4WD maintenance

Discussion in 'GM Powertrain' started by Skarch, Aug 17, 2007.

  1. Skarch

    Skarch Rockstar 100 Posts

    I know on our old Scout, we had to put it into 4WD every month or so, so that the transfer wouldn't freeze up. On modern trucks (1997 Suburban) do I need to use it every few days or weeks to keep it working, or is it self maintaining. The truck will be a street driver in the land of little snow, so it won't be used hardly ever because of need.

    Any advice?
  2. unplugged

    unplugged Epic Member 5+ Years 1000 Posts

    Good question

    I'm old school on that too. I don't know if is required on the GM trans/transfer case, but I try to drop mine into 4wd high/low at least once a month. I was stranded one time in an 80's Bronco because the 4wd wasn't working and I didn't know it! That was an expensive off road tow.
  3. tbplus10

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

    The transfer case uses the splash and oil bath method for oil circulation, which means no pump to spray oil on top of the gears. When in 2wd you dont get a lot of lubrication to the 4hi/lo gears (4 hi/lo dont spin unless their meshed to a drive gear) so it's not a bad idea to run it every once in a while to put a fresh coat of oil on the gears and bearings.
  4. CaJuN625

    CaJuN625 New Member

    AutoTrak transfer case

    Every so often, I drive around in Auto4WD. From what I've been told, this gets everything turning, lubricating and building up heat which helps "boil-off" excess moisture in the various components. Every 50K miles, you should change the transfer case fluid, too. Basically, when you're going to be on the highway for a while, throw it either into 4HI or Auto4wd to help keep things lubricated. I use Auto4wd every time it rains because it's fun to see what it takes to get it to kick in.

    NOTE: the AutoTrak transfer case uses SPECIAL BLUE FLUID. If you put regular automatic transmission fluid in it, it'll have problems which will surface as a driveline clunk that ALOT of people have problems with.

    I had a clunk in my transfer case and found a few different remedies - only to read somewhere that SOME AutoTrak cases were accidentally filled with Automatic Tranny fluid. The fix was to replace the red tranny fluid with the blue stuff: drain red, add blue, drive around for 50 miles, drain, add more blue. My clunk went away - it was like magic, I tell you. Now, it's starting to feel like it's coming back, so it's time to change the fluid again.
  5. Skarch

    Skarch Rockstar 100 Posts

    Thanks for the responses guys.

    After some thought, I instituted "4-wheel Friday", so that she will drive to work every Friday in four wheel drive. That way its easy to remember, and I don't have to keep track of it on my calendar. I figure the 1-2 MPG she will lose on that trip will be worth the extended transfer case life.:glasses:
  6. TrailLeadr

    TrailLeadr Epic Member 5+ Years 1000 Posts

    As unplugged suggested, this is a good question. I myself would say when in doubt "give it a workout".

    hmmm, I think everyone should have a "4-wheel Friday"!!:great:
    It would be even better if you could find a way to off-road the whole way to work.

    Awesome advice guys

  7. skivhere

    skivhere Rockstar 100 Posts

    I prefer the "4-Wheel Saturday and Sunday"!!

    I just bought a K1500 Suburban and the previous owner said he didn't use the 4X4 but a few times, so I am trying to remedy that fact. Had the truck 3 weeks and only been on the beach once...but I plan to do it at least every other weekend! My transmission does seem to clunk a bit when it warms up...hoping to do a tranny tune up soon...hope it clears up that problem.
  8. v8nos

    v8nos New Member

    if youre goning to do a tranny tune-up i would also suggest putting in a shift improver kit. i had my trabby rebuilt about a year ago and i had the shop install one when they were in there. greta improvement. good firm positive shifts.
  9. skivhere

    skivhere Rockstar 100 Posts

    I will probably do a mild tune up myself...change out the fluid and filter. Hell, I don't even know what tranny I have!!! I think it is a 4L80, but not positive. Had the 4L60 bolted to the 305...anyone know???
  10. CaJuN625

    CaJuN625 New Member


    It's not likely you have a 4L80E with a 305. More than likely it's a 4L60E. The 4L80E is a workhorse: high power or high abuse situations. They take up more power from the engine, but they take the abuse of tow / work vehicles that spend most of their time moving more than just themselves. Sticking a
    4L80E behind a 305 (or even a 350) would be serious overkill and a MAJOR power loss. A 4L60E in standard configuration will handle about 450 horsepower in a heavy vehicle - up to 750hp if built well and in a light vehicle like a Camaro or Firebird.

    I've got a 4L80E behind a 6.0L in my 2004 Sierra 2500HD ... but it's a 1-ton configuration and it's geared towards a tow/work vehicle - expected to have high abuse over it's life. Let me tell you, towing my trailor in the middle of summer, up hills and keeping 80mph on the flats ... tranny temperature gage never got above 200 degrees. These 4L80Es are incredible, let me tell you.

    Back to the subject, though - REALLY not likely that you've got a 4L80E behind your 305. Sorry.

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