Info on Isuzu/GM cabover trucks please!

Discussion in 'Trucks and Trailers' started by DLM155, Aug 23, 2013.

  1. DLM155

    DLM155 LawnSite Member
    Messages: 53

    The Isuzu/GM line of cabovers. Isuzu labels em NPRs, GM just calls them W3500/4500. I am looking at 00+ models and specifically an 02 gas truck. They generally sport an auto transmission that I assume is a 4L80e and either a GM gas smallblock or a little 4cyl diesel. I know everything there is to know about the GM gas burners but nothing about the diesels these trucks featured. I assume they are also mated to the 4L80? Adequate power? Can they do interstate speed comfortably or is it running with its tongue out? Are there any problem areas with the truck? I know the GM power plant is bullet proof but I don't know anything about the rest of the truck or the diesel engine.

    I'm going to have a small dump bed on it that wont see much more than 2,000lbs in it. Usually it'll be empty or just have some grass clippings or leaves in it. I am positive the truck is well above that task, but 99% of its duty will be hauling my lawnmower trailer which is a tandem axle unit and weighs <4,000lbs loaded including the trailer. I have never seen one of these trucks tow anything. Ever. Considering its #1 job is going to be towing, is it a suitable candidate? These trucks seem inexpensive for what they are, only come in the cab configuration I want in the color I want and are generally wholesaled cheap as dirt with reasonable miles unlike the standard pickup truck market.

    The only snag I see with this truck is it is extremely rare to see a 4wd one and they look top heavy as all ****. I don't really want to buy one of these in that trim, but I think I can get by with a locked rear end. I'm not familiar with what make or size the rear end is on these trucks but is there an aftermarket for a locker/posi unit? What gear ratio do these usually run?
  2. Deererunner

    Deererunner LawnSite Senior Member
    from NJ
    Messages: 320

    Curious as well as I am in the market of buying one, a diesel though.
  3. windflower

    windflower LawnSite Bronze Member
    Messages: 1,098

    I've got the 4 HE1T diesel. Seems to do fine at 70 once it gets there. When I was looking for the truck, the gas version was way cheaper than the diesel. Probably because the diesel is supposed to last 300K before needing a rebuild. I've towed 2500lbs with no problems. Seen a picture on this site of one towing a bobcat or something like that.
  4. hosejockey2002

    hosejockey2002 LawnSite Bronze Member
    Messages: 1,195

    The diesel is not really "little", it's 5.2 liter with about 200 hp/440 torque. IIRC it can be had with either an Aisin sourced auto or a manual. The gas is the 6.0 GM with a 6L80E 6 speed auto. The diesel has a B90 rating of 310,000 miles and the 6.0 200,000. B90 rating means that 90% of engines will last to 'x' miles with proper maintenance without a major engine repair. Both engines have the same tow rating. I haven't driven either one but I can imagine that the diesel gets much better mileage, and the 6.0 better acceleration with a roughly 150 hp advantage.
  5. TNGrassCutter

    TNGrassCutter LawnSite Bronze Member
    Messages: 1,321

    My 02 NPR has the gm 5.7 not 6.0. It has a 14' landscape bed on it with 2 mowers on it and it has plenty of power. Its been trouble free the 20000 miles I've had it, has 183000 miles.
  6. ncpete

    ncpete LawnSite Senior Member
    Messages: 288

    Ran 6 separate diesel NPR's in my past. Stupid reliable. Only one service problem that I can remember now, one of my trucks wouldn't shift well, with the auto, and would shut down automatically - with warnings - as a result. So, the truck protected itself. I forget what the issue was, but it happened during the first year of ownership with it, and never re-occurred after serviced.
    If I could justify one now, I would jump on it in a heart beat.
    Hosejockey's information is correct for the current vehicles as far as the gas versions go but it was a 5.7 and 4L80e in the early 2000s. I think the 5.2 liter diesel and the Aisin transmissions have been paired up on these for as long as they have been making the NPR though it would be a four speed for an 02, and 5 speed for more recent trucks?
  7. hosejockey2002

    hosejockey2002 LawnSite Bronze Member
    Messages: 1,195

    Older trucks had smaller less powerful engines- the late 80's early '90s had a 135hp 3.9 liter IIRC. Still reliable, just not very fast. Not sure when they went to the 5.2.
  8. lawn king

    lawn king LawnSite Silver Member
    Messages: 2,407

    Im on my 10th season with a 2003 npr/auto/diesel. Best work truck we have ever owned. I often haul my 7800 lb. trailer/kubota, with 2000 lbs. of fert and a 450 lb ride on in the body. It takes a while to get her moving with that load, but she gets it done!
  9. Southern Lawn Care  LLC

    Southern Lawn Care LLC LawnSite Senior Member
    from Alabama
    Messages: 314

    I have a 2005 NPR Diesel and I wouldn't trade it for the world! It's turning radius alone makes these trucks awesome. Pulling a trailer would be different of course. I have a flat bed for hauling and a box and dovetail on my NPR. So I don't pull anything with it at all.
  10. Echelon

    Echelon LawnSite Member
    from ohio
    Messages: 95

    ive had an 89 gmc w5000 aka isuzu NRR for seven years now and its been a great truck. its got an allison, not aisin, 4 speed auto hooked to a 6.5 liter straight six with no blower. its a tractor. slow, noisy, and rides rough, but it gets the job done and turns on a dime. no trailer hassles and i can park it in a normal parking spot. little over 290k on it now and it still always seems to get 12-13 mpg. great truck, ill run it till it dies. heres a pic from when i first got it. still looks about the same:


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