New shoes, but not sure of the look of the spare

[towagon]

I finally got the new XZL's, and had them installed today. It really settled the truck down getting the XL's off.

The only problem is, I don't like how the spare sits. It is too big and in my estimation, detreacts from the lines of the truck.

Is this something I need to get used to? Tell me what you think, no hard feelings either way. I will leave it on for a while to see if it grows on me, but it certainly is not a slam dunk.

I took this picture just prior to heading to the tire shop:




At the tire shop:




Here's the finished product:



By the way, I got two fairly good XL's for sale. The front were really worn, I don't know of any value for them. But the back look good still. There is the normal cracking on the top sidewall, but the tubes are good and they have good tread left on them. Anyone interested?

[Cheyenne Dave]

Looking sharp! Does the spare actually touch the cab? That would be the deciding factor for me. I suppose you could keep a stock size spare...I would get very limited use.

C.D.

[HWooldridge]

Nice shoes and the truck looks great, too - I agree with Dave; use a stock sized spare.

[towagon]

Dave,

No, it does not touch the cab.

With your sharp eyes, you may have noticed the rim does not center on the bracket either, and, I was also unable to put the washer under the nut because of the additionl width of the tire. The stud was long enough to just get the nut on.

I'm going to give it some time, but have a feeling I will either remove it, or, look for a stock tire. Problem with a stock tire, if I ever have to use it, it sure would look goofy, not to mention possible mechanical problems of having different sized tires on.

Aloha

Barney

[Charles Talbert]

Running a stock size tire with these will absolutely kill a differential. That's the highest cost gear box on the truck to rebuild so it isn't smart to do anything you know will damage it. I'd just get used to the look, maybe reposition the spare mount bracket for a better fit. It will be much cheaper than diff repairs.

[Joe Flo]

Running a stock size spare just to get home or to the tire shop should not ruin your axle provided it doesn't have lockers in it. If you can get your money refunded for the spare I would do that. If not, leave it. Either way, it looks really nice, good luck.

Joe

[Bruce]

Like It

Take Charles' advice, move the mount & maybe add an inch more thread to the bracket.

[Charles Talbert]

Running a stock size spare just to get home or to the tire shop should not ruin your axle provided it doesn't have lockers in it. If you can get your money refunded for the spare I would do that. If not, leave it. Either way, it looks really nice, good luck.

Joe

Inquisitive minds want to know. Could you explain your proof to back your advice to this gentleman? Do you realize the calamity this much difference in tire height sets up in the core of a differential? Have you torn down a unit to its core, seen the damage this can cause, & repaired a differential that has been trashed from such action? Do you have any idea the cost that is involved in a rebuild these days? If you are thinking along the lines just a little won't hurt, I have to inform you differently, in this scenerio, a little does a lot to say the least.

Like I said in a prior post, I would do whatever I needed to carry the appropriate spare safely, it certainly can be done. Otherwise I would carry no spare at all & keep the phone# of a local towing service or tire dealer road service in my glove box. The cost of a tow, roll-back service, or on the road tire repair will be much less costly than the diff repair bill.

Another view on the original concern here, the thought or sight of the huge tire on the spare rack being an eye sore. In my opinion, (you know we all have one), a 9.00X16 hanging on the bracket would look worse on this truck than the 11.00X16 does. It will have the appearance of BIG FOOT carrying a spare from a Tonka toy.

[HWooldridge]

I have never liked side mounted spares as they seem to catch on things when you aren't paying attention. In the past I owned two Willys jeeps with side mounts that had been damaged at some point before I got them. After repair, I wound up catching one on a fence post that was leaning into the roadway (the best thing Jeep ever did was move the spare to the tailgate).

That is why I've always preferred the bed mount of the M37, which might be what I would add to this truck - unless it's not driven off road much.

[74w300uteline]

looks to big

as a fan of overkill, I never thought I'd say something looks too big. could you post pics with and without. I see what you mean about the lines of the truck. I bet a less perfectly restored truck with some battle scars could wear that spare . Im wondering if photoshoping a silver ring inside the spare, matching the other wheels would create the optical illusion of symmetry???

[Cheyenne Dave]

Inquisitive minds want to know. Could you explain your proof to back your advice to this gentleman? Do you realize the calamity this much difference in tire height sets up in the core of a differential? Have you torn down a unit to its core, seen the damage this can cause, & repaired a differential that has been trashed from such action? Do you have any idea the cost that is involved in a rebuild these days? If you are thinking along the lines just a little won't hurt, I have to inform you differently, in this scenerio, a little does a lot to say the least.

Like I said in a prior post, I would do whatever I needed to carry the appropriate spare safely, it certainly can be done. Otherwise I would carry no spare at all & keep the phone# of a local towing service or tire dealer road service in my glove box. The cost of a tow, roll-back service, or on the road tire repair will be much less costly than the diff repair bill.

Another view on the original concern here, the thought or sight of the huge tire on the spare rack being an eye sore. In my opinion, (you know we all have one), a 9.00X16 hanging on the bracket would look worse on this truck than the 11.00X16 does. It will have the appearance of BIG FOOT carrying a spare from a Tonka toy.

You raise some interesting points, Charles. The aesthetic issue certainly has it's merits. I kinda like the way thing look now.

However, I wonder if you would explain the difference between having two different size tires and say, driving around in a circle for a day.

And yes, I have rebuilt these differentials, from the bottom up. Fortunately, mismatched tires have not been root the cause.

You might also find the irony in Barney needing to call a tow service, as he owns one! Of course, we would all want to prevent the necessity for a tow or a costly repair. I know several trucks that have carried and used different sized spares, much like modern cars in the effort to save space, with no ill effects. So I am wondering what the differences are...like you say, inquisitive minds want to know!

