2008 4.8l chevy silverado towing problems

Discussion in 'Chevy Truck Talk & GM News' started by outdoorsboy87, May 29, 2013.

  1. outdoorsboy87

    outdoorsboy87 New Member

    Hey guys new on here this is the first forum that i have been part of. I have a question about towing and wanted to see if anyone else has had the same problems that i am having with my truck. I have a 2008 chevy silverado regular cab with the 4.8l v8 and i am having a problem when i tow my boat. Now this isnt a big bay boat or anything its a 16' aluminum jon boat that might weigh 1600 lbs at the most. i have noticed that when i am crusing at 70mph at about 1800rpms the truck will down shift and the rpms shoots up to 3000 rpms and this is on flat highways around the houston texas area. i have also noticed that the transmition temp goes from about 165°f to around 195°f. Is this a major problem? When i bought the truck i didnt get the towing package could this be why i am having trouble also? and the truck does the same thing when it is empty going through the texas hill country. Thanks in advance
  2. h0serdude

    h0serdude Member

    I've never towed with a half ton and I'm betting it doesn't have a heavy duty transmission cooler like the 2500 and 3500s do so that is probably why the temperature spikes when it downshifts. Not having the tow package probably eliminated the tow/haul button on your console as well which helps the transmission find the sweet spot with a heavier load. You may want to look into an aftermarket transmission cooler or see what it would take to have an OEM one installed.
  3. nonnieselman

    nonnieselman Member 1 Year

    with the 4.8 i think those have a 4L60E, and i bet you have 3.23 gears which is horrible for towing in a stock truck.. next time try and down shift one gear and see how it does.
  4. MoBillyAla

    MoBillyAla Rockstar 100 Posts

    For comparison sake, I have a '07 4.8 with tow package. I have towed cars from Texas to AL, and AL to NY without any issue. I normally push the tow button "on" when I remember. I will be towing a u haul and my bike in back of my truck from NY to WA at the end of the month (8 days on the road), I will pay close attention to the shifts and oil temp and compare. FWIW it doesn't sound like your transmission is shifting efficiently and as mentioned already, is causing the higher temp, but even 195 isn't too high (I think 230-240 is the caution range). It might be a good idea to get it looked at if you keep noticing this. BTW how many miles do you have on it?
  5. nonnieselman

    nonnieselman Member 1 Year

    The cooler you can keep the trans the longer it should last.
    Anything over 200 and its asking for trouble. The clutchs dont like heat thats for sure.

    So cooler the better. Mine rarely breaks 150*. On the daily commute it might hit 140*, and even while towing it never gets to 175*, once the converter locks its starts dropping pretty quick.

    Im running the fluid thru a TruCool 40k trans cooler and it works awesome! I bypassed the radiator so the engine coolant wouldnt be heating the trans fluid.
  6. MoBillyAla

    MoBillyAla Rockstar 100 Posts

    So far midway through my 8 day cross country trek I am averaging about 180-185 degrees. I have been using the tow selector as well This is generally 70-75 degree ambient temps outside. The only time I have gotten hotter is while going through the mountains in the PA/West VA/OH area that had my tranny up/downshifting frequently. I am towing my Harley in the bed and pulling a 5x8 Uhaul. Total vehicle weight is just over 8000lbs. I am going to Mt Rushmore tomorrow and then continuing on through the Rockies. I'll see if there are any differences.

  7. tbplus10

    tbplus10 Epic Member Staff Member 5+ Years 5000 Posts Platinum Contributor

    Glad to hear your having an uneventfull trip so far, enjoy Mt. Rushmore and I hope you continue the rest of the trip uneventfull.
  8. MoBillyAla

    MoBillyAla Rockstar 100 Posts

    Thank you, overall pretty good trip little rain here and there, only one traffic delay (3 hours). Drove through Chicago about 10:30 PM Thursday night, that was probably the most scared I have ever been driving..lol

    Also I meant to say the hottest temp was 197 in the mountains when the tranny was doing a lot of up/downshifting. I have been watching my trans temp the entire trip.
  9. JTWard

    JTWard Rockstar 3 Years 500 Posts

    Well first off, I'm new here too. I have a 90 Silverado and it's got a 5.0 liter V8, but it has a 700R4 trans, which is a ancestor of your 4L60 and a child of the old turbohydramatic as is the 4L60 or 80 for that matter. Just some have evolved with time but they all share the same family genes. But just my opinion, I tow a double axle car trailer and at times a 4500 pound car, My capacity is 10.600 pounds. But my towing is not @70MPH and I never tow in Overdrive, only in third gear. Your boat and trailer wouldn't feel like a load in my truck but you shouldn't be reving to 3K RPM's, and your temps are kinda on the high side. I'm betting your transmission doesn't have a good 5 row Hayden trans cooler, I'd install one ASAP. And I'd find a good transmission shop and have your trans looked over, it shouldn't be down shifting unless you on an incline, but with your load of under 2000 pounds shouldn't phase your trans so that is why I think you have a shifting problem. How many miles on the truck ? And 195 degrees isn't a big deal, but the trans is bolted to the engine and the two will normally get close to each other, but that is why a trans cooler is necessary in your case. Nothing, nothing kills a transmission faster than heat. The clutch packs get VERY hot. They need both fresh clean synthetic fluid and it needs to be cool as possible. Good luck. :neutral:
  10. Barnettamb

    Barnettamb Rockstar

    How do yal know the temp of your transmissions?

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