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gandolphxx

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If you own a 2500 this is the pair of mods to dramatically improve the driveability and performance of your great truck.

In previous posts I have referred to the Roadmaster Active Suspension as the way to control sway, wheel hop and dandruff - I still believe it - and enjoy the ride with them. ;D

Now i have the perfect companion - Rear Wheel Alignment System - "spacers" to most of us.

This is where you start - narrow rear.
gxx_ctbefore.jpg


It turns out that GM decided that our front axles needed to be 3+ inches wider than the rear - makes for an interesting effect - understeer, etc.

Now you put in these incredibly sturdy 2" spacers,

gxx_ctspacer.jpg


And with a little "torquing" ...

gxx_ctafter.jpg


I can tell you without qualification that this results in a 100% improvement in tracking and damn near that much in steering - this beast tracks like my GTO which is hard to beat. >:D If you own a 2500 don't let this pair of mods go by (y)

Special thanks to TexAVFan for doubling checking my handiwork after I thought I broke my torque wrench - make sure you have a 1/2 US and Metric set [long] to do the work.

Very curious to see how they track at the track^^
 
02_2500avalanche said:
Great find Grandolphxx, yet another mod to add to the list. But do you feel they were worth $350?

Alex
Click to expand...
Absolutely, every penny - these things are very well machined - the pair weighs 30 lbs - they really make a difference - the first day I had them on I drove 40 miles just enjoying it. ;D
 
Could you achieve the same results from a wheel with a different offset? It is kinda expensive since a complete wheel cost about $100 - $200.

Another possible option would be Hummer H2 take off wheels. They are running about $250 + shipping for 4 on ebay. They are 17 x 8.5 (+2 inches) and will fit the 2500... The only negative is that you will need new tires since the stock tires are 16". It would be an interesting setup with 17" 285's sitting on 8.5 inch wide wheels for the 2500.

I wonder how that would perform compared to the 2" extenders. It sounds like the additional 2 inches makes a B-I-G difference.
 
The additional 2+2 inches = 4 inch increase in rear track should make the vehicle a lot more stable and reduce the center of gravity. ?I found some more info on spacers here:

http://www.off-road.com/chevy/reviews/spacers/

spacers-sm.jpg


The aluminum versions are lighter (about 5lbs each) and I believe less expensive ($100 each??). ? ?Would these also work to achieve the same effect?

before-after-sm.jpg


How about 2 inch spacers + Hummer H2 wheels? ?Now we are really talking about ?a
w - i - d - e ?track rear end. ?A dually AV anyone?
 
The problem with wider wheels, and I have 8" rims as is, is that you just change the tracking width, you don't fix the difference front to back - that is what I really wanted to correct.

I think it would be difficult to find matching wheels that corrected for the spacing difference - not even sure I would want them - lots of headaches.

As to the 1.5" versus 2", the 1.5" could be tight with the lugs, some had to file them down - i didn't want to get into that situation. Maybe 1.625 would have been ideal.

And finally, the aluminum versus steel, well I am just old fashioned, like steel - given what I do to the rear wheels on mine I just feel more comfortable - the extra 5 lbs isn't that much of an issue to me.
 
I did not realize that there was a difference between the front and rear axle widths. ?The rear spacers would definitely compensate for the variation.

Keeping "stock" wheel widths and offsets should minimize and sizing and fitting problems. ?I do like the ideal of increasing the width of the vehicle since it has a high center of gravity (either in stock form or with taller tires)


This size issue is something to think about. ?I do not have exact measurements but according to the website, it list a 3" difference between front and back. ?If this is the case, then going 4" will put the back out too far. ?1.5" may have a clearance problems with the existing lugs. ?I would think a 1.6x should work fine. ?Since most of these are custom made to order, ?it should not be difficult to order a size that would not put the back out of alignment with the front.


As for steel vs aluminum; steel is definitely stronger but the wheels are aluminum so i don't think there would be much to loose or gain with either model. ?It really comes down to cost $350 vs $200 or whatever (do I see a GP here?) ?If we can find something like this under $100 (wishful thinking) it would practically be a no brainer for that extra measure of handling and safety.
 
It is my understanding that the 1500 axles are the same width, front and back - one of the reasons that they have an easier time with larger tires fitting the front wheel wells without rubbing.

BTW, the Silverado 2500HD has the same problem, but to a lesser extent - different wheel wells.
 
If you are in the greater Los Angeles, California area, there is a company that will custom build spacers while you wait. I talked to the owner of the company and he will take actual measurements from your vehicle and build the spacers for an exact fit. The price seems quite reasonable too.

1.jpg


The guy Fred Goeske has a background in drag racing and his company builds a wide range of wheel products.

http://www.wheeladapter.com

I am still surprized that GM would produce a truck with a variance between the front and rear. It would be a simple OEM fix. I guess it is hard to quantify the effect of such a variance so it is easy to slip that to the customer.
 
