Looking for answers - 97 Suburban towing and overdrive

Discussion in 'Chevy Suburban Forum (GMC Yukon XL)' started by BuckeyeBandit, Jul 15, 2008.

  1. BuckeyeBandit

    BuckeyeBandit New Member

    I have heard so many different things, i would like to know the truth.
    I have a 97 GMC Sub 1500 4x4, I pull a trailer that weights 3500-4000 lbs, the manual says i can tow in OD but i have heard so many different things about it. May i add the only time i drive this truck is to pull this trailer.

    So can i tow in OD? I heard yes and no...lol

    And whats the towing capacity? I have heard 5000, 5500, and 6200
  2. retired2001

    retired2001 Epic Member 5+ Years 5000 Posts

    You are right, there are a lot of different theories on this question. I personally do tow in OD, unless I am in hilly country. When the tranny has to keep shifting up and down, I would just as soon take it out of OD. I do use the "Tow/Haul" mode (button on the end of the gear shift) when towing. Maybe some of the other folks can help with the tow capacity.
  3. ChevyFan

    ChevyFan The Sheriff Staff Member 5+ Years 1000 Posts

    Most heavier trucks I've ever driven have specifically stated NOT to tow in OD, but rather keep it in the highest gear otherwise. I'm not certain about the '97 Suburban, but I guess if the manual says that it's ok, then it's probably ok. :neutral:
  4. Skarch

    Skarch Rockstar 100 Posts

    As a tack on to this thread, I just recently returned from a 2800 mile "jaunt" from Dallas to South Dakota and back, pulling a 5x7 u-haul loaded with crap. The thing that I noticed the most is that there doesn't seem to be much sway control in the 'burb. Is there a stiffer roll bar that I could install that would help out with this? It wasn't bad, but with a cross wind the thing really got to rocking.
  5. Crawdaddy

    Crawdaddy All hail the Mad King!! Staff Member 5+ Years 1000 Posts Platinum Contributor

    Skarch, you might want to invest in a trailer hitch with sway control in it. You have to install a weird coupler thing on the frame rail of the trailer, but they are usually bolt-on jobs that can be installed in less than 10 min and removed in the same time.
  6. MrShorty

    MrShorty Epic Member 5+ Years 1000 Posts

    There are a variety of opinions out there. Assuming this is a 5.7 L gas engine (from what I can gather there may have been a very few diesel 1500's made during that time), here are a couple of points that I consider when I tow:

    1) The 4L60E doesn't have a very good reputation among those who work their trucks. One of the weak points appears to be the sun shell. The stresses on the transmission will be less in 3rd gear, giving you a better chance for longer service.

    2) The 4L60E also has a fairly tall 4th gear (0.70:1 I believe). Depending on rear gear ratio, this means that even at moderate highway speeds the engine can be running well below 2000 RPM. From published information I have seen, the 5.7 torque peak is at 2800 RPM. In 4th gear, you're going to be well below that. 3rd gear will put the engine running in a range that it "likes". Some people have even reported better gas mileage towing in 3rd rather than 4th, probably because it allows the engine to work at a speed it works better at. The other thing that the computer may do at moderate speeds in 4th gear is choose to unlock the torque converter clutch (TCC) rather than downshift into 3rd gear. Because of the heat and slippage generated by an unlocked TCC, you're generally better off in 3rd-locked rather than 4th-unlocked. Being in 3rd gear and the PCM will be less inclined to unlock the TCC.

    With all that said, I tow in 3rd gear most of the time, unless the terrain and speed allows me to feel comfortable letting it upshift to 4th gear.
  7. ct9a

    ct9a Epic Member 5+ Years 1000 Posts

    What about driving in OD when you're NOT towing? I've always just thrown the shifter into OD for every day driving, but when it came up lately, a couple of people looked at me as though I was crazy and mentioned they rarely use the OD option. Good, bad, no difference?
  8. sysmex

    sysmex New Member

    Regarding the tow button on the gear shifter, I don't have one. My Burb is a 99 1500 with a 4l60e. Was this a option?
  9. retired2001

    retired2001 Epic Member 5+ Years 5000 Posts

    It may have been offered on the "next" generation. I know my '04 has it. I'm not sure when it came into play.
  10. Crawdaddy

    Crawdaddy All hail the Mad King!! Staff Member 5+ Years 1000 Posts Platinum Contributor

    Do you have an OD and a D on the gear selector? If so, there's your tow/haul switch ;) All tow/haul does is disable overdrive and slightly modify the shift points

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