I myself have a smaller spare the those on the ground. I also have a rear locker. In the event of a rear flat, I will move a front tire to rear and put the spare on the front. That is a viable alternative for anyone with concerns of differing tire sizes, and it costs nothing but time. Interestingly, since changing to tubeless radials, I haven't had a flat.

C.D.

[Cheyenne Dave]

I have never liked side mounted spares as they seem to catch on things when you aren't paying attention. In the past I owned two Willys jeeps with side mounts that had been damaged at some point before I got them. After repair, I wound up catching one on a fence post that was leaning into the roadway (the best thing Jeep ever did was move the spare to the tailgate).

That is why I've always preferred the bed mount of the M37, which might be what I would add to this truck - unless it's not driven off road much.

Mounting a tire of this size behind the cab, as seen on the M-37, would drastically impair visibility out the rear window, and limits cargo capability Not a great idea for street or off-road driving.

Of course, the stock side mount has similar drawbacks, though not as bad. The only place the spare does not impair driver visibility or sacrifice cargo space is over the cab, and that is a costly modification, and limits overhead clearance. Nothing comes without sacrifice.

C.D.

[towagon]

Thanks all for the input. I take it all under advisement. There are some interesting points to consider.

I believe that the spare, in my case, is cosmetic at this point. The island of Oahu that I live on, is ony 40 miles square, so if the look bothers me enough, I can leave the spare at work and call for it in the unlikely event I will need it.

The mileage issue is not as significant as you folks there in the 48 states, but time is our enemy. It can take an hour to go 5 miles sometimes with the gridlock we face.

I will get some pics with and without the spare, and put them side by side for comparison.

[Charles Talbert]

You raise some interesting points, Charles. The aesthetic issue certainly has it's merits. I kinda like the way thing look now.

However, I wonder if you would explain the difference between having two different size tires and say, driving around in a circle for a day.

And yes, I have rebuilt these differentials, from the bottom up. Fortunately, mismatched tires have not been root the cause.

You might also find the irony in Barney needing to call a tow service, as he owns one! Of course, we would all want to prevent the necessity for a tow or a costly repair. I know several trucks that have carried and used different sized spares, much like modern cars in the effort to save space, with no ill effects. So I am wondering what the differences are...like you say, inquisitive minds want to know!

I myself have a smaller spare the those on the ground. I also have a rear locker. In the event of a rear flat, I will move a front tire to rear and put the spare on the front. That is a viable alternative for anyone with concerns of differing tire sizes, and it costs nothing but time. Interestingly, since changing to tubeless radials, I haven't had a flat.

C.D.

Running a smaller tire on a wheel that has a lock-out hub is acceptable as it can be isolated from the diff.

All I'll say about driving in a circle is if it happened that way, it would set a similar scenerio, but at a much slower rate than driving on road at 35-45MPH, thus heat build up & wear would be at a drastically slower pace. Yes if you drove in a circle all day continuously, a shorter than normal diff life span could be expected.

Back to the original question, the tire height difference between a 9.00X16 & a 11.00X16 is significant. Of course the smaller tire is rolling at a higher RPM rate. These differentials as you know are set up on 4 spider gears & a side gear for each axle. The side gear supplying power to the smaller tire will be turning much faster than the other creating an out of sync operating factor in the diff core gearing. The spider gear thrust washers are bronze, side gear thrust washers are fiber unless they have been updated to bronze. These are considered the normal wear items in this unit. The out of balance ratio created by 1 tire spinning at a higher RPM rate will create a much higher than normal temperature within the unit. What happens very quickly is the extra heat will cause the lube oil to actually run away from the overheated components instead of clinging to them. As the heat increases, the lubrication decreases. This is exactly the opposite of what needs to happen. As the process continues, the thrust washers are the first to go, as they wear & disintergrate the spider & side gearing loses its preset backlash set up. This lets the gearing get extremely lose which causes heat build up to increase even more. Once the side gear thrust washer is gone, that gear face starts to rub & wear directly on the differential carrier housing machined surface, this creates more extreme heat & further lube oil starvation & will ruin the carrier housing with irrepairable damage in short order. In 100% of the cases that I've seen where we knew running tires of differing heights was the culpret, the entire carrier unit & all the components within were totally trashed. In some cases it has gone as far as trashing the ring & pinion gears as well. Once heat build up becomes extreme, the end is very near. Most we have seen were running over the counter 90 weight gear lube, ok as a get by oil in normal circumstances, but when high heat becomes a factor it gives up like gas on a fire. Some higher end gear lubes that are available today will offer better & longer protection, however there are none that will stand up to extreme heat created once a unit starts to go down. I'll also mention bearings are always trashed as well, they will usually be a blue tinted color from the extreme heat they have encountered. Cost of new bearings for a diff is over $500, carriers are practically extinct except for take-outs, expensive also if you can find a good one. At this point spider gear kits are still available from surplus at a reasonable cost, when will supplies be exhausted, who knows? Many parts for these trucks are in short supply with no more being made, taking the best care of every component that you can is in order & the owners best interest.

[Cheyenne Dave]

Well, thanks for the explanation. I've been trying to calculate the difference between the two tire sizes in question. The tire calculators I've tried using have trouble with non-metric sizes. But I'm going to be generous in saying they amount to about 100 revolutions per mile difference, max. You are saying that these differentials can't handle that in the short-term? Interesting...

What are you recommending as a gear lube these days? I know you've mentioned your preference in the past, I just don't recall.

C.D.