Setting up 99 Sierra for towing

mcbearbryant · May 20, 2004

I have a 99 Sierra (new body) that I have been using for work/play. I want to start towing a car trailer with 2K# 240Z (3K# total). I checked RPO's and I have the Z83 (Solid Smooth Ride Suspension). The truck is at 70K miles and it is about time for new shocks, etc.

What would be the recommendation to bring the truck closer to spec for trailering?

Thanks.

citydriver · May 20, 2004

Do you know if yuou have the trailering pakage(classIII hitch,tranny cooler,wiring harness)???

If so that should cover it,just watch the trl tongue weight so you dont overload the hitch and suspension

mcbearbryant · May 20, 2004

The truck has the harness and the hitch but the RPO codes do not reference a 'trailer package' such as the Z82 or Z85.

My question is 1) what shocks would still keep decent ride yet be good for trailering and 2) would any rear suspension components need to be beefed up.

GONZO · May 21, 2004

well unless you have some kind of really light trailer you can count on a decent 16' car hauler weighing in at 1400+#. my 16" car hauler with brakes on both axles weighs in at 1500#. also i would bet the 240z weighs closer to atleast 2500# also, unless it's undergone some weight reduction plan.

unless your shocks are shot, your shocks should be fine. if you want to change them try the adj rancho 9000, they alloy you to adjust the ride stiffness. this way you could firm it up while towing and soften up the ride other times. with a properly loaded trailer your looking at 400-500# of tongue weight on the truck. might cause it to just start to squat a little, just watch how much junk you then throw in the bed of the truck. i towed my car hauler (5k# loaded) with my 88 blazer and it squatted down about 2" from unloaded height. what gears are you running, 4.10 or 3.73 gears would be better for towing, especially if you have larger than stock tires.

you will need tranny cooler, at least a class 3 hitch, 6 or 7 pin plug (depends on trailer) and a brake controller. you could add weight distributing hitch to help distribute the weight more evenly on truck, but not really needed i think.

az'03Silverado · May 21, 2004

On my last truck ('98 S-10) I put a set of Monroe Sensatrac Load-leveling shocks on the rear. They were the regular Sensatrac shocks with a coil-over spring. They allowed the rear suspension to feel smooth when unloaded and travel rather freely but when the rear end was loaded it would settle a couple of inches and then the springs would kick in. Very effective. I would carry bags of concrete, bricks, etc in the back with very minimal sag. They weren't any cheaper than the regular Sensatrac shocks either. Just my $0.02.

mcbearbryant · May 21, 2004

I appreciate the input. Sounds like I will be able to pull this off without much problem. My 99 Jimmy does have the towing package but I have been worried about the 4.3 doing that kinda work.

The trailer I have weighs just 1100 pounds (it is part aluminum and part steel with the middle 60% open except for cross members). The Z is right at 2075#. It has had everything from bumpers to seats and carpet removed. Also much lighter wheel/tire combo. Right now it has about 250HP for 2075 pounds. Wish I had that power to weight ratio for the Sierra!!

Right now is does solo autocross and time trials but I am thinking of showing some of these young kids how to really drift.

GONZO · May 21, 2004

sound like a nice set up in the z!

do you know what gears your truck has? the 4.3 would be happier pulling that weight if it had at least 3.73, but preferably 4.10 gears.

check your glove box for the codes...

GT5=4.10

GT4=3.73

GU6=3.42

GU5=3.23

GU4=3.08

mcbearbryant · May 22, 2004

Both my Jimmy and Sierra have the 3.42 rear. Guessing they had a surplus of those in 99. I have towed 2K# with the Jimmy with no problem in the past so it may end up as the tow car. I can always explain it that the Jimmy does match the colors of the Z.