Front Shackle (Stock) hole spacing??

[Greg72]

Hey All,

Making the best of a 2" spring lift that was installed by a P.O. many years ago... but eventually intend to return this '89 Grand Wagoneer to stock ride height. (Speaking with Alcan Spring about a set of soft-riding, stock height leafs to get that done)

In my previous post, we figured out that the caster was basically "zero" on this setup and it was wandering like crazy... I purchased a set of 6* shims and am in the process of cleaning up the springs & bushings and bolting the shims to the existing springpack. Was also cleaning up the front shackle and based on the thickess of the metal (and the hammertone paint finish) this is likely an aftermarket unit as well.

If the shackle is longer than stock (which I suspect it is) then that is likely contributing to the lousy caster values that I saw at the alignment shop. The measurement (eye-to-eye) is 5-1/2"...




Anyone know what the stock shackle would have been? At this point, there's probably not much point in swapping in a shorter one.. because the shims are probably going to get me a good caster value by themselves. But since it's so simple to swap in new shackles... I might experiment with it if I can find a set of "takeoffs" somewhere.


Thanks!

-G

[tgreese]

Yes, the longer shackles will make the caster issue worse. Plus they don't help the lateral stability of the springs.

TGW has them under the original part number J5352863. I recall there is a work-alike Ford part that's the same but lighter gauge? Maybe from a Ranger pickup? No time for an extensive search now - maybe you could.

[BPDRacing]

Stock shackle is approximately 3" from bolt center to bolt center. That shackle is 2 1/2 inches longer which will give you about 1" of lift and bad caster angles.

[Greg72]

Stock shackle is approximately 3" from bolt center to bolt center. That shackle is 2 1/2 inches longer which will give you about 1" of lift and bad caster angles.

Interesting.

If the "stock" shackle is THAT much different, I am tempted to drill a second set of through-holes in my existing shackles closer to that 3" value and install it that way as an experiment. The 6* shims are going to add some extra lift (which I really don't want) so shortening up that shackle length should calm down the lift height and will probably add even MORE caster back into the front end.

....maybe TOO much caster, but I'll have to try it and see. Swapping front spring eye mounts in a multi-hole front shackle is super-simple to do. Experimenting will be easy.


-G

[candymancan]

The rear leaf springs use a XJ shackle. Their identical. When i replaced mine i used those. Been fine.

Believe tje front if also the same as those rears. But its been awhile since i messed with leaf springs on these

[Yeller]

There really is no such thing as too much caster. the "ideal model" says 6.5 degrees, where that is from I have no idea but GM used that number on their leaf sprung 4x4's. My J truck is at 3.5 (stock spec) and I feel it could use more. My bronco is at 11.5 and it drives like its on rails but steering is very heavy, but that is what ram assist is for LOL. I actually have ram assist on both trucks.

[Greg72]

There really is no such thing as too much caster. the "ideal model" says 6.5 degrees, where that is from I have no idea but GM used that number on their leaf sprung 4x4's. My J truck is at 3.5 (stock spec) and I feel it could use more. My bronco is at 11.5 and it drives like its on rails but steering is very heavy, but that is what ram assist is for LOL. I actually have ram assist on both trucks.

Good to know....

It looks like the current shackle is long enough that I can drill 2 more sets of holes (3 mounting options / caster options total)... I will lay it out to be sure there is enough material around the holes to be safe, but I'm definitely tempted now to get the shackle as short as possible.

Not sure if these lift springs (2" Rusty's Offroad brand) are flexible enough that they will flatten out and potentially "max out" a shorter shackle and cause the truck to ride super stiff over bumps... but guess we'll find that out soon enough as well.


-G

[Stuka]

Not sure you will be able to get those shackles as short (or close to) as stock. There is room for a closer hole sure, but the spring eye will likely hit the shackle where it narrows. But its certainly worth a try.

But as noted above, those shackles will not only ruin your caster angle, but they will also allow the axle to move side to side.

[Greg72]

Not sure you will be able to get those shackles as short (or close to) as stock. There is room for a closer hole sure, but the spring eye will likely hit the shackle where it narrows. But its certainly worth a try.

But as noted above, those shackles will not only ruin your caster angle, but they will also allow the axle to move side to side.

Measurements this AM show that the best improvement possible will be 3-7/8 hole-center spacing. That's not perfect, but still an improvement of more than 1-1/2".

That should add some extra caster and hopefully tighten things up on the current springs.


-G

[rocklaurence]

There really is no such thing as too much caster. the "ideal model" says 6.5 degrees, where that is from I have no idea but GM used that number on their leaf sprung 4x4's. My J truck is at 3.5 (stock spec) and I feel it could use more. My bronco is at 11.5 and it drives like its on rails but steering is very heavy, but that is what ram assist is for LOL. I actually have ram assist on both trucks.

What Yeller said. With lifteted and bigger tires I shoot for 3-6 Degrees caster. The bigger and wider the tire [supposedly] the less caster you need. The idea being the distance from center [pivot/spindle] increasing the weight and drag of a wider tire increases the effect of caster on the road.

[Greg72]

What Yeller said. With lifteted and bigger tires I shoot for 3-6 Degrees caster. The bigger and wider the tire [supposedly] the less caster you need. The idea being the distance from center [pivot/spindle] increasing the weight and drag of a wider tire increases the effect of caster on the road.

