Jump to content

JoeH

Pedigreed Bulldog
  • Posts

    2,283
  • Joined

  • Last visited

  • Days Won

    14

Posts posted by JoeH

  1. Looking for dimensional drawings for Mack MR600 series cab/chassis.  Cab/axle, wheelbase, etc.  Ultimately looking for a mid 90's to 2001 triaxle MR with a cab/axle of 168", but don't know what that will translate to in wheelbase because I can't find drawings!

  2. Are you flipping the headlight switch on the dash up or down?  Up is headlights, down is clearance lights, middle is off.  The switch up on the left of the dash is a high beam momentary switch.  It doesn't activate low beams.

    If you're flipping your switches properly then start with putting new bulbs in and checking the wiring as mentioned above.  You can lose a low beam filament without losing the high beam filament in a bulb.

  3. I've driven oil and propane single axle autos, the exhaust brake will throw you through the windshield.  The feedback I heard years ago is that they suck off-road, because the torque converter doesn't lock up at low rpm, so you sit there winding up the engine trying to get enough friction built up in the TC to move the truck through soft ground or over obstacles like curbs.  The other day on a job I had to back my right drive tires on my triaxle onto 6 inch blocks to keep from tipping over in a soft spot.  Do the older autos lend themselves well to this sort of maneuver?

  4. 10 hours ago, 1965 said:

    The true automatic (Allison)  in dump trucks around here will out perform any standard. They’ll go places offsite that standard want try. There quicker off red lights too.

    Is that the new stuff or pretty much all Allison's?

  5. Looking into using an MR688 or 690 (mid '90s fully mechanical hopefully) to mount a concrete mixer (volumetric type, not barrel) on.  Most are automatic, but the few that I glanced at look like the auto trans has very little ground clearance.  Does anyone have any experience with MR's? We hop curbs once in a while, back into people's yards, the usual things Macks are supposed to do. How do the automatics perform in these conditions?  Do they have a good torque converter lockup to be able to hop over curbs or soft ground without much fuss?  Chances are an auto is a terrible fit for us.  Ideally I'll find a gem e7-350 with an 8LL, but I'm curious about the automatics.

  6. Citing low back pain, get something with light duty springs and a longer wheelbase, plus an air ride cab is a must.  Not sure when they started, but Mack offered an option on the R model where the rear cab mount is air bags.  Night and day difference on operator back pain.

     

    You can convert any truck to single axle air ride, would likely give you a much better ride quality than traditional springs.

    • Like 1
  7. What kinda hobby truck? Hobby dump truck for picking up your own mulch? Hobby rollback to support an existing automotive hobby?  5th wheel for towing some old John Deere tractors?

    The possibilities are endless.  A bit of mechanical know-how is important, and so are some big wrenches! 

    As with all things metal, rust is the biggest enemy to watch out for. Solid bones are important.

  8. In PA those trucks are good for 73,280. Tandem axles are only good for about 58k I believe in PA.  What you're able to get on the truck depends on the axle weight ratings.  Example, steer is probably good for 18k, and the drive tandem is probably good for 44k.  Combined you're looking at a legal weight of 62k loaded without that lift axle, depending on what your state regulations are. In PA the lift axle only needs to be down if you're over 58k or the weight rating of any particular axle.

  9. I'd be surprised if they are the same, but then again the oil pans use the same gasket.... Get VIN numbers from an E6 truck and an E7 truck, ask your dealer for the part number for each timing cover gasket.  Same for the front main seal.  The E7 can run the steering pump on the front of the timing cover, so I'm sure the covers are different.

    I'd just sift through a Mack junk yard and find a donor front engine mount.  Don't know where you live, but Coopersburg PA has a good one at the Kenworth dealership.

  10. Also make sure those 2 little pins in the side where it says "TOP" are mounted top, they're air bleeders so you don't get a pocket of air against the thermostat when you refill the system. Air won't conduct heat to open the thermostat properly on the first heat cycle.

     

    Automotive thermostats frequently don't have those so I drill a pin hole in them to serve the same purpose.

    • Like 2
  11. Should be running at 180, that's where all my Macks run, 1979-1995. Dont know what your truck setup is, if it's real light and you have no hills it'll take forever to warm up, it's meant to work hard.  A new thermostat would have been a good idea, they're not expensive.  Running cold slobbers up the valves, can make them sticky.

    • Like 1
×
×
  • Create New...