TnA's 86 Jimmy Shop Build / Product Development Thread - (Trailing Arms?!?!)

[CFMi]

Hey! It's been forever, sorry. Just been super busy.

Something I picked up a bit ago. She's ugly. I know. But she has a straight, unmodified frame, kinda like how the Jimmy started out. Unlike the Jimmy though, this one is going to be something for me, not only for development purposes (of course there will be some of that too though).

I haven't had a fast truck in a very long time, so I can't get a certain idea out of my head. There isn't a ton of terrain out here for it, but it might do okay in the mild rocky stuff. I started fooling around on the computer a while ago, and came up with this for it (maybe):

And, I have a little bit of stuff hanging around the shop. Some of it was destined for other projects, but I am contemplating re-allocating to this project instead... I have a 6.0L LS (needs a cam, wiring harness and computer), 4L60E, GM 14-bolt rear axle with ARB and 4.56's, AAM front axle out of a 2014 Dodge 3500 (will need gears, possibly a locker), set of used 16" and 14" travel coilovers, and a set of new 42" TSL swampers on beadlocks. With all that readily available, I just can't get the idea out of my head of building a go-fast K10. I've always wanted one, but with the rocks out here I have always concentrated on slow-speed crawlers. So keeping with solid axles on both ends and keeping it 4wd, it won't really be a true pre-runner, but it will be much closer to that than a crawler. I don't know though, there isn't a bunch of sand out here. But it would be a blast on the street too.

SO, should I build something like a pre-runner / crawler hybrid? I really want to... But I'll have to finish up a turbo Honda first and get it sold to be able to afford this one. I'm already thinking about color schemes too - I really like the idea of a super dark gloss blue body with lots of flat black accents.

Throw me ideas guys!!

 

[swettysblazer]

In for the prerunner build

 

[Smokinthehippies]

Do a trail runner. I always thought that was the best mix.

Enough shock and power to go fast, but with low range t case you can wheel and craw most things still

 

[sreidmx]

Sweet, cool trailing arm, I see the short course style thing you might be shooting for. Lots of guys out here do that and it works out and is not as much work as the canoe style arms.

 

[Babaganoosh]

I say do what you have in mind, you already described exactly what I want, toss in some expeditionary stuff and you have my dream.

 

[CFMi]

Do a trail runner. I always thought that was the best mix.

Enough shock and power to go fast, but with low range t case you can wheel and craw most things still

Yeah, that's pretty much the idea... just leaning a little more towards the go-fast and a little less towards the rocks. I have built so many rock rigs over the years, and although some of the parts for this build will be coming off one of the crawlers, I'll still keep my v8 Wrangler on 3-links and coilovers for the hard core rocky stuff. Of course I still may build my Cherokee into a crawler and sell the Wrangler off later on, but either way I'll still have a dedicated rock rig. I wanna go fast through some whoops.

Sweet, cool trailing arm, I see the short course style thing you might be shooting for. Lots of guys out here do that and it works out and is not as much work as the canoe style arms.

It's a little bit "canoe-y" (I'm pretty sure that's the correct terminology, lol) - the sides are angled in at 10 degrees - not enough to make things overly difficult, but enough to get a little bit O' triangulation in there. The center rib being there as well should make these super stout and really quite light-weight too. I haven't run any FEA on them yet to see just how strong they are, because there are a few areas that still need gussetting/attention. But in current form they show to be about 35 lbs each, including the bushing and joint!! I'm thinking that in the end they should come in around 40 lbs each - not bad for a 5' long trailing arm!

I say do what you have in mind, you already described exactly what I want, toss in some expeditionary stuff and you have my dream.

Cool! After I get the trailing arms finished up, I think I'm going to turn my attention to the trans crossmember / front link mount design. I know lots of people have been asking me about a link kit for these thrucks, so now it may finally become reality!! Fingers crossed that I can find the time to get this done asap!

 

[Babaganoosh]

Cool! After I get the trailing arms finished up, I think I'm going to turn my attention to the trans crossmember / front link mount design. I know lots of people have been asking me about a link kit for these thrucks, so now it may finally become reality!! Fingers crossed that I can find the time to get this done asap!