Interesting Factoid: Current tires are a set of old, crusty Goodyear Wrangler 31x10.50-15LTs. They recently measured out at 29.50" actual diameter (floor to digital level balanced on top of tread). When this GW goes back to the original whitewall tires in the factory size (235/75-15) the diameter will be 28.88"...... only -0.64" smaller overall from the current tires.

I was expecting a much larger difference.


-G

[tgreese]

Probably more accurate to measure the circumference and divide by pi. I get the same diameter as you for a 235/75R15 using arithmetic. Supposedly the tire manufacturers routinely overstate the height of a given tire. TireRack will list the actual diameter if you find your tire on their site.

[devildog80]

Found the same on my '84 GW tires as I was only a smidge over 1/2 inch smaller diameter to go back to the stock tire 235/75R/15 for road use. vs the 31/10.5/15's the PO had on it, but were literally cooked from sitting for 18 years.
And the shims you will add to correct caster will not add any height to your rig persay as they are tapered with maybe 3/8 inch width at the actual spring pak bolt. Not enough to worry about height when you get the benefit of driveability.
Not to mention the new tires will be your biggest improvement there.
I would change tires first, adjust your shackles as planned, then see if you still need caster adjustment.

[Greg72]

Probably more accurate to measure the circumference and divide by pi. I get the same diameter as you for a 235/75R15 using arithmetic. Supposedly the tire manufacturers routinely overstate the height of a given tire. TireRack will list the actual diameter if you find your tire on their site.

Yeah.. circumference on both would be more scientific and accurate, but was just looking for a ballpark understanding of how far off the current tires are.... I thought for sure that the original whitewalls would be puny on there and would look incredibly odd with the existing 2" lift. Anyone have a photo of something like that? I really need new tires in the near future, so maybe I mount the whitewalls "black side out" for now to make it look a little less awkward, until I have the funds to completely swap out the suspension to get this truck lowered to stock height again.

-G

[Greg72]

Found the same on my '84 GW tires as I was only a smidge over 1/2 inch smaller diameter to go back to the stock tire 235/75R/15 for road use. vs the 31/10.5/15's the PO had on it, but were literally cooked from sitting for 18 years.
And the shims you will add to correct caster will not add any height to your rig persay as they are tapered with maybe 3/8 inch width at the actual spring pak bolt. Not enough to worry about height when you get the benefit of driveability.
Not to mention the new tires will be your biggest improvement there.
I would change tires first, adjust your shackles as planned, then see if you still need caster adjustment.

3/8" of extra lift would certainly be a visible change, especially if the rear stays unchanged.. but I figure shortening the front shackle will pull out some lift so they should cancel each other out pretty effectively.

Only one way to find out. I'm just about done with a LOT of cleaning and painting of the parts and will be bolting all of this back together soon.


-G

[Yeller]

Sure you are getting lift with the shim? It goes in top if the spring and the axle sits on top of that so it would lower it by the thickness of the shim, not lift it. That is unless you have a spring over but that is a long way from stock. Now if you used a shim on the rear to correct pinion angle, that would lift it by the thickness of the shim, it is spring over.

[Greg72]

Sure you are getting lift with the shim? It goes in top if the spring and the axle sits on top of that so it would lower it by the thickness of the shim, not lift it. That is unless you have a spring over but that is a long way from stock. Now if you used a shim on the rear to correct pinion angle, that would lift it by the thickness of the shim, it is spring over.

You are right again!!!

I have to recalibrate my brain from the full-size Chevy truck world (spring over lifts)... and you are 100% correct. In this case we are talking about a spring-under (my 1st one ever) lift spring which makes everything backward from the way I usually think about these things.

Anyway... it's a little tedious because I'm only doing one side at a time and am too neurotic to put dirty parts back onto the vehicle. So everything in the general area gets fully degreased, cleaned, Scothbrite prepped and gets a couple coats of black Steel-It before reassembly.









There is some really cheezy welding on the PHB extension bracket, but I will address that later when the part gets cut off. Overall the front quadrant of this vehicle looks a LOT better. Next up: Installing the parts and moving on to the driver's side.



-G

[rocklaurence]

Be careful with all that cleaning of parts. A FSJ may reject clean and painted parts. It will only accept parts covered in its own oil.

[Greg72]

Be careful with all that cleaning of parts. A FSJ may reject clean and painted parts. It will only accept parts covered in its own oil.

HA... no doubt!

Made some decent progress over the weekend. Got the front shackles redrilled, and mounted up the 6* shim on the passenger side leaf.



You can clearly see the "old" vs. "new" front leafspring shackle mounting position here...




Decided to replace the old and worn shocks with a more appropriate option. Can't go wrong with the Bilstein 4600!!




The only problem now is that the old shocks were longer with around 10.25" of travel and the new Bilsteins only have 8" of travel total. Since the truck is still lifted, that puts the shorter new shock too close to the bottom of it's travel... so the simplest solution will be to drill and sleeve a new upper shock mount into the factory bracket. 3" lower than the current stud will give it basically a perfect 50/50 split of bump/droop travel (4" each).. and I suspect that is how the Bilstein is expecting the shocks to be set at ride height.

Basically if the new stud is installed where that extra hole is on the front face of the bracket, everything should be perfect.






-G

[tgreese]

With lift springs, often longer shocks are insatalled. This is fine as long as the compressed length of the shock is longer than the minimum distance between the pins at fully compressed. Appears you have extra spacers between the frame and bumpers, which may be meant to address the increased length.