C5500 TopKick 4x4 Crew Cab Build

[mog]

BUT, news flash..... After my 3rd blowout in 2 years, I switched to standard 24.5" commercial wheels and DRW. I've done three trips since the switch, all involving off-road, and I really don't notice a difference. Then again, I'm not pushing the limits. On the other hand, I've never understood the logic of pushing the limits in a truck that weighs almost 25,000lbs. It's scary to change a tire, let alone attempt a recovery.
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A lot of great info there, thanks! I'm guessing the blowouts were with XZLs? If so, do you think it was prolonged high speed driving (relative to the tire speed rating) or another cause?

 

[tmckenna13]

I got my wheels and spacers from Stazworks. He knows the military wheels and tires as well as anybody. Since I'm in Utah, I've sourced replacement tires from Boyce Equipment.

BUT, news flash..... After my 3rd blowout in 2 years, I switched to standard 24.5" commercial wheels and DRW. I've done three trips since the switch, all involving off-road, and I really don't notice a difference. Then again, I'm not pushing the limits. On the other hand, I've never understood the logic of pushing the limits in a truck that weighs almost 25,000lbs. It's scary to change a tire, let alone attempt a recovery.

Switching back to DRW has made driving on the highway (where all three blowouts occurred at sub 65mph) a better experience. The truck tracks better, especially in the right lane "grooves". I'm far less stressed about carrying highway speeds, and I get a replacement tire/wheel just about anywhere. In addition, I had to replace the bushings on the front axle last fall. When looking at the worn bushings with the mechanic, we theorized that the extreme early wear could have been brought on by running the Hutchinson/MichXZL combo up front. I've developed an opinion that it's best to stick with a wheel and tire setup that adheres to the truck's specifications.

I'll be the first to admit that the big military wheels and tires look super cool. I'll also be the first to admit that I'm just too lazy to air up and air down tires of this size without a CTIS. It takes at least an hour to air back up from 50-60PSI to 105PSI. And my confidence in the surplus tires has diminished greatly. I tried to get the freshest ones available, but despite the specs on the XZLs indicating they'd be fine for SRW, I had one too many bad experiences. I was afraid every time put the chuck to the valve stem!

PS- I have 5 Stazworks wheels and 4 low miles XZLs that need a new home.....

I'm going to be building my rig on a RAM 5500 chassis and looking to be closer to 15k pounds than 25k pounds. Would you still recommend keeping the DRW setup? And if so, any preferences on something with good offroad tread?

 

[NeverEnough]

A lot of great info there, thanks! I'm guessing the blowouts were with XZLs? If so, do you think it was prolonged high speed driving (relative to the tire speed rating) or another cause?

I'm not certain of what caused each failure (all XZLs), as each situation was very different, except they all happened on pavement. Only one happened at the end of a long day of driving. I've always been paranoid of a tire failure, so I paid close attention to tire pressure. And I've always stopped every two hours to check heat buildup and usually set cruise to about 60mph. The last one happened in a blizzard and 20 degrees after 30 minutes on the highway. It's likely a combination of factors- vehicle weight, age of the tire, etc.

 

[NeverEnough]

I'm going to be building my rig on a RAM 5500 chassis and looking to be closer to 15k pounds than 25k pounds. Would you still recommend keeping the DRW setup? And if so, any preferences on something with good offroad tread?

I'm not a tire expert, and certainly not an expert on the topic of SRW vs DRW. But I know from personal experience that sourcing SRW components for a heavy rig (anything over 10,000lbs) isn't easy, and the military spec wheels and tires have the right numbers. As much as I like the idea and cost of surplus, I just don't want to be at the wheel of a big rig blowing a single again. I like to travel in my truck to have fun, and nothing about blowing one of those tires is fun. It's frightening during and after. And it causes damage. DRW diminishes the fear factor of a blowout, so I can have more fun!

My wheels are 24.5, so choices are limited and boring. Currently have the General Grabber OD's. I didn't do a lot of research, just have a lot of trust in the guys at SLC's Tire World Commercial Truck Center. They've been kind enough to work on my truck's funky setup for years and are one of the few places that will mess with big split rims.

 

[tmckenna13]

I'm not a tire expert, and certainly not an expert on the topic of SRW vs DRW. But I know from personal experience that sourcing SRW components for a heavy rig (anything over 10,000lbs) isn't easy, and the military spec wheels and tires have the right numbers. As much as I like the idea and cost of surplus, I just don't want to be at the wheel of a big rig blowing a single again. I like to travel in my truck to have fun, and nothing about blowing one of those tires is fun. It's frightening during and after. And it causes damage. DRW diminishes the fear factor of a blowout, so I can have more fun!

