>>Plot THICKENS: "DEATH WOBBLE" afflicting my 4x4 (Torsion Bars) Ranger--missing PVH hubs allow half-shafts to flop around!!

[19Walt93]

The new tires you bought weren't load range E were they? If so they don't belong on a Ranger.

 

[fixizin]

The new tires you bought weren't load range E were they? If so they don't belong on a Ranger.

Obi-wan, you may have nailed it AGAIN!... i.e. I think they sold me too LIGHT of a load rating, that require TOO HIGH PSI to meet that load!

Old Goodyears marked 40 PSI Max, shop always filled to 35, NEW Firestones marked 'Extra Load' 50 PSI Max, shop filled to 40!

More to the point, Firestones rated for 2183lbs @ 50 psi, BUT door placard says 2710 Front @ 30 psi/2750 Rear @ 35 psi... (gotta admit, I never noticed the Front/Rear difference before--only saw the Rear #--always ran 35 psi on All 4)... CRIKEY, rock-hard tires "over-stimulating"
my front end...??

Having trouble w/ ancient Android and Photos, but the Load *Index* (not Range) is 108T...? NO letters at all after the P235/75 R15 text.

See pic for other markings:

Fook Mi, hope I don't have to get into a legal donnybrook with no-longer-competent shop...

 

[don4331]

The 2,710 Front/2,750 lbs Rear is for BOTH tire at that end of the truck; the 2,183lbs @ 50 psi is for a single tire. Lower the pressures to the values on the door and you're within margin of error.

The OEM tires on your truck were probably something like P235/75R15 Firestone ATX tires (Ford and Firestone fallout didn't happen until 2001).

P = Passenger - light duty​

235 - width​

75 - aspect ration​

15 - rim diameter​

​

Firestone ATX have a load rating of 1,985lb at 50 psi.​

Your installed tires are 10% higher than OEM, but that is within reasonable margin - probably LT - light tire, not P series; maybe a D range with the extra load rating.

The 3719 you show, says the tire were produce week 37 of 2019; not yet a year old.

 

[fixizin]

Thanks for the .edu Don, will soften the skins and see if the wobble trigger changes or goes away. Actually these current/new Firestones DO have the P235 designation, not LT. I should add that my shocks are still original, just celebrated their 21st birthday... still suprisingly good on the bounce test @ 78k miles, but... Got some Gabriel ProGuards ready to swap in.

... actually my '99 did come with the Infamous Exploding Firestones, BUT... since they seemed to be causing approx. zero problems on Rangers (all dire reports were on heavier Explorers), I kept driving them to 18k miles... finally got the "This is REALLY your last chance" nastygram from Ford in Aug 2001... went to the designated Firestone store and got some Falkens instead, which served me very well from 18-44k miles, though they weren't the best rain treads.

 

[19Walt93]

The "SL" after the 235/75R15 means standard load. Load range E's will cause problems, LT's might. The psi spec on the side of the tire is the maximum recommended, the spec on the door decal is what's recommended for that vehicle. I had a "customer"(came to us for warranty, never spent a dime) who bought tires for her Escape from VIP and had a terrible noise. They'd sold her W rated tires with super stiff sidewalls that belonged on a sports car.We replaced one wheel bearing and I told her she needed new/different tires. She said she bought the ones VIP recommended because she trusted them and absolutely buried us on the customer survey. Then she called and asked me to email her why I said she needed different tires. I shouldn't have but I wrote her an explanation and VIP gave her a credit toward some suitable tires.

 

[fixizin]

EUREKA!... OMG!... and a "Crikey" for the frosting... it was just OVER-inflated tires all along. Bled the fronts down to 30 psi and the rears to 35 and was attacking all my former butt-clenchers (RR crossings, manhole covers, potholes, rumble strips) all the way to and from work--not a jiggle! A tiny bit mushier on the corners, but it's not a sports car, not with those huge sidewalls, right?

Mega-Thanks and Much Grass to all who responded, all GREAT and insightful suggestions which eventually solved this puzzler!

Fook Mi for putting blind trust in this formerly switched-on shop (*cough* M@d H@tt3r *cough*), after their founder/guru left (Ol' Chvck was like House MD on such issues, NEVER would've let it leave the shop like this...) ... Every muscle/exotic car in town had their custom exhaust made there, turbo plumbing, suspensions set-up, after-market/oversize wheel-tire-extender combos sorted out...

Anyway, very interested to hear if anyone else wants to run this simple experiment--i.e. pump up all 4 corners to 40.000 PSI, and drive around town, hitting the usual road imperfections.

I'm still going to scrutinize all 4 ball-joints, replace all 4 shocks, and bleed the power steering, but it would seem there's always some finite amount of "play" in the multi-axis assembly known as The Front End, and it relies on semi-squishy tires to DAMPEN induced impulses.

Moral of the story: READ the placard (both halves), BEE-lieve the placard, OBEY da placard!

