(Another) Forest Living Suburban Build Thread

[Burb One]

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Replace the T-bars completely? How does that work? Link to the kit?

Yep, keys and bars would come out completely (weight savings!? lol)

Puts a coil over in place of where the current shock absorber sits. Includes reinforcement for the upper shock mount (According to the posts, some people say you don't even need the reinforcement, however because GM only designed the top shock mount to hold shock, and not support the whole weight of the vehicle, I am definitely going to get the reinforcement- It puts all the weight directly into the frame, and from the looks seems well designed, I don't see any problems). The link I put above, is the only link he;'s got. His first post (first post of the thread) covers it all. I just read through all 24 pages of the thread and people seem to love it....

I can't believe in all the research I've done for the truck I never stumbled across this until today. I am 99% sold. I emailed the guy, and he already emailed back within 15 minutes, and once bought also helps with picking the length of your shock/springs.

I'll try and setup a group buy if people are interested. It will work with whatever lift, or non-lifted kit you already have, you just adjust the length/travel of the shock and spring you buy to your height.

 

[Burb One]

Been emailing with Richard, the guy who makes these, he's open to a group buy if we can get five people. Hopefully we can get some interest!

 

[OR2BAJA]

I am personally shocked torsion bars are still around.

 

[Martinjmpr]

I am personally shocked torsion bars are still around.

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Well, they're not, at least not for GM trucks. 2006 (GMT 800 platform) was the last year for the T-bars. All the 4x4's after that have coils.

 

[Burb One]

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Well, they're not, at least not for GM trucks. 2006 (GMT 800 platform) was the last year for the T-bars. All the 4x4's after that have coils.

Interesting didn't know that.

I do think they have their uses....
We are far beyond what these trucks were designed for. A torsion bar, quite simply, is as simple as it comes, and if they break, it's because your truck quite literally, broke in half. For reliability and being able to carry the truck, to get a ton of stuff and people down the highway as these trucks were designed for, there's nothing more reliable and easy.

For our uses, not so much....

 

[Martinjmpr]

Been emailing with Richard, the guy who makes these, he's open to a group buy if we can get five people. Hopefully we can get some interest!

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Well, I'm intrigued but I'm going to do a little more research. I'd like to see what these look like, as in how much lift do they give compared to a typical 2" leveling kit or similar. I also would want to know if there are any issues (frame cracking or weakening, handling issues, CV issues, etc) before pulling the trigger.
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When it comes to suspension I think I'd rather not feel like I was a beta-tester for somebody's kit. Others may be less risk averse than me, though, so if you do it, take lots of pictures and do a writeup because I'd love to hear more! I'm going to ask the question over on the Tahoe/Yukon board as well (though unfortunately that seems to be a much more "street/slammed" board than off-road oriented.)

 

[Burb One]

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Well, I'm intrigued but I'm going to do a little more research. I'd like to see what these look like, as in how much lift do they give compared to a typical 2" leveling kit or similar. I also would want to know if there are any issues (frame cracking or weakening, handling issues, CV issues, etc) before pulling the trigger.
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When it comes to suspension I think I'd rather not feel like I was a beta-tester for somebody's kit. Others may be less risk averse than me, though, so if you do it, take lots of pictures and do a writeup because I'd love to hear more! I'm going to ask the question over on the Tahoe/Yukon board as well (though unfortunately that seems to be a much more "street/slammed" board than off-road oriented.)

Agreed... I'm in the same boat regarding caution. I looked through a bunch of pictures there, (there are a few lifted trucks) and haven't seen any problems. If I can't find anything wrong, and after analyzing the area later this week, I might pull the trigger next week... or if people are interested start up a group buy list.

The length of the springs you choose will give you how much lift you want. The CV angle, will then depend on how much lift you add, (IE the added spring length over the stock resting position will be just like cranking the bars). The cool thing, with a diff drop like my lift kit, the same is said.

I also have worry of the shock post holding the weight of the vehicle and compression loads.. I am going to wait until I can take a look at that area on my truck. However, from memory and the pictures in that thread, I don't seen any reason why the frame won't handle the load especially with the reinforcement bracket transferring load directly into the frame, and not even the shock bracket. It should be pretty sturdy IMO. I'll hold my for sure judgement until I can analyze it closer. It would also be interesting to compare it then to the newer trucks with coil over mounted there.

