Topic: Project: The '81 "Yoter"

[Gnarly4X]

I go down to about 12psi, could probably go a bit lower without losing a bead.

I go down to 4 psi in snow and the sand dunes.  Never had a bead pop off!!

Gnarls.

[LittleSteve]

I ran ten on the Rubicon, which was fine until a rock found it and took a dim view of it having a sidewall in it

[a1gemmel [OP]]

Traction update:

Made 2 marmounts, installed them.



Made a traction bar out of scrap laying around too, if it works well it'll be the best $0 upgrade ever.

[a1gemmel [OP]]

Well, it's getting weirder.

I bought a Skys Offroad high steer kit and threw the arms on, it definitely will not work at my ride height. The tie rod sits about 1/2" off the oil pan. I could notch the pan, or gain a bit of clearance by pushing the axle forward. But neither is going to give me all the up-travel I have now. So, I have a new plan. Convert the front end to spring-under, and run a set of flat high steer arms from Front Range Offroad. I ordered the steering arms without holes drilled, so I have the option to drill the taper from the bottom and run the tie rod and/or the drag link under the steer arm.

As for the spring-under, I started with a set of '86 rear springs and rearched them. Too short, bad shackle angle. Also, axle too far forward even with pin relocation shims moving it an inch backwards.



Next up, a set of '89 xtra-cab rear springs. I don't think the xtra-cab part matters since I'm not using the full pack, but I thought I'd mention it. This looks much better.



I need to re-arch a bunch more springs to make the front packs and I'm still waiting for the flat steering arms to arrive, but this is a good start.
I could just run a bunch of lift like the normal folks and use a conventional hi-steer setup, but I'm a stubborn guy and need to do things the hard way.

[LittleSteve]

Check your shock lengths...

[Gnarly4X]

Will those traction bars bang into rocks?

Gnarls.

[a1gemmel [OP]]

Check your shock lengths...

Yeah, I'm going to do shock hoops soon too to get longer travel. The front shocks are "right" but will also be the limiting factor at both extremes.

Will those traction bars bang into rocks?

Gnarls.

It runs parallel to the driveshaft, so if it hits rocks it just might save my drive line!

[toyodaaddict]

Now you're really getting creative!


I've been interested in the anti wrap bar idea for a long time but have yet to do it.  One thing I've seen come up a lot is that they put alot of stress on the axle housing. Sounds like you really want to reinforce/brace where the mount attaches to the housing. The torque can warp the housing enough that the diff will leak, or rip the mount right off, taking some housing with it. When you get em right, sounds like they work great though.

[a1gemmel [OP]]

Now you're really getting creative!


I've been interested in the anti wrap bar idea for a long time but have yet to do it.  One thing I've seen come up a lot is that they put alot of stress on the axle housing. Sounds like you really want to reinforce/brace where the mount attaches to the housing. The torque can warp the housing enough that the diff will leak, or rip the mount right off, taking some housing with it. When you get em right, sounds like they work great though.

I'll be sure to beat on it hard and give a trip report once it's all back together. Hopefully none of the above happens, but you can't make an egg without breaking a few omelettes along the way...

[Gnarly4X]

... you can't make an egg without breaking a few omelettes along the way...

You mean you can't make an omelet without breaking an egg? 

Gnarls.

[a1gemmel [OP]]

Hey man, you make breakfast your way and I'll make it my way 

[a1gemmel [OP]]

Another small update on the spring-under situation.

This is your leaf pack, this is your leaf pack on drugs:



The flex steer is pretty wild, the axle moves about 4.5 inches backwards from full droop to full stuff. Of course this is true for any arched leaf spring, but for me it means clearances are pretty tight.





With the tire at full steer and full bump, we have clearance, Clarence:



I guesstimated on 1/2" lift boomerang shackles from a YJ (5" center to center) and they're alarmingly perfect. I'll be setting the bumpstops so that they don't actually contact the frame here. Some body mount trimming was done to get the full angle.



And here. This will get cleaned up and painted.



Spring-under plus an elocker diff means the u-bolt plate for the passenger side had to get transmogrified a bit.



And, as it's sitting now. Suspension done save for the bump-stops, next up is steering.

[a1gemmel [OP]]

Playing with it more tonight I've found a few things I'll have to change.

With the full leaf packs installed the shackles invert at full droop. Will need a 6 or possibly 7 inch shackle.

I currently have 14 degrees of caster, that's a little severe so I've ordered angle shims. Longer shackles will make this marginally worse too.

Going to need a long travel driveshaft too, I happen to have the right steel square tubing laying around so I'll just need to get a donor to cut up for the yokes. My current one is too new and balanced, I can't bring myself to cut it up. Keep it for the 4runner, or might sell it.

On the plus side, it looks like the tie rod is going to work on top of the flat arms  It occurred to me that I can drill the steering arms both ways and swap them side to side to give the option of running the tie rod over or under if I need to change it, which makes me feel better about moving forward with drilling the holes in them.

[Ritchie]

How does the trac-bar pivot at the front?
My modified Bud-Built unit has a Heim joint at the front, allowing full articulation all while serving as a trac-bar.

[a1gemmel [OP]]

I'm using a factory leaf spring shackle on the front. We'll see if it breaks or binds once I have the truck back together...

[a1gemmel [OP]]

Today's job was drilling / reaming the steering arms for the tie rod and drag link. I was feeling pretty antsy about cutting up these relatively expensive parts.

