Rear Suspension Rehash

[rechinca]

OK, here we go again on this topic and please spare the search comment. I've done it already with similar but not exact results and I think I am now blind after reading all the results for the last 2 hours and taking notes!!!

Local shop used a ProComp 4" spring up front with all the steering components, and about a 5 1/2" rear block. I love the looks and the handling is 10x better.

My question is: What rear spring set-up to use to eliminate such a tall block and keep my clearance? Ideally I would like to run level or rear 1" higher. The shop tried a couple of things and said it didn't look right? I didn't see so I can't verify or tell you what they did. Anyone with some experience or good advice. I am open to buying/bartering for whatever I need.

ABSOLUTELY NO BLOCK STACKING!!!!!!!!! And by the way, that is what ProComp tech said to do. Stack a 1" block and 1" add a leaf to my existing block/spring!

[FamilyRide]

Myb first guess willbe that the #1 reply willbe to use F350 rear springs with the factory blocks. I think that would get you 2"-3". [img]/ubbthreads/images/graemlins/shrug.gif[/img]

[rechinca]

Copy on that, but are there different codes for the rears as well, and if there is, which do I properly select for the desired outcome.
Bruce1954 are ya out there? I will send to you as I was advised you're the resident guru on our rides.

[birdman127]

as far as I know the f-250 & f-350 have the same rear springs....just a different size block. 6820 I beleive??

[Snowman269]

Scott, you are correct, but there are different codes for different heights just like the front.

Dennis

[FamilyRide]

Are you sure? I thought the rear springs were the same on any config but the blocks were different for ride height, like a SRW to DRW where the DRW has smaller blocks. Just an example, but I thought they were the same. Oh, and some have the overloads and some don't, but those are bolt on anyhow.

I could be wrong......

[caryt]

Your correct [img]/ubbthreads/images/graemlins/biggrin.gif[/img]

Cary

[Bruce1954]

[ QUOTE ]
.
Bruce1954 are ya out there?

[/ QUOTE ]

Some yes, and I will post what I have, first though ordering guides and PDF spec sheets do not agree.

As far as I now all springs were the same 99 through 2004 so I will use the 2002 and 2004 data I have and can find on the net.

from 2004 ordering guides,

250 rear axle is rated at 6084 Std
250 rear springs are rated at 6084 (4x4) or 6830 (4x2)

350 SRW rear axle is rated at 6830 std
350 DRW rear axle is rated at 9750 std
350 SRW rear springs are rated at 6830
(with over loads if you buy the camper or snow plow package)

350 DRW rear springs are rated at 8250 has over loads as std.

Not sure why the axle is rated for less on the 250 from here however see the info from the 1999 spring sheet below that shows a CODE A spring as the only rear spirng available on the 250 and it is rated at 6084!

From 2002 body builder PDFs-it has many listings for std load and heavy loads so here we go ------------>

250 rear axle is rated at 6084
250 rear springs are rated at 6084 or 6830 with over loads if you buy the camper or snow plow package We will get to rates codes and my conclusions below.
In another location under just rear spings it says the 250 and 350 are the same at 6830. Are you confused yet???? [img]/ubbthreads/images/graemlins/shrug.gif[/img]

350 SRW rear axle is rated at 6830
350 DRW rear axle is rated at 9750

350 SRW rear springs are rated at 6830

Also shows a 9750 option Chassis cab only in SRW ????????

350 DRW rear springs are rated at 8250 has over loads as std.

============================

Ok now on to the facts as best I can put the above together with the 99 spring code sheets I have. Here is what I think is true as best I can tell

250s can get code As or code Bs

Code A specs rated at 6084 and I can not find the rate, has no overload option that I can find

Code B specs rated at 6830 base at a rate of 320# per inch
Now add the overload at 694# and a rate of 350# per inch and you have 670# / inch with overloads

It says the main + aux spring + the unsprung weight give you a GRAW of 8218 for the 250 and 350 SRW and this makes sense to me.