Also, an added benefit may be that all the load is going up into the bracket, unlike the torsion bar, which when acting on the arms, also has a rotational force that also tries to pull or twist out..... just thinking

 

[rayra]

Looking forward to reading more about your 'build' choices. I'm basically in the same Sub, looking to do much the same things.

I've got to get busy and finish my SketchUp plans for my sleepign platform / storage drawers and power module and the roof rack tray / shade I'm working up. I'm doing a plywood roof rack tray that is suspended form teh Z71 rails on cross bars. Mostly solid to shade the roof of the vehicle (most of my outings will be in the deserts) and I'm making it in two long lateral halves and each will have peripheral handhold openings and be readily removable to serve as backboards.

I've been farting around a bunch with radio setups and other plans, but progress is slow and budget is tight. One of these days soon I'll do a 'build' thread as well, so I can gather all the scattered pieces together in one place.

 

[Atomic178]

Hey Geron, I joined to post on your build thread here. Wow what a crazy amount of stuff you have going on in there! That whole electrical setup is pretty ************ and it sounds like it would be an awesome truck to take out into the desert for a couple weeks on a long safari or something (assuming you could refuel). Where did you put the second alternator?

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My background is really in racing these trucks and performance stuff, not really offroad. But I can tell you broken CV joints happen because of the angles; if you keep them flat they will be just fine. I have launched my truck (99 Silverado z71) on the strip with 4 slicks and the factory 250k mile cv on one side and the oriellys brand replacement on the other have been just fine at 1000rwhp+, also on the stock transfer case. Truck eventually ran 6.05 at 118mph at 5000lbs in the 1/8th before I broke the factory transmission input shaft. The G80 is actually a good design, its just a little small for a fullsize truck. Its biggest issue is trying to lock up at high differential speed under high load, the classic example being trying to kick out the rear end around a corner on the street. Offroad they actually do pretty good.


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For 4wd guys, the 4l80e is 1 11/16" longer, so your rear driveshaft would have to be shortened that amount (if you can find a suitable replacement) and the front lengthened that amount, although the stock front will still have about half engagement if you don't extend it. The mounting points for the crossmember need to be moved rearward 2.5" I believe from the 60e spot. Most guys either weld on another piece to the existing bracket, or there is a guy on makes a tubular replacement at a reasonable cost (same guy that makes the balancer install tool for scoggin dickey). The electronic part can be done through the computer (or using a relay), and all you have to do with the harness is swap a couple pins. You will need to add 2 wires for the front input speed sensor on the trans, but that's just running 2 wires to the pcm. You will need a 32 spline input shaft for the tcase (I got mine from tbtrans I think), and installing it requires taking about the tcase (not hard). If you have an AWD tcase you are out of luck unless you have one made, or there is still a guy making them. The transmission cooler lines might also have to be extended. You will also need a torque converter made to fit the 60e flexplate, or you can use an 80e converter but have to have an 80e flexplate. The 4l80e is a very strong transmission, even in stock form with just a shift kit they will live a long happy life with a stock or semi stock motor in front of them.

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I am also the guy that makes the coilover brackets. I have sold roughly 80 sets over the last few years and never had a single failure or issue with the parts, so I am very confident in the strength and durability of my parts. There are several options on doing the swap, and you can basically go from a ~5" drop to a 4" lift on factory LCA/UCA/Spindle hardware. I have a couple guys with lift kits in the 7-9" range without issue. Your CV and steering angles depend on your height, not how you lift the front, so this wont help you there. What it does give you is a much much better ride than the torsion bars can offer, and a much more robust and adjustable setup. You can set the ride up to be very soft and gentle or very stiff and aggressive depending on your goals and the type of driving you do by selecting the proper spring and shock (which I am happy to help with before you buy anything). Im not trying to come over here to just advertise or anything, but if this is a swap guys would be interested in doing I would be glad to help any way I can! I cant post links here (kinda odd?), but other forums where guys have done the swap include: Performancetrucks dot net (my main forum), gmfullsize dot com, tahoeyukonforum dot com, and silveradoss dot com. I go by Atomic on all of those forums. Feel free to message me or email me at rkwayne at gmail dot com with any questions!

