Leaf Spring on Ex-MOD 109 Ambulance Question

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  • kenscs
    Low Range
    • Nov 2011
    • 72

    Leaf Spring on Ex-MOD 109 Ambulance Question

    Hi all,

    My Ex-MOD 109 Ambulance that now has a basic flatbed with canvas top has a pretty intense "bucking" when I go over any kind of road bump. My suspicion is that it is related to what are likely heavy-duty leaf springs on the truck to accommodate the initial ambulance back. It definitely has the long MOD shackle and leaf springs that have 8 "leafs" in them. I am likely going to take off the springs and either grease them or put UHMW tape between them (i have read all the debates here about that), but what my question (finally) is whether I can/or should remove any leafs while I am at it. I see lots of posts out there about 2 or 4 leaf springs, but nothing related to 8 leafs.

    Anyone have any thoughts about best way to go assuming I don't want to go towards new parabolics and just try to make the best of the original MOD springs?

    Thanks!
    1971 Series IIa 109 Ex-MoD
    1994 Landcruiser FJZ80, ARB Front Bumper, Old Man EMU suspension
  • SafeAirOne
    Overdrive
    • Apr 2008
    • 3435

    #2
    Hmm....Bucking: To make sudden or jerky movements...


    If, by "bucking" you mean bouncing all over the road laterally whenever you hit washboard-like bumps, especially on curves in the road, then you probably need more weight in the back, where the very light flatbed now exists. The springs are stiff and for all intents and purposes are inoperative without some weight to actuate them. This means that the wheels are bouncing up, off the road surface, and a tire that's not in contact with the road surface will do nothing for you, vehicle control-wise.

    TeriAnn's site has helpful information on Rover leaf springs if you endeavor to seek a factory replacement with a different spring rate: http://www.expeditionlandrover.info/spring_rates.htm

    Speaking personally, If I was had a spring with too many leafs, I would probably start taking leafs off the bottom of the stack, one at a time, till I found something that works in both my empty AND fully-loaded configuration.

    If, by "bucking" you mean that when you hit a bump at a throttle setting near the cusp between driving under power and coasting, the whole vehicle begins oscillating between lunging forward and coasting, then you have a driveline slop/backlash issue.

    If, by "bucking" you mean that whenever you hit a decent bump, your steering wheel shakes back and forth (sometimes violently), then you have slop in your steering system or your steering box isn't attached firmly to its mount or the mount isn't attached firmly to the chassis (among other causes).
    --Mark

    1973 SIII 109 RHD 2.5NA Diesel

    0-54mph in just under 11.5 minutes
    (9.7 minutes now that she's a 3-door).

    Comment

    • luckyjoe
      3rd Gear
      • Oct 2006
      • 335

      #3
      I had the same configuration - '65 ambulance converted to 3-door, retaining ambi springs.

      Yes, you need 100's of pounds of weight over the rear axle to tame those springs into submission. I found that painting them with motor oil, multiple times over a month of driving, did improve 'smoothness', but there is no substitution for some additional payload...
      Tom P.
      1965 exMoD 109
      1995 RRC LWB w/EAS

      Comment

      • I Leak Oil
        Overdrive
        • Nov 2006
        • 1796

        #4
        My old ex mod amb. conversion also had swaybars. If yours still has them, they aren't making the ride any more comfortable.
        Jason
        "Clubs are for Chumps" Club president

        Comment

        • kenscs
          Low Range
          • Nov 2011
          • 72

          #5
          Originally posted by SafeAirOne
          Hmm....Bucking: To make sudden or jerky movements...

          If, by "bucking" you mean bouncing all over the road laterally whenever you hit washboard-like bumps, especially on curves in the road, then you probably need more weight in the back, where the very light flatbed now exists. The springs are stiff and for all intents and purposes are inoperative without some weight to actuate them. This means that the wheels are bouncing up, off the road surface, and a tire that's not in contact with the road surface will do nothing for you, vehicle control-wise.

          TeriAnn's site has helpful information on Rover leaf springs if you endeavor to seek a factory replacement with a different spring rate: http://www.expeditionlandrover.info/spring_rates.htm

          Speaking personally, If I was had a spring with too many leafs, I would probably start taking leafs off the bottom of the stack, one at a time, till I found something that works in both my empty AND fully-loaded configuration.
          Thank you all for feedback. Definitely am referring to the first form of bucking. I will throw some sand bag in the truck to start actuating the leaf springs to start.

