How are you carrying your oversized spare with your FWC?

[Oryguntroutbum]

I have 35" tires. A full size spare is too big to fit in the stock spare location. I was considering getting a Wilco Hitchgate but at nearly $800 its out of my price range (or at least my wife's). Anybody doing anything other than a full Aluminess set up or throwing it on top of the camper? Anyone aware of another hitch option that will swing away easily to allow access to the camper?

Thanks

 

[fuzzymarindave]

I can't help with ways to carry a large spare but have you considered just carrying the stock spare? Maybe supplemented with a good patch kit to and compressor to increase the opportunity repair the 35s. considering how often is a spare used.

 

[Oryguntroutbum]

I do carry a plug kit and compressor but would feel comfortable with at least one spare that I could drive a couple hundred miles on if need be. I think my tires are about 2" taller that stock and I'm afraid I'd damage something by running a smaller spare.

 

[rotti]

I had 35s on my previous truck and just carried the original factory spare. My plan, if I had a flat, was to get the smaller spare to the front axle and not use 4wd. Two different size tires on the rear axle would cause problems. In the twenty some years I had that truck I never did have a flat.

 

[ntsqd]

What I did:
http://www.wanderthewest.com/forum/topic/8110-so-i-built-a-spare-tire-carrier/

 

[Oryguntroutbum]

Very nice ntsqd. I would do something similar but have two things stopping me. Lack of fabrication skills and lack of engineering skills.

 

[M1010 Mike]

HitchGate has been a perfect solution for us. I found (and see them) mine on Craigslist for about a 1/3 of the cost but having used it for the last 3 or so years, I would gladly pay the full price, if I didn't have fab skills or tools to build a custom bumper.

 

[Oryguntroutbum]

cummins_mike,
I think that's going to be the ticket for me. Looks great on your rig. Keep your eyes peeled for me because I've been striking on craigslist in the PNW.

 

[specjoe]

Have been using a CBI fold down tire carrier for the last 5 years and it works well for my 33" spare. I think I paid ~$350 for it.

Kind of a heavy lift back up (have to remove and put spare in camper if gf uses truck), but its a nice step up to the camper.

 

[cdbrow1]

Have been using a CBI fold down tire carrier for the last 5 years and it works well for my 33" spare. I think I paid ~$350 for it.

Kind of a heavy lift back up (have to remove and put spare in camper if gf uses truck), but its a nice step up to the camper.

Do you use the CBI as a step as well?

 

[ntsqd]

I'd have gone with a commercial unit to fit the receiver socket if we didn't occasionally tow a tow'd and I hadn't built our handy step.

 

[Ace!]

Doesn't it only matter if you have a locker? An open differential compensates for different amounts of rotation from side to side (i.e., turning corners without "chirping"). If you have a rear locker, put the spare on the front, even if you have a limited slip up front. I think (read on the interwebs once) that a limited slip only provides a relatively small amount of torque bias/transfer (allows a considerable amount of difference from side to side before engaging). The difference between a 35" and stock is 6% or so (if a 2" difference). I would think that even a limited slip would allow 6% difference side to side before engaging. Am I way off base?

 

[camelracer]

Doesn't it only matter if you have a locker? An open differential compensates for different amounts of rotation from side to side (i.e., turning corners without "chirping"). If you have a rear locker, put the spare on the front, even if you have a limited slip up front. I think (read on the interwebs once) that a limited slip only provides a relatively small amount of torque bias/transfer (allows a considerable amount of difference from side to side before engaging). The difference between a 35" and stock is 6% or so (if a 2" difference). I would think that even a limited slip would allow 6% difference side to side before engaging. Am I way off base?

Most limited slip units have clutches that will wear out if run with mismatched tires for an extended period of time.

 

[Ace!]

Those clutches only engage when there is enough bias. I don't think 6% is enough to engage them, but maybe someone else knows better. Beside that, I was really trying address the OP's concern, because I wasn't clear if he or she had a locker/lsd and even had to worry about it.

