Has anyone put in 4.56 gears or 4.88 gears in their quadrasteer? I have 35" tires on my truck now, and I tow some heavy trailers. I would like to put 37" tall tires on my truck, but I think that it might be too much without changing the final drive ratio. I know the front can be done, and I know that they have ring and pinons for Dana 60's, I am just not sure if our Dana 60 is different. Does anyone know if it can be done?

The QS is programmed to work through the computer with the only two gear ratios options that came with the truck.

By throwing 35 or 37" tall tires, you are effectively changing the gear ratio. By changing the ring and pinon, you are getting the final effective ratio back to stock, or near to it. So you are much closer to the stock design my changing the ring and pinon.

I have added a hyperpac to compensate for the tires, and now my speedometer reads correctly, and everything functions as it should. It also has the ability to reprogram the computer to compensate for a gear ratio change.

quote:

Originally posted by luchenbach:
By throwing 35 or 37" tall tires, you are effectively changing the gear ratio. By changing the ring and pinon, you are getting the final effective ratio back to stock, or near to it. So you are much closer to the stock design my changing the ring and pinon.

Agreed, didn't mean there was any difference with the rear-end assembly(in general), just the addition of the attached QS steering component on the diff cover. Tie rods, ball joints would be my concern though.

What type of backspacing are you using with the 35" and 37" tires?

quote:

I have added a hyperpac to compensate for the tires, and now my speedometer reads correctly, and everything functions as it should. It also has the ability to reprogram the computer to compensate for a gear ratio change.

Good to hear, I just wouldn't use Hypercrap for my programming, IMHO.

quote:

What type of backspacing are you using with the 35" and 37" tires?

That is a very good question. I have not purchased the 37's yet. I am using Hummer tires and wheels, which have a 5.5" backspacing. It really tucks the tires in tight, which I like because the quadrasteer rear is so much wider than the standard truck. The BFG all terrains are about 35" tall, and about 12 inches wide. The tires are on the verge of rubbing the A-arm at full turn, so I have to be very carefull when buying new tires to not go any wider if using these wheels.

I also have 4.5" backspacing wheels, which I may have to use if the new (possibly 37" tall) tires are wider than the BFG's.

With the 5.5" backspacing I have no problem turning, when not moving, while on asphalt. I know this is a bad practice, but it is necessary sometimes. With the 4.5" backspacing, the power steering pump bypass would open making the steering difficult. I believe that there is a factory service bulletin that addresses this issue.

quote:

Good to hear, I just wouldn't use Hypercrap for my programming, IMHO.

I agree with your comment on using the hypertech to change the tune. I only use the hyperpac to adjust for the tires and it also has a bunch of cool monitoring functions and performance monitoring and graphs that are cool to play with.

That's good information to know about the 35" tires that you've shared. Not many use that size tire with our trucks.

I have the leveling kit from Cognito also and if I remember correctly, the factory stance of your '05 1500HD 4X4 is approx. the same as my AWD. I haven't had the time yet to install, but that will come.

Possible to post up a pic of the truck with the those hummer wheel/tires? It would help to visualize and help me decide on the overall size of the wheel/tire after I do the leveling.

I'm sure it looks killer.

The cognito levelling kit is good. Be very careful when installing it, that you do not over tighten the uppen 'A' arm. In the cognito instructions it says to 'tighten to factory specifications'. Well the factory specifications are like 140 ft. lbs. The cognito assembly is not as stout as factory. When I tightened close to factory spec's, the frame mount was driven into the anti-crush sleeve, and deformed. When I took it to be aligned, they could not make any adjustments, because of this. It was a pain to dis-assemble it and get it all fixed.

In my Pro-comp lift instructions, it said to not tighten the 'A' arms unless the wheels were on the ground with weight on the suspension. Maybe this would prevent over-tightening.

In order to fix the Cognito system, I had to get some big washers and place them between the Cognito 'A' arms and the frame mounts, and I did not tighten it more than about 100 ft. lbs.

When I had the cognito system, I also put a 1" flat block in the rear. It seemed to me that 1.5" of lift in the front had levelled the truck, and I was able to get 2.5" with the stock keys cranked.

Good Luck.