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Front Coil Springs

Discussion in 'General Truck Info' started by greg0187, Apr 29, 2008.

  1. greg0187

    greg0187 Moderator Staff Member

    I have found the need to replace my front coil springs with stiffer rate springs to maintain the added weight of steel front bumper, winch, tool box, and fat Americans. The current front suspension bottoms out regularly even without the added weight. Given all the after market springs available I did some research and found that I'm able to replace them with Eibach, Hypercoils, etc... My 99 Hijet has 3" ID springs and I have found a local chassis fabricator shop that has a coil spring rater (Spring Rate Gauge) to rate the OE springs for a baseline to replace them with. I figure I need at least a 30-50% stiffer spring. I have already thought about loss of articulation, but with the added weight it may be OK. Any other thoughts, suggestions, tips?

    -Greg
     
  2. topherztoyz

    topherztoyz Member

    Please keep us posted on what you find this issue. Mater of fact.. I called a local spring shop here in Phx. and got nowhere with them.. They said it could be done, but they would send out and test GVW, spring length, etc, and said it would be costly and take months. :mad:
    You would think we should be able to cross referance these struts.. I myself would like stiffer springs in front. Mine is a 2001 Daihatsu Hijet.
    Chris
     
  3. greg0187

    greg0187 Moderator Staff Member

    Will do. It took a couple dozen phone calls and messages to find someone with a spring rater. Anyway, I just got the spring out. Its got 4.25 active coils and the wire diameter is 0.41". Your 01 springs should be the same. According to the spring rate calculators I have found its rate is about 185-235lbs/in which seems reasonable but a definate baseline is better. I do not trust this calculation b/c there are other factors involved that are unknown, elasticity of the steel used etc... I'll try to get it down to the chassis shop to have it rated in the next day or two after that its fun in the sun in Mexico for a week! I'll keep you posted

    -Greg
     
  4. greg0187

    greg0187 Moderator Staff Member

    Its no wonder why these things bottom out so much, They only have 3" of travel before hitting the bump stop. Anyway, got an appointment at the chassis shop tomorrow. Hopfully they don't have any issues, If they can't test the spring for some reason then I think the calculated rating is in the ball park. Today I was messing around and tried to gage the rate myself with a tape measure (don't laugh :eek:). I locked the tape measure about the length of the spring and clipped the end onto one end of the spring with the back of the tape measure on the floor next to the other end of the spring, I compressed the spring a little (1/4"), took note of the measurement and put all my weight on the spring. It compressed ~1", I weigh ~215lbs witch would make the rate ~215 lbs/in, so the calculation may not be too far off. Here's my plan, the spring is 10" long and has a 3" inner diameter. I found some springs at Fisrt Over All Suspension. Depending on what the chassis shop finds out I figure I will need about a 325 lbs/in - 350 lbs/in spring. My only worry now is that the outer diameter may be larger than the spring seats assuming the aftermarket spring uses heavier gauge wire.

    -Greg
     
  5. Acerguy

    Acerguy Moderator Staff Member

    Hey, putting a known weight on it and measuring the deflection is a perfectly fine way to do it assuming they're not progressive wound. Granted, I work on a lot smaller springs (full suspension mountain bikes) but it works! :)

    It's not an ideal solution but, if you can't find good springs, have thought about just playing around with the bump stops? I once had a variety of stops from a friend who used to work at Eibach and basically the idea was to use them to do a final "tune".

    There are also some "coil over conversions" out there. I have one for my VW but haven't installed it yet. Basically, a coilover adapter sits in the normal spring perch and allows you to both use standard 3"(?) coil springs AND adjust the height. I'll have to did around in my stuff and see if I can find the name of them....
     
    Last edited: May 1, 2008
  6. greg0187

    greg0187 Moderator Staff Member

    I played with this idea but found that they are normally used with 2.5" ID springs. I found some adapters so you can use them with 3" but I figured I was going to have some interference problems with the dust boots and the spring rate wasn't really going to change, they just increase the preload. Its not a bad idea and I think it would definatly work.

    -Greg
     
  7. greg0187

    greg0187 Moderator Staff Member

    The verdict is in. 210 lbs/in. Cost $5. The chassis guy can order me springs same day cheaper than the ones I found and he even gave me a used one he had on the shelf to test fit before I ordered to make sure they would work. He gave me a few good tips, which I would expect from a guy who builds race car and race buggy chassis. His place is right next door to where they film all the hot rod/4x4/truck shows that are on the Power Block on spike TV.

    -Greg
     
  8. Acerguy

    Acerguy Moderator Staff Member

    Cool! So you were real close with your estimate of the spring rate. Can't wait to see the results.
     
  9. greg0187

    greg0187 Moderator Staff Member

    He He He, I must of ate light yesterday, off by 5lbs. Update: After talking with the guy he pulled out his caliper and took some measurements and suggested I use a 2 & 5/8" standard coil-over spring as they have more coils and therefore a thicker wire. The 3" ID springs would have been too large. He let me borrow a 2 & 5/8" spring and it fits beatifully. He also gave me some advise on the increased rate so I'm gonna order 275lbs/in springs which is about a 30% increase, hopefully that won't be too stiff. That should be good to handle the extra load wile providing a decent ride. I'll post some pics when I get the new springs w/ side by side comparison and installation

    -Greg
     
  10. TRAX and HORNS

    TRAX and HORNS Well-Known Member

    What was the price? Please let us know what the ride is like after installing.
    I was recently quoted 250.00 for 2 stiffer shocks for the front. Also thinking about air shocks for the rear. What do you think?
     
