Diesel front springs on a 712?

[audiocontr]

I believe my front springs are in poor shape as the nose rakes very low compared to the rear. I also have a large, solid front winch mount which adds significant weight.

I recall someone mentioned using Diesel springs on the front of a 712. Is it a direct replacement? Are they a better spring knowing i have the additional weight? Or will they cause the front to raise to the extreme unless i replace the rear leaf springs as well?

[krick3tt]

It may be that the rear is sitting higher as it is supposed to be filled with soldiers and lots and lots of equipment to even out. My 710 sits lower in the front when not loaded.

edit: When I added the new bumper and winch to the front it lowered the front about 1/2 inch. Not such a radical change when one figures that there is about 14 inches clearance anyway.

I can always depend on Jim to have an answer for what might be amiss with a pinz. He was very helpful to me the other day when I had an issue with the RPM module. Problem is now solved.

[Jimm391730]

Years ago, Stephen at SoCal sold me "TD" front springs for my 712W since it carries even more weight than an ambulance. Unfortunately I do not know exactly which springs he used.

Then I was going through the manual over the weekend and saw that it shows three different springs for 710/712s: one red dot, two red dots, and three red dots in increasing stiffness. I guess I could go look this weekend to see if any marks are still visible on my springs and what color they might be. IIRC the change between 1, 2, or 3 dots is only 7-10% per increase.

The pins that hold the ends of the springs are also available in different lengths which would adjust right height without changing the spring rate.

Lastly, I have found that the rear elliptical leafs in the 712s don't flex much; most of the "suspension" comes from the balancing between the two axles. Adding 1,000 lbs to the read doesn't change the rear ride height by much at all. So I would suspect that your winch and 40 year old coils in the front are what is causing the sag.

[Pinz710m2]

If you look in the book, they list exact measurements
of front, middle, and rear springs, or in the case of a 712
Front springs, rear leafs.

I would suggest that if you decide to replace them,
go with OEM spec, unless you have significant weight
in the front. (Like 300 lbs more than stock - something
significant). Any custom spring manufacturer can make
them. (I checked and one place wanted $278 for a pair
for the front of my 710). They can change the spring rate
as desired.

I don't have it with me right now (I'm in the UK until
tomorrow) but I think they give ground-to-bumper height
so you can see if they are at the correct height.

[edzz]

If going aftermarket keep in mind that the stock springs are progressive.
(from the book). 4x4 “Both front and rear wheels are suspended by progressive helical springs with inconstant wire diameter and additionally by rubber hollow springs, acting also progressively.” This also applies to the front of the 6x6.

[audiocontr]

Went with OEM replacements via Scott's suggestion. We'll see if there is a difference.

[David Dunn]

I believe my front springs are in poor shape as the nose rakes very low compared to the rear. I also have a large, solid front winch mount which adds significant weight.

Post a pic of the winch setup so a weight can be estimated with the word "significant". . Second, do the springs bottom out at any time? If no, I'd probably start by changing the pins length (and before anything else, CHECK the spring cups to be sure they aren't rusting through).

Degree of rack is a subjective thing also. The winch will add to the rake, and original springs sag from age, but the simple way out is to add shims to the cups until you're happy, then order pins for the combine sum of the shims and pin.
The Pink Cow had some bizzare setup the Sweds had done as the none of the springs were as they should have been from the factory, the front pins were the longest and they had 3/4" extentions on top of that. And when I removed the complete hydraulic winch setup, the bumper came up 1". Drove and rode fine, so left it.

The GG sits nose high, could be everything is new and the springs haven't had any weight on them to take a set , OR the truck is a snob and thinks she better than everyone else.

[audiocontr]

This picture is a bit misleading. There is less than an inch of room between the internal bump stops within the spring. The ground is sloped giving the illusion of level. Notice the spacing between tire and fender.

[audiocontr]

Larger image

[David Dunn]

Did you check the spring cups? Truck is probably ready for new springs, but it won't do any good if the cups are bad.

[audiocontr]

Spring cups appear solid. No major rust beyond minor surface. No debris trapped in the cup.

Both sides sag equally.

Was "significant" the correct adjective?

[Jimm391730]

Was "significant" the correct adjective?

Appropriate in my book! I agree, that is a "large, solid winch mount"!

[TechMOGogy]

That is a solid winch mount for sure!
Will be interesting to see the difference new springs make.
Be sure to so some measurements before and after

[Pinz710m2]

They do look a little low, but it's hard to tell
from a pic. Here's the company that quoted
me $278 per pair.

http://www.coilsprings.com

He said to be 100 % sure they are correct! I
could send him the originals and he would make
a new set to spec.

[audiocontr]

Swapped out the front springs for a new pair from EI.

I have to say, i do not see much of a difference. Its possible there is a slightly less sag, where the tow appears almost vertical, if not slightly out still. This tells me the springs were not the issue originally. Anyone in need of a good used set?

Could the cups bend? They didnt appear stressed when i inspected during the swap. Is it possible that the upper mount attached to the tub could bend up?

Its weird - I didnt see any signs of broken paint or stress marks