Need advice on when to replace shocks and what brands are good. - Don't want to change the ride. Just want to know which maker and at what mileage.

Don't want to change the ride. Just want to know which maker and at what mileage.

definately can't go wrong with bilstein. and it all depends on how much you tow and haul and what not and how hard you are on your suspension! living on a minimum maintenance road and doing alot of towing and hauling and running accross fields i tend to wear mine out quite a bit faster than most!

make sure you get the correct shocks when you do replace them..the Z71 package took special shocks for a stiffer ride. From what i heard the 4x4 shocks differ from the Z71 package shocks

Yes. The Z71 shocks were special. Before you buy shocks, ask the store about their return policy. Some of them will take them back if the ride is not what you expected. Just don't wait too long. Installation tip. When you replace shocks, try to compress the suspension to as close to sitting on the ground compression as you can and THEN tighten the hardware. Use hand torque, not air tools!

I agree with koolz, I've got a 99' 2500 4x4 Seirra, the shock are very specific. I just ordered and installed Rancho 5000. My 5.7 lt. changed every thing when ordering. My truck has org. shocks, with 170000 miles. I will let you no about the ride.
P.S. 4 wheel drive.com had the best $$.
Also, ordering on line was cheaper $30.00 than on the phone....

I've got pro comps on my Z71 and they are a great ride. They also cost less than Rancho.

I'll agree with everyone on getting the exact replacements if you have a z71 package. I took off my z71's Bilsteins at 100,000 miles and replaced with Monroe shocks (don't remember which ones but they were expensive and recommended by the parts people at Autozone. WELL........ They really stink! The ride is totally different, soft, rolly, bouncy after hitting bumps in the road, like the wheels aren't staying in contact with the pavement. Will definitely go back to the Bilsteins as soon as the wallet can afford it.

shocks start to fade between 40k and 60k , a good truck shock in my opinion would be monroe gas magnum, there tuned for trucks and suv,s the have twice the fluid capacity and a bigger bore. nitregen filled, and cost effective at around 50$ each

Aren't Bilsteins guaranteed for life?

Yes, Bilsteins are guaranteed for life, BUT only if there is a defect in materials or workmanship. Their warranty does not cover normal "wear and tear" as they state on their website. My Bilsteins were worn out at over 100,000 miles when I replaced them and I was told they were not covered under a warranty because they simply wore out! Buyer beware. I've had this same experience with Advance Auto Parts Stores when returning items that have a lifetime warranty. Since running into problems there, I've taken my business to Autozone which stands by their lifetime warranty and replaces items no matter if they've worn out or are defective. Just be careful where you buy your parts!