[asonico]

What is the spec angle for the leaf spring perch flat surface in relation to the horizontal? It looks like that surface is also in the same plane as that of the knuckle.

This is on a 79 Ford350 D60 axle.

 

[asonico]

I'm restating my question:

For those of you who have a front D60 with leaf springs, what is the vertical distance of the front eye to the ground; what is the vertiocal distance of the back eye to the ground. Since I'm putting la D60 with leaf springs onto my van, which never saw leaf spring before, I need to know the proper mounting height of the hanger and the shackle.

I'm trying to determine the yaw angle of the spring - I know the mounting perch plane is not a perfect horizontal inorder to maintain proper caster. The axle tilts somewhat to the rear. Is this angle the same as the caster angle?

 

[JGVABronco78]

I think you are going to have to install everything, and then shorten or lengthen the shackle to adjust your final caster, or possibly use some shims if very minor. You don't know how much the springs are going to deflect, unless you are planning on using the same exact springs as the conversions, and you are fairly certain of their expected compression. However, the conversion axles are not the same as the 78/79 60's, therefore they may have a different caster setting to begin with. I have a 79 F-250 with a D44, but they are identical in mounting and springs as the D60, so if you'd like I can still take the measurements you are asking for. I assume you are just looking for the difference in heigth, so the tire size does not matter? One more point. You cannot change the relationship between the built-in pinion angle and caster, so when looking at both, you may need to make compromises on one or both to get it to run at all.

 

[asonico]

. . . "I have a 79 F-250 with a D44, but they are identical in mounting and springs as the D60, so if you'd like I can still take the measurements you are asking for. I assume you are just looking for the difference in heigth, so the tire size does not matter?"

Yes, please take the measurements, the difference in height from a flat pavement - I will use them as my baseline reference. I agree I will have to make adjustments to the hanger/shackles later. But I have to have a starting point.

Thanks,
Art

 

[jagular7]

Leafs wouldn't matter what the locations of the frame mounts are. The leaf mount on the axle is flat horizontally and will only be flat with the weight on it. The caster and pinion angles are built into the axle with the leaf mount horizontal. So unless you have a drastic difference in the horizontal plane between the front and rear leaf frame mounts, then it wouldn't matter.

Do note, the van's frame should be along the lines of the F-truck frame, depending on the year. So using stock Ford brackets will give you the correct geometry. If you plan to put the shackle in the rear eye of the leaf, then you'll be doing a shackle reversal. After the late 70's, Ford put the shackle in the front leaf eye till the Superduty's came out.

What you can do rather easily is to put wood blocks to act as mounts and put weight on the springs. Attach the leafs to the axle with ubolts and spring plates, put the axle under the frame, lower the frame down onto the leaf and take your caster angle. Find out what the stock caster angle is for either the F-truck the axle came from or your matching F-truck year of your van (if the frame is F-truck based). Add spacers to the leaf eyes till you get the proper geometry on the caster with the weight. Bet your axle mount will be horizontal. You can't do much with the pinion angle unless you rotate the knuckle on the axle tube. Or go out to the parking lot and take measurements off a truck out there.

I'd also suggest if you are going to take measurements off the ground, that you actually use the Ford frame. The frame should have some general points that you can use. My 92 Bronco has 4 pegs off the bottom of the frame, 2 front and 2 rear.

 

[JGVABronco78]

Jagular7, you do realize that the van is 2WD, and has no similarities to a Ford 4WD frame, either 1/2 ton like your Bronco, or 3/4 ton like the axle in mention came from? The difference in elevation between the front and rear spring eyes will most certainly affect the angle at which the spring pads sits after compression.

 

[asonico]

Additional info, my 2wd van's (well, it's a G35 GMC frame for sure does not line up with the spring perches of this 79 D60 axle. So, I will be fabricating offset brackets onto which to attach the hangers behind the axle. Additionally, I will have to fabricate a cross member of some sort behind or under the front bumper to attach the shackles. I will make provisions for adjusting the spring eyes up or down, but I'd like to start at a near ballpark situation.

Thank you both for the inputs.

JGVA, i'd appreciate if you could measure the eye heights for me.

 

[JGVABronco78]

The center of my hub is 13-3/4" from the ground with 31" tires. The front spring eye center is 19-7/8" from the ground, and the rear spring eye center is 16-1/2" from the ground for a difference of 3-3/8" higher in the front. The readings were taken on a level surface, and the spring pad appears to be parallel with the ground with no more than a half to one degree sloping down aft.

 

[asonico]

. . . and the spring pad appears to be parallel with the ground with no more than a half to one degree sloping down aft."

---that's very interesting, if I made my 79 D60 axle' spring pad horizontally level, the center of the pinion yoke would pointing way up and higher than the top of the axle tube. here's the pic.http://www.tmobilepictures.com/asonico/public/ps/ALBUM/VIEWWEBSITE?foneblog=1213927307917

thanks for the measurements.

Art

 

[JGVABronco78]

I don't what you consider way up, but looking at it, I would estimate the pinion angle from the horizon to be between 5 and 8 degrees up. Of course its well above the axle centerline; it is, after all, a high pinion. On this same level ground, the top of the spring pad on the diff measures 15-3/4", and the center of the yoke measures 16-1/2", for a rise of only 3/4" on the 44. The pinion angle for the 60 should be the same for this model, but the snout is much longer than the 44, therefore the yoke reading will be higher yet. Measuring a 78/79 D60 from another vehicle w/o leaf springs, I get 17-3/4" at the pad, and 19" at the center of the yoke. While I can't be certain that the pad recess in the diff compared to the axle centerline is identical between the 44 and the 60, I would still say that with the measurements I gave you, it would be a very safe assumption that the D60 yoke measurement would be 17" as compared to the 15-3/4" pad if that D60 were in its original vehicle like the one I took measurements from. This just an estimate, but hopefully it gets you in the ball park like you wanted. Another note, my front springs are perfectly flat, no positive or negative arch at all at rest.

 

[asonico]

JGVA, your measurements are right on! On my D60 axle, the spring pad when its perfectly level is 1.25 inches lower than the pinion yoke center. Thanks so much, you're a heaven sent.

ANd while we're at it, a newbie question - springs, I have the Superlift 6-inch springs i got through ebay. Which eye goes with the shackle - the end whose second leaf is a few inches short? or the end that has a full-length second leaf?

 

[J-Roc]

JGVA, your measurements are right on! On my D60 axle, the spring pad when its perfectly level is 1.25 inches lower than the pinion yoke center. Thanks so much, you're a heaven sent.

ANd while we're at it, a newbie question - springs, I have the Superlift 6-inch springs i got through ebay. Which eye goes with the shackle - the end whose second leaf is a few inches short? or the end that has a full-length second leaf?

The "fatter" end of the leaf spring goes to the front...

 

[asonico]

Found the answer to my question: From superlift's website/instructions, the longer end (from center bolt) goes to the rear. The shorter end (fatter - full-length 2nd leaf), goes in front.

 

[JGVABronco78]

On my stock springs, the second leaf wraps around the first at the eye in the front, and that eye looks like it may take a slightly larger bolt than the rear. The second leaf is also full length to the rear, but it just rests under the end of the first, it does not wrap at all. The shackle is, of course, on the rear of the spring.