Rockcrawler Senior Project... Help...

chuckhines · Sep 17, 2003

I'm formulating my ideas for my senior project, and I'm pretty certain that it is going to be a full on rockcrawler. Since I've never built a crawler before, and Michigan doesn't exactly have too many rocks, I figured that I'd ask on here for some advice. This project will have 4 members, and we will have about a year to finish it. We have full access to a fabrication lab in addition to any resources we have on our own. The kicker is that it must be completely funded by us, and any donations we can find. This is going to make this project very cost prohibitive. Okay, with that out of the way, I want to get the general take on my plans so far.

I'd like to build a frame that is completely custom. I know this is a major task to do, but I can't see the raw materials costing more than a couple hundred bucks. Would this be the best route to go or should we just try modifying the frame of something existing?

Now for an engine and transmission, we'd like to use something from a late model vehicle like a Blazer. I'm thinking a injected 4.3L and automatic transmission would work fine, but a V8 would be nice. I have an '85 S10 Blazer I can scab for parts. I put a '95 Vortec 4.3L in it, and it has a 700R4 behind it. This would probably work really good. Any advice on this issue?

As for axles, I'd like a D60 front, but cost may not warrant this. Is there a particular D60 like say an older Dodge D60 that would be considerably cheaper to use? Also, for a rear axle, I'm thinking FF 14 Bolt. I figure I can find one for around $150-$200. I already have a D60 FF I can use for free, but a buddy offered me $250 for it already. I'm thinking I'll sell it, and find a 14 Bolt. Any objections here?

Now for a transfer case, I was thinking something like a 203 or a 205, but I want a good ratio, and good strength. I also need something that is readily available and requires as little money as possible to upgrade. Something that would bolt up to a 700R4 or a 4L60E would be nice too. Do you think either of these are good choices, or am I missing something obvious?

As for suspension, I'm thinking coilovers with a 4-link stlye setup, but again cost is going to be a major issue. I don't really want to use leafs, but it would be easier and cheaper to do. Any input here? For wheels and tires, I'd like to get into the 37" and up range, but I do have a set of 36" hummer tires on rims sitting around right now. I know they aren't really the best tires for what I'm trying to do, but they are free. Any ideas here?

I guess my general question is, if you were going to be a crawler, and you wanted it to be strong, yet as cheap as possibly without cutting corners, what parts would you use??? In Michigan, it is much easier to find parts for a Chevy, Ford, or Dodge than it is for anything Foreign. People build '80s style Chevy trucks like Legos out here.

jdjanda · Sep 17, 2003

Since cost is an issue, I'd look for a solid axle donor vehicle. Maybe a YJ or XJ complete with drivetrain. Or a full-width ride, Bronco, or even a Scout.

If you go with a Blazer or other IFS rig you are still going to have to track down axles.

95steel · Sep 17, 2003

you could chop up your s-10 and get a set of J-10 axles for next to nothing, run 2wd chebie springs in the back and coil the front using a modified long arm kit. Y design with a track bar. Put a nice cage and a set of 36-37 inch tires and you are done.

PS, if you want to use the j-10 axles let me know, I have a set 4-sale:flipoff2:

TRD · Sep 17, 2003

cost for material is HUGE depending on what you use. you should expect matl to be well over $1000 for a full buggy (if using DOM)

chuckhines · Sep 17, 2003

Thanks guys,
I thought about using the Blazer, and that is still definitely an option. I'd like to build something from the ground up, but I guess If I removed the body and hacked out the front suspension, I'd be light years ahead of the game. I wouldn't have to worry about fitting the engine, transmission, transfer case, or rear axle under it that way. Do you think the stock transfer case (not sure what is even in it) would be strong enough? Do you think a 10 bolt would hold up in the front of this truck? That would save some major bucks too. I'm thinking I'll want one ton axles under it for strength though. My main points of concern are axles and transfer case. I want those to be overkill if possible. I know a 700r4 will be plenty strong, and an injected 4.3L should be plenty strong enough give the gear ratios. What do you guys think?

JohnnyJ · Sep 17, 2003

If you are trying to build a budget rig, why not try and shoot for something like a legends type vehicle that would meet the rules for EROCC (since they are the closest sanctioning body).

I see a couple of benefits from this:

1) It gives you a set of rules that you must build to, this should help the project focus and not let it get out of hand. (Yeah, a years seems like a long time, but I remember my senior project deadline screamed up on me with all the other crap I had going on.. like finding a job and making sure I passed my other classes)

This would also make sure that you build something that is useable and safe since you'd have to meet the specs from that class.

It's also much cheaper to get started in Legends and be competitive than building an unlimited vehicle, so that would play more towards your budget concerns.