Looks like I found my next couple of mods, however, the Active Road system does not list Avalanche. Which one should those 2500 4x4 owners go with. Also goes the same for the spacers. They have 9/16" listed and 14mm listed. Which one. Thanks for the advise.
 
You want the MK II (XXF) - 2500 AV is the same as a 2500 4x4 Suburban.

Spacers, you want the 2" - will clear you axle lug bolts and put you about 5/8" out on each side - way better than the original.
 
Here is a link to another company that makes spacers. http://www.performancewheel.com/, then click on adapters and spacers.
They are $95 each for 2", and they have other sizes, as well.
I bought 4 for a handling test I was doing, and they are quite robust.
As for aluminum vs. steel - you have aluminum wheels, don't you?
BTW, the Suburban also has a 3" narrower rear wheel spacing than front, as has for at least the last 7 years. :B:
 
Thanks for the info Grandolphxx. However, there are 4 spacers to choose from:
C341T2916 1980-1991 Chevy/GMC 3/4-ton & 1-ton 4x4 Trucks & Suburbans, 2" thick spacer (9/16" stud )
C341T214 1992-1999 Chevy/GMC 3/4-ton & 1-ton 4x4 Trucks & Suburbans, 2" thick spacer (14mm stud)
C34T11214 2000-2002 Cheyv/GMC 3/4-ton 4x4 Trucks & Suburbans, 1 ?" thick spacer (14mm stud)
C1T214 2000-2002 Chevy/GMC 1-ton 4x4 Trucks, 2" thick spacer (14mm stud)

Which one do I need? I know that a couple of these are 1.5" spacers so not those but of the other 2" ones which part number? I would like to order today....
 
The set that will do the job with clearance is the C1T214 2000-2002 Chevy/GMC 1-ton 4x4 Trucks, 2" thick spacer (14mm stud) one
 
BTW, the Silverado 2500HD has the same problem, but to a lesser extent - different wheel wells.
Click to expand...

I've noticed this on my '02 HD but I have to really look for it. I might have to pick up a set or two :)

I am still surprised that GM would produce a truck with a variance between the front and rear. It would be a simple OEM fix. I guess it is hard to quantify the effect of such a variance so it is easy to slip that to the customer.
Click to expand...

Ever notice the mid '90's Impala SS? The rear wheels weren't centered in the wheelwell from the factory. I've always wondered why they built them like that.

Tom
 
Thanks for the tip, gandolphxx. Tire stiping helped to a certain extent, but anything that can reduce the squirrelly back end on wet/loose surfaces is welcome.
 
Dumb Questions!

Will this help me when I am towing?

What will this fix or correct?

What invprovment should I see?

Finally, Why do we need it?



 
I'm with you MrBill. I have the same dumb questions. I tow a travel trailer and if these things really help my stability I'll invest in them.
 
MrBill said:
Dumb Questions!
Click to expand...
No questions are dumb.
Will this help me when I am towing?
Click to expand...
I have yet to tow anything, but the characteristics of the rear end of the 2500 changed dramatically after the Roadmaster install when I loaded up the bed - kept it from bouncing - and more importantly added the effect of sway bars to the rear on conering.
What will this fix or correct?
Click to expand...
The combination will fix:
1. Bounce when unloaded
2. Understeer - huge improvement in conering
3. Tracking - much better on ruts - on rht road or off
4. Reduced wheel hop - for those moments ;D
What invprovment should I see?
Click to expand...
All of the above
Finally, Why do we need it?
Click to expand...
I can say without reservation that everything that both vendors promised in their respective presentations worked. You can read about it and decide if those make sense to you.
 
Thanks!

I had questions and you had answers.

 
I have heard the reference - shouldn't make a difference - call them and tell what you have - it is the same as the 2500 Sub or 2500 HD
 
gandolphxx,,

I remember you mentioned these a while ago... I was wondering how they went as you didn't mention them 'til now... I bet you're happy !!!

Until GM came out with the new 1500 frame and front suspension, this "offset" was on all the 1500's too ... Once you notice it, it's kinda dorky ... IMHO

Now if GM could only "fix" this on all the IFS 3/4 > tons and non ZR2 S-10's !!!

Good deal ... That makes buying a bigger truck easier to swallow knowing you can fix that ...

11H
 
Hey Gang,

I just ordered a set of 2" T6061 Aluminum spacers from Performance Wheel and Tire. I am looking forward to getting the installed, as I have always despised the way the rear of my AV 2500 seems so narrow. I have MT Classic II wheels with LT295/75/R16s on them. The backspacing on the wheels is 4" which really makes the difference pronounced. So much so that I have been questioned on two occassions as to why my truck is "crooked"......ugh! I'll post some pix when I get the installed. ;D
 
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