Do torsion bars wear out?

[bgiff]

When i backed out the tosion adjusting bolt, the keeper key was already loose. I didnt hardly need the unloader tool as just a couple turns by hand on the tool gave me clearance to remove the keeper.

Also, it appears the bar might have a slight bend to it. All the gm parts places say the part is discontinued. Anyway, I suspect now that the vehicle may have suffered some abuse from one of my boys years ago. (theyre grown now and I have had the truck in storage for 10 years) Also, the main skid plate has some damage (bent rear bolts, and denred pretty good, difficult to reinstall as holes dont line up)

Is junkyard the only option for replacing tosion bars? This is a 2500 with z85 option and 8600 gvw so it needs HD bars

 

[Marky Dissod]

Here is part of a torsion bar chart batboy found Dec 2017.

my torsion bar adventure - PerformanceTrucks.net Forums

GM Drivetrain & Suspension - my torsion bar adventure - I've owned a 2006 Tahoe 4WD for almost 6 years now and love it. But, I never cared for the tires, they were something called Wildcat A/T Radial (255/70R16). I wanted a couple sizes larger, but could not initially justify getting new one...

www.performancetrucks.net

Added to the list from this post

https://www.performancetrucks.net/f...rformance-21/torsion-bars-180259/#post1440904

Hopefully you find this list helpful.
15048307-LH (6XK) & 15048308-RH (7XK) (Max torque 4553)
15048309-LH (6XL) & 15048310-RH (7XL) (Max torque 4626)
15712407-LH (6WX) & 15712408-RH (7WX) (Max torque 4863)

15048311-LH (6XM) & 15048312-RH (7XM) (Max torque 5638)
15712407-LH (6WX) & 15712408-RH (7WX) (Max torque 5826)
15528955-LH (6GF) & 15528956-RH (7GF) (Max torque 5826)
15058267-LH (6YH) & 15058268-RH (7YH) (Max torque 5913)
15712409-LH (6WY) & 15712410-RH (7WY) (Max torque 5913)

15528957-LH (6GG) & 15528958-RH (7GG) (Max torque 6709)
15528959-LH (6GH) & 15528960-RH (7GH) (Max torque 7161)
15712411-LH (6WZ) & 15712412-RH (7WZ) (Max torque 7267)

15528963-LH (6GK) & 15528964-RH (7GK) (Max torque 8615)
15528965-LH (6GL) & 15528966-RH (7GL) (Max torque 8782)
15732338-LH (6XG) & 15732339-RH (7XG) (Max torque 9054)

If anyone has more to add to this list, PLEASE DO!

 

[Fless]

Here is part of a torsion bar chart batboy found Dec 2017.

my torsion bar adventure - PerformanceTrucks.net Forums

GM Drivetrain & Suspension - my torsion bar adventure - I've owned a 2006 Tahoe 4WD for almost 6 years now and love it. But, I never cared for the tires, they were something called Wildcat A/T Radial (255/70R16). I wanted a couple sizes larger, but could not initially justify getting new one...

www.performancetrucks.net

Added to the list from this post

https://www.performancetrucks.net/f...rformance-21/torsion-bars-180259/#post1440904

Hopefully you find this list helpful.
15048307-LH (6XK) & 15048308-RH (7XK) (Max torque 4553)
15048309-LH (6XL) & 15048310-RH (7XL) (Max torque 4626)
15712407-LH (6WX) & 15712408-RH (7WX) (Max torque 4863)

15048311-LH (6XM) & 15048312-RH (7XM) (Max torque 5638)
15712407-LH (6WX) & 15712408-RH (7WX) (Max torque 5826)
15528955-LH (6GF) & 15528956-RH (7GF) (Max torque 5826)
15058267-LH (6YH) & 15058268-RH (7YH) (Max torque 5913)
15712409-LH (6WY) & 15712410-RH (7WY) (Max torque 5913)

15528957-LH (6GG) & 15528958-RH (7GG) (Max torque 6709)
15528959-LH (6GH) & 15528960-RH (7GH) (Max torque 7161)
15712411-LH (6WZ) & 15712412-RH (7WZ) (Max torque 7267)

15528963-LH (6GK) & 15528964-RH (7GK) (Max torque 8615)
15528965-LH (6GL) & 15528966-RH (7GL) (Max torque 8782)
15732338-LH (6XG) & 15732339-RH (7XG) (Max torque 9054)

If anyone has more to add to this list, PLEASE DO!

