The Last Gen 2 Shock Swap Thread

[Stricken]

I got tired of the trolls and bickering in the other thread with no one actually posting objective evidence of why Gen 2 shocks will/won't work in a Gen 1 truck, so I decided try it out myself. My shocks are in need of rebuild, and I was able to pick up a brand new set of Gen 2 shocks for $650. That's basically the cost of the rebuild, so even if they only perform as well as the stockers, it's worth the swap.

****If all you have to add is "blah blah you're wrong because I'm so smart blah blah" go back to the other thread. If you actually have some measurements that contradict my conclusions, let me know because I'm going to the dunes soon and plan to run hard.

**I'm not endorsing you trying this experiment on your truck. These are my findings, and I may be wrong. Your results may differ so proceed at your own risk.

REARS
___________________________________________________________________________________

The Gen 2s can be bolted right in. However, the obvious potential issue is that the Gen 2 shocks are too long and cannot be compressed as small as the stockers.



So I compressed both and took the eye-to-eye distance for each. I used a ratchet strap to make sure I was hitting max compression.



The Gen 2 shocks compressed down to 19.125". I found that the suspension drooped about the same distance with either shock. Since the Gen 2s obviously have more extended length, all I care about is that the bump stop will prevent the Gen II shock from bottoming out. I measured the top shock mount to be 14" forward of the axle. Let's assume the axle travels perfectly straight up and down, and this offset stays constant. This offset, the shock, and the line of axle travel form a triangle. Now, I measured the distance from the bump pad on the axle up to the metallic cup of the bump stop to be 7.75" (these aren't ride height numbers, just what I happened to take). I doubt the rubber would compress this far, but it was the best reference I had.



Now, I measured the eye-to-eye distance of the shock to be 25.625". Knowing this, I can figure out the length of the shock at full bump. Google Pythagorean Theorem if you don't understand the math.



Thus, the shock length at max bump is about 3/8" more than the fully compressed length of the Gen 2 shock. Drop the rears in and send it.

 

[Stricken]

FRONT
_____________________________________________________________________________________

Similar to the rear, the body on the fronts is about 1.5" longer.

Since the body is basically the bump, you're losing that 1.5" straight out of your compression travel at the shock. I measured the wheel hub to be roughly 2X farther from the LCA pivot than the shock mount (you can get the exact number if you want, but I don't need to for my own conclusion), so remember that you are losing DOUBLE that much on compression. I suppose you could cut your bump stop down, but that has other implications that I don't care to mess with. Now, the only way to get that back (without modifying the shock mount) is more droop. I went through the trouble of installing the Gen II shock with the Gen I spring and hat swapped over, and it is very difficult because you have to compress the springs and the shock while prying the LCA down and not breaking the brake and vacuum lines.

I did this to see how much extra droop I could get. The UCA appeared to be the limiter as it was riding the spring. Once again, I used the spring hat brim as a reference. Here are the numbers for the hat-to-eye distance for each:

Gen 1 - 25.375"
Gen 2 - 26"

The datum doesn't really matter. What matters is I was only able to get an extra 5/8" droop and the UCA was riding the spring. Since the spring is not a proper limiting device, let's say I could set my limiting strap to give an extra .5" of droop at the shock. I'm still losing 1" of shock travel and potentially double that at the wheel, and more than that in compression travel.

You can make your own decisions, but for me, this doesn't seem like a good solution if you off road hard. It seemed the people in the other thread that were touting the front swap were also like me in that they had high mileage shocks. If you don't off road hard, I don't know why you would go through the trouble.

General notes:
-All of the Gen 2 shocks seemed a bit softer in than the Gen 1s, so on-road ride may be nicer.

-Ride height in the rear is about .75" lower with the Gen 2s.

-Installing the Gen 2s in the front is not easy. I had to use spring compressors and a ratchet strap to compress the shock itself along with a prybar to push the LCA low enough to push the shock in.

-I've driven with the rear shocks installed, and haven't noticed much difference.

-The rock guard on the rears can rub on the U-bolt perch on the axle. The rock guard is plastic and the perch is steel, so I'll let that sort itself out. May need to re-address later if it makes a hole in the guard.

-I don't know if the front CVs would take the extra angle from the 5/8" droop, but I would think Ford gave a bit of margin there. They seemed to turn fine and would presumably not be seeing much torsion in that scenario (jumping, wheels free-spinning). Figure that out for yourself if you are so inclined.

-The front spring perches are about 1" higher on the Gen 2s which doesn't seem to fully offset the extra length as the spring is almost loose when mounted to the Gen 2 shock


Additional measurements for reference. It's not comprehensive as I was able to draw my conclusions with this. Note that some may not add up quite right because I was rounding to the nearest 1/8" so errors could stack up:

Rear shocks fully extended eye-to-eye
Gen 1- 28.5
Gen 2 - 31.125"

Rear shock travel:
Gen 1 - 10.75"
Gen 2 - 12.25"

Rear Shock Compressed length:
Gen 1 - 17.75"
Gen 2 - 19.125"

Rear Compression travel at ride height (bump pad to brim of bump "cup"):
Gen 1 - 5.875"
Gen 2 - 5.125"

Front Shock compressed eyelet-to-hat distance:
Gen 1 - 18.5"
Gen 2 - 19.75"

Front Shock eyelet-to-hat at max droop:
Gen 1 - 25.375"
Gen 2 - 26"

 

[Tx State]

Thank you so much. This is what I was wanting to see.

 

[Canuck714]

Im a full year in on Gen 2 3.0's out back. I made a custom leaf pack that adds 1/2 inch more distance (extends lower shock mount 0.5 inches ) Have had zero issues and I run hard offroad.

 

[5280_TIM]

How would gen 2 rear shocks pair with deaver springs at full droop and full compression?

Sent from my SM-G965U using Tapatalk

 

[Stricken]

How would gen 2 rear shocks pair with deaver springs at full droop and full compression?

Sent from my SM-G965U using Tapatalk

Funny you should ask. I just finished installing Deaver +2s tonight. I got 3" more droop before the brake lines started to bind. I cannot get the wheels off the ground without breaking the brake lines.

So, I'm going to have to rig up limiting straps.

 

[5280_TIM]

Looks great. I just installed deaver +3's with RPG drop shackles a few weeks ago. Please post pics once u have the straps installed I'll probably do the same

Sent from my SM-G965U using Tapatalk

 

[5280_TIM]

Instead of limit straps you could just do extended stainless steel brake lines. That way u still keep your extra droop travel

Sent from my SM-G965U using Tapatalk

 

[Stricken]

Instead of limit straps you could just do extended stainless steel brake lines. That way u still keep your extra droop travel

Sent from my SM-G965U using Tapatalk

That's what I wound up doing. SDHQ is 4 miles away from me and had the brake line kit in stock. They don't advertise it, but their replacement lines are 2" longer. I'm now able to get the wheels off the ground. I gained almost 4" of droop!

 

[5280_TIM]

Just wondering how it will affect the up travel and the use of my fox 2.5 bump stop. Can anyone chime in on that?

Sent from my SM-G965U using Tapatalk