Hauling VERY heavy with an '02 Tahoe Z71, NEED stiffer springs

[Marky Dissod]

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Tried asking over @ TYF, zero responses as of now ...

GMT800 Stiffer front torsion AND rear coil springs?

Yday I did a friend a HUGE favor: folded down the seats & loaded about 450SqFt of rolled-up Kentucky BlueGrass into the back of my Tahoe Z71. (Any idea how much that weighs?) Wish I'd had the presence of mind to take measurements, damnt, but I know these things: 1. Unloaded, my Z71 is too tall...

www.tahoeyukonforum.com

Hauled 46 5ft by 2ft rolls of Kentucky BlueGrass in my '02 Tahoe Z71's cargo area on Friday,
which shoved the trailer hitch down to about 12" off the ground at rest.
Since I'm very likely to do some very heavy hauling like this again in the near future,
the idea of turning my Tahoe into a '2500' in hauling terms (NOT TOWING!) is about to become a necessity.

I really think I need stiffer SPRINGS front and back. Now I'm trying to figure out how much stiffer a Tahoe can safely go.
1. Any '2500' vehicle owners in the NYC area, whether pickup or Suburban? I'd like an idea of what I'm getting into.
2. Anyone know which front torsion bars and coil springs were used by a Suburban 2500?

 

[ORVietVet]

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I would use a weight distribution hitch set up. That way you can leave it stock. IF you ever tow.

Good luck finding torsion bars. Just roll them up at the adjusting bolt. If do that, keep track of the turns, so you can adjust back down.

Use air bags at the rear. IIRC, the next stiffer rear springs would be the Moog 81069 but further research is needed.

Or, buy you a 2500 Suburban.

 

[Marky Dissod]

NOT gonna use my '02 Tahoe Z71 to tow anything anytime soon (although of course I'd use a weight distribution hitch setup!).

How much does 46 rolls of Kentucky BlueGrass weigh? That's how much I hauled Friday the 8th,
and I'm extremely likely to do something like that again.

No room to adjust height upward AT ALL, will lose access to too many NY / NJ / CT garages.
(Lowering even 1.0"-1.5" will grant access to more garages, considering S10 frame-body mounts.)

@ORVietVet, I cannot afford to buy any other vehicle presently.
Can definitely afford to buy your Suburban 2500's torsion bars, though, if suspensionmaxx.com will sell them or the like.
Do you know your Silverado's front torsion bar RPOs? (Your rear springs are leafs, which I can't learn much from.)

If I knew of anyone with a Suburban 2500 locally, I'd go for a drive just to find out which front torsion bars it has.
Do they all use the same front torsion bars? How do they feel? 'cause mine were way too soft for hauling all that grass.

Also seriously considering 17" wheels & 265/70R17 XL tires for safety margin;
my 255/70R18 did pretty ok, but not quite well until after I inflated them to 42psi cold.

 

[ORVietVet]

NOT gonna use my '02 Tahoe Z71 to tow anything anytime soon (although of course I'd use a weight distribution hitch setup!).

How much does 46 rolls of Kentucky BlueGrass weigh? That's how much I hauled Friday the 8th,
and I'm extremely likely to do something like that again.

No room to adjust height upward AT ALL, will lose access to too many NY / NJ / CT garages.
(Lowering even 1.0"-1.5" will grant access to more garages, considering S10 frame-body mounts.)

@ORVietVet, I cannot afford to buy any other vehicle presently.
Can definitely afford to buy your Suburban 2500's torsion bars, though, if suspensionmaxx.com will sell them or the like.
Do you know your Silverado's front torsion bar RPOs? (Your rear springs are leafs, which I can't learn much from.)

If I knew of anyone with a Suburban 2500 locally, I'd go for a drive just to find out which front torsion bars it has.
Do they all use the same front torsion bars? How do they feel? 'cause mine were way too soft for hauling all that grass.

Also seriously considering 17" wheels & 265/70R17 XL tires for safety margin;
my 255/70R18 did pretty ok, but not quite well until after I inflated them to 42psi cold.

C6W for 9200 GVWR and the torsion keys codes are FT2 for the left and FT3 for the right.

 

[Marky Dissod]

C6W for 9200 GVWR, and the torsion keys codes are FT2 for the left and FT3 for the right.

C5U 6800lb, largely due to GM OE's very soft spring choices: 6XL & 7XL.
want to improve / increase my Tahoe's ability to load & haul
My torsion keys are FK2 & FK3; not sure I want to go any lower than FF6 &FF7 which were used by SSVs, can't go a single hair higher.

@ORVietVet, you mentioned your key RPOs, but not your torsion bar RPOs ... ?

Still hoping for input from others with 2500 vehicles, pickup or Suburban.
For now, my goal seems to be finding/using 2500 Suburban or pickup front torsion bars,
also finding stiffer rear coil springs, since mine are far too soft whether unloaded or loaded.