Not that it matters to anyone but me, my '04 Tahoe LT has the first line item (6XK & 7XK) for RPO codes. Lowest Max torque on that listing.

I wonder if that has to do with the short body, or the Premium Smooth Ride.

 

[Roilux]

Not that it matters to anyone but me, my '04 Tahoe LT has the first line item (6XK & 7XK) for RPO codes. Lowest Max torque on that listing.

I wonder if that has to do with the short body, or the Premium Smooth Ride.

I've a '04 Tahoe LT also with premium smooth ride. My codes differ as 6XN and 7XN. I've not found a source anywhere that lists max torque for those codes.

 

[Marky Dissod]

My codes differ as 6XN and 7XN. I've not found a source anywhere that lists max torque for those codes.

Mentioned that it is a PARTIAL list - please feel free to add to it if you find pertinent missing data.
Plug your VIN into GM Part's Giant's VIN Decoder

Free GM Vin Decoder | GMPartsGiant

Free GM VIN Decoder - Do a VIN lookup to acquire specific car information. Ordering exact-fit parts has never been this smooth and hassle-free on GMPartsGiant!

www.gmpartsgiant.com

it'll be interesting to see what comes up to replace those 'ostensibly obsolete' parts.

 

[strutaeng]

When i backed out the tosion adjusting bolt, the keeper key was already loose. I didnt hardly need the unloader tool as just a couple turns by hand on the tool gave me clearance to remove the keeper.

Also, it appears the bar might have a slight bend to it. All the gm parts places say the part is discontinued. Anyway, I suspect now that the vehicle may have suffered some abuse from one of my boys years ago. (theyre grown now and I have had the truck in storage for 10 years) Also, the main skid plate has some damage (bent rear bolts, and denred pretty good, difficult to reinstall as holes dont line up)

Is junkyard the only option for replacing tosion bars? This is a 2500 with z85 option and 8600 gvw so it needs HD bars

Do they wear out? IDK. My truck has almost 300k and they still work just fine.

But if they are bent, then that's a problem. Sounds like they took the truck rock climbing.

The Z85 towing package was some wiring harness and other stuff, nothing suspension related that I can recall. Just stick with the GVWR of 8600 lb (2500 Suburban, I think 2wd or 4x4 may not matter, IDK on that?). Also, compare part numbers with the Avalanche 2500 and pickup trucks that are 2500 or 2500HD. Those were GVWR of 8600 lb and 9200 lb, respectively. I've never wondered if they are dimensionally the same as the Suburbans. But if they are the same parts, then that will help widen chances of finding replacements. I'd be hitting the wrecking yards.

 

[NardDog]

I asked the suspension shop this question just last week and as he squinted his eyes he said “maybe but not much” . Which to me means either - I dont know or No one can ever know.

 

[Marky Dissod]

Of course springs wear out, don't matter if they're coils or torsion bars. Thankfully they wear out VERY SLOWLY.
Spring pockets / torsion bar sockets likely wear out more quickly than the springs / torsion bars themselves.

 

[Roilux]

Mentioned that it is a PARTIAL list - please feel free to add to it if you find pertinent missing data.

Thanks, I understood that and hoped to add to list. The best I've located so far is https://suspensionmaxx.com/torsion-...vC1W-Ujl6uuqMMfZoPqcLB86_5GYWfkCJXxcPHHuj1c5V My bars don't appear and remain elusive.

 

[Marky Dissod]

My bars don't appear and remain elusive.

Once a GM vehicle is +10 years old, GM stops making LOTS of stuff for it.
As said, put your VIN in the GM Parts Giant VIN Decoder, then search for the closest match.
Personally will not recommend going any softer.

(I'm looking for torsion bars from Z60 Sielverrados ...)

 

[Marky Dissod]

I've a '04 Tahoe LT also with premium smooth ride. My codes differ as 6XN and 7XN.
I've not found a source anywhere that lists max torque for those codes.
My bars don't appear and remain elusive.

Unfortunately, they've eluded me as well.
Until you or I find a real torsion bar guru, my best guess would be -
assuming you're one of those who goes by the strictest definition of GM OE:
find an '05 or '06 Premium Smooth Ride Tahoe LT as similar as reasonably possible to yours,
use its VIN to find out which torsion bars it used, and replace yours with those.

