I think you are trying to make general statements about 2wd vs 4wd vs different year ranges for GMT800 pickups and SUVs and mixing things up a bit. What is it you are after? Trying to figure out?

I dug out my Haynes manual (24066) to see if it had anything definitive on the frames and section 10 talks about disassembly of various suspension components. 10.4 talks about torsion removal and even asserts the crossmember mounting bushings are replaceable, 'they must first be unstaked, then driven out towards the front of the vehicle.' Guess I'm heading back to my local GM dealer to see if such a thing as a replacement bushing is available. Can't find one online.

torsion bar crossmember bushings

www.gmfullsize.com

mentions a 'torsion bar support / insulator,
GM Part # 15001006 - INSULATOR, Front Spring Front

Part No.	15001006
Part Description	Insulator,Torsion Bar Support
Replaced By	20829013

But none of that crap looks anything like the donut I'm trying to replace. And I can't even find a pic of 15001006


digging around some more I find a similar replacement mount with bracket and now the 'unstaking' makes a little sense -

you can see that in this mount, the rubber is inside its own steel ring, set in the steel ring of the mount. And that bits of it are bent up, staked, so it can't move out of the mount ring. That might be a later-year mod. I don't see any of that on my mounts.

I'm looking right now at a set of pics I took when I had things apart, before I put the rubber washers in. I really can't see any staking. There's damage / shiny metal on the forward face where the crossmember was making contact with the mount and MAYBE the appearance of a separate ring given by a change in appearance of the gunk on the mount. The pic of the rear face seems to show two rings, but I took that to be a separation or movement of the rubber core out of the mount ring. I never blasted them clean or got a good look. And with the washers in now, I can't.

Guess I'm going to the Chevy dealer at lunchtime to see what I can find out.


Dorman Products - 905-507

clearly shows staking of an inner ring. I suppose that part could be bought and the core mount drive out and put in the vehicle mount. Sure to be a pain in the rear. And that's withOUT a lot of vehicle corrosion. I also note the same part is $60+ at Summit, $45 on amazon described as an Escalade part, $35 everywhere else. And I find other similar mounts for GM products and Hummers. The brackets are different, the core of the mount looks the same and I bet that the dimensions of the inner donut are identical, given GM's persistent 'economies of scale' design methods.

I've got to get ready for a conference call, once I'm free I'll head for the local GM dealer and see what's available.

Rayra- all this work, time and $ and you're like 25% of the way to just ripping it all out and putting coilovers in

All kidding aside, your persistence is great- I'm sure you'll find those bushings from the dealer- if it exists theyll at least be able to get you a part number

 

[rayra]

well I went and their system only pulled up the 2500 diagrams, with the double-ended link connector, had to go get my registration / VIN to get the right diagram on their screen and then all it showed was the same all in one replacement part discussed earlier. It's GM part no 15003006, $115ea and it's the whole metal frame mount that has to be cut off and welded on. No separate bushing insert available. It's the same-shaped part as Dorman 905-507 -

Dorman Products - 905-507

Suspension Torsion Bar Mount

www.dormanproducts.com

Here's an eBay dealer selling unnamed brand part for $32ea

Front Torsion Bar Mounting Support Pair for Chevy Truck 4WD 192659184283 | eBay

Correct for 4WD vehicles. 2002-06 Chevy Avalanche 1500 4 Wheel Drive Front Pair. 2002-06 Chevy Avalanche 2500 4 Wheel Drive Front Pair. 2000-06 Chevy Suburban 1500 4 Wheel Drive Front Pair. 2000-06 Chevy Tahoe 4 Wheel Drive Front Pair. | eBay!

www.ebay.com

looks the same as dorman, same sort of staking, too.

From the looks of things it looks possible to grind out the staking then drive the insert ring and bushing out of the mount. Then try to do the same on the vehicle. Then use some c-clamps and judicious hammer-tapping to get the sleeved bushing inserted. And since the bolt sleeve is centered fore-aft, drive the side of the new insert in which had the staking ground off, so the side with good staking is to the front of the vehicle mount. So it resists the rearward thrust from the torsion bars, good as new. And you don't even need to re-stake the rear face, IMAO. And I'd probably STILL put my rubber washers in place, at least on the front face.