          I guess the next question, which I know is a can of worms given all the posts I have read, is "Do I just get 3-Spring Parabolics for it?" Seems like an easy route and I wont have to carry 200 lbs of sandbags around normally and reduce gas milage. Primary purpose is for Vermont dirt roads (which have LOTS of washboards) and paved roads to those dirt roads. At this point, no serious offroading intended. I use this to get to trailhead to mountain bike on the crazy terrain.
          1971 Series IIa 109 Ex-MoD
          1994 Landcruiser FJZ80, ARB Front Bumper, Old Man EMU suspension

          Comment

          • yorker
            Overdrive
            • Nov 2006
            • 1635

            #6
            Try to free up your stock suspension like Tom says first. It is more or less free to do. If you never really use the truck heavily laden then you could try different springs (Maybe 109 SW springs) or buy parabolics.
            1965 SIIa 88",1975 Ex-MOD 109/Ambulance, 1989 RRC, blah, blah, blah...

            Land Rover UK Forums

            Comment

            • disco2hse
              4th Gear
              • Jul 2010
              • 451

              #7
              Get standard duty springs unless you intend to carry heavy loads, then you will need to use ballast.

              With standard duty springs your carrying capacity will be limited to around 400kg but the heavy duty springs increase that to 750kg.

              You will find your ride and on-road safety are well improved with standard duty springs if you are not carrying heavy loads. The bouncing you refer to become dangerous if you are cornering or braking and you start to tramp. Additionally, the behaviour in wet or wintry weather become very risky.
              Alan

              109 Stage 1 V8 ex-army FFR
              2005 Disco 2 HSE

              http://www.youtube.com/user/alalit

              Comment

              • kenscs
                Low Range
                • Nov 2011
                • 72

                #8
                Thanks all for input. I loaded the back with Sand Bags and Kids resulting in HUGE improvement! Since I won't be carrying this kind of load normally, I think I will be switching to standard springs for Rocky Mountain Parabolic's. PS, as I was testing the springs with a full load of 10 year old girls in the back along with leaf springs, the truck died. If I had a picture, no one would believe it. Four ten year old girls pulling on a 30 ft snatch stap trying to pull a Camo ex_MOD truck home at 11 pm through the neighborhood. I am sure a few people looking out the windows had their vision checked or alcohol content of previous drinks checked. For more flair, the girls had painted their faces in Clown Paint. I am not making this up. Ultimately, the wife was called with Suburban to tow it home for real.

                Something to remember for the weekend journal in school...
                1971 Series IIa 109 Ex-MoD
                1994 Landcruiser FJZ80, ARB Front Bumper, Old Man EMU suspension

                Comment

                • disco2hse
                  4th Gear
                  • Jul 2010
                  • 451

                  #9
                  Aaargh,

                  Take a camera every time you go out. Or your phone.
                  Alan

                  109 Stage 1 V8 ex-army FFR
                  2005 Disco 2 HSE

                  http://www.youtube.com/user/alalit

                  Comment

                  • LaneRover
                    Overdrive
                    • Oct 2006
                    • 1743

                    #10
                    Originally posted by kenscs
                    Thanks all for input. I loaded the back with Sand Bags and Kids resulting in HUGE improvement! Since I won't be carrying this kind of load normally, I think I will be switching to standard springs for Rocky Mountain Parabolic's. PS, as I was testing the springs with a full load of 10 year old girls in the back along with leaf springs, the truck died. If I had a picture, no one would believe it. Four ten year old girls pulling on a 30 ft snatch stap trying to pull a Camo ex_MOD truck home at 11 pm through the neighborhood. I am sure a few people looking out the windows had their vision checked or alcohol content of previous drinks checked. For more flair, the girls had painted their faces in Clown Paint. I am not making this up. Ultimately, the wife was called with Suburban to tow it home for real.

                    Something to remember for the weekend journal in school...
                    Yes, pics are good - especially if you are sitting on the truck with 'reins' to control the team.
                    1958 107 SW - Sold to a better home
                    1965 109 SW - nearly running well
                    1966 88 SW - running but needing attention
                    1969 109 P-UP

                    http://www.facebook.com/album.php?ai...2&l=64cfe23aa2

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