Code C specs for 350 DRW rated at 8250 base at a rate of 350# per inch
Now add the overload at 694# and a rate of 380 # per inch and you have 730# / inch with overloads

It says the main + aux spring + the unsprung weight give you a GRAW of 9638 for the 350 DRW.

There are also a D code at 9750# and an E at 6830 for the narrow frame Chassis cab looks like DRW and SRW


OK now in a nut shell some of the above does not all fit so here is what I think to be true-->

250s get A codes std, B Codes with Camper or snow plow opt.
As do not have overloads and The Bs do.

350 SRW get the Bs

350 DRW get Cs also has overloads as std.


BTW what is the difference between a 250 and 350 if both have Vs in front and Bs in the rear???? the height of the rear blocks???? [img]/ubbthreads/images/graemlins/shrug.gif[/img]

Again this is as best I can tell but you can always go to the dealer and ask. [img]/ubbthreads/images/graemlins/vulnerable.gif[/img]
Oh; what I ment to say was ask to see the newest spec books and look it up your self [img]/ubbthreads/images/graemlins/biggrin.gif[/img] Like I have

Some can also be found here https://www.fleet.ford.com/truckbbas.../techspec.html

WARNING: again this is "as best I can figure" and hope it helps


Bruce

[Bruce1954]

One more tid-bit of info

2002 spec sheet on the rear springs of the X are as follows

Capacity 5250 lower than any SD spring
thicknes 2.5 + .66 for the anti-windup leaf. on the 4x4 only.
Rate is 410# per inch, stiffer than any 250 or 350 pickup as they are

A code = I do not know could just be the B W/O the overload
B code = 320#/" and is 2.94 thick 5 leaf
c code = 350#/" and is 2.32 thick 5 leaf

Not sure if these thicknesses are backwards or if the leafs on the C code are longer

Is this why some who have put other rear springs on report a improved ride??

Heck by the specs it should be a softer ride the rate is less [img]/ubbthreads/images/graemlins/crazy.gif[/img]

Makes be re-think about adding bags

Could I get a better ride with As or Bs ???

To tell the truth this is the first time I ahve looked into the rear springs but I hope this info helps


Also the 2004 specs show a 3 stage rear take a look here on page 64

https://www.fleet.ford.com/truckbbas...essd_04abb.pdf

also found this at the above

[ QUOTE ]
Auxiliary rear springs are not standard with 5.4L engine SRW applications and are available with certain option packages only
(Effective 12/1/03, auxiliary rear springs will be deleted as standard on all SRW pickup models regardless of engine and available
with certain option packages only).

[/ QUOTE ]

Oh yes; that clears it right up for me, how about you? [img]/ubbthreads/images/graemlins/rolleyes.gif[/img]

Can we say "information overload" [img]/ubbthreads/images/graemlins/zombie.gif[/img]



Bruce

[Snowman269]

Bruce1954,

Yes info overload, I am very interested in the lower rate per inch vs load capacity of spring issue. Someone must have an answer as to why the X has stiffersprings with lower load capacity.

I would be interested in finding out why Ford made these decisions.

B codes, Higher capacity, better ride. What's the downside here?

Ford needs to offer a these as factory options / Heavy duty Pkg.

Thanks for your hard work, I am very interested in your discovery.

Dennis

[MrBill1]

If you try and wrap your head around Fords marketing genius's (oxymoron) and accept who they are actually targeting with these vehicles, it makes a little more sense.

The target demographic for most SUV's are WOMEN; Mom's, Child care providers, Taxi service, and of course Grocery getter.
Thus the need of the soft ride that the fairer sex demands.
Also, the ride height must be low enough so as not to over exert her as she CLIMBs into the truck, and of course hoists the typical 2.6 young-uns and family pet of choice. The vehicle must also be able to enter the typical garage, so the kids don't get wet in a rain storm, or the fresh fruit and veggies don't get exposed to adverse elements.

