valve stem points inside on rear dual tires?

burlmart wrote:
I am no mechanical engineer (though 11 yrs of service work on an RV oughta be worth some kind of certification!), but i recal from engineering mechanics-dynamics a term Iw^2 about rotary inertia. 6" of metal sticking out from a 16R wheel spinning along at 60mph does not immediately appear to be a good idea.

If you want to rig something up, Borg shows replacement "stabilizers" on the webpage, available separately. The inner stem in Borg's kit for Ford is about 7" long, and calls for the stabilizer in the hand hole of the outer wheel.

Your time doesn't have to be worth all that much $/hour before it makes sense to get something that smart people figured out to do the job.

I suppose those "airless" extenders, properly supported, would be OK, still on metal valves.

Another thing I cannot recommend is attaching extender hose brackets to the wheel simulators. Usually the hub cover part of the simulator... If a simulator wants to come loose and fly away, I want it GONE! Not flailing around on an extender hose, beating up the coach body, then finally separating and possibly letting the air out of a tire.

You made me go look! There are threads inside my chuck's, I have never noticed them before and have no idea why they are there? My tire gauges are decent quality not the Dollar store kind and do not have threads?

Agree with your synopsis of rotary inertia, not a good thing, however there are a bunch of doohickey's to fasten the extender to the rim, something else to go wrong or get in the way in my humble opinion.

11 years of maintenance does entitle you to a "Shade Tree RV Technician" certificate and T shirt. Likely available somewhere online :)

jjrbus wrote:
Seems nobody feels qualified to comment on weather it is safe or not? Is it safe, I don't know, would I do it, no.

If a straight 4" metal extender makes it easy to access then a straight air chuck should access the stem with no problem.

Only my opinion and I am biased against extenders. Jim

i agree w/ j-d that all metal is best. the situation at TCI made just changing the bad stem to metal most expedient at the time.

my OEM short rubber valves never gave a problem in 6 yrs, so i am somewhat comfortable with metal on the inner duallys only.

i am no mechanical engineer (though 11 yrs of service work on an RV oughta be worth some kind of certification!), but i recal from engineering mechanics-dynamics a term Iw^2 about rotary inertia. 6" of metal sticking out from a 16R wheel spinning along at 60mph does not immediately appear to be a good idea.

i am thinking i might find a hollow tube/sleeve that i could put on my 4" extender and slide over the metal stem to more easily line the threads up to easily screw the extension on.

i bought a nice straight foot dual chuck by Milton, but the threads inside the shoes are more a hindrance than a help IMO.

but finding a sure-fitting straight foot dual chuck w/o inner shoe threads could obviate the need for the 4" extension tool. any links to a good one?

Google valve stem cap remover

We have metal valve stems....was very difficult to get the valve cap off and on the inter dual so our local tire store installed a 4in solid metal extender. One of those that will not leak if they loosen. The outer dual metal stem faces inward.

Use a dual chuck and can check and air up both inter and outer. Not as convenient as the more expensive solutions but it works for us.

Seems nobody feels qualified to comment on weather it is safe or not? Is it safe, I don't know, would I do it, no.

If a straight 4" metal extender makes it easy to access then a straight air chuck should access the stem with no problem.

Only my opinion and I am biased against extenders. Jim

took to TCi shop and they put a metal valve (about 1.5") that matches the other one, so both inner duallys now have rigid metal stems. the other 4 still are 1.5" rubber, but are very easy to get to w/ 30 degree back gauge shoe on rears and anything on front. per this thread, i remover all the metal extenders on 4 rubber stems.

a friend had an extra 4" metal extender that, when added to inner dually stems, will bring valve out just beyond the outside rim for easy access. i have chevy rims and no hubcaps.

i could use the 4" piece to easily check/add air to both inner duallys, but is it safe if i got another and permanently screw them to the 1.5" stems?

burlmart wrote:
good discussion, here.

help me see what i am missing. wouldn't a short stem on all wheels and a straight shoe chuck w/ a 45 angle shoe (for outer 2 duallys) be best system?

If you have the "right" valve stems for your wheels, installed so they are accessible and the air chuck that reach's them. Then yes it is the best way to go.

I almost lost a new $400 tire because of valve extenders years ago and when I purchased this MH had a blowout on the way home. I don't know if the broken extender caused the blowout or if the blow out broke the extender. But I will not put them on my tires! Too easy and cheap to do it right!

Jim

burlmart wrote:
good discussion, here.
help me see what i am missing. wouldn't a short stem on all wheels and a straight shoe chuck w/ a 45 angle shoe (for outer 2 duallys) be best system?

Ok for reaching straight through the big rim hole to the inner tire valve. But the stem on the outer wheel has to be long enough to enable the short backward pointing gauge shoe to reach it. My original wheels had plastic extenders to provide an extra inch. They worked well for several years but I got Costco tire shop to put longer valve stems in with my new tires. Costco also aligned the two stems on the dual wheels so they were both accessible through the same rim hole.

burlmart wrote:
is this possible for an air valve stem to only work 1 way?

Yes. I couldn't draw a convincing picture, but the valve core has to press the chuck and the chuck has to press the valve , WHEN the chuck's gasket is sealed to the body of the valve. If those three don't happen at once, air from the chuck won't go in the tire, chuck will let air out of the tire, etc etc.

Tell your tire store these rubber valves are making you nervous, please put metal ones in - all of'em.