Towing question

sjenson1 · June 9, 2004

I have a 2001 1500 LT 4x4 Z71 5.3 with 3.73 gears and tow package (including stock transmission cooler). RPO code for vehicle weight is 6400 lbs. I believe my gross combined weight is 13000 for this truck, which leaves me with 6600 lbs available for towing (someone correct me if I am wrong). I am buying a new boat that will have a dry weight of 5900 lbs with trailer. While I will be storing the boat in a slip, I will occasionally tow it short distances. I know I won't go over the extra 700 pounds I have left with the gear I take with me and will tow the boat empty (or close to it) of gas. I do have a trip planned this summer that is 2000 miles each way and would like to take the boat with me. I plan to flush the tranny and change the differential fluids and transaxle fluid prior to the trip. My question is does anyone here routinely or occasionally tow this close to the limit with their truck, and if so, have you had any problems or is there anything else I should do before this long trip (or is it a bad idea to even pull it that far)? I have never pulled more than 3500 lbs with this truck, so I'm not real sure what to expect with this much weight and I certainly don't want to ruin the tranny. Thanks in advance for any input anyone can give me.

srmrvette · June 11, 2004

My 2001 is a 2500 4wd with the 6.0 engine, so I am not an expert on your particular configuration. I don't think you should have any problem towing that boat, although from your location on a long trip you might hit some mountain passes which will let you know right away that you are hauling a big load. Stay out of overdrive in hilly terain to cut down on the shifting. I assume you have the full tow package which includes a tranny cooler.

sjenson1 · June 11, 2004

Yes, I have the tranny cooler, although I don't know how good an OEM one works. Maybe someone else out there could give me some insight? I have a route that I use when making this same trip that keeps me on fairly flat ground with gentle inclines and declines as I go through the mountains, so hoepfully it won't be too bad. Thanks for the reply.

BlackSilver · June 12, 2004

My previous truck was a 2001 5.3L 3.73 gears 2WD. I pulled my old (7,000#-plus) 5th wheel trailer with it on some long trips. Your boat is probably a little more streamlined.

Be prepared for poor gas mileage (6-8MPG tops) and a lot of time in 2nd and 3rd gear at high RPM's. But the 5.3L is a willing worker, and you won't hurt anything (except your pride when Yugos pass you on 2% grades!) Never had an issue with cooling, using the OEM cooler which comes on the "towing package".

snoman · June 12, 2004

Although so people get by, 3.73 with a 5.3 and 31's or better is a poor towing combo for 6 ot 7000 lbs . Youl need to get the RPM up a bit when town and that means at least 4.10's. The fact the one poster here was getting 6 to 8 mpg tend to comfirm the engine was being overworked for the load due to gearing and not being very efficent. I would regear to at least 4.10's and it would pull better nad have less strain on tranny and it should run cooler to. 13,000lbs GCVW with a 3.73 and a 8.1 might work okay but with a 5.3 it would be overloaded most of the time.

dr9672723 · June 12, 2004

OK, nobody laugh, but I towed a 5,000 lb. trailer with my '03 with a 4.3 liter and 3.42 axle, 4L60E with a large cooler. Overdrive was out out the question. Slowed down to 55 on the steep grades, but otherwise did 70 mph OK.

Obviously, I won't do this anymore except in an emergency. 3.73 or lower gears in back would have helped a lot. Still managed 13 mpg even though it was working hard.

snoman · June 12, 2004

OK, nobody laugh, but I towed a 5,000 lb. trailer with my '03 with a 4.3 liter and 3.42 axle, 4L60E with a large cooler. Overdrive was out out the question. Slowed down to 55 on the steep grades, but otherwise did 70 mph OK.

Obviously, I won't do this anymore except in an emergency. 3.73 or lower gears in back would have helped a lot. Still managed 13 mpg even though it was working hard.

Do not make a habit of it but slap in some 4.10's and you will be amazed how well the 350 minus 2 cyl's will pull! Plus, it should not hurt MPG because you do have OD still whci is really to tall with 3.42's

dr9672723 · June 12, 2004

Well, after all, the 4.3 has torque and horsepower numbers that look like a mid 70's V8... but then again, we drove about 55 MPH then. Thanks.

