Full-Size Spare Fits

[RyF]

I've read hundreds of posts on this forum over the last few years, but I finally signed up as a member tonight. 

 

I've seen many of you ask about the largest tire that will fit in the spare location. I can definitively say that I have the answer. I'm running Nitto Trail Grapplers (325/60R20). Nitto lists the tire specs as 35.59"x 13.03". I've always run a five-tire setup in the past. I rotate myself using a five-tire pattern to ensure equal tread life across all five. I get longer tire life using this system, and I don't have to worry about destroying my rear end by driving on a much smaller spare if the worst-case scenario occurs in the woods.

 

This is 100% certainly the biggest tire that will fit in the spare location. It just barely touches the hitch receiver and a portion of the frame on the driver's side. It's about 1" from the driver's side rear shock, 1" from the rear differential, and 2" from the exhaust. I cut my exhaust to dump without a visible tailpipe, so I removed the plastic heat guard that was bolted between the spare and the exhaust pipe. My truck is a 3500HD with a standard bed. 

[Big Whiskey]

Dang, that's a lot of tire!  Any more pics of the truck?

[RyF]

This is the only decent picture I have on my phone right now. I need to get a few before/after type shots in here. 

[gearheadesw]

Nice truck, good info on the spare.

[RyF]

Here's a pretty good before/after. I'll post a couple of step-by-steps in the forum when I get a chance. 

[Zachlovesfood]

Does the tire still have clearance when the rear has a heavy load? I wouldn’t want to use the tire as a bump stop, but I’ve always coveted the peace of mind having a full sized spare down there.


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[RyF]

The rear transmission is close, but the angle of the tire relative to the transmission means it would have to sag almost a foot to make contact with the sidewall. It's a 3500HD with the overload leaf springs, and I put the heavy duty Firestone air bags on it. That helps too. 

[RyF]

....and, while I've been lucky enough to never actually need the spare in any vehicle I've ever owned, I also covet that peace of mind. I really like rotating all five tires through as well.