I wouldn't mind purchasing a nice built trans cross member. I really like where you are going, I have even thought about doing trailing arms on my truck...

 

[CFMi]

ALSO...
I have a front HD D44 Axle that I might need to let go. I don't have any pics tonight, but it is a '79 F250 D44 (High Pinion, Driver's side drop, HD axle tubes) that is built as well as you can build one. It has an ARB locker, 4.88:1 Yukon gearset, American Made bearing set, ORU pass side one-piece cast high steer knuckle, Moser axle shafts, Randy's Super Joints, etc... It has bracketry for a 3-link / coilover setup already on it and hydro assist mounts. LOTS of $$ into building this axle - but I just picked up a 2014 Dodge 3500 front axle with the really large joints in it, and I think I want to run that one.
Anyone interested in it?? I'm thinking about cost right now, and am not sure on a firm price just yet. Just putting the so-called "feelers" out there.

-Darren

 

[CFMi]

I wouldn't mind purchasing a nice built trans cross member. I really like where you are going, I have even thought about doing trailing arms on my truck...

My current thought on the truck is Parallel 4-link in the front with a track bar and mechanical crossover steering & hydro assist. But I'm also considering a reverse-triangulated three link setup like I did on the last big Jeep Cherokee build (which works amazingly well BTW) - and full hydro. I'm just thinking I don't want full hydro and no mechanical linkage on a speedy truck, and if I were to run that on a triangulated setup I'd end up with bump steer. But I also don't really want all the sideways motion that a track bar will give with lots of down-travel. Hmmm, I just don't know. But regardless of that, I'm thinking on the crossmember that I'll make some beefy side frame brackets, and then a center section that bolts in. That way I can make multiple center sections for different transmissions, and different linkage types.
Lots to think about!!

 

[sreidmx]

Lots of great ideas here!!
We need more link stuff out there, keeps us all honest and develops this platform that much more! Super stoked on what you got going on for this rear link kit!

 

[CFMi]

Lots of great ideas here!!
We need more link stuff out there, keeps us all honest and develops this platform that much more! Super stoked on what you got going on for this rear link kit!

Oh, don't worry, it's not just the rear that's gettin linked! I'm thinking the rear is going to be a standard triangulated 4-link though, with nice long links. I'll have to be cutting the inner bed to do it, but I'm not sure how far I want to go with that aspect. On the one hand, I'd like to only cut just enough to mount the cage and run the coilovers up through. On the other hand, completely gutting the bed, tubing the whole rear, building in a fuel cell and spare tire mount(s) would be completely awesome. I'm currently leaning towards the former though and keeping a little bit of bed usability.

 

[sreidmx]

Uh oh I smell some MAW syndrome around here.. you know as well as I do what that does to a build.. -----> the deep end is that way!

 

[CFMi]

Uh oh I smell some MAW syndrome around here.. you know as well as I do what that does to a build.. -----> the deep end is that way!

Well, this whole thing came about kinda partially as a MAW after looking around the shop and realizing I have too many projects going, and not enough parts to finish them all, but mostly enough to finish just one. The other reason is that my day-job thing might be changing in the future, and other than the Jimmy, the only truck-like vehicle I use is the work truck. If that truck were to go away, I would not have anything to go pick up, say, a piece of plywood even (other than my trailer and the Jimmy). So the idea of dumping the bed and going full tube on the rear really doesn't make sense in accordance with the initial thought. But hey, I could always go pick up a beater pickup, right? That's just what I need - ANOTHER vehicle, lol! This project might actually end up paring down some of the vehicles I own too - which is not a bad thing for certain!

Also up for sale soon:
2004? Hyundai Tiburon GTv6 - just completely gone through and ready to go! Beautiful car, need to sell it before I start driving it and realize I can't get rid of it!
1989 Honda CRX - D16 Turbo, manual, not finished just yet, but will be in the 400HP region very soon! This car was ridiculously fun at only 250 HP, I can't wait to drive it again!