I have an air chisel with a variety of sharp and dull pointed bits. I expect I could drive those inserts out with a lot of hammering noise and hassle, laying in the driveway.
It would be even more hassle than the course I've already set. I've got a replacement flanged bushing solution ready. All I need to do when I replace my lower control arms - have to pull the torsion bars for that anyway - is... lessee... 1-7/8 ID, minus 1" bolt sleeve OD, 7/8 divided by 2, 7/16" or a 3/8" drill bit, drill a bunch of holes thru that rubber donut and hog out as much rubber as possible before freeing the bolt sleeve. Then rasp and drum-sand out the remaining rubber of the mount and just stick in the bushings I've fashioned. And drilling rubber is a lot more quiet than jackhammering on steel in my residential suburban driveway.

If I were to buy the dorman mounts it would be an excuse to finally buy a low-budget hydraulic press. Suppose I should have done that before I started replacing control arm parts. Cheaper cost-wise to buy the ball joints and bushings, and the cost of having them pressed out and in for a set is about the price of a press. But it was so much easier to just buy a new arm with everything already installed in it.

$50 per side for new front lower bushings and ball joint. vs $115 for the whole arm with new bushings and ball joint already installed. So $65 vs a bunch of hassle, per side. A 12-ton floor standing harbor Freight bottle-jack press is $130-20% So there goes any "savings", whether you buy the press or pay someone else to press the parts.

Probably be a month before I get other needful stuff done and get to changing the lowers and installing my hockey puck bushings. I MIGHT buy a set of those Energy Suspension polyurethane bushings and try re-shaping them. I don't think they'll 'mill' as readily as the vulcanized rubber did.

 

[rayra]

ooh wait, that eBay seller is a PAIR for $31. Man that calls to my inner cheap Scot. For $31 I could buy them and dismantle them to get the sleeved insert freed. I'd just carefully cut the outer ring and pry it open to free the insert. And if it measures as a match to the vehicle, do the same drill-out of the mount guts and then deliberately and carefully cut thru the inner insert ring and pry it out. Then it's just a matter of lubing and tapping / drawing the new insert into the mount ring. And still adding my rubber washers.

But I've already got the flanged bushings made. So I'll probably just use those and see how they hold up. Way I use the vehicle they'll probably last the rest of its life anyway.

Oh and one other thing, the Haynes manual specifically mentions lubing the torsion bar ends and the top of the adjuster key, before re-assembly. Which is nice, since I went ahead and smeared the torsion bar ends with disc brake grease and shot the crossmember rub / contact with hi-temp bearing grease anyway, last week.

 

[rho]

rho that picture you posted is clearly a full lift kit install, those are new brackets attached under the frame rails to relocate the torsion bar crossmember lower to keep the proper geometry in the torsion bar setup. You can see the original donut mount right above those new mount brackets, that's the mount I'm making bushing replacements for. The circled thru-hole in the next crossmember forward is where the torsion bar normally passes thru.
I think you are trying to make general statements about 2wd vs 4wd vs different year ranges for GMT800 pickups and SUVs and mixing things up a bit. What is it you are after? Trying to figure out?

Yep! It is indeed a pic of a full lift kit install but the old torsion bar mount and all those bits are visible, and it serves as a good visual reference.

I don't think i was as clear as i could have been with sone of my goals with this, I'm looking at what the feasibility of moving from 2wd coils to a 2wd torsion bar setup on this truck to facilicate more durable LCA's and sort of get the chassis in a stronger place. Biggest reason for this is my partner generally romps on her poor trucks and having a sturdier suspension is not a bad thing for our uses.
From what i've seen on the 1500 pickups, it looks like most of the torsion bar stuff should drop in or fit in with out too much trouble. Like, i'd have to drill holes to mount the torsion bar crossmember mounts and I'm sure for other things... but its looking more like this is something that could work. I'm going to start digging through junkyards here to see if I can scare up a cross-member and torsion bars here. If it looks like it'll go together and work I'll do a swap for it otherwise a 2wd performance kit might be the ticket, but not sure how those will do with having to be used as a truck...

Looking at this again in detail- Ryra is correct I think- It's all the same. The rearmost circle is just a torsion drop bracket from the lift kit. My truck has the middle circled holes (4wd).

I am 99% sure the only difference in the yukon/burb/silverado GMT800 1500 is the work truck 2wd coil models.

I'm starting to think that even the coil models have a lot of similarities...

Y'all are sending me down a rabbit hole of GMT800 sillyness, this is gonna be bad or fun depending on how you look at it, haha.

