Front Suspension

Discussion in '<a href=http://www.plowsite.com target=_blank ?>Sn' started by Psyclopse, Dec 11, 2000.

  1. Psyclopse

    Psyclopse LawnSite Member
    from In
    Posts: 118

    I have seen conversions for the 88 and up Chevy/GMC trucks that replace the tortion bar setup with a traditional leaf/solid axle setup. What are your thoughts on which would provide a better suspension for plowing? I am not actively considering this swap anytime soon, I am just curious as to the thoughts of others.

    Also, how does the tortion suspension on my 3500 differ from tortion suspensions on 2500 or 1500 trucks of the same body style? Any special concerns I should keep in mind about the front suspension on my truck?

    By the way, I just got an 8 foot Western setup cheap and didn't need to modify anything (thanks for all the input).
     
  2. Deere John

    Deere John LawnSite Senior Member
    Posts: 327

    Welcome. I have used both torsion bar and leaf spring styles, and I wouldn't change anything with your rig. I found the torsion bar system rides so much better that the plow does not get tossed into the air (on big bumps while travelling) nearly as much. Regarding the differences, the bigger components on the 3/4 tons and bigger are similar to the 1/2 ton stuff, just more robust, durable and foregiving.

    Attention to detail of the "small" things are what will keep you mobile and make you successful. I wouldn't want to stake my living on my re-engineering of a suspension sytem that had millions of dollars of R&D money spent on it. Hope this helps.
     
  3. CT18fireman

    CT18fireman LawnSite Senior Member
    Posts: 611

    On my first toyota I converted it to a solid axle for off roading. After installing leafsprings I found that the plow frame would no longer fit. Had to customize it heavily.
    I also agree that the torsion bars to seem to ride better. It is possible to get heavier torsion bars for most trucks.
     
  4. plowking35

    plowking35 LawnSite Bronze Member
    from S.E. CT
    Posts: 1,687

    My k-3500 has much heavier a arms than on the 1500 and 2500 series truck. Add to that torsion bars that are heavier and with the 8.5 v plow the front sags about a 1/2". I also have load boosters just in case. I personally wouldnt go through all that trouble to change over to a solid axel design. If you like solid axel that much go back to a pre 88 truck.
    Dino
     
  5. Psyclopse

    Psyclopse LawnSite Member
    from In
    Posts: 118

    Thanks for the input. I don't really have any qualms with the torsion bar setup (other than my misspelling it as tortion more than once). This is my first GM truck with torsion bars, and for a 1 ton, it is a smooth riding rig. All my buddies that told me I should swap are into lifted off-road trucks, which is probably why they like the idea. I didn't buy this thing to toy with, I bought it to WORK- so a lift is out of the question anyway.

    One question though (and this may belong in the truck forum)- how much lower should the front of the truck sit as compared to the back (bed empty and plow off the truck)? I have a noticeable 'rake' to the front when sitting on a level surface. The front doesn't sag much more with the plow on- maybe 1/2 to 3/4 inch but I haven't had snow in the last 24 or so hours since I got the plow to test it out.

    The front end doesn't seem worn and my father claims that the 3500's just sit like that anyway, but I want to be sure. Is it fine, or should I crank up the bars a little? Should I add some type of helping device?

    Am I being overly cautious or paranoid? With the Ford, I just get in and go- I know the truck well and I know the plow well. The GMC is all new to me (including the plow), cost me more to buy, and is even more expensive to fix.
     
  6. TLS

    TLS LawnSite Fanatic
    Posts: 7,937

    Psyclopse,

    I also have a K3500 its a 1990 Single Rear Wheel (SRW). Is yours a SRW? These have different torsion bars than the duallys. I have the extended cab and I run a Boss V plow. Its one of the heavier plows out there and I haven't had any problems. It does sag a bit, but with a pallet (2400lbs) of salt and a tailgate spreader, this brings the rear down too! So I am now a lowrider! It will go through just about anything (withen reason)! I have seen the straight axle conversions also, but they are all lifts of 4-6". The straight axle would fix the horrendous turning circle of the IFS GM's. I have a '75 Suburban and its turning circle seems like it is half that of the '90!! I wish GM would address this IFS turning issue as mine is a long wheelbase truck. The only time I would go lock to lock would be in parking lots and snowplowing. Makes me want to get out the grinder and grind down the turning stops to gain that 1/4" that those nubs prevent. Any thoughts on this anyone?

     
  7. Psyclopse

    Psyclopse LawnSite Member
    from In
    Posts: 118

    Yes, mine is a single rear wheel model, but mine is a standard cab. I have to put a significant amount of weight in the bed before it starts to drop any. I had 12 sheets of 5/8 drywall, 10 sheets of 1/2 OSB and 40 2x4's a few weeks back and the front end was still slightly lower (without a plow on). Like I said, it seems to ride fine- the ride is better with a bed-full of weight than my other trucks.

    What brand and size of tires to you prefer?
     
  8. fordkilla454

    fordkilla454 LawnSite Member
    Posts: 28

    Maybe this deserves to be in the Chevy Truck Forum but oh well it started here. I to have considered converting my 1995 IFS to a solid axle with leaves. Unlike most of yall I am interested in off-road performance instead of pushing snow. My question is will the suspension lifts for 81-87 be a direct bolt up or will spring perches and the like have to be moved around. I realize spring perches will have to be placed on the front axle.
     
  9. John DiMartino

    John DiMartino LawnSite Silver Member
    Posts: 2,555

    I think the rake is normal,since the payload is around 3500lbs,even on the SRW model,I bet it takes at least 2500 lbs in the bed to make it sit level.I think this is normal,thats how all the ones I see sit.
     
  10. TLS

    TLS LawnSite Fanatic
    Posts: 7,937

    Psyclopse,

    Try turning up your torsion bars another inch or two. In 1988 (first year) they didn't offer the HD torsion bars for the snowplowing prep package. Yours may be a tad smaller than mine. (good ride) If your "pork chops" are resting on your crossmember, turn them up till the adjusting bolt takes them up a 1/4" (2-4 turns). In winter I run 235/85 Goodyear Workhorse Extra Grip and in the Summer I run Michelin LTX M/S 265/75's (very nice comfortable quiet driving tires)

    John,

    My truck weighs 5900 lbs empty and with the 8600 (yuck) GVWR that leaves me only a 2700 lb payload. Well Im way overloaded when plowing. It takes it though, and I'm careful and don't beat it.

    fordkilla454,

    I believe the solid front axle kit is a 4-6" lift already. With that and a 3" body lift, you can fit some pretty big meats under it then. If your interested in off-road performance, then stick with the IFS. There are nice lifts for this and torsion bars that are spongier for the off-roaders.


     

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