k2500 8600gvrw trucks tow ratings have gotta be under rated

Discussion in 'Towing' started by seth9199, Oct 2, 2019.

  1. stutaeng

    stutaeng OBS Enthusiast

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    I believe 2500 diesel and 454 have the full floating 14 bolt. 2500 5.7 got 8 lug SF. All 3500 got the FF, regardless of engine.

    I can't remember on the hydroboost if some 2500 had that or not. Again, I "think" some options had that. The biggest deal is stopping when towing, at least in my experience. Accelerating will be slow and cars can pass you (no big deal,) but when you got to stop in "x" feet, you have no option.

    Also, I believe the all towing options had the engine oil cooler.
     
  2. Trenton

    Trenton OBS Enthusiast

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    You can, I have a 1998 K3500 CCLB SRW with the 350 and a full float rear end. It's honestly more truck than engine lol.
     
  3. Sparkysikes

    Sparkysikes I'm Awesome

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    Some 2500 came as 6 lug. That'll be your 1500 radiator on the 2500 frame with a SF.

    My 91 k2500 with 6.2 diesel had a 12 bolt rear 10 bolt front and 4l80e. It had huge cooling (hum I wonder why lol) but had that 8600gvwr and I did exceed that by A LOT. But going up a decent grade was 25 mph letting the truck do her thing. Going down the grade was butter. (not slippery and out of control but easy) the brakes held up great and I felt in control. The truck was weighing around 7500 lbs plus the 8 to 10k behind me. I got almost 15 mpg for that trip. 18-21 was normal. But I drove her like Mrs. Daisy.
     
  4. tachrev

    tachrev Newbie

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    To some extent, GVWR is a made up number anyway to force vehicles into a specific registration class. Manufactures play with these all the time to put vehicles in the class they want.

    Your GAWR front and rear tells the truth on payload. My Suburban is an 8600gvw truck. But the front axle rating is 4500 and rear is 6000 according to the door sticker. That's 10500lbs.

    Lots of variables to consider when you are talking ratings.

    Now they have SAE tests that the manufactures all agreed on to do tow ratings. I don't believe that had those in the 90's so I have no idea how GM decided on the tow ratings they gave these trucks. Probably based it on the probability of warranty claims. :D
     
  5. rcm9364

    rcm9364 Newbie

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    GVWR is a measure of what the chassis can physically hold (safely, and for warranty purposes.) So if you cross the scales at 8600 lbs (truck, cargo, you, everything) then you’re maxed out. You can still be overloaded if you have too much distributed unevenly between the axles (see axle weight rating) In the gmt400 platform they didn’t really push it, but the information you really need is GCWR (gross combined weight rating) which is what your truck and trailer can hold. They’ll do more than what they’re rated for but every pound over increases your risk for system failure (axle breakage, break failure, etc.)
     
  6. rcm9364

    rcm9364 Newbie

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    Also, you need to look at tongue weight. A properly loaded trailer should have about 10% of its weight on the tongue. So a 5000 lb load would result in only 500 lbs on your truck.
     
  7. stutaeng

    stutaeng OBS Enthusiast

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    I guess the limit on these would be the rear leaf springs? I don't know what the payload on OPs truck is, but 10,000 lb trailer will have 10%-15% tongue weight, not including other stuff on your truck: gear, coolers, passengers, etc.

    My dad has a '89 Sierra 1500 RCSB, and I know loading the bed with 1000-1200 lbs makes rear sag moderately. If I had to guess, rated payload is likely around 1,300-1,400 lbs range on his. P-series tires start looking suspicious with that load. Definitely upgrade to LT-series.

    Not sure what the payload is on 2500. Depends on the configuration and rear axle.
     
  8. L29Sub

    L29Sub OBS Enthusiast

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    IMHO, a k2500 BB will not safely pull a 10k tagalong. I just bought a RAM 3500 that will. The Burb will "pull" the load. But the suspension isn't up to dealing with it. It went down a smooth highway great. Hit a dip or anything that caused the trailer to lurch and it became "white knuckle express".
    About 7500 is right...no matter what the tow rating. Even new Chevy 3/4 ton diesels SRW are known for loose feeling with max tow loads.
    I spent a load trying to make this work. Never was safe. I was pulling a Vengeance Rogue 31V you hauler on a 12k reese hitch with 12 I trunions. Excellent tires at 80 psi. New shocks, rag joint, poly bushings, (and bought a Firestone air suspension and compressor that I never installed) really no change. Truck drove great with 7500 and less.
    Bought a Ram 350O that pulls my toy hauler without issue. All about the bucks I reckon. I'd find a chevy 1 ton dually and gitrdone.
    IMHO.
    Anyone need a reasonably priced Firestone 2101 and 2097 suspension? Still in original packaging. This fits 2wd and 4wd '88 '99 Burb K2500s. [​IMG][​IMG][​IMG]

    Sent from my SM-G965U using Tapatalk
     
  9. tachrev

    tachrev Newbie

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    You may be right. A lot of things can come up when you are right at the edge of your ratings.

    I looked up your trailer because it was curious. It's a monster for a conventional trailer!
    The "dry" tongue weight is 1250 on forest rivers site! Thats 15% of the "dry" camper weight of ~8500lbs.
    That is not unheard of, but it is higher than most campers. And we know the advertised dry weights are usually BS anyway.

    So by the time you load it up to 10K, you are looking at at least 1500lbs tongue weight, probably more.

    If you load it up to the full 11500 gross weight that camper is rated for, 1700lbs tongue weight.

    Add in your 12k WDH, 42G of gas aft of the rear axle, and your family and road trip snacks in the suburban...I can see why it isn't happy.

    I feel like campers are a different ballgame anyway. A 2500 Suburban might pull a car trailer loaded to 10K fine..camper, not so much.

    Your 3500 Ram will be a much better tow vehicle for that camper!

    Both trucks look great, btw. AND the camper. :D
     
  10. L29Sub

    L29Sub OBS Enthusiast

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    Tachrev, you're right about the tongue weight. Most large toy haulers have the axles biased towards the rear in order to prevent flexing. Plus, the overall height is greater for the same reason... box rigidity.
    I knew the truck was going to be maxed out with the trailer. And you are right again regarding a car hauler or low COG trailer. I pull close to 10k (50 hp JD tractor on 20' Hudson Bro trailer) without issues. Travel trailers tend to "grow" and always lots of crap in the back of the truck. Anything behind the axle compounds the problem and becomes leveraged swinging weight.
    Factor in the ever present possible loss of trailer brake circuit and we're about to have a bad weekend. I was dependent on the trailer brakes. Then of course there's that golf cart...
    Big pendulum...? Actually, it tows the same with the 800 lb cart or not. Probably loss of a bit of hitch weight offset the swing effect of the cart. [​IMG][​IMG]

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