 

[lilkia]

Rayra thats what I was talki g about earlier when i said to cut out the inner ring on your truck and cut the outer mount off the new one then press the new bushing and steel ring into the old mount. Once you get the pieces apart you should be able to use a ball joint press or fashion a small press out of two pieces of 1/4 plate and a nut and bolt.

 

[vargsmetal]

Yep! It is indeed a pic of a full lift kit install but the old torsion bar mount and all those bits are visible, and it serves as a good visual reference.

I don't think i was as clear as i could have been with sone of my goals with this, I'm looking at what the feasibility of moving from 2wd coils to a 2wd torsion bar setup on this truck to facilicate more durable LCA's and sort of get the chassis in a stronger place. Biggest reason for this is my partner generally romps on her poor trucks and having a sturdier suspension is not a bad thing for our uses.
From what i've seen on the 1500 pickups, it looks like most of the torsion bar stuff should drop in or fit in with out too much trouble. Like, i'd have to drill holes to mount the torsion bar crossmember mounts and I'm sure for other things... but its looking more like this is something that could work. I'm going to start digging through junkyards here to see if I can scare up a cross-member and torsion bars here. If it looks like it'll go together and work I'll do a swap for it otherwise a 2wd performance kit might be the ticket, but not sure how those will do with having to be used as a truck...



I'm starting to think that even the coil models have a lot of similarities...

Y'all are sending me down a rabbit hole of GMT800 sillyness, this is gonna be bad or fun depending on how you look at it, haha.

I don't think going from coils to torsion bars is an upgrade. I had a 2wd 2002 1500 and those LCAs were every bit as beefy as the 4wd units. For most people the upgrade path for a 2wd will be a long travel setup with coil overs and tubular control arms. Unless you wanted an inexpensive way to get 4wd I don't see the point of the work. You'll most likely lose travel with the torsion bars. Depending on what you do with the truck will decide long travel and stay 2wd or SAS, in my opinion. Neither of which would involve torsion bars.

Sent from my SM-G965U using Tapatalk

 

[rho]

I don't think going from coils to torsion bars is an upgrade. I had a 2wd 2002 1500 and those LCAs were every bit as beefy as the 4wd units. For most people the upgrade path for a 2wd will be a long travel setup with coil overs and tubular control arms. Unless you wanted an inexpensive way to get 4wd I don't see the point of the work. You'll most likely lose travel with the torsion bars. Depending on what you do with the truck will decide long travel and stay 2wd or SAS, in my opinion. Neither of which would involve torsion bars.

Sent from my SM-G965U using Tapatalk

I'm starting to lean towards coilovers/UCA's with spherical/uniball/whatevertheyare joints to allow more travel. After just doing the springs in our truck the limited range of motion of the UCA ball joints is apparent and is very much a limit to usable travel.

I did some digging and it looks like there are some 4wd kits that might be modifiable to work in this application and some 2wd specific ones? Not sure what the difference is between the two with seeing dimensions of the various UCA's however.
They all look like the upper shock/spring mount on the frame would have to go away and a new shock tower/bracing setup installed, so that'd be a project.
I have a small welder (and I can use it!) and access to a shop for small projects, so some limited scope fab stuff could be done, so who knows.
Maybe this will turn into rho designs a coil-over suspension, lol.

We're not planning on doing a 4wd conversion on this truck, I mean, we could do it,sure. But I think all the little details and "gotcha!" bits would make the project a tough one to get through without having space to tear the truck apart for an extended duration.

Anyone have any idea what the spring rate is for the OEM 2wd springs?

 

[vargsmetal]

I'm starting to lean towards coilovers/UCA's with spherical/uniball/whatevertheyare joints to allow more travel. After just doing the springs in our truck the limited range of motion of the UCA ball joints is apparent and is very much a limit to usable travel.

I did some digging and it looks like there are some 4wd kits that might be modifiable to work in this application and some 2wd specific ones? Not sure what the difference is between the two with seeing dimensions of the various UCA's however.
They all look like the upper shock/spring mount on the frame would have to go away and a new shock tower/bracing setup installed, so that'd be a project.
I have a small welder (and I can use it!) and access to a shop for small projects, so some limited scope fab stuff could be done, so who knows.
Maybe this will turn into rho designs a coil-over suspension, lol.

We're not planning on doing a 4wd conversion on this truck, I mean, we could do it,sure. But I think all the little details and "gotcha!" bits would make the project a tough one to get through without having space to tear the truck apart for an extended duration.