 

[Martinjmpr]

Hey Geron, I joined to post on your build thread here. Wow what a crazy amount of stuff you have going on in there! That whole electrical setup is pretty ************ and it sounds like it would be an awesome truck to take out into the desert for a couple weeks on a long safari or something (assuming you could refuel). Where did you put the second alternator?

/

My background is really in racing these trucks and performance stuff, not really offroad. But I can tell you broken CV joints happen because of the angles; if you keep them flat they will be just fine. I have launched my truck (99 Silverado z71) on the strip with 4 slicks and the factory 250k mile cv on one side and the oriellys brand replacement on the other have been just fine at 1000rwhp+, also on the stock transfer case. Truck eventually ran 6.05 at 118mph at 5000lbs in the 1/8th before I broke the factory transmission input shaft. The G80 is actually a good design, its just a little small for a fullsize truck. Its biggest issue is trying to lock up at high differential speed under high load, the classic example being trying to kick out the rear end around a corner on the street. Offroad they actually do pretty good.


/

For 4wd guys, the 4l80e is 1 11/16" longer, so your rear driveshaft would have to be shortened that amount (if you can find a suitable replacement) and the front lengthened that amount, although the stock front will still have about half engagement if you don't extend it. The mounting points for the crossmember need to be moved rearward 2.5" I believe from the 60e spot. Most guys either weld on another piece to the existing bracket, or there is a guy on makes a tubular replacement at a reasonable cost (same guy that makes the balancer install tool for scoggin dickey). The electronic part can be done through the computer (or using a relay), and all you have to do with the harness is swap a couple pins. You will need to add 2 wires for the front input speed sensor on the trans, but that's just running 2 wires to the pcm. You will need a 32 spline input shaft for the tcase (I got mine from tbtrans I think), and installing it requires taking about the tcase (not hard). If you have an AWD tcase you are out of luck unless you have one made, or there is still a guy making them. The transmission cooler lines might also have to be extended. You will also need a torque converter made to fit the 60e flexplate, or you can use an 80e converter but have to have an 80e flexplate. The 4l80e is a very strong transmission, even in stock form with just a shift kit they will live a long happy life with a stock or semi stock motor in front of them.

/

I am also the guy that makes the coilover brackets. I have sold roughly 80 sets over the last few years and never had a single failure or issue with the parts, so I am very confident in the strength and durability of my parts. There are several options on doing the swap, and you can basically go from a ~5" drop to a 4" lift on factory LCA/UCA/Spindle hardware. I have a couple guys with lift kits in the 7-9" range without issue. Your CV and steering angles depend on your height, not how you lift the front, so this wont help you there. What it does give you is a much much better ride than the torsion bars can offer, and a much more robust and adjustable setup. You can set the ride up to be very soft and gentle or very stiff and aggressive depending on your goals and the type of driving you do by selecting the proper spring and shock (which I am happy to help with before you buy anything). Im not trying to come over here to just advertise or anything, but if this is a swap guys would be interested in doing I would be glad to help any way I can! I cant post links here (kinda odd?), but other forums where guys have done the swap include: Performancetrucks dot net (my main forum), gmfullsize dot com, tahoeyukonforum dot com, and silveradoss dot com. I go by Atomic on all of those forums. Feel free to message me or email me at rkwayne at gmail dot com with any questions!

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Thanks for you input. I think the reason you can't post links is because you just joined (unfortunately this is something that had to be done to reduce the avalanche of Spam that popular boards like this get.) Participate some more and you'll be able to post. I think I can speak for most of us here on the Full Size sub-forum that the more contributors we get here the better! I came from the Toyota world and I have to admit I got spoiled - when you own a Toyota you can get just about everything you want for it, us domestic/full size guys have to scrounge around!
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Welcome to the board and as I said, I'd love to hear more about the coilover swap.

