GMT800 People - Opinions wanted on upgrades/mods

[stomperxj]

Let me start by saying I think the GMT800 series SUVs are a great platform for camping/expedition and off road travels. I have a 2001 Tahoe that I have started to mod for my uses. I am noticing that there are not a lot of upgrades/mods as far as aux fuel tanks and roof racks that don't just clamp to the OEM rails. It seems the imports and other domestic rigs like Jeep have an enormous aftermarket for anything and everything. I am wondering if any GMT800 people are interested in such things or is the demand just not there for these rigs? Seems like the price of these rigs are coming down to extremely reasonable, replacement parts are plentiful and cheap, drivetrains are pretty robust. Looking online there seems to be a market gap for these rigs.

I am planning to build some of my own mods since none are available and was curious if there's any sort of interest in mods like this

Any opinions on the matter?

 

[rayra]

400mi+ range stock. Not much call for a bigger tank in either. But yes. there's a dearth of aftermarket products and worse so as they age. Few 'new' products are offered for them. So a lot of us have been makign our own stuff, or modifying other products to fit / suit.
The second link in my sig has a roster of most of the GMT800 folks there, lots of build threads. A few have rear swingouts with MFC and spare mountings.

And we're selling our well-kept '05 Tahoe right now, if anyone's interested.
https://www.expeditionportal.com/fo...1-4wd-200k-mi-but-very-good-condition.198825/

 

[02TahoeMD]

You don't need much to get out there and explore with your 2001. Just some good tires and doing a lift of rear coil spacers and front keys crank will get you enough clearance for most of your travel. Get the Z71 skidplates if your vehicle does not have any. Maybe get a plug in fridge for the rear cargo area, then go play.

I modified my truck a LOT but I did most of the mods for the fun of it. I like to tinker in the garage and some of the things I did were because it interested me to work on. Once I get an idea in my head, and do research on feasibility I have a hard time stopping until I have made it a reality. Agreed, aftermarket support for the GMT800 is about 2% of what Jeeps and Toyotas get, so you may have to modify things to work. Thus, my modifying an ARB bumper for a Landcruiser, same with the snorkel. The roof rack is sized for a Grand Cherokee if memory serves correct.

 

[stomperxj]

400mi+ range stock.

I barely get 380 on freeway trips which is about 17mpg. Normal is 12.5mpg in town with a fresh tune up.

...some good tires and doing a lift of rear coil spacers and front keys crank

Yep I pm'd you about your mods before. Thanks for the advice

Thanks for the feedback guys. Seems like a lot of DIY guys buy these rigs and just figure it out as they go.

 

[rayra]

380, 400, I get worse because I have a lead foot. Point's the same, they have a large (potential) range already, 26gal in the Tahoe, 32gal in the Sub. And not a lot of free space for an Aux or expanded tank without a custom solution and / or a relocation of the spare out from under the cargo deck.

I have seen one where an aluminum 'fuel cell' was put in place of the spare and the filler ran to the same place, mounted side by side under the same door. I don't recall if the 2nd tank was used as a transfer tank, or if it was also plumbed.

With a custom-made tank filling the space between the frame rails where the spare sits, you could likely get another 30gal in there easily.

I've doodled ideas for a 'bugout' trailer with a ~25gal tank under its deck / over its axle, set up with a transfer pump and a QD connector at the rear bumper, plumbed into the metal portion of the fuel tank inlet. Rig it right and could even do it on the move. Be a good way to stealthily refuel without waving red jugs around in a mega-quake disaster area. Figure to build such a trailer in the future anyway, kept partially loaded and ready to go. Northridge quake wiped me out in '94, still living within 20mi of the San Andreas fault, on the north edge of Los Angeles. My best plan after 'the Big One' is to load up and run like hell, get as far away as possible from 20 million desperate people, as fast as possible.

But it would be better to have it in the vehicle, as an Aux / Transfer tank. And that means a swingaway spare mount and a lot of expense. For both the swingaway and the tank.

 

[rayra]

I think the 'market gap' is unfortunately going to stay that way, despite how many of these are on the road. The newest GMT800 is 12yrs old. two generations out of date. Few manfs will make new products for such.

I'm still working on a fuel tank skidplate design that might have a limited market. But I'm not enthusiastic about a market price. Plate aluminum just costs too much. And any fabrication efforts is going to be costly, unless I get a small batch all done at once. I ever get off my butt and finish the design / mounting, I might be able to promote a group buy-in on a finished project. BurbOne was workign on some similar ideas, he'll probably get something done long before I do. I'm pretty slow on most projects, matter of focusing enough attention to complete something. I've still got my roof deck solar panel mounting frame in the Mk1 / prototyping stage. Been screwing around with that off and on all year, keep getting sidetracked with more pressing projects.

 

[stomperxj]

With a custom-made tank filling the space between the frame rails where the spare sits, you could likely get another 30gal in there easily....................But it would be better to have it in the vehicle, as an Aux / Transfer tank. And that means a swingaway spare mount and a lot of expense. For both the swingaway and the tank.

I was looking under the back of the Tahoe at the same situation. A nice size tank would fit but the spare relocation is the issue. I designed a spare bracket to fit inside the cargo area in the back that can fit up to a 37" tire that bolts in. My guess is most people don't want to take up interior space with a spare tire though. I prefer it and don't like swing out carriers. Drove an XJ for years with the interior spare and it was never in the way.