 

[CFMi]

Spent some of my only day off working on the trailing arm design. Added a bit of extra material, and am close to a finished design, I think. They are now sitting just under 40 lbs each, not too shabby I think. Next step is to run some stress analysis on them to see how strong they really are. Here are some renderings from today:

Here's a view of the bottom with a sort of "skid plate" under it, hopefully it will help out with hard hits.

End detail:

 

[yellowK20]

Length , ballpark price , who's joint do they use

 

[Deuling]

If you don't have a lot of sand, full out 2wd go fast is kind of a waste.

Do the link stuff, keep it simple. Build it so it is enjoyable on and off road in many situations. That has been the whole idea behind mine and I have really enjoyed it. A few more inches of travel front and rear would be really nice though.

 

[yellowK20]

If you don't have a lot of sand, full out 2wd go fast is kind of a waste.

Do the link stuff, keep it simple. Build it so it is enjoyable on and off road in many situations. That has been the whole idea behind mine and I have really enjoyed it. A few more inches of travel front and rear would be really nice though.

Have you seen the this episode of Dirt Every Day ?

We have some sand and some whoops

 

[CFMi]

Length , ballpark price , who's joint do they use

I don't know yet, lol. I haven't figured out material costs, haven't stress tested it in the computer yet, don't know for sure if this is the final design even. But I think it's close. I'm thinking about making it out of cold rolled plate, and using a combination of Mig/Tig to put it together. If I had to guess right now, I bet they'll end up in the $750-$900 range for a pair, but please don't hold me to that! As far as the joints go, I have a manufacturer in mind until I can start making them myself, but they will definitely be beefy and rebuildable, with a poly lined setup - no hard metal against hard metal for me!

If you don't have a lot of sand, full out 2wd go fast is kind of a waste.

Do the link stuff, keep it simple. Build it so it is enjoyable on and off road in many situations. That has been the whole idea behind mine and I have really enjoyed it. A few more inches of travel front and rear would be really nice though.

Oh, I'm definitely keeping it 4wd - I have an AAM front axle out of a 2014 Ram 3500 sitting here for it with the massive U-joints. If I don't use that though, I'll probably get an 2008+ F350 front end and use that. But either way it'll be linked and coilover'd with a solid axle in the front - that's why I was saying it won't really be a pre-runner, but a hybrid sort of rig. Leaning a little more towards the go-fast sand, fire-road, whooop filled stuff, since I already have crawler(s) for the slow speed rocks. Plus it'll be fun on the street that way. But lots O' wheel travel for sure!

Have you seen the this episode of Dirt Every Day ?

We have some sand and some whoops

I hadn't seen that episode, no. I just watched the highlights of it real quick, maybe I'll watch the whole thing over lunch. Looks like fun out there though. One thing I noticed was that they didn't do any sort of anti-sway bar in the front for the higher speed stuff - and there is a noticeable problem when they lift a rear tire off the ground trying to spin the truck around. Not cool. Good for the camera though, lol. But talk about a mis-matched front to rear suspension - but I bet they blew through the budget on the portals so they couldn't afford to match the rear suspension to the front, haha! I'd love to get some portals designed some day - I have a preliminary design from years ago - before Axle Tech ever came out with them, but never went anywhere with it since I just didn't have the means to do it. I'm getting closer and closer to having the capability, so maybe someday I'll get back on that


If I do complete this project - however it turns out, I'll need to test it in all types of terrain! So that sounds like a good excuse to get a little travel in and see some different places!!

 

[deadman]

In one of the Dirt Every Day Extra episodes(the ones on their pay website) He commented that it really could use a sway bar because of that and that he was looking into it

 

[CFMi]

In one of the Dirt Every Day Extra episodes(the ones on their pay website) He commented that it really could use a sway bar because of that and that he was looking into it

Oh, I'm sure they knew about it, not saying they did a bad job or anything, that thing is cool. Just saying they needed one, and they need to build the rear end up to match the front. Maybe in another episode later on they will tackle it.