Dan

teamjnz · June 13, 2004

I would plan on stopping at a truck stop with a truck scale and get yourself weighed. I was weighed for 8 bucks. Fill up the tank with gas and the items you are going to be traveling with. Most places will have a scale that will measure the weight of each axle and total it up for you. Then you will have a accurate number of your remaining GCWR. Watch your rear axle weight. The numbers in the brochure aren't "real world" numbers. They are for a bone stock truck, no options. Your LT has many options which add weight.

Before I bought our 2500 Silverado we just had the 1500 Suburban. The Suburban is rated to tow 6000lbs. After I got weighed with just my family, 3 kids under the age of 6, and full tank of gas the rear axle was at 3300lbs. That didn't leave me with much extra. Then after the rest of my calculations I really ended up with a 4500lbs "real world" tow capacity.

Get another set of wheels and much smaller tires than the stock ones. This will effectively change your gear ratio without having to replace the gears. Then when you are back home from your trip put the other ones back on. This is an alternative option to changing the axle gears.

teamjnz

sjenson1 · June 14, 2004

I thought if you went by the RPO code for the vehicle weight, that it was for the truck as it sits, not the standard base weight?

Wingnut · June 14, 2004

Although so people get by, 3.73 with a 5.3 and 31's or better is a poor towing combo for 6 ot 7000 lbs . Youl need to get the RPM up a bit when town and that means at least 4.10's. The fact the one poster here was getting 6 to 8 mpg tend to comfirm the engine was being overworked for the load due to gearing and not being very efficent. I would regear to at least 4.10's and it would pull better nad have less strain on tranny and it should run cooler to. 13,000lbs GCVW with a 3.73 and a 8.1 might work okay but with a 5.3 it would be overloaded most of the time.

My 5.3 has had absolutely ZERO problems towing a 6k plus boat with it's 3:73s and 285 tires. This is at least 40 miles every weekend with several trips of up to 1000 miles under the belt. It never felt overloaded, and would maintain 75 mph for the entire trip. Easy-peasy-japaneasy.

4:10s would be nice, but it would kill the everyday driving mileage (for my type driving).

sjenson1, you will be fine with your setup for the type and distance of towing that you described.

snoman · June 14, 2004

I would plan on stopping at a truck stop with a truck scale and get yourself weighed. I was weighed for 8 bucks. Fill up the tank with gas and the items you are going to be traveling with. Most places will have a scale that will measure the weight of each axle and total it up for you. Then you will have a accurate number of your remaining GCWR.

It is cheaper and easier to go to a farmers mill or grain depot as they all has scales and that is were I weight something when needed.

snoman · June 14, 2004

Although so people get by, 3.73 with a 5.3 and 31's or better is a poor towing combo for 6 ot 7000 lbs . Youl need to get the RPM up a bit when town and that means at least 4.10's. The fact the one poster here was getting 6 to 8 mpg tend to comfirm the engine was being overworked for the load due to gearing and not being very efficent. I would regear to at least 4.10's and it would pull better nad have less strain on tranny and it should run cooler to. 13,000lbs GCVW with a 3.73 and a 8.1 might work okay but with a 5.3 it would be overloaded most of the time.

My 5.3 has had absolutely ZERO problems towing a 6k plus boat with it's 3:73s and 285 tires. This is at least 40 miles every weekend with several trips of up to 1000 miles under the belt. It never felt overloaded, and would maintain 75 mph for the entire trip. Easy-peasy-japaneasy.

4:10s would be nice, but it would kill the everyday driving mileage (for my type driving).

sjenson1, you will be fine with your setup for the type and distance of towing that you described.

I define tow capacity defferently than GM does as they are more generous than I. I have little doubt that you boat tows well but tak a trip thru hilly terrain with long climbs at speed and it will change. A proper tow vehical for the load should never have to drop below drive to maintain speed on a long grade on a highway.

Wingnut · June 14, 2004

I never took it out of drive...And it never dropped below 75 mph.

13000 lbs of truck and boat have no business going over 75 mph anyway. Really shouldn't be going even that fast most of the time in my opinion.

snoman · June 14, 2004

I never took it out of drive...And it never dropped below 75 mph.

13000 lbs of truck and boat have no business going over 75 mph anyway. Really shouldn't be going even that fast most of the time in my opinion.

On on very flat ground too! BTW, OD towing on that tranny is not a wise idea and puts extra strain on it that it was not designed to handle.