Anyone have any idea what the spring rate is for the OEM 2wd springs?

Camburg's mid travel 6.5in setup uses the stock spring pockets and control arm mounts. It replaces the UCA and spindle to give a ton more travel over stock. Looks like a bolt in project.

Offroad design has perfected the SAS on these trucks. It's a bolt in deal but you have to source the right axle and transfer case. You'd need a 4wd transmission, and add the transfer case shifter. Still, it would be easier than designing your own long travel coilover setup and would make for a rock solid truck.

Sent from my SM-G965U using Tapatalk

 

[02TahoeMD]

Offroad design has perfected the SAS on these trucks. It's a bolt in deal but you have to source the right axle and transfer case.

Out of curiosity about the cost of this project, I just went to Offroad Design's website. This is posted on their site:
"At this point in time we do not have a solid axle conversion for the 6 lug GMT800 trucks"
Found here
You gotta have either an older GM truck, or a 2500 series of the 2000 to 2010 body style to use their kits as sold.

 

[XJLI]

I'd rather get this than SAS anyway...

Chevy 1500 99 to 06 4x4 Long Travel Kit

YEAR – 99 to 06 MAKE – Chevy – GMC 1500, suburban, Tahoe- H2 LIFT – 2” to 4” TIRES PUSHED FORWARD – 1” WIDER PR SIDE – 4” TIRE SIZE RECOMMENDED – up to 37” WHEEL TRAVEL – 14” UPPER ARMSOur plate powder coated upper arms are made from 10g cold rolled steel with ¾” rod ends and stainless steel...

jdfabrication.com

 

[rho]

So, this is the partners truck we're working with. We just got done going through the cooling system (rad, WP, hoses, etc...), Shocks, some suspension bits and other small odds and ends on a 16yr old truck. Both sides of the truck are pretty dinged up from wear and use and school parking lot but it runs great and the thing scoots. I want to get some oem flares for it when to help hide some of the body damage, but not sure if she'll go for that.

The current plans are for a 2" lift on it. As its 2wd so there is only so much we can do before going to a full mid travel setup like the camburg one mentioned earlier.
In addition to the 2" lift, Its going to get some 285/75/16 tires, A soft topper to replace the hard cover and we're going to build a sleeping platform for it to make use of the fullbed slide that it has. Something else We've been trying to deicide on is ****** to do the with spare tire. The stock winch/mechanism thing thats under the bed is broken or sized or something as neither one of us has been able to acutaly get the spare out/down/off in order to assess the condition of it. So we're looking at building up a bumper that can hold a tire and swing out to allow us use the tail gate and bedslide. We don't tow anything so we don't need a hitch and I wouldn't mind a bit more departure angle as we've dragged the hitch on a lot of stuff already.

Some other near term mods I'm looking at doing this are re-doing the headlight harnesses to handle higher wattage bulbs and get more of the lights on when the high beams are on. Also some better flood lights up front and in the back...
I'm also trying to figure out what i need to do to add an engine oil cooler. The radiator has inside it in additon to the transmission cooler, but its not being used and I didn't want to re-plumb the power steering cooler into it.
I might also replace the external transmission cooler with a bigger unit. I might also add a UHF/VHF radio to it, there are some smaller units that are floating around now that would fit into the weird awkward cubby in the overhead console and I could rip the onstar antenna out to mount a 1/4 wave antenna to the roof. I

I've been giving more thought to the rear end of thing and I'm really starting to think that a Eaton truetrack or a Detroit locker in the rear is going to be the way to go if the G80 thats in there blows up on us.

This truck doesn't see a lot of way off the beaten path offroading but it does spend a lot of time cruising on dirt roads in the national forests around California and the end goal is to get something reliable, simple that my partner can use to go escape and write when she needs to get out of the Bay Area. I think this could be a great platform for some of that stuff with the limits of the truck in mind. After all is said and done the goal is to get out there and go camping and have fun in the woods or the desert or the pains or whatever!

 

[rayra]

You'll have to really abuse that G80 to break it, as in keeping your foot in it while slamming and bouncing up a hill climb or while jumping the vehicle. Airtime. Normal use they're sturdy enough. the only other times I hear of them breaking is when people load their vehicle up and really wedge them in a trough or crack, something with a lot of resistance to the vehicle moving. Then they stick their foot in it and stuff breaks.

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.

 

[rayra]

@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.