I'd consider your situation to be a unique opportunity to loosen my definition of GM OE,
and suit things to your taste ...

 

[Marky Dissod]

I've a '04 Tahoe LT also with premium smooth ride. My codes differ as 6XN and 7XN.
I've not found a source anywhere that lists max torque for those codes.
My bars don't appear and remain elusive.

@Roilux, your front torsion bars are rated @ 4553.
Looks like 'your' torsion bars
15051907-LH (6XN) & 15051908-RH (7XN) (Max torque 4553)
have been superseded by
15048307-LH (6XK) & 15048308-RH (7XK) (Max torque 4553)

 

[Roilux]

@Roilux, your front torsion bars are rated @ 4553.
Looks like 'your' torsion bars
15051907-LH (6XN) & 15051908-RH (7XN) (Max torque 4553)
have been superseded by
15048307-LH (6XK) & 15048308-RH (7XK) (Max torque 4553)

Bless your lil' heart. I appreciate the effort and now have a proper reference ID and rating. Thank you.

 

[Marky Dissod]

@bgiff, by now, hopefully you see that you need to find or provide some kind of data ...

 

[houstontaylor]

My 2003 Tahoe has 360,000 miles with the original torsion bars and no problems.

 

[bgiff]

Do they wear out? IDK. My truck has almost 300k and they still work just fine.

But if they are bent, then that's a problem. Sounds like they took the truck rock climbing.

The Z85 towing package was some wiring harness and other stuff, nothing suspension related that I can recall. Just stick with the GVWR of 8600 lb (2500 Suburban, I think 2wd or 4x4 may not matter, IDK on that?). Also, compare part numbers with the Avalanche 2500 and pickup trucks that are 2500 or 2500HD. Those were GVWR of 8600 lb and 9200 lb, respectively. I've never wondered if they are dimensionally the same as the Suburbans. But if they are the same parts, then that will help widen chances of finding replacements. I'd be hitting the wrecking yards.

The z85 in the VIN decoder is described as “chassis increased capacity” the Z82 is the trailer hitch/wiring. Also says it has the 9900lb brakes which i noticed some of the rock auto parts descriptions for this truck mentioned as an option. Anyway, it looks like i need 6gk and 7gk torsion bars which are rare as hens teeth apparently.
thanks fer all the info gentlemen, i am replacing everything on this truck that could break as i’m converting it to a camper and taking it to alaska this summer.

Completed so far
-knock sensors
-valve civer gaskets
-fuel filter
-water pump
-upper lower rad hoses, all
new heater hoses with new metal Dorman upgraded quick connect fittings (
-alternator
-spark plugs, wires(iridium new old stock acdelco)
-power steering pump (psc duramax version bolted right up)
-steering gear (blue top rebuilt my original)
-hydro boost (replaced with 2011 dyramax model, bolted right up)
-power steering cooler, all power steering pressure and return lines (edelman “elite” )
-replaced both front wheel hub/bearing assemblies even tho only one was going bad. Used mevotec “upgraded” as genuine GM are like 400 bucks now!
-inner/outer tie rods, idler arm, pitman arm all dorman “heavy duty” supposedly upgraded.
-upper control arms, shocks, torsion keys (all part of rough county 3” lift)
-lower control arm bushings (major pita) actually called a shop “can you remive/replace lower control arms bushings?” “sure bring’em in”
I bring them in “we cant do these, wont fit our press, might take us several hours at 175/hour” New GM ones are 600 a piece!!
replaced rear hatch window (infamous glued on hinge failure, junkyard 63 bucks) fits perfect, hope it holds) new one is 600-900 bucks!
-though the truck never had one, i added the bilstein 5100 steering stabilizer as the frame and OEM center link had the mounting provisions for it. Not sure how it will affect handling….


left to do:

-master cylinder
-new rotors
-stainless brake hoses
-new calipers
-oil pan gasket
-replace factory block heater
-replace
engine oil cooler gasket.
-trans cooler lines
-mushimoto 40k style cooler
-255-85-16 34” tires


The only parts that were really warn on this 130k mile grocery getter were the drinker’s side front hub bearings, the bump stops, one trans line cooler, the power steering pump and or the gear, or maybe it was just one of the lines were leaking. I just fired the parts cannon and replaced everything.

-

 

[Aquamania001]

I just looked on the LMC Trucks web site and they have torsion bars there. Check it out.