Gecko gets some mods (1 Viewer)

[4xsteve]

About time for a major overhaul of my crawler, so I'll see if I can document some of it here instead of all over other threads.

I'll start off with a quick explanation.

I have successfully talked myself out of major mods for a long time now. Main reason being that the Gecko works pretty darn good as it is. For being "all Toyota" still - primarily meaning Yota axles and still running leaf springs - it holds up great and flexes awesome. Problem is that with all that flex, almost everything related to the leaves doesn't last very long anymore. I bend or break leaves at least annually, I go through bushings about twice as often, I bend up shackles and hardware about every 12-18 months, bend up U-bolts and top plates every couple of years, break center pins about one a year (due to U-bolt issues probably), demolish bump stops about every other hardcore trip, and even bending down the front side of my spring perches and cracking their welds on the axles. Lastly, because of having so much flex, I started breaking front drivelines - which is saying a lot since I run square tube shafts.

All that being said, I finally decided it's time for links. I'm scared of all the setup, geometry, time and cost, but I think it'll be worth it in the end. Should gain flex, gain stability and greatly reduce suspension repairs.

Current plan (always changing)
Front suspension:
3-link, keeping hydro assist
16" ORI struts (already have)

Rear suspension:
Dual-tri 4-link, set up like a 4 Wheel Underground system, and using aluminum lowers
ORI struts or Fox 2.5 air shocks

Other changes:
W56 with triple cases will get swapped for a W59 with stock chain-drive, driver-drop case and divorced dual gear cases. Chain case front output will be utilized as a PTO.
Since I won't need so much driveshaft extension with links, I will try to swap back to round driveshafts.
Gas tank will be moved up and behind the cab to clear the links.
Bed floor will be recessed to get weight lowered.
Rear Detroit locker getting swapped out for a Yukon Zip locker.
Rear cutting brakes added with the addition of the rear air locker.
Large belly pan will have to be heavily modified or totally removed.

 

[jynx]

Looking forward to seeing how it progresses Steve. You plan on keeping the wheelbase and all the same? What is the chain-drive divorced t-case setup with a pto output? Of everything you posted, that is the most foreign and interesting sounding.

 

[TeddyBoy]

Looking forward to seeing how it progresses Steve. You plan on keeping the wheelbase and all the same? What is the chain-drive divorced t-case setup with a pto output? Of everything you posted, that is the most foreign and interesting sounding.

A divorced case setup is essentially taking 2 complete t-cases and connecting together with a real short driveshaft. Hes going to use the output of the front case to drive a front mounted pto winch, the benefit will be outrageous speed in the winch. Watch on youtube some of the euro guys in off road races winching up hills at breakneck speeds, its cool.

 

[jynx]

But what cases does it use? I didn't know toyota ever made a divorced case. What are they from? Same idea, Crawl box from one mounted to the front of another? Do they make a special plate that lets you convert a toy box to accept a yoke input or will you have to use a different brand case? It sounds very interesting, just new concept to my ears. I'm gonna have to Google it.

The PTO winch setup sounds cool. I need to read up on that.

 

[TeddyBoy]

you're complicating it, Toyota never made a divorced t-case. you simply use 2 t-cases (or in Steve's case 3) and it goes like this:

(transfer case) - driveshaft - (transfer case)
​

maybe this helps, bad pic but you get the idea.

both t-cases are complete only connected via the +/-3" long driveshaft.

 

[jynx]

I got the divorced t-case deal (sami has one) but normally behind the transmission only. Layout is

W59-chaindrive case(rear) - driveshaft-divorced doubler

(front)-pto winch

Correct?

And found this dude from inchworm

Which makes this

Is that what's going on the Gek or is it the other setup?

Leave it to Steve to be bringing all this new-fangled super slow wizardry up in here.

Ted what are those cases in? One looks like a sami case, the other I'm not sure about. This is some crazy S! My head looks like those people on the jet dot com commercials after reading this. Pop...

 

[tgreco]

Looking forward to watching this. Is going with the divorced case to a dual case going to put the shifters anywhere close to reachable? I'm not very knowledgeable about link setups and along the same lines as the shifter question, are you worried about pushing the t-cases and crossmember back so far that you end up with shorter than desired or highly angled rear links? Keep the pics coming.

 

[TeddyBoy]

I got the divorced t-case deal (sami has one) but normally behind the transmission only. Layout is

W59-chaindrive case(rear) - driveshaft-divorced doubler

(front)-pto winch

Correct?

And found this dude from inchworm
View attachment 1311806
Which makes this
View attachment 1311807

Is that what's going on the Gek or is it the other setup?

Leave it to Steve to be bringing all this new-fangled super slow wizardry up in here.