 

[ORVietVet]

I did not find the torsion bar RPO's. I looked in numerous places but with no luck.

 

[Marky Dissod]

I did not find the torsion bar RPO's. I looked in numerous places but with no luck.

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your VIN after the 'equal' sign, your torsion bars are represented by 6-- & 7--

 

[ORVietVet]

6GK and 7GK

 

[AuroraGirl]

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I would use a weight distribution hitch set up. That way you can leave it stock. IF you ever tow.

Good luck finding torsion bars. Just roll them up at the adjusting bolt. If do that, keep track of the turns, so you can adjust back down.

Use air bags at the rear. IIRC, the next stiffer rear springs would be the Moog 81069 but further research is needed.

Or, buy you a 2500 Suburban.

coil springs makes this the best suggestion, there is too much sway and give with coils for this purpose

 

[ORVietVet]

Hellwig sway bar kits make a big difference.

 

[stutaeng]

How much weight is that you are hauling? Are you overloaded compared to your gvwr? You can't rent a trailer so most load in the trailer axle? Or make 2 trips instead of one? How far are you going?

The 2500 Suburbans didn't come with coil springs on the rear, they used leaf springs.

 

[Marky Dissod]

6GK and 7GK

Commonly used by Suburban 2500s as well, I think? @stutaeng, may I ask what front torsion bars your bubba 2500 has?
If you both don't find your front bars 'too stiff', may want these. Not shy about considerably stiffer torsion bars / springs.

Hellwig sway bar kits make a big difference.

I'm also crazy enough to consider thickest/stiffest GM OE swaybars available.
Never been crazy enough to take turns 'too quick' when heavily loaded, but definitely want stiffer swaybars as well.
Long before this heavy haul, wanted - and still want - my Tahoe to swerve / lane change better,
but initially only considered stiffer swaybars ... now I know I want stiffer springs too.
Accustomed to Caprices 9C1, I'd PREFER a reasonably stiffer ride without hesitation.
(Regret Bilstein 4600s, will replace with 5100s with the stiffer springs I decide upon.)

How much weight is that you are hauling? Are you overloaded compared to your gvwr?
You can't rent a trailer so most load in the trailer axle? Or make 2 trips instead of one? How far are you going?

46 Kentucky BlueGrass rolls x 45lb each = 2070lb Is that overloaded compared to a Tahoe's GVWR?
Earnestly trying to figure out to what extent I can safely increase my GVWR with stiffer springs.
Did not rent a trailer 2 days ago, drove 40 miles with trailer hitch about 12" off the deck (at rest).
WHEN I do something like this again, don't want to do a broke@$$ Carolina Squat again,
want to be able to haul 2200-2500lb safer / better than I did two days ago.

If there's no such thing as stiffer rear GM OE coils that are compatible with my Tahoe,
then I'll go aftermarket, no problem.

 

[ORVietVet]

Run Load Range E tires at the higher air pressure when hauling. Will handle sway control better.

 

[ORVietVet]

I think what you need to take from all this, is that you definitely overloaded the Tahoe and if you don't care what it is doing to that Tahoe, then stiffen it up any way you want and live with the consequences. The best thing to do is pull a trailer.

 

[stutaeng]

Commonly used by Suburban 2500s as well, I think? @stutaeng, may I ask what front torsion bars your bubba 2500 has?
If you both don't find your front bars 'too stiff', may want these. Not shy about considerably stiffer torsion bars / springs.

I'm also crazy enough to consider thickest/stiffest GM OE swaybars available.
Never been crazy enough to take turns 'too quick' when heavily loaded, but definitely want stiffer swaybars as well.
Long before this heavy haul, wanted - and still want - my Tahoe to swerve / lane change better,
but initially only considered stiffer swaybars ... now I know I want stiffer springs too.
Accustomed to Caprices 9C1, I'd PREFER a reasonably stiffer ride without hesitation.
(Regret Bilstein 4600s, will replace with 5100s with the stiffer springs I decide upon.)

46 Kentucky BlueGrass rolls x 45lb each = 2070lb Is that overloaded compared to a Tahoe's GVWR?
Earnestly trying to figure out to what extent I can safely increase my GVWR with stiffer springs.
Did not rent a trailer 2 days ago, drove 40 miles with trailer hitch about 12" off the deck (at rest).
WHEN I do something like this again, don't want to do a broke@$$ Carolina Squat again,
want to be able to haul 2200-2500lb safer / better than I did two days ago.

If there's no such thing as stiffer rear GM OE coils that are compatible with my Tahoe,
then I'll go aftermarket, no problem.

I'm not sure what torsion bars my 2500 suburban has. Is there a part number or something stamped on it? I can check when I get back home tonight.

