Axle Shaft Damper 5th shock question

[SoNic67]

Seems like the 5th shock would only control lateral movements of the axle assembly, probably helps keep the axle centered side-to-side under the frame. The leaf springs alone allow for quite a bit of lateral movement during impacts.

Exactly. The 4 door are longer and, during a turn, will torque more the leafs to move "sideways". That's why, at rebound, the leafs will make the rear end oscillate side-to-side. It might be felt like a "wobble" when exiting the turns - at least that's what I felt. The horizontal damper is there to stop that extended oscillation, same like a shock on vertical movement. However, it has no effect on straight runs.

Probably that Ford find out that the shorter 2 doors don't deform laterally that much the leafs and decided to do some value engineering by eliminating the shock: $50 less in production cost might end up $500 in retail price...

 

[drdoom]

Still holding up ok?

I had a look at the KYB one on Amazon, $238AUD shipping.

I got a box of stuff sent over including jack stands, spring compressors, an impact socket set and several CV boots and suspension bushes for $80 shipping.

Yeah, flash, it is holding up fine, had it on for a few years now.

 

[traveler]

Exactly. The 4 door are longer and, during a turn, will torque more the leafs to move "sideways". That's why, at rebound, the leafs will make the rear end oscillate side-to-side. It might be felt like a "wobble" when exiting the turns - at least that's what I felt. The horizontal damper is there to stop that extended oscillation, same like a shock on vertical movement. However, it has no effect on straight runs....

So can I assume that the damper would help battle side to side sway induced by a single axle trailer? Provided of course that the shock is still in working order.

 

[koda2000]

So can I assume that the damper would help battle side to side sway induced by a single axle trailer? Provided of course that the shock is still in working order.

No one here has ever figured out exactly what this 5th shock is supposed to do (it's also known as an axle damper) or why it's only found on the 4 door Explorers/Mountaineers. I figure Ford put it there for a reason, so I replaced mine when I noticed it was leaking. In my experience, trailer sway is caused by incorrect tongue weight.

 

[SoNic67]

There is nothing to figure it out. It stabilizes the rear end sway, because the leafs will not do enough (they will twist slightly and let the rear balance sideways). With it, the rear feels more "stable" in tight turns (especially if you drive like I do, I don't completely stop before turning like some people), I assume it helps with the rollover issue at highway speeds (probably that was the main drive to install them).
But I doubt is enough for a trailer sway, that's a lot more weight and a lot further away in rear.

 

[Nolastcallss]

My Monroe axle shock failed in short order. I tossed it in the garbage where it belonged and replaced it with a Bilstein. Huge difference in quality and performance. More expensive, but I guess in this case you get what you pay for....

BK

i can vouch for bilstein shocks, they are one of the best shocks i have ever used, yeah they are expensive but worth the price if you are looking for a quality part that will last vrs some cheap part that will need to be replaced in 2 years but hey some people want to take that route and by all means do. as for me i chose to pay a high price only because i plan on driving my tuck for the next 5 years and more

 

[96eb96]

If you look up statistics on rollovers(for all vehicles), the 2 doors have a significantly higher rollover rate than the 4dr vehicles. There could be many reasons for this, but it is a fact. The 4wd 4drs rollover stats approach some sedans.

2wd sports (going strictly by the federal statistics, not looking to debate that) are extremely rollover prone, and do not have the shock. I'm sure the wheelbase comes into play, but I wonder if that shock gives that last push to keep your rubber on the road. Most rollovers happen from a "hook" evasive move, and it seems that shock could help stabilize things a bit. In normal driving you may not feel really the effect, but remember that shocks are velocity sensitive and act on fast changes in speed and direction (dv/dt), which would be present in a quick, evasive maneuver.

 

[J_C]

^ Don't the 2-drs have one less leaf in the springs? I'd think that would reduce rollover tendency from sway reduction more than a 5th shock. Come to think of it, are the sway bars the same or also reduced?

 

[SupaSwope]

So I just got the Monroe real axle dampener from RockAuto and like some have said I can compress and contract it by hand but its not easy to do. Some of you guys are using it and some people sent it back for a different one?

Whats the conclusion on this?

 

[koda2000]

So I just got the Monroe real axle dampener from RockAuto and like some have said I can compress and contract it by hand but its not easy to do. Some of you guys are using it and some people sent it back for a different one?

Whats the conclusion on this?

All shock absorbers (and dampeners) are compressible with effort. That's the point. It doesn't sound like there's anything wrong with the one you received. Gas shocks will expand by themselves after being compressed, but the dampener is not a gas shock, so it will stay wherever you leave it. Install it. It's fine. Why do you think there's something wrong with it?

 

[J_C]

So I just got the Monroe real axle dampener from RockAuto and like some have said I can compress and contract it by hand but its not easy to do. Some of you guys are using it and some people sent it back for a different one?

Whats the conclusion on this?

Yours seems to be doing exactly what it's supposed to.

 

[SupaSwope]

Okay thanks guys, I just wanted to make sure. It seemed like some people were unsure if was supposed to rebound. Me included.

 

[Spuddy]

Hi everybody...

Does anyone know what size the mounting bolts are? Are they standard or perhaps grade 5 or 8?

Or, does everybody just reuse the rusty old ones?

My KYB didn't come with new hardware!

Wtf ?!?

 

[toypaseo]

I just reused mine, but I live/lived in dry climate WY and CO, so mine were in good shape...

 

[J_C]

Hi everybody...

Does anyone know what size the mounting bolts are? Are they standard or perhaps grade 5 or 8?

Or, does everybody just reuse the rusty old ones?

My KYB didn't come with new hardware!

Wtf ?!?

If you can get the existing fasteners off without destroying them, then reuse them. It's a rust, "can I get it off or swear and break things" scenario.

 

[nameskreen]

I think they were 18mm. I just did mine and I was able to re-use them and I live in Pa and my Explorer had the original shocks with 300k miles

 

[Spuddy]

Thanks, everybody.

Since I'm also in PA and only at 160K, I reckon I'll be looking to reuse mine as well. Just very strange to me, that new hardware would not be included. It just seems to me that every shock I've ever bought came with new hardware, even the cheapest.

If anyone knows the length on these, and also if they're grade 8, etc, please post it. I'd like to have some on hand if I need them.

Because, I have a feeling that even if I don't really need them, I'm still gonna be tempted to run to the hardware store and pick up new bolts.

 

[J_C]

^ This is not a high stress or critical part, if it fails the vehicle is still driveable. Even so, I would buy the highest grade the local hardware store sells since we're only talking a few dimes cost difference.

Keep in mind that since the vehicle is still driveable without it, you can just take it off, pull the bolts out and take them with you, even if you have to shear or angle grinder them off, you still have the pieces from that.

 

[Spuddy]

Ah, yes. It is not a shock absorber, it's an axle damper. Two very good points I hadn't thought through all the way.

Thanks JC!

 

[SupaSwope]

Does anyone have any torque specs for this? I was able to find all the specs I needed but this. Was not under suspension or driveline in the workshop manual, Even when removing the axle in the workshop manual in does not recognize it is there.