2002 Tires Cupping

[bk10s]

This is our 2nd Explorer - Had a 2000 with a V8 that was an awesome vehicle. Just like the 2000, this 2002 Sport Trac is showing cupping on the tires despite diligent rotation. Sport Trac is in fantastic shape, no rust whatsoever (PO went to FL in the winters and left it in the garage!), and 95K miles. I would like to address this problem. Have done plugs, wires, pulleys, tensioners, fluids, etc. Would it be wise to "refresh" the front end with new control arms, ball joints, tie rod ends, shocks, etc? Plan to keep it forever. Many thanks -

Bill

 

[swshawaii]

Alignment DOES NOT CAUSE CUPPING. Cupping is caused by the suspensions inability to keep the tire firmly planted on the ground. The usual cause is weak shocks or struts followed by tire imbalance. An alignment issue will not cause the tire to not be planted on the ground unless it is so drastically off that the vehicle is literally not driveable.

http://www.mysporttrac.com/shared/msgboard9e.asp?BOARDNAME=MSG&VIEW=1249136&SUB=1249179

If you're still on original shocks at 95k you're long overdue anyway. If black they're probably OEM or aftermarket Monroe SensaTrac's.

Never hurts to "refresh", but I'd find a FREE written front end inspection at a reputable independent shop before throwing parts at it. JMO

Cupped wear - This may be the result of badly worn shocks or struts, or wheel and tire imbalance.

Worn Struts or Shock Absorbers

Tire wear can also be caused by worn struts or shock absorbers. The dampers help keep the tires in contact with the road as it encounters bumps and dips. Wear shocks or struts allow the wheels to bounce too much, which typically results in a cupped wear pattern on the tread.

http://www.aa1car.com/library/tire_wear.htm

 

[bk10s]

You're right! The shocks are black! PO put on these Wranglers at 90K. What shocks would you recommend?

 

[swshawaii]

Unlikely, but if the previous owner installed Goodyear Wrangler RT/S in the 255/70-16 size only, here's a TSB for feathering, not cupping.
http://www.revbase.com/BBBMotor/TSb/DownloadPdf?id=128166

http://www.bbbind.com/free_tsb.html

Regarding tires, obviously there is no single best tire for all applications. Depending on use and your Wisconsin location, an all weather snow tire may be best for you. Some use two different sets of mounted seasonal tires, but that's not always practical. Let people with snow tire experience chime in, obviously I'm not qualified to give credible advice living in Hawaii.

Regarding shocks, depends on driving conditions, off road, street only, and if ride comfort or better handling is more important. I'm using Monroe SensaTracs (replaced by OE Spectrum) because I prefer ride comfort over firmer handling and performance.

 

[crankyjew]

I have bf goodrich all-terrain ko2s on my 2004 ST. in 33x12.5 flavor, some funny wear and road NVH is to be expected. that said, with about 25,000 on them, I've been very pleased. I use them year round in rural western NY, and have been thrilled with how quiet they are on the road and how capable in snow, rain and mud. I rotate them religiously with every oil change (5k). I expect to use them until my truck blows up. they are of course available in stock size.

I'm running rancho rs5000 shocks on all four corners. I have about 50,000 on them- getting to the point where they don't seem to be able to hold those big tires down, and I am considering changing them, but have been very happy with how they act, all around. I use them on my SAS'd 92 Ranger, in a 14" travel version.

If you're into the idea of some dedicated winter tires, I had very good experience with Cooper M+S snow tires on my old 2002 Ranger fx4.

 

[Paul Fithian]

I fought the same issue a few years ago on our 2006 Mustang. Repeated alignments did not help. I replaced struts, lower control arms, ball joints, and all 4 tie rod ends. Problem solved.

Consider installing this kit on your Sport Trac, I just completed it on ours. https://www.rockauto.com/en/moreinfo.php?pk=5734623&cc=1366680&jnid=417&jpid=0

 

[bk10s]

I've had the truck about 6 months, and I can already see the cupping on the tires. Shocks are original. There is a Moog front end kit on RockAuto that includes inner and outer tie rods and upper and lower control arms. If I am going to keep the truck (forever I hope!), is it recommended to do it all (including shocks) on a truck this age?

 

[Paul Fithian]

I've had the truck about 6 months, and I can already see the cupping on the tires. Shocks are original. There is a Moog front end kit on RockAuto that includes inner and outer tie rods and upper and lower control arms. If I am going to keep the truck (forever I hope!), is it recommended to do it all (including shocks) on a truck this age?

That is what I did, but with Mevotech kit I listed above, not the Moog kit.

Lifetime warranty on components and lower cost. See previous posts I have on this and DIY alignment

 

[koda2000]

As I recall from looking at the wall at most tire places, cupping is supposed to be caused by worn shocks. Cupping can also be the result of roads with high crowns for water run-off,

 

[ptf18]

We purchased our '02 new..... in 2002. About that time frame the issue of tire cupping was well known about and affected alot of the S/T's. Ford's "recomendation" was to rotate the tires at every oil change....3k.

Not a fix for the CAUSE of the problem.... just "hiding the symptom.

The cupping issue showed up on our '02 at around 12k miles on the car. After alot of searching what eliminated the cupping issue was the replacement of the shocks, something I do routinely at 40k (you can debate if its overkill... I do the work and it makes me feel good, Lifetime warranty shocks).

AND!!!!!! a change in the alignment specs.

IMHO the alignment specs had the biggest effect. With 12k miles on the S/T when I began noticing cupping it wasn't due to front end parts being "worn out" BUT the cupping was and to this day (202k on the odometer) has been eliminated.

 

[firefly1246]

@ptf18. What specs did you align your ST to eliminate the cupping? On my ST the entire suspension is all new and had an alignment to factory spec, all done 1 year ago and I get the cupping. Mind you I did do a TT twist and the shackles. I assumed it was cause I was going too fast on the twisty roads around the house with an all-terrain tire.

 

[koda2000]

Did you do the TT after you had the alignment? If so you should get another alignment. When you raise, or lower, the front end it effects the alignment camber. The rear's height has no effect on the front.

 

[firefly1246]

I did the alignment right after the TT and shackles.

 

[ptf18]

@ptf18. What specs did you align your ST to eliminate the cupping? On my ST the entire suspension is all new and had an alignment to factory spec, all done 1 year ago and I get the cupping. Mind you I did do a TT twist and the shackles. I assumed it was cause I was going too fast on the twisty roads around the house with an all-terrain tire.

Firefly. Here are the spec's that were put on our S/T:

L/H Toe .05* R/H Toe .05*
L/H Caster 3.23* R/H Caster 3.68*
L/H Camber .33* R/H Camber .53*