The Mysterious Fifth Shock

[BigODave]

It's been posted here that removing the third rear shock didn't make any difference in vehicle dynamics... people have removed them and it didn't result in any change. Of course, others have pointed out that those who have removed the third shock have removed a worn out shock...

Well, I have about 138,000 miles on my Explorer and I just installed a new replacement for the third shock, and it made a significant difference in reducing ride harshness and vibration.

It's an unusual setup to have three shocks on the rear axle of a vehicle, but it apparently works pretty well in this case!

 

[shortstack]

do you mean the sway shock?

 

[BigODave]

do you mean the sway shock?

Yep!

 

[BIGHVM]

Well I ll be!
I often wondered if that part really made a differance- could be worth buying a new one if it makes that much change- I love my Explorers but have always thought the ride was a bit crude- I have always put that down to it being a capable off roader and a compromise on tarmac...................I believe they are reasonable to buy new from Fraud and will look into that as an improvement for my car- Thanks for the info!

 

[ThePhoenix]

which models have the sway shock? all of us?

Chaz

 

[aldive]

I removed ine when it was new. It made no difference whatsoever.

 

[BigODave]

I removed ine when it was new. It made no difference whatsoever.

There must be a reason (or reasons) for our differing experiences, and I can assure you that it is not that one of us has a valid observation and the other does not.

One example of such a difference would be a vehicle that is at stock ride height versus one that is not. Another (related) example is difference in the amount of wheel travel between vehicles. Age, mileage and bushing condition are other potential differences. So are wheel/tire and shock combinations. And, the types of roads driven on also come into play.

A good use for a public forum such as this would be to chronicle the characteristics of vehicles for which the "fifth shock" is or is not effective. Then we could come to some valid conclusions as far as under what circumstances to use or not use the "fifth shock."

I'll start. My vehicle is at stock ride height, is fitted with Monroe SensaTrac shocks (except for the "fifth shock," which is a Monroe Steering Stabilizer). I am using LT235/75R15C Michelin LTX A/T tires inflated at 30PSI at all four corners; these are mounted on stock 15 X 6.5 aluminum Explorer Limited wheels, which are quite light in weight. I live in a rural area with subpar roads (lots of potholes, cracks, etc) and I commute eight miles each way on these roads to and from my business.

As I said above, for me, my truck and my driving conditions, the "fifth shock" makes a substantial positive difference.

 

[aldive]

I am using LT235/75R15C Michelin LTX A/T tires inflated at 30PSI at all four corners;

And here lies the problem; you are running the tires way underinflated.

these are mounted on stock 15 X 6.5 aluminum Explorer Limited wheels, which are quite light in weight.

Are you certain about the wheel size? And, by the way, those wheels are not particulat light in weight.

 

[Turdle]

Ummm,
My wife noticed this 5th shock missing from our truck and I didn't tell her it was removed.
How's that?

 

[BigODave]

There is no problem - they are not under inflated. The door placard calls for 26 PSI with P-metric tires. I'm happy with the way my truck rides and handles now.

And, compared to the typical 15 X 7 cast aluminum Explorer wheels, these are relatively light - I should know, I see lots of them all the time.



Jon, my point is that it is baseless to make a blanket statement that this "fifth shock" is ineffective and not needed. I contend that there are cases where it does make a positive difference, and what I'm trying to determine is under what conditions it either is or is not effective. I have a hard time believing that Ford would waste money including it if it did nothing.

 

[Turdle]

There is no problem - they are not under inflated. The door placard calls for 26 PSI with P-metric tires. I'm happy with the way my truck rides and handles now.

And, compared to the typical 15 X 7 cast aluminum Explorer wheels, these are relatively light - I should know, I see lots of them all the time.



Jon, my point is that it is baseless to make a blanket statement that this "fifth shock" is ineffective and not needed. I contend that there are cases where it does make a positive difference, and what I'm trying to determine is under what conditions it either is or is not effective. I have a hard time believing that Ford would waste money including it if it did nothing.

Maybe road quality has something to do with it? Most of the driving we do between towns is on county blacktop roads. They aren't very smooth.

 

[aldive]

[/B]

There is no problem - they are not under inflated. The door placard calls for 26 PSI with P-metric tires. I'm happy with the way my truck rides and handles now.

The door sticker was long ago amended. I believe 30 psig is too low. Most people on here run 35 psig I believe.

And, compared to the typical 15 X 7 cast aluminum Explorer wheels, these are relatively light - I should know, I see lots of them all the time

What size are your wheel? I believe you said earlier that they were 15 x 6.5. Lay some data on us, how much do your wheels weigh and how much does aluminum Explorer wheel weigh? What are your wheels made of?

By the way, what do you do to see "lots of them all the time"?

I have a hard time believing that Ford would waste money including it if it did nothing.

Ford as well as all manufacturers do many things they defy reason.

By all means if you are happy with the 5th shock, use one. I personally see no reason for it and will not use one. Mine has been off a very long time and a lot of miles.

Good luck ....

 

[aldive]

Maybe road quality has something to do with it? Most of the driving we do between towns is on county blacktop roads. They aren't very smooth.

Jon, most of my driving is on high quality roads, yet I do travel to many kayaking locations on marginal roads and when at the ranch, ever dirt roads.

I may reinstall one just to see what it does or doesn't do for the truck.

 

[MustangP51]

I don't see what the purpose of that shock is, I was going to replace it to see if it made a difference, but I was unable to find the replacement part, and Im not going to the dealer. So I have left it alone, it still has the oem shock on it now at 115,000 miles. If someone has the part number id replace it just to see if it makes a difference, or just another opinion on the subject.

 

[Turdle]

I don't see what the purpose of that shock is, I was going to replace it to see if it made a difference, but I was unable to find the replacement part, and Im not going to the dealer. So I have left it alone, it still has the oem shock on it now at 115,000 miles. If someone has the part number id replace it just to see if it makes a difference, or just another opinion on the subject.

Napa has it listed as a "steering stabilizer"

 

[aldive]

From Ford, its part F77Z4A489AA and lists for $75.92.

 

[BigODave]

Napa has it listed as a "steering stabilizer"

MONROE part # sc2958

 

[SkanlaxJMO]

i need to try and replace mine along with all four shocks the ride on my truck is terrible(for a lifted truck its terrible) Michigan roads are bad but still the ride shouldnt be that bad....and i run my tires at 35psi when on road.

 

[BigODave]

http://appserv.actioncrash.com/cgi-bin/order/wheelinfonl?stockcode=FC52UN6400M/]1995 Explorer Limited Wheel

I own a tire/general automotive repair shop, and I haven't formally weighed each wheel, but I have hefted them back-to-back (I was thinking of switching to the 15 X 7's).

According to the latest RMA (Rubber Manufacturers Association) databook, the inflation with P235/75R15 tires on 2001 and earlier Explorers is 26 PSI. Somewhere I have a memo from Ford that approves inflations up to 30 PSI...

 

[JDraper]

Ford did change the pressure after the Firestone incident. They sent out stickers as part of a recall to bump the tire pressure up to 30 PSI.

I too removed the 5th shock with no problems. From what I remember, it was installed to keep the rear axle from skating and vibrating at high speeds. I ran my '01 without it for 50k miles without noticing any vibration.