For the rest of us, it's just a talking point. Myself, I wouldn't worry much if I had an open diff or lsd. But, someone more in the know could certainly explain the damage that could be expected with a lsd or open diff.

I would check with the manufacturer of any given unit. At one time, before Eaton bought Detroit, I was told by a Detroit engineer that the True Trac (as an example) only transferred "up to" 30% to the wheel with traction, meaning there was plenty of "slip" still at the other wheel (which 6% wouldn't be an issue). Also, tire sizes are not equal. A semi-worn 35" may be 34" and a stock 33" would then be much closer in size. If you've got lockers front and rear you're probably still not going to do much mechanical damage, my opinion is that the tire is more likely to wear funny than damage a quality locker.

Running the stock size only until you can get the 35" repaired or replaced shouldn't mean running it very long.

 

[ntsqd]

If the tires are a different OD those clutches with be working. Whether or not they're providing limited slippage is another story. The clutches are alternately keyed to the diff housing and then to the side gear, so any relative motion between side gear and the housing (differentiating) causes the clutches to be slipping as well.

With a Detroit in the rear I can feel the difference of a couple psi between the two rear tires, shows up as a rather dramatic wonkiness in how the truck drives. Granted, that's not an LSD, but it is illustrative of how sensitive these things can be. I'd put the Detroit at the top of the pile in sensitivity to a difference in tire OD with other designs being less sensitive to varying degrees.

 

[Ace!]

I'm just trying to get across that there may not be a reason to worry. You can spend a $800-$1k on a tire carrier, or suffer scuffing your tire(s) for the (likely) short period of time you have to run it that way. If you don't have a traction aid, you don't have to worry at all. A tire carrier costs more than a replacement tire (when and if you ever have to buy one), so you could be running around with an expensive new tire carrier and expensive new tire you never need. You can spend $1000+ on the new carrier and new tire, or just buy the tire if ever you need it.

The flip side is the stock tire will work fine for a limited time if you ever find yourself in a pinch.

The amount of damage you're going to do is the same amount of damage to your rear tires by turning in a circle (if you have a rear locker).

 

[specjoe]

Do you use the CBI as a step as well?

Sorry for late reply - been on the road with camper since last post and must have missed you question.
Yes - have used it as a step up into camper throughout the life of the camper. Was anxious about wear on sidewalls of tire, so got tire cover and it works well to protect it. No issues from stepping on inside sidewall of tire with shoes/feet. Very nice place to stand for middle-of-the-night pee breaks when there's snow/mud on the ground and don't fee like putting on shoes...

 

[ntsqd]

The damage done isn't to the tires. The damage done is to the clutches if a limited slip and to your nerves if a Detroit. Not sure what a Tru-Trac will do, but I'm guessing it ain't good.

As stated though, if no traction adding differential then no worries!

 

[Ace!]

I think you and I will have to agree to disagree. You have your opinion, I have mine. I don't know if the OP is running open, LSD or lockers.

Eaton/Tractech/Detroit Lockers and TrueTracs are the strongest part of the drivetrain components behind the transmission (stronger than driveline/shafts or axle shafts).

Yes, your tires are going to wear long before you damage the Detroit Locker/TrueTrac. That's why you hear scrubbing or squealing of tires.

Clutches may or may not wear, but they can be replaced if you purchase a quality, rebuildable differential; however, the worry over them wearing is misplaced. They are designed to engage (i.e, centrifugal force or springs) but there needs to be more sufficient difference than a five or six percent difference in tire size. Let off the gas and let them un-engage. The amount of rpm/bias with a 33" vs a 35" tire isn't likely to engage it. If it does, let it disengage.

Edited to add: just my opinion of course.

 

[ntsqd]

My opinion is rooted in what I've heard and read of the mfg's of those various LSD's specifically say not to do, coupled with my own experiences in dealing with a so-called "Soft-locker" rear Detroit over 100,000 miles in one truck and about 30k in another truck.

Simple enough to put the smaller spare on the front, and move a full sized tire to the rear should it be a rear flat on a truck with any sort of rear limited slip differential. Not fun, but I've done it myself.