TV: tranny or E-brake slip?

[FatDog]

I had a problem a couple days ago.
Well, ... I hope the problem is now gone.

I posted this plea elsewhere, where renowned tranny man Mark K. and others reside, and found my answer where I least would have suspected ...

I had just gotten new tires, same size I've always had: 35x12.50x18r Load-E's, put on my truck. These are big meats, load E, mud tires, and they are heavy. Ugly heavy.

I had it done at a place a couple miles from home, tossed the used tires in my bed, and drove right home.
I pull up my very steep driveway, put the tranny in N, mash the E-brake preparing to then let the diesel idle down, like I always do, and I notice that my truck is slipping back down the hill !!!
So i then also slip the tranny into Park ... and the truck is still slipping backwards, at about 1'/minute, maybe even a couple feet per minute !!
I am really bummed !!!!!!

So, E-brake is mashed, tranny is in Park, and me and my truck are now getting closer and closer to dropping into a 4' drainage ditch 30' away at the end of my concrete drive.
I take off the E-brake, slip the tranny into Reverse, and drive to flat ground, my brow swimming in sweat of fear.

The tranny parking pawl (the P in Park) hadn't been chattering on my driveway, and i tested it 10 seconds later after i had immediatly left my house and headed for level streets. The parking pawl doesn't ever 'slip', it either works or it doesn't work.(?) The E-brake then also seemingly started grabbing again on level ground.??!!?

I typically leave my truck on this steep driveway overnite with some amount of regularity with either my trailer or my boat behind it when something needs to be washed, so I am/was really upset that I might not be able to risk it anymore.

Any guess as to what was deduced to be the problem and/or solution ??
This could effect everyone, although usually these coincidences absolutely only happen to me.
I'll have a beer to settle down and then post the curious answer.

[BigSkyBob]

Tire beads slipping on the rims?

[FatDog]

wow!
O.K. see, I would have never guessed that,
but thats what it was,
the tires were so heavy, there was a fair amount of soap used, and the tires slipped in the rims on a Very steep incline within a couple miles of them being soaped

i can't really believe anyone guessed that

but, i'm now (prayin') figuring that since within a few more miles the tire soap has worn off, that the tires are 'set in stone' and I'll never see anything like that occur again for another 60,000 miles !!

were you a tire man Bob ?

[BigSkyBob]

No, I'm not a tire guy but I've seen this happen many times in the past with newly installed tires, especially large ones. The problem usually occurs when the installer uses mounting jell that hasn't been properly diluted. With use, your tires will seat properly but I would watch them closely on steep grades for a while.

[Ray,IN]

Never heard of that! Now re-balancing is required.

[FatDog]

thanks Ray, good idea,

I went back to the tire place to see about them re-balancing the tires/wheels, and although I was as gentle as a just-fed-baby with my explanation of what had happened, I was met with skofs, denials, and laughs from the 3 counter men. As expected I guess.
(What, did I just decide to lie about it so i could get a second redundant tire balance a day later? )
One of the counter guys told me to "why don't you just wait a few thousand miles and see if I feel any vibration"

I said
" if the tires have slipped in the rims, By Definition they are out of balance"
unmount, clean the tires and wheels, remount, new weights, ...

The manager saw things differently then his staff however. He agreed it happens. He also said it can happen with heavier trucks and then looked out the window and saw that I was driving one.

I also called Toyo Tires for their opinion.
http://marktg.toyotires.com/file/rimslip.pdf

I have an appointment for Wednesday to have it done again.
jese ....

Any one who gets large wheels and large tires, or a heavy PU or MDT, I would recommend putting a little chalk line on your wheel/tire to index them as soon as you get new rubber. Keep an eye on it for a day or two.

[Jeff_in_The_Dalles]

Wow. I figured both the parking pawl and the parking brake both failing at the same time wasn't likely, but I would never have thought about the tires slipping on the wheel...