2) The tire limitations allow you do downgrade a few of the expensive pieces.
- you can find used 35s around for relatively cheap compared to trying to find used 37s or larger, especially if you want something on 17's and beadlocks
- less axle is needed, you could pull a set of 44s or similar combo from a Wag and build them and they would hold up to the abuse of <36s and you would probably spend about the same as a rebuildable front D60 alone (unless you stumble on a good deal)

(and next time, use the return key a few times to make some paragraphs.. that's f'n hard to read)

chuckhines · Sep 17, 2003

cost for material is HUGE depending on what you use. you should expect matl to be well over $1000 for a full buggy (if using DOM)

Wow, I've bought DOM for around $2.50-$3/ft, and I was thinking 100-150ft. That would be like $300-$450. I wanted to use some big square stock for the frame rails, then add a cage to that. Maybe I'm way off since I've never built one before though. Anybody have any idea how much raw material would be needed to build a typical chassis? I can get really good prices on materials through school, but not sure exactly how cheap yet.

redramsport · Sep 17, 2003

How about if you built it a little smaller, such as a full tube frame, but use a Toyota 4 cyl., 5 spd., transfer case, and either some Toyota axles or a used set of Jeep CJ axles. Limit your tires to 35" and keep the weight down. The axles and such might survive some punishment if you kept the weight down with a little less power.

Might not be able to climb over the biggest rocks like some of the others out there, but it wouldn't cost near as much either. A used set of Jeep axles are a hell of a lot cheaper than 60's and such.

UP_ROKTOY · Sep 17, 2003

I got a great toyota for sale, all you need to add is a front axle

Maybe another t-case, sell my bed (REAL CLEAN) fab up a flat bed some bumpers, throw some 35's or 38's on it and call it done......and i can deliver

Other options would be to throw your 4.3/700r4/231(most likely) into a cheap ass YJ and grab some scout axles, waggy axles etc. slap some 35's on maybe do a 4 link front and rear with stock tj coils to impress your professor (since your no longer doing a straight axle swap like on my yota or your balzer) and grab a set of 35's

Sammy? cheap yota axles 6-1 tcase and some 33-35's YJ leaves all around, rockin for pretty cheap yet again.

buggies are cool, but not to practical in michigan, you get WAY muddy, and that in return means you freeze your ass off on the trails 9 months out of the year. KISS and use an existing rig. Making a buggy will require all new mounting points for EVERYTHING with no reference as to what is already there.

Of course an all out buggy would be the ultimate way to go, but i dont see time and $$ being on your side right now.

four_by_nut · Sep 17, 2003

Man!!! That's a big task! And expensive. Why don't you guys focus on a 4 link rear design? You guys can do a lot of analysis work up front and then look into coil overs, versus air shocks, versus 1/4 eliptics, versus coils. You can make a small model to "proto" and tweak the design. Then you can actually implement the design. It would cost you WAY less money and probably get you a better grade because the up front analysis and research is a good thing to show.

I had a friend do this about 5-8 years ago as a senior project in college. He designed, proto'd, built and tested a 1/4 eliptic rear. He won all kinds of awards including some prizes.

Think about it. If it's your first rock crawler, your looking at a LOT of stuff to do for a first time as well as a lot of $$$$. Keep it simple and do it right.

chuckhines · Sep 17, 2003

Thanks for the responses guys, keep 'em coming!!!

I was thinking of doing a similar setup to what is under my '98 Ram, and what is under a new TJ. Coils up front with a four link setup. This is a pretty easy design to emulate. The suspension geometry and design all seem pretty straight forward. I could easily change the coils to coilovers if money permits. I could use Johnny joints or Heims in the four links to allow for more travel, and slap a track bar under there to keep everything centered. That part wouldn't be too bad to do.

For the rear, I would like to do something other than leafsprings. I could get away with the leafsprings though and change the design a bit. If I put in some Johnny joints or allowed the shackles to pivot, that would probably work pretty good. I think a coil or a coilover rear would be pretty damn sweet too though. I could probably pretty much copy the design up front, and reverse it for the rear. With coils front and rear, this thing would flex like a mother!!!

I'm really thinking using the Blazer frame might be best. I could really just cut and change anything I don't like on it easier than starting from the ground up. I'm also thinking 35s or 36s on a Blazer sized truck would be plenty for almost anything around here. If I set the axles up so the overhangs are minimal or even negative, this thing would be pretty unstoppable. I'd like to stay away from using stuff that is going to be hard to find, and frankly, the Toyota stuff isn't that cheap and easy to get around me.

What about axles under a truck of this size? I would probably scrap the entire body because it is pretty nasty, so I'd save some weight there. Do you think a 10-bolt or D44 would be enough up front? I'd prefer to go one ton, but if it isn't completely necessary, the cost difference may be the deciding factor. Also, could I use an old Dodge D60 front, or some other fairly unpopular application D60? I'd be looking for a passenger drop, wouldn't I? I can't remember which side the transfer case drops on (or even what model it is for sure).