My idea was to design a rotomolded plastic tank to replace the spare and move the spare to the interior. If enough people showed interest I'd do a run of them.

I really like your platform rack you built. Turned out nice.

 

[XJLI]

350-400 mile range is pretty sweet when you compare it to the sub 300 people get with loaded LC100 and 200s.

 

[Martinjmpr]

Yeah, 350+ is pretty decent for a vehicle the size of a Tahoe/Suburban. Pity the folks with the heavily modified 3rd gen 4runners on 33"+ tires, they're lucky to get 200 miles before the low fuel light comes on.

Have to agree with Rayra about there not being much potential for aftermarket.

Let's face it, the guys with the "money cannons" are all driving Toyotas, those of us driving domestic iron are doing so because we're frugal (i.e. cheap) and don't care about having all the ExPoTactiCool gear.

 

[Anak]

I have no idea how the Tahoe is set up, but my Suburban has a second tank (factory) up above the spare tire.

Has anybody looked into the feasibility of adapting such a thing to the Tahoe?

I expect there would be some space challenges, but if GM fit a tank above the spare tire in one chassis then it may be possible to accomplish the same thing in another chassis. If nothing else it may be a useful starting point for that rotomold concept, especially since it would provide an off the shelf solution for a pump assembly.

 

[stomperxj]

...but my Suburban has a second tank (factory) up above the spare tire.

I have looked at one briefly but not enough to see if the cross members are the same or not. I'll have to go to the junk yard and see if I can find one and take some measurements. I think part of the problem will be that the Burb cross members unbolt off of the chassis rails and the Tahoe is welded. I'll need to investigate further.

 

[Ducky's Dad]

The big SmittyBilt Defender racks (6.5 and 7 feet long) should fit the roof nicely, and can bolt through the sheet metal with supplied well nuts. They have a pretty good installation video on YouTube. I just installed a 6.5 on my fiberglass shell but I did not use the well nuts because I have full access from inside. Invisible silicone, no leaks. With the well nuts, you won't have to remove the headliner. Could add solar to that rack and have room for gear and gas in RotoPaks.

If your Tahoe does not have rear A/C, there should be an empty battery tray up by the radiator, ideal for a dual battery setup. If you don't want dual battery there, it's an ideal spot for a small OBA, like the ARB Twin Portable, hard mounted in the tray.

My GM is a '98, so a bit different than yours, but 33's fit easily on stock suspension and I have run a couple sets of 35s with minor rubbing. Key for big tires on stock suspension is to maintain close to stock wheel offset and backspacing, and don't go too wide on tire cross section.

If yours has the G80 option, it's a decent auto-locker (unless that G80 is a limited slip like the Escalade G80). The half-ton diffs are weak, so don't hammer it too hard and plan to rebuild it at some point. That would be a good time to put in a better locker if budget allows.

 

[stomperxj]

....bolt through the sheet metal with supplied well nuts. .....33's fit easily on stock suspension.

I was more talking about no one making a rack that mounts to the factory insert nuts in the roof. That would be ideal and probably something I'll fab myself.

I have 285/70/17's on it now with the stock keys cranked up a bit. I have lift keys and some spacers sitting in the shop waiting to go on.

 

[rayra]

The area around the spare is essentially the same, just a few more inches front to back on the Burb. But the difference is not the same as the difference in overall length.

I'd like to see pics of a tank above the spare, there's really not much room for such. But it would solve the transfer issue since it could just gravity-drain. The Sub tank ends at the axle, but the links on the rear sway, the panard bar, the exhaust all impinge on the space.

But just figuring something the size of the spare, call it 32" x 32" x 10", maybe 12" tall if you strip the spare hanger hardware, that gives you a little over 7cu'. At about 7.5gal/cu', that's a 50gal tank. Could make it 8"T to retain some departure angle on a vehicle which hardly has any and still DOUBLE your fuel capacity. Make it 6"T and still have an additional 25gal

But you'd still have to relocate a big heavy spare.

Being in the desert rocky southwest, I'd almost rather have a water tank there than fuel. And have a swingaway for a 2nd spare. I'd rather have a 2nd spare than an aux tank.

eta... hmm a thin tank in the area of the spare, sandwiched between the spare and the frame, with a donut-hole pass-thru for the spare hoist. ~17gal. But again, the vehicle drags its butt already. And such a tank would have to be metal. Or a very thick rotomold. IT would be getting squeezed between spare and frame and heaven help it if you bottom out the spare on a boulder, it would crush the tank.

I've got provision for fairly secure stowage of (5) 20L jugs in and on my rear storage drawers / platform, inside the vehicle and the Sub is just so big inside that they don't really impinge on anything else. And that can be a mix of fuel and water. I usually carry one of each on any weekend jaunt into the high desert or Sierras. But again with the native range of the thing I carry the fuel for a random stranger as much as for myself.

 

[stomperxj]

Here's some pics I found online. The secondary tank has its own pump that triggers when the main tank gets to a certain level. Supposedly 11 gallons from what I have read but I'm not 100% sure on that.






I'd love to fine one in the wrecking yard and pull it to check fitment. That would be cool if it fit in a Tahoe.