What is the hole diameter on the 2021 F450 Rear wheel? I am trying to locate the rubber valve extension grommets(supports) , so that I can purchase the above German Extensions, then add the grommets to support. Any help would be appreciated here.

 

When I measured the stem distance, the hole opening is about 2". I found these in my searching Valve Stem Extension Stabilizer for Alcoa Wheel w 2″ Hand Hole .

 

Thank you for your help. Getting all my little accessories ordered while I wait for my truck to be assembled.

 

What length of extension works the best for the 450 dually?

 

You're welcome. I'm going to go without the grommets/stabilizers to start with as it might interfere with getting an air chuck onto the outer valve. On mine the hand hole for the inner is in the same location as the outer as seen in the photo in post 13.

 

It was my understanding that these stems should be opposed to each other when properly mounted. Am I wrong?

 

Went back to read thread again. I guess I go with the 6" extension. Sorry for carrying on.

 

That's quite alright. I made the photo below, and when I returned to post it, then realized that I must have been speed reading as I missed the fact that @sneil already measured his Ford OEM aluminum wheel hand holes to be 2". But I can't change the photo now, so forgive me Sneil!

As for diametrically opposing valve stems between the inner and outer wheel, it depends on the number of hand holes and wheel material. I run steel 19.5" wheels that have 5 hand holes, so it is impossible to clock the valve stems 180° from each other, due to the odd number of hand holes. But F-350 dually steel wheels with 4 hand holes can clock diametrically opposed to each other at 180° without issue.

With hub piloted aluminum wheels on a dually, it gets tricky, since the hub pilot land isn't machined for the thickness of twin aluminum wheels within a single pairing, so the inside dual wheel that we are mounting the extender on is going to be steel. And if it is an F-450, it is going to have an odd number of hand holes (5), while the outside aluminum wheel has however many hand holes aluminum wheels have. So essentially, the clocking is more of a matter of aligning hand hole access, over wheel balance.

Ford ships the 19.5" dual rear wheel vehicles with the inner and outer dual wheel valve stems clocked inline together on the same side, visible through the same hand hole, not at all opposing.

 

No worries Y2KW57! The more information the better and I've always found your posts to be informative and enjoyable to read. That combination can be elusive on internet forums So far I haven't noticed any balance issues with the wheels in having the valve stems aligned and good to know that's how Ford installs them (even if they didn't match the tire properly to wheel when mounting to the indicators on the wheel).

 

"leveraged away from the wheel" ?


My 2011 F-350 17" rims had 5 holes, Although an exact 180 was not possible, 1 closest to orientation had no access and the opposite orientation had good access, not perfect but good.

When I tried extensions with that truck I used braided stainless extensions (see post below). No extra support and the end had a TPMS sensor on it, sitting against the rim. I put a piece of clear tape under it and there was never any wear.

https://www.ford-trucks.com/forums/1...l#post14466579

 

Quick checks are available in a little longer size. That's all you need. Extenders corrode and leak.. Equalizers can fail and equalize the pressure right down to 0 PSI. Seen all of that happen.

 

These are all valid concerns, illustrated by the "Risk" photos posted up thread, and even further illustrated by the expanded version of those photos, as explained in this document Fuhrpark-Check-De.pdf previously linked up thread. (all the photos are self explanatory without the use of Google Translator).

So it appears that we are all on the same page when it comes to the risks of using tire valve extenders in an attempt to make checking the inside dual less of "a pain in the rear" (literally and figuratively) to do.

Arguably, the traditional solutions presented by popular legacy products such as Crossfire by Dual Dynamics, alluded to by @porthole in his post above, along with any other type of pressurized tire valve extension passing between the wheels, regardless of what material it is made from, (rubber, stainless steel braid, brass, steel, plastic, no matter) presents risks that are not worth the reduction in the "pain in the rear" factor.

But the pain in the rear factor presents an equal risk... that being the inside dual not being checked as frequently, simply because it is such a pain in the rear to do.

This is likely why there are so many products on the market attempting to meet this need. The demand is undeniable...



So enter @Flitastic to this scene stage left, who likely already understood these well known risks, and after looking at the sea of solutions on the market to seek out a good one, poses the original question. It is an age old question. It is a continually asked question. And it is an important question, as there are a lot of bad solutions on the market, and a lot of bad experiences to go with them.

What stands out about these yellow Air-Flexx tire valve extenders are that the black threaded ends are made from some type of non metallic material that cannot corrode. (I do not know the material....but due to its toughness I'm guessing nylon or a cross linked polymer of some type).

And as far as air loss from impact, abrasion, severing, or wear and tear, one could take a pair of giant bolt cutters, or a cordless grinder with a cut off wheel, and slice the these Air-Flexx extenders in half between the duals, and suffer no air loss in the tire. These extenders are not pressurized at all. There is zero risk of air loss using these extenders.

It is important to note that the air-flexx extenders are not the only pressureless extenders on the market. I've already mentioned the "live stem" offerings of other popular manufacturers up thread. And I've looked them over carefully in hand. Several times in fact, over the years. But I chose not to use them, preferring instead to continue incurring the (very real) risk of the "pain in the rear" factor of doing without extensions altogether. But the air-flexx's are lighter in weight, and are constructed and layered differently from the rest. Clearly, professionals in the industry, such as Haltec Industries, and Goodyear Truck Tires, believe so as well, as they have never adopted the bevy of traditional flexible extension solutions that have been available all along, but on the other hand have put the rugged reputation of their brand name behind these Air-flexx extenders.

Picking them up and wrangling them around in hand, one can feel that these are different. My problem was, when they were given to me, I left them in the package, and had that "yeah, just another extender (risk) like the sea of similar products" attitude, without fully considering the details that distinguish these from the others, and thus denying myself freedom from the risk of not checking my inside dual tire pressure as often as I should. Now that I've installed the air-flexxes, it is easier for me to check the inside dual than it is for me to check the outside dual or even the front steer tire. Now I check the inside dual rear just for kicks, because it is finally so much easier to do!

 

Extentions aren't really needed. Buy a Milton 553 air chuck. I have no problems reaching the inner dual....even with the wheels "lined up" and have to use the same hole as the outer wheel valve stem. Plenty of room to reach hand between the tires to release the chuck.. Now granted, when I rotate wheels, I will clock the outer wheel so it is easier.

 

I have oversize tires on my F450. It is not possible to get a hand on the inner dually. I dont know how most people get to the valve cap on the inner dually. My hand wont fit through the holes in the outer wheels and there is not enough space between the tires to reach the valve cap.

These are exactly what I've been looking for.

 

Quick check valve caps. Any truck stop will have them.. These are slightly longer than normal ones, but any will work... Just about every Semi around will have these at least on the inside duals.