UP_ROKTOY · Sep 17, 2003

are you nuts? with about a grand plus tire money i could have a sweet yota outta mine, parts are WAY easy to find. Maybe even better or easier then stock jeep parts which michigan also has a ton of. the 10 bolt in stock for is essentially a dana 44 close enough for now anyway. a rear 44 should also do you fine.

chuckhines · Sep 17, 2003

are you nuts? with about a grand plus tire money i could have a sweet yota outta mine, parts are WAY easy to find. Maybe even better or easier then stock jeep parts which michigan also has a ton of. the 10 bolt in stock for is essentially a dana 44 close enough for now anyway. a rear 44 should also do you fine.

Nope, not nuts. I'm just telling you what I know. I only know one guy near me that runs a Yota. Everybody and their mom has an '80s style Chevy. I talk to the guy every now and then, and he said he has trouble finding parts for it. He said he usually has to call out west to get good parts and prices on his Yota stuff. I'm just saying, there aren't really too many junkyards near me that even have a single Toyota truck in them. I'm not opposed to using Toyota parts, the just aren't readily available near my house (or at least I haven't found a Toyota graveyard yet).

I know that a 10 bolt and a D44 are essentially the same, and I was talking about using one as a front, not a rear. I'd think that a D44 or 10 bolt would be fine in a light truck like this, but, maybe it isn't my best bet. I'm thinking I'll need to stuff these with at least 4.56 gear for this thing to really crawl, but I'd like to go even lower than that. I'd just assume stay with common axles like a D44, D60, 10 bolt, or 14 bolt, just for convenience and availability of parts around me. Another reason is that I would like to stick with the 8-lug rims and tires I already have to save some extra money. Man, budgets really do suck!!!

As for the T-case, what Yota case is the best? Is there a cheap one that has a super low ratio, and will handle abuse? Sorry, I really don't know shit about Toyota stuff. If I could get something around the 4:1 ratio, without blowing a ton of money, that would kick some ass. I'd assume I'd need to run one in a divrced style though, wouldn't I? Don't really know enough about the Toyota stuff I guess.

I would like to get a good outline set before I even think about actually building this truck. If I can get all the parts I want down pat, that would really help this project move along. I guess I have a good idea of axles, engine, and transmission. Not really sure on the transfer case. Not 100% sure on frame or building a chassis, but I'm thinking just use the frame. Anybody have any really good or bad reasons I should consider going one route or another with any of these parts???

anonymity · Sep 17, 2003

Theres a place just a few hours North of you in canada that sells mog axles pretty cheap I think Tass got his there. I think he has them under a toyota too.

Its a small world.

MudzerK5 · Sep 17, 2003

Contact Dyna-crack and Avalanche.... maybe you can get some "FREEBIES" "FREEBIES" like in Mahnster Garage.

Good luck on your project though. I would seriously call some vendors and explain your situation - maybe they will help you out.

JonB · Sep 17, 2003

Hey Chuckines, where are you going to school? MTU? If so, you REALLY need to send me a PM. My dad is the president of the board of controls for MTU, and I competed in an ERoCC event. Not to mention I have a BSME degree as well.

I don't know where Algonac is, or if that is where you are from, or where you go to school, so let me know.

I also have access to a factory full of welders, lasers (for cutting sheets of steel), and others. My buddy has a nice little fabrication in da' UP as well. Let me know if I can help.

TRD · Sep 17, 2003

chuckhines said:
Wow, I've bought DOM for around $2.50-$3/ft, and I was thinking 100-150ft. .

i have never built a fullsize buggy however this is ~125 feet

Camp · Sep 17, 2003

Here is my buggy we just built. It has just under 200ft of DOM in it, if that gives you some idea. Don't get me wrong though, the guy that built most of this is REALLY good and we ended up with less than 10 ft of scrap. Count on having more than that if this is your first try.

Camp · Sep 17, 2003

Here it is right after paint. Gives you a better look at where the tube was used. By the way, where is Algonac? I am originally from Fenton

American · Sep 17, 2003

given the resources, constraints, and such of your project... this is what I would suggest...

Hack the hell out of the S10 (or build a tube chassis)
3/4T d44 front
D60FF rear (keep it)
4.3
700R4
NP241 (241 has a pretty low ass low range)
5.87 gears
37" MT/R's or 38.5 SX
Rockstomper beadlocks, or Hummer wheels
Coils w/ 4link

Are your buddy's going to be pitching anything in? They damn well better.

Rockcrawler Senior Project... Help...

chuckhines

jdjanda

95steel

TRD

chuckhines

JohnnyJ

chuckhines

redramsport

UP_ROKTOY

four_by_nut

chuckhines

UP_ROKTOY

chuckhines

anonymity

MudzerK5

JonB

TRD

Camp

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Camp

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American

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