Layout fluid and calipers come out for making hole locations. I'm not going to share my measurements, firstly because your wheelbase and pitman arm lengths are likely to be different than mine, and secondly in case I've set the math up wrong and I don't want anyone to copy my mistake. Just look up ackerman geometry and learn from people far more intelligent than me. I've gone with a 100% ackerman setup here. Did I get the math right? Is 100% ackerman the right move for a daily driver that's regularly abused on trails? I don't know.



Set up in the drill press, breaking out a dial indicator to level the face I'm drilling since there's no 90 degree reference surface on the part. Drilled to 9/16", ignore the step bit.



Still crying from the pain of the $80 taper reamer tool. I used layout fluid again to monitor how deep the taper was cutting. Go slow, check the tie rod often. You're going to want the 16" tap wrench I switched to after taking this picture.

[a1gemmel [OP]]

Truck is now back on the road... I forgot to take pictures for a long time so I'll need to take some "finished" pics.
Made a front driveshaft tonight, $20 total cost.  Tomorrow night I take the truck out for a shake-down on some trails for the first time.

[Gnarly4X]

I'm just curious....

What does the square driveshaft do that the round one doesn't?

Gnarls.

[OVRAROK]

I'm just curious....

What does the square driveshaft do that the round one doesn't?

Gnarls.

Keeps the pocket book a bit heavier.

[OVRAROK]

Truck is now back on the road... I forgot to take pictures for a long time so I'll need to take some "finished" pics.
Made a front driveshaft tonight, $20 total cost.  Tomorrow night I take the truck out for a shake-down on some trails for the first time.

Nothing better then a 20 dollar front driveshaft.

[a1gemmel [OP]]

12+" of slip for $20... These new springs need much more driveshaft travel than a stock splined shaft can give.

[Gnarly4X]

12+" of slip for $20... These new springs need much more driveshaft travel than a stock splined shaft can give.

Is the tolerance in the "slip" tight enough to prevent vibrations??

There's a reason for splines.

Gnarls.

[LittleSteve]

Is the tolerance in the "slip" tight enough to prevent vibrations??

There's a reason for splines.

Gnarls.

Balancing and proper assembly of yolks into tubing prevents vibrations, splines are for transmission of torque over a greater area than would be presented by other methods whilst still allowing the joint to slide.

Technically the square is a spline...

With the hubs unlocked in 2wd, then the shaft wont spin which, in my minds eye, if it cant spin it cant be out of balance. When it is in 4wd its likely to be bouncing limiter so balance and vibration go out the window amirite

[a1gemmel [OP]]

Exactly, locking hubs means it's a moot point. It's for offroad only, though I've now tested it up to 30mph with no vibrations.

Shakedown went pretty well:

Few things to address:

- Will be adding another leaf to the pack, it's a little too soft and brake divey.
- Need to weld up and set the steering stops, have a bit of rub at full lock
- The power steering pump is LOUD and will become a spare. I paid $25 for that and the steering box used from some guy so I'm not mad at all
- As predicted, the factory shock mount is the travel limiter in both directions. That needs to change, but not imminently.

[a1gemmel [OP]]

My oil pan cracked right at the drain plug so I picked up another one to install... it also came with most of a 4runner 



This is an untitled '88 4Runner with most of a 22re and an automatic that is destined to become spare parts for both of my running trucks. Not bad for $650.

[LittleSteve]

My oil pan cracked right at the drain plug so I picked up another one to install... it also came with most of a 4runner 



This is an untitled '88 4Runner with most of a 22re and an automatic that is destined to become spare parts for both of my running trucks. Not bad for $650.

Smart thinkin

[a1gemmel [OP]]

Good flex ramp performance with the driver side shock pulled. Steering at full stuff is not really happening, so I'll set my bumpstops a bit lower. With shocks in, it won't stuff that high right now. Need shock hoops soon.







Hitting Moab next weekend which I'm pretty jazzed for.

[a1gemmel [OP]]

Today's task was an onboard welder. Started with a Powermaster 7102 alternator, pretty much copied this write-up from Pirate4x4 for the wiring:

https://www.pirate4x4.com/threads/diy-onboard-welder-obw.631100/

Sketchy bracket:



Control box:



I made a hand throttle that will do double duty for rock crawl cruise control as well as regulating the welder's output.
You'll have to click through for the demonstration video of that. It just routes through the firewall with the stock harness and pulls on a second cable mounted to the carb throttle linkage.
The cable is a Buyers Products VCGTX06, it also twists for fine control and it stays where you set it.
https://i.imgur.com/HvdWHI8.mp4

I'm not much of a stick welder, but this seems to burn rod as good as my home unit does.

[LittleSteve]

More power, go slower

[a1gemmel [OP]]

Well, points to Toyodaaddict for guessing the outcome of the traction bar - my friend flopped his XJ on the escalator on Hell's Revenge, I raced my truck up the backside at mach ten to be a winch anchor and get him recovered, and when the recovery was done there was a puddle of gear oil under the rear diff. Cracked the housing right where my weld met the factory weld.

Onboard welder came in handy, I cut the bracket off and welded the seam back up. The next morning it was "moist" so I sealed it with JB weld for good measure. I'll revisit this later, maybe with the wider axle housing from my parts truck.





Otherwise, the trip was pretty breakage free and a great test of the truck's capabilities (and my driving skills!). I'll probably put together a video once I have some time.











We also hit Dotsero Crater on the way back, which is a very cool volcanic gravel trail I'd recommend to anyone near Glenwood Springs.