  11. Acerguy

    Acerguy Moderator Staff Member

    Greg, it will be interesting to see if you're going to need stiffer dampers to go with those stiffer springs. So that you don't end up with a bouncier ride...boing...boing...boing... :D
     
  12. greg0187

    greg0187 Moderator Staff Member

    The springs are $61 a piece. Air shocks will most definately stiffen up the rear, maybe too stiff if you plan on having them aired up all the time.

    I wish I could find stiffer dampers, well I found some but I'm not willing to fork out $2000 for them. I already have the boing, boing. :p

    -Greg
     
  13. greg0187

    greg0187 Moderator Staff Member

    Just got back from Mexico. :p I ordered the new springs this afternoon. I should have them by Thursday and installed by this weekend. I'll let you know how they work out.

    -Greg
     
  14. greg0187

    greg0187 Moderator Staff Member

    Got the springs today and installed them. I have not tested them out yet, I'll let everyone know tomorrow how they ride. Here's some pixs.

    [​IMG]

    [​IMG]
     
  15. topherztoyz

    topherztoyz Member

    Looking foward ror you're ride test results..
    I may be interested in a pair.. How hard is the project to take apart and replace? Tools needed.. etc..
    Chris..
     
  16. greg0187

    greg0187 Moderator Staff Member

    OK. Took about an hour, basic sockets and wrenches, you can use the trucks weight to de-compress and compress the springs with a jack under the control arm (if your good) or rent a spring compressor. Just make sure its for small diameter springs, the tool should be similar to the type used for Honda automobiles. I know this because I rented a standard strut spring compressor from Autozone and I can tell you it doesn't work.

    The ride: I don't have a lot of wheel time in my truck but have used it on and off road several times. The OEM spring provides a very good ride on the road but leaves something to be desired off the road. The front consistently dives hard on dips and bottoms out. My first impression after installing the new springs was that it lifted it ~1" and "Oh crap, Its too firm". Although, upon driving, it was definately an increase in performance. I could drive considerably faster on my property than I ever could before, and I was jumping the curbs in my neighborhood into my property at ~5 mph without having to worry about breaking anything (A full beer flew out of the dash cup holders twice). I'd have to say the ride was quite firm, but forgiving. Being a trial and error study my gut feeling is that if you don't have alot of extra weight in the cab with heavy steel bumpers, winch and a tool box in the bed like I do, my recommendation would be to go with 250# springs instead of the 275# I used. I would say you would have a choice if three levels of performance; 225#, 250#, and 275# depending on how you use your truck.

    -Greg
     
  17. topherztoyz

    topherztoyz Member

    Cool..... How about another report after you get a week or two of driving with them? Eather post, PM, or email me.. huh?
    I noticed when I take mine offroad.. it is eather bottoming out, or toping out on the washboard roads.. definitly a cluncking sometines.. It felt like my '04 Yamaha Rhino did with orig shocks.. up front. ( before I replaced with '07 take off shocks) though only on real major 4w/d roads. My Rhino shocks were worn out from heavy 4 w/d roads, and a few years of doing them.. and were toping out..(rebound) hitting hard going back up from compressed.
    antway.. lets see how you like them after a few miles... And then maybe. I could see if you can hook me up with a pair.. eather I buy a set from you, or I deal direct from your buddies.. OK?
    Chris..
     
  18. greg0187

    greg0187 Moderator Staff Member

    Thats cool. I don't plan on making any money off these, however I would like to bring some business to the chassis shop that helped me out, if possible. My guy is going to find out if he can have the springs drop shipped. Other than that the springs can be ordered on-line direct through the manufacturer, but they were a few bucks higher in price + whatever shipping would be. I did the testing without my heavy front bumper and winch, and by myself, so its basically a stock truck with a 5" lift and 25" tires. The biggest benifit that I have seen so far was that the front doesn't feel like its going to plough into the ground. There is a lot less pops/cluncks comming from the front, probably because the suspension is not going through its entire cycle top-to-bottom continuously. I had to get quite aggressive to even getting it close to a full cycle. I'm taking it to do some serious wheeling next weekend, and I can also get some opinions from other people that have ridden in the truck before the swap. I don't want to post the link to the parts just yet as I don't want to steer a bunch of people in the wrong direction, nor do I want any hurt feelings if they do not work out for someone. I still stand by my suggestion of a lesser rate of 250#'s. If you have the extra money to take the chance I would like to see how they work out for you.

    -Greg
     
  19. jimhoodag

    jimhoodag New Member

    Greg,

    Did you also replace the front shocks/struts inside the new springs?

    Jim
     
  20. greg0187

    greg0187 Moderator Staff Member

    No, Just the springs, my struts are in good shape still.

    -Greg
     

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