2070 lb sod is a "ton," literally. Not sure what your curb weight is, but google says around 5,262 lbs and a GVWR of 6,800 lbs, so that gives you a payload of 1,538 lbs, so you are over for sure. You can't increase the GVWR, that's what the factory rated the vehicle as a "system." I would simply make 2 trips, but that's just me. How much is the extra gas on 2 trips vs buying torsion bars and other suspension stuff? If this is for a larger project, just look for delivery service or rent a 3/4 ton truck.

 

[CPB]

Why not a helper spring? I have rear air springs on my 2500HD. I adjust the psi get the ride level.

 

[Tonimus]

First, any overloading is obviously at your own risk and subject to your local laws.

On a Tahoe there's not much room back there for aftermarket air stuff. If you're going that overloaded and you want simple bolt in stuff, an Air Lift 1000 kit and some Timbren "springs" which are basically big bump stops may be what you're looking for.

The front torsion bars should be fine if you crank them all the way up, then lower them back down later. I would highly suggest a torsion bar unloading tool so you don't strip out your keys.

 

[Marky Dissod]

I think what you need to take from all this, is that you definitely overloaded the Tahoe ...

Agreed.

... if you don't care what it is doing to that Tahoe, then stiffen it up any way you want and live with the consequences.

I do care (although you all may not see it that way), which is exactly why I (think I) need stiffer rear coils.

The best thing to do is pull a trailer.

Again, agreed.

not sure what torsion bars my 2500 suburban has. Is there a part number or something stamped on it? I can check when I get back home tonight.

Check your RPO SPID sticker, or plug your VIN in after the equal sign in this link

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The RPOs that start with 6 & 7, as in 6-- & 7--, are front spring codes
(not just for trucks & suvs, but nearly all body-on-frame vehicles in GM history since late 80s).

2070 lb sod is a "ton," literally. Not sure what your curb weight is, google says around 5,262 lbs and a GVWR of 6,800 lbs,
gives you a payload of 1,538 lbs, so you are over for sure. You can't increase the GVWR, that's what the factory rated the vehicle as a "system".
I would simply make 2 trips, but that's just me. How much is the extra gas on 2 trips vs buying torsion bars and other suspension stuff?
If this is for a larger project, just look for delivery service or rent a 3/4 ton truck.

Luckily the part of the project requiring heavy hauling is over. 1500lb payload, NOTED; I'll not repeat that mistake.

The OTHER reason why I want stiffer torsion bars and coils and shocks is because - unlike most of you -
I have preferred stiffer springs & shocks for the past 30 years (admittedly on a different set of body-on-frame vehicles).

 

[Marky Dissod]

Why not a helper spring? I have rear air springs on my 2500HD. I adjust the psi get the ride level.

PPVs & SSVs did not use helper springs (nor did the Hummer H2, which is the closest thing to a Tahoe 2500 I can think of).
Granted that's not exactly an argument, but the tendency to use GM OE stiffer springs & shocks has yielded positive results in the past.

First, any overloading is obviously at your own risk and subject to your local laws.

On a Tahoe there's not much room back there for aftermarket air stuff. If you're going that overloaded and you want simple bolt in stuff,
an Air Lift 1000 kit and some Timbren "springs" which are basically big bump stops may be what you're looking for.

Any overloading in the future will NOT exceed 1800lb, and will not exceed 1500lb until after I've installed stiffer springs.
Had not considered heavier duty 'bump stops'; think I'm already sold on the idea of them though.

The front torsion bars should be fine if you crank them all the way up, then lower them back down later.
I would highly suggest a torsion bar unloading tool so you don't strip out your keys.

If I crank them all the way up, does the front increase in height / angle? Need to avoid this, must avoid any height gain front or rear.
A torsion bar unloading tool also sounds like an idea I'm already sold on, though.

 

[stutaeng]

Or maybe some Timbrens? Looks like the rears are $270 and seem pretty easy to install.

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Agreed.

I do care (although you all may not see it that way), which is exactly why I (think I) need stiffer rear coils.

Again, agreed.

Check your RPO SPID sticker, or plug your VIN in after the equal sign in this link

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

The RPOs that start with 6 & 7, as in 6-- & 7--, are front spring codes
(not just for trucks & suvs, but nearly all body-on-frame vehicles in GM history since late 80s).

Luckily the part of the project requiring heavy hauling is over. 1500lb payload, NOTED; I'll not repeat that mistake.

The OTHER reason why I want stiffer torsion bars and coils and shocks is because - unlike most of you -
I have preferred stiffer springs & shocks for the past 30 years (admittedly on a different set of body-on-frame vehicles).

Ok, I checked and both Suburbans (04 4x4 and 06 2wd, both 2500 with the LQ4) have the 6GK and 7GK RPO codes.

Regarding cranking the torsion keys, yes, that will raise the height of the suspension (what most will call "leveled"), and will also make the vehicle ride a bit harsher. My 06 had the keys cranked when I bought it from the PO. I rebuilt the suspension about 2 years ago and when I got an alignment, completely forgot that I had meant to restore it back to factory settings, so I just left it like that.