 

[Martinjmpr]

I am also the guy that makes the coilover brackets. I have sold roughly 80 sets over the last few years and never had a single failure or issue with the parts, so I am very confident in the strength and durability of my parts. There are several options on doing the swap, and you can basically go from a ~5" drop to a 4" lift on factory LCA/UCA/Spindle hardware. I have a couple guys with lift kits in the 7-9" range without issue. Your CV and steering angles depend on your height, not how you lift the front, so this wont help you there. What it does give you is a much much better ride than the torsion bars can offer, and a much more robust and adjustable setup. You can set the ride up to be very soft and gentle or very stiff and aggressive depending on your goals and the type of driving you do by selecting the proper spring and shock (which I am happy to help with before you buy anything). Im not trying to come over here to just advertise or anything, but if this is a swap guys would be interested in doing I would be glad to help any way I can! I cant post links here (kinda odd?), but other forums where guys have done the swap include: Performancetrucks dot net (my main forum), gmfullsize dot com, tahoeyukonforum dot com, and silveradoss dot com. I go by Atomic on all of those forums. Feel free to message me or email me at rkwayne at gmail dot com with any questions!

.
OK so I know I said I wasn't interested above but I can't keep my brain from buzzing about this. So I hope you don't mind if I ask a few more questions (and I certainly hope you decide to stick around on this forum, though I did find your posts over on the Tahoe/Yukon forum as well - like you I post under the same handle there that I do here.)
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So my questions: First of all, your kit includes the brackets and hardware, right? So how do we know which springs & shocks would work best for, say, a mild (~3") lift? Can we use, for example, GMT-900 Z71 front springs, or would those likely not give enough lift? What other options are out there?
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The second question is more on-point for me (and I'm sure for others here.) There's no way in hell I would be capable of installing this myself which means I'd have to find a shop to do it. Do you have any idea what a shop might charge to do this work? I realize I'm asking you to speculate about a lot of things but even if you could give a ballpark figure for the number of hours (say a competent mechanic could install in 3 - 4 hours of shop time) would help me a lot in determining whether this is feasible from a cost perspective.
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And the last question, which I'm sure you addressed in one of the other message boards, is the removal of the stock T-bars. Are there any tricky or difficult aspects to that?
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Thanks in advance! :ylsmoke:

 

[Atomic178]

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Thanks for you input. I think the reason you can't post links is because you just joined (unfortunately this is something that had to be done to reduce the avalanche of Spam that popular boards like this get.) Participate some more and you'll be able to post. I think I can speak for most of us here on the Full Size sub-forum that the more contributors we get here the better! I came from the Toyota world and I have to admit I got spoiled - when you own a Toyota you can get just about everything you want for it, us domestic/full size guys have to scrounge around!
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Welcome to the board and as I said, I'd love to hear more about the coilover swap.

I am a moderator on performancetrucks so I know all about spam accounts, no problem. Thanks for the welcome! I had never heard of this website before he sent me a link to his build thread. This seems to be a pretty mature audience that puts a little more thought and effort into their projects than the typical 16-24 year olds that play around with vehicles. Although my main interest is performance type stuff (current project is working on a setup for direct nitrous shot with methanol under a blower), I appreciate all projects with different focuses.

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OK so I know I said I wasn't interested above but I can't keep my brain from buzzing about this. So I hope you don't mind if I ask a few more questions (and I certainly hope you decide to stick around on this forum, though I did find your posts over on the Tahoe/Yukon forum as well - like you I post under the same handle there that I do here.)
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So my questions: First of all, your kit includes the brackets and hardware, right? So how do we know which springs & shocks would work best for, say, a mild (~3") lift? Can we use, for example, GMT-900 Z71 front springs, or would those likely not give enough lift? What other options are out there?
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The second question is more on-point for me (and I'm sure for others here.) There's no way in hell I would be capable of installing this myself which means I'd have to find a shop to do it. Do you have any idea what a shop might charge to do this work? I realize I'm asking you to speculate about a lot of things but even if you could give a ballpark figure for the number of hours (say a competent mechanic could install in 3 - 4 hours of shop time) would help me a lot in determining whether this is feasible from a cost perspective.
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And the last question, which I'm sure you addressed in one of the other message boards, is the removal of the stock T-bars. Are there any tricky or difficult aspects to that?
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Thanks in advance! :ylsmoke:

So I managed to attach my spreadsheet to this post so you can play around with it. I made this to help me and everyone pick out the correct shock and spring you would need. Really the only requirement to figure out what you need is you measure from the middle of the lower shock bolt to the top of the frame shock pocket with the truck at ride height (basically the shock mounting distance), and you need to know the sprung corner weight. On the trucks 1400-1500lb is pretty common, but with this crowd and the amount of accessories it may be helpful to go to a scale and weigh the truck. CAT scales are certified to within 20lbs I think, and will usually give you steer axle (front) and drive axle (rear).
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You cant use stock springs because of the room available. This swap is based around using a 2.5" coilover shock and 2.5"ID spring. I prefer QA1 shocks since they are relatively cheap and perform well, but guys have always used Viking and fox shocks with success. My spreadsheet has the details for these as well as basically all the springs from eibach, hyperco, and pac. Complete parts list is on the second tab. You would also select which bracket package you want. In general using the normal kit with the procomp bracket, a ds303 with a 1100lb spring is pretty common for a leveled truck.
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Since I cant post links to files, I put the links to the two PDFs I wrote in my signature. I apologize if this is against the forum rules, but it really is the best way to answer 95% of the questions I get about this. I wrote them to be a singular point for guys to read that are interested in the swap and want to know more since researching through forums is a hassle. I tried to be as thorough and coherent as possible.
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The installation is actually very easy and if you have basic hand tools you can do this in your garage in a couple hours. If you only use the bottom brackets (upper reinforcement brackets aren't 100% mandatory, they are just reinforcement for that area), then you literally just remove the shock and slip on my bracket over it. There are a couple other things that need to be done, like trimming a piece of the frame and installing the bumpstop, but that is easily done with a sawzall and drill. Have a look through the installation PDF above. The upper brackets are a little harder just because there isn't much room to work, but again all you need is a 1/2" drill and drill bit. If you just do the lowers, total time might be 2-3 hours, and doing the uppers around 3-4 hours. Its really not hard at all. The uppers could be welded as well if you would rather do that instead of drill. All the brackets are 3/8" mild steel.
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I highly recommend using the torsion bar removal tool, which you can rent from a parts store for free (or buy from ebay for ~$50). I have used a 2 jaw puller in the past and it is very sketchy. Once they are unloaded a couple wacks with a hammer and they usually fall right out.

 

[Burb One]

Atomic-

Thanks for the input on the 4l80E definitely will help when i am forced to go that route in the next 100k miles...

Thanks for posting over here and answering some of the questions. I'm going to take a look at the truck when i get home, and probably try it all out. Look for an email from me in the next couple days. My only worry now is the bumpstop solutions.

 

[justcuz]

The other nice thing about the 4L80E, first gear is 4-1. So your low range is 4x2.72x4.10. Your crawl ratio numerically goes from 33.4 to 44.6 and that does not factor in your torque multiplication at stall and just above which can range from 1.5 to 2.

This is why in 2015 the lowest gear you can buy with the tow package in a Suburban is 3.42 and also part of the reason GM uses the 14 bolt semi-float in the back of all Suburbans.

Also 5th and 6th gear are over drives .70 for 5th and .58 for 6th I believe.

The 2015 with 3.42 gears and a 4L80E with 4-1 first gear has a torque multiplication ratio of 13.68.
A 4L60E with a 3-1 first gear has to have 4.56 gears to achieve the same torque multiplication ratio of 13.68.

 

[Atomic178]

The other nice thing about the 4L80E, first gear is 4-1. So your low range is 4x2.72x4.10. Your crawl ratio numerically goes from 33.4 to 44.6 and that does not factor in your torque multiplication at stall and just above which can range from 1.5 to 2.

This is why in 2015 the lowest gear you can buy with the tow package in a Suburban is 3.42 and also part of the reason GM uses the 14 bolt semi-float in the back of all Suburbans.

Also 5th and 6th gear are over drives .70 for 5th and .58 for 6th I believe.

The 2015 with 3.42 gears and a 4L80E with 4-1 first gear has a torque multiplication ratio of 13.68.
A 4L60E with a 3-1 first gear has to have 4.56 gears to achieve the same torque multiplication ratio of 13.68.

I think you are talking about the 6l80e (the new 6 speed trans). The 4l80e has a higher first gear than the 4l60e. The 80e ratios are 2.48, 1.68, 1, 0.75.