 

[sgtsandman]

The only time I deviate from the placard is if the tires require it to meet the required weight ratings. That rarely ever happens. I look at the new tires weight rating at max psi, divide the weight rating by that psi to get the load per 1 psi. Then calculate what psi it takes to get to the rating on the placard. Most times it is darn close if not spot on. The 31X10.5R15s I run in the summer really need 33 psi to meet the load rating but for simplicity in reading the tire gauge, I use the 35 psi on the placard. 2 psi high isn't going to make that big of a difference. As opposed to the 40 psi the tire shop put into the tires when they installed them.

They did the same thing with the winter tires I put on the 2019. 40 psi during installation. The truck calls for 30 psi. I ran the math and 30 psi is the right number.

 

[fixizin]

Right, I mean maybe 40 psi helps the bead get "seated" after mounting, but after a loop 'round the block, they should've been adjusted to 30/35... but to take it back 4 months later, with a serious complaint, and they STILL don't get a clue... unforgivable.

Hoping the shop '4x4 Tire Country' lives up to its Google and Facebook reviews.

 

[sgtsandman]

The tire shop I went to didn’t have a clue either. The workers, especially one particular one, couldn’t wrap his head around the concept of five tires with five TPMS sensors. Even after explaining I do 5 - tire rotations. The shop manager had to explain it real slow like several times before he told him “I pay you to do the work, not question what work is being done”.

 

[fixizin]

ALLLLL-RIghty THEN!... so seemed to be "bulletproof" at any speed, but 2 days later employer says "Here's your 'puter and twin monitors, work from home, Corona-rona, etc." (annual mileage just dropped from 5k to 2k... note to self: call insurance carrier, seek further discounts... ;')

Long-short: Faithful Ranger sat for 11 days, now it's triggering at a LOWER speed than ever, as low as 30mph... shee-yat. Was very close to home when it started again, had perishables on-board, no time to test power-steering "jimmy-ing", etc., BUT... it triggers only when the RIGHT wheel hit a bump! ... never the Left. Manhole covers are great for isolating left-right, and this road had plenty.

So, I'll rotate/swap RF <> RR this weekend (hopefully lugs not impact-torqued off the charts), hit the 21-years-in-place shock bolts w/ PB Blaster for later... test again, and hope my new-fave 4x4 shop is "essential" and open next week to check/replace those ball-joints...

 

[Ramcharger90]

Mess with that brown wire coming off the Tcase motor that was ALWAYS the problem with my 98's 4wd not working.

My 98 got the death wobble when just the nut rusted off the top of the one sway bar link.

But on my 96 exploder the one rusted off and it never reacted violently.

 

[fixizin]

Wow, that's amazing that the front sway bar would cause that. My (anti-)sway bar bushings--esp. the 2 main bracket ones--disintegrated in 2012, and the noisy racket of that beefy bar banging on those U-brackets caused me to remove the bar+ links entirely--drove around for 2 weeks waiting for the Moog parts kit, didn't notice much difference in mild town driving, maybe a tad more body roll... got bored and painted the sway bar a Ferrari RED... combined with the BLUE Moog bushings, VERY sexy, lol.

ANYhow, just took a peek, and there's now a GAP up at the top of the links, perhaps from bushing compression/shrinkage over time...? IIRC those were Nylock nuts, will crank them down this weekend. Maybe drive test before rotating tires, just to control the variables. Great tip, thanks!

I'm familiar with the infamous Brown Wire on Transfer Case Shift Motor (would MUCH rather have the Manual lever), but that was the one thing NOT foozed up on mine--the whole motor AND the printed circuit board contacts were corroded to crap... getting motivated to remedy that.

 

[fixizin]

>>>>>>>>>>>> OOOO-kay, think we FINALLY got it: Went to the "real" 4x4 shop, and they drove it around, problem "cooperated" by showing up, they pulled the fake lug/hub covers off, were shocked to see NO HUBS AT ALL, and said "yeah, there's your prob--left "half" (1/3?) shaft is shorter, but right (2/3?) shaft gets to flexing at the CV joints to the point the half-shaft splines "engage" either the edge of the hub's pass-thru hole, or... the hub splines themselves--CHAOS ensues!

Went home, snapped an orphaned PVH on the right hub--SOLVED. Will do the left one after a brake-cleaner douching to remove dried grease blobs. (Might re-lube w/ Motorcraft XG-8 PTFE uber-lube.) Have converted both hubs to manual operation BUT... they should still work with vacuum as the "hat" seal under the now-removed screen is still incredibly new-ish and pliable. (Will get some RED silicone vacuum hose and do it right!)

As 19Walt93 said: Also, if one of my techs handed a customer parts that he decided to leave out of their vehicle he would have been a former tech before I was a former service manager. Find another shop ASAP.

I know, right, WTF!??... At the time I didn't know enough to ask intelligent questions. Had been years since the vacuum hoses went to dust... OTOH, there's NFW they were totally off and rattling around in those plastic snap-on lug covers! First of all the noise would've been tremendous, and secondly they do NOT come off easily, unless you have the special "6-finger" tool.

Yet Another case of... Duh South Florida Slacker-Factor (SFSF)!... it's the humidity, rots their brains... of course that applies to me too... D'OH!