We he-man men folk are not the primary sales focus. Since women buy about 50% of all new cars, and directly influence the purchase of the other 50%, targeting to women makes sense (in a perverse sortta way).
Therefore, SD axles, SD springs, SD frame, SD truck is of minor importance to brand sales.

Of couse, only those of us who are testosterone(ly) challenged would drive a station wagon any way. LOL-Just kidding!!

This, like sufferage, is just another item to add to the list of failed social experiments we can blame on women.

My $0.02
Bill.

[Bruce1954]

[ QUOTE ]

I would be interested in finding out why Ford made these decisions.

B codes, Higher capacity, better ride. What's the downside here?

Ford needs to offer a these as factory options / Heavy duty Pkg.

Thanks for your hard work, I am very interested in your discovery.

Dennis

[/ QUOTE ]

Thanks Dennis

Why did ford do this: See MrBill1 above he said it well

Downside: er uhh IdunKnow, Height when empty? see above.
Stock X will not go in my garage anyway

Ford offer more options using parts already in that plant and make us pay for them when they would cost next to nothing; naw, it makes way to much sense, what were you thinking! [img]/ubbthreads/images/graemlins/phoney.gif[/img]


If you look back at some of my older posts I give a rather long dissertation on how and why a softer spring can hold more weight.

Also if you had softer springs you increase the need for a rear sway bar.
Gee, that is a "NO BRAINER" needs one anyway, right after your first fill up. [img]/ubbthreads/images/graemlins/grin.gif[/img]

Sorry,my Humorous side must have come out on this one.


"The spring guy"

[Snowman269]

First, MR BILL, ROTFLMAO [img]/ubbthreads/images/graemlins/biggrin.gif[/img] You are sooooo right!

Bruce1954, I'll do some searches for your dissertion on softspring more weight. Not to sound stupid, but If Ford wanted softer springs for women, B codes it would be, right?

But they may have picked a stiffer (flatter) rear spring for ride height reasons & that may be part of the real answer. Hmm.......

Thanks

Dennis

[Bruce1954]

[ QUOTE ]
Bruce1954, I'll do some searches for your dissertion on softspring more weight.

[/ QUOTE ]

Link
http://forums.thedieselstop.com/ubbt...mp;o=&vc=1

[ QUOTE ]
But they may have picked a stiffer (flatter) rear spring for ride height reasons & that may be part of the real answer. Hmm......

[/ QUOTE ]

Now you are getting it, Also the ratings on the spings seem to be: well lets just say "variable" So far I think the spring rates given hold up pretty well.

Take the stock X spring codes D front and G rear
Now most of us know that prior to the stop change in late 2002 you could not even put the rated 4700 on an Ex front without being just about on the stops and that is with new springs.

The rear however I know I had over 6K on the rear with more than a inch of travel left. So you are correct it is in the rate and total travel.

When you know the empty weight, travel available and the rate the rest is easy to figure. If you have single rate springs.

Bruce

[Snowman269]

Thanks for the link! Great info!

Where can we get all the Ford details on springs rating's and rates?
I would like to figure out the whole A code spring Rate / rating and ride height. Could offer best ride & if installed factory overloads, that would take care of trailer issues. Whadda think?

Also, I (out of absolute frustration) grabbed a butcher knife & cut the accordian blocks down to the first rib, Now they are the same thickness & my F250 blocks. Front rides excellent (never bottoms) & I'm not thinking of going to truck springs anymore. But the rear is stiff (as we have discussed spring rates, we know why) & now I'm contemplating Kelderman air ride back there or truck springs. I'm going to install Landyot Radius Rods soon. This was designed to help with ride, but found to help handling more. Have you done the radius Rods yet?

Ford should offer a HD package! For the Guys, I mean woman who want a Man's, I mean Real WoMAN's Rig! Heh Heh...

Thanks,

Dennis