My wheels are 24.5, so choices are limited and boring. Currently have the General Grabber OD's. I didn't do a lot of research, just have a lot of trust in the guys at SLC's Tire World Commercial Truck Center. They've been kind enough to work on my truck's funky setup for years and are one of the few places that will mess with big split rims.

Similar to you, I'm not a tire expert myself. I'm assuming theres a max width you can run on the tires before the rear tires crowd themselves together?

 

[NeverEnough]

Well, I guess it's time to check back in with EP. Our big rig (named "Greg" by my boys, not sure why) continues to serve our adventure needs. Issues have been very few and far between these last 12 years: two water pumps, three blow outs, had to repair cracks in the aluminum subframe twice, two inverters, and lost track of how many times I've ripped the exterior utility lights off the sides of the truck with trees. The biggest issue is that it's embarrassingly big for just one or two people. My boys are now adults and while we still get together for adventures, it's increasingly rare that Greg is used as a family basecamp. A few years back I designed a much smaller camper for a flatbed, and I finally got started. At some point I'll probably start a thread, but time is too tight these days to document the build like I did before. I'm lucky to squeeze in time at the shop to move it along. But I thought the EP community might find the contrast interesting.

Greg next to the yet to be named baby brother (2019 Isuzu NPR Crew Cab, gasser, 4x4 conversion and custom flatbed)



The camper box is 12' long, 7' wide, and 6' tall. The upper shell lifts 28" (shown here). The camper can be used with our without unfolding the right and left side "rooms".

It's fun to be back in the shop again. Things go so much faster with CNC, laser and water cutting! Hoping to be done by fall, and I'll probably put a thread together then. In the mean time, Greg will continue to provide- albeit with a much higher fuel cost!

 

[baipin]

Great looking rigs! I was reading your thread yesterday, so, timely of you to post an update.

I'm currently in the process of choosing between 20" military singles, 22.5" singles, and 22.5" duals. This for a 4WD bus that'll weigh in around 16,000lbs, with a kid and a girlfriend on board. Because of that "cargo" I'm hesitant to go with singles without runflat inserts. Especially if I'm not the one driving. I was considering 12.00R20 XZLs but they're 8 years old and your thread makes me hesitant to touch those. When you had your blowouts, how old were the tires, did steers or drives blow, and did you have runflat inserts or at least beadlocks?

I see that you have 11R24.5's What kind of terrain have you taken these through, any thoughts on their capability versus the singles you had? I'm seriously considering duals as the best option, but I hear all the things about how singles are superior... I just don't know if that realistically applies to how rigs of this size are used 99% of the time - you have a lot of experience with this truck in particular so I'd be curious to hear your opinions on tires in more depth!

 

[NeverEnough]

Great looking rigs! I was reading your thread yesterday, so, timely of you to post an update.

I'm currently in the process of choosing between 20" military singles, 22.5" singles, and 22.5" duals. This for a 4WD bus that'll weigh in around 16,000lbs, with a kid and a girlfriend on board. Because of that "cargo" I'm hesitant to go with singles without runflat inserts. Especially if I'm not the one driving. I was considering 12.00R20 XZLs but they're 8 years old and your thread makes me hesitant to touch those. When you had your blowouts, how old were the tires, did steers or drives blow, and did you have runflat inserts or at least beadlocks?

I see that you have 11R24.5's What kind of terrain have you taken these through, any thoughts on their capability versus the singles you had? I'm seriously considering duals as the best option, but I hear all the things about how singles are superior... I just don't know if that realistically applies to how rigs of this size are used 99% of the time - you have a lot of experience with this truck in particular so I'd be curious to hear your opinions on tires in more depth!

All of my XZL's were stamped 7-8 years old when purchased, all three blow outs were rear- two driver side, one passenger side. Wheels are Hutchinson split rim w/bead lock, no inserts. I actually still have the full set with a spare if anyone wants them.

I'm content with the duals, and I'm taking my rig on the same type of terrain I did before. Sure, the feel is a little different, but they work just fine and definitely don't hold me back. However, the highway ride is WAY better, and faster, which is 90-95% of the miles. And less worry is worth a lot as well. But they don't look as cool : (

 

[trackhead]

Never saw this thread, amazing build and engineering. Bravo to you for actually using your build for so many years.