Ted what are those cases in? One looks like a sami case, the other I'm not sure about. This is some crazy S! My head looks like those people on the jet dot com commercials after reading this. Pop...

I've not talked to him about this so Steve had better explain further but from what I gather a t-case will be mounted to the tranny as usual then a short driveshaft where he will then mount his double setup. The end result will leave 2 outputs, the front will be used to drive the PTO and the 2nd to drive the front axle. YES, a very unusual config and YES leave it to Steve to come up with this but that;s how Steve rolls.

no idea what that setup is Matt, just googled divorced dual case setup for a pic and that was the closest rep I could find.

 

[4xsteve]

And found this dude from inchworm
View attachment 1311806
Which makes this
View attachment 1311807

Is that what's going on the Gek or is it the other setup?

This is exactly what I'm doing as far as the divorced case(s). Only problem is that OTT doesn't make those plates anymore, so I'm having one fabbed up for me (but it's not going well).

Matt, when you say "found this from Inchworm", you just mean the picture I guess? If they've started making those, I need to know, cause I sure as heck didn't find it.

The setup is very simple - even simpler than Ted's explanation actually. Just picture a standard trans and t-case all by itself first. Then take your pic with the divorced cases (with the flange on the front) and bolt that front flange to the rear output flange of the case that's already in place. So: (W59 & chain case) > (chain case rear output flange bolted to input flange of adapter plate) > (adapter plate bolted to front of crawl box) > (crawl box adapted to rear gear-drive case normally).
That'll make the chain case have a driver drop front output for PTO use (with high and low range options) and the rear gear case works the same as it always has but sits about 6-12" further back than now.

 

[jynx]

10-4 Steve, that is what I had in my mind after I found that picture of the adapter plate. And yes it was just the picture, but I will see if I can find it again.

So you essentially keep the triple cases, but will end up with an additional shifter for the "pto" on the front case. Can the chain case be twin-sticked? So with the transmission you would have 6 shifters ...

I love stuff like this. It is fascinating to me how things evolve and the things that are or have come and gone that I never knew even existed. LC toy box is another perfect example. I'm tuned in.

 

[4xsteve]

Yes, still triples. I'll remove the first crawl box and adapter, and the chain case will replace that essentially. This will actually lower my final drive by a tiny bit too since the gear cases are 2.28 low and the chain cases are 2.57 or thereabouts. I THINK it may help my streetability a little too. Partly due to the gear reduction in the chain case being an in-line planetary assembly rather than offset gear-to-gear reduction; A lot less mass spinning, smaller parts and a lot less power loss from pushing large gears through gear oil.

I will twin-stick the chain case. If not, I wouldn't be able to utilize triple low range without engaging the front "PTO" output. I want to make that PTO lever (2wd/4wd shifter) either smaller, lower or have a safety latch on it to prevent accidental engagement. So yes, my shifters will be "1-2-3": Single shifter for trans, dual shifter for chain case, triple shifter for duals. Let's not forget about my dual cutting brake levers.

 

[4xsteve]

Looking forward to watching this. Is going with the divorced case to a dual case going to put the shifters anywhere close to reachable?

Right now I have triple cases and my triple-shifter, which mounts to the middle case (2nd crawl box), is nicely positioned to get to easily (so well that my hand rests there most of the time). Doing this divorced setup will move them back to a less desirable location, possibly close to the back of the seats, but nothing extreme. It'll just take a little getting used to. If it becomes an issue for any reason - comfort, interference, mechanical or sheet metal issues - then I can probably modify the shifter arms somehow to regain a little distance. I'm hoping to be able to utilize the space between the forward twin-stick and the rear triple-stick to make a small storage compartment and/or at least some cup holders.

I'm not very knowledgeable about link setups and along the same lines as the shifter question, are you worried about pushing the t-cases and crossmember back so far that you end up with shorter than desired or highly angled rear links?

My rear link setup will certainly have to take into account the shorter rear driveshaft length available, but I don't foresee it being a big issue. Right now my front and rear are both 43" long and while my front probably uses 10+ inches of slip, the rear uses less than two inches. Going to longer links and a shorter driveshaft in the back will probably cause the need for a bit more compression slip as well as a little more angle at the t-case, but hopefully the Toyota double CV's I'm using now will still be sufficient. The front will have the opposite issues, one good and one bad. The good is since the links will cause the axle to arc down and back as opposed to it's current down and forward motion, my slip requirement will go way down. The bad is that my front driveshaft will get so long that it will be a lot harder to protect. BUT.... considering both of those issues simultaneously, I may end up using an intermediate shaft for the front like a lot of the long wheelbase Yotas do from the factory in the rear. This will allow me to put the front output pivot point wherever I want (in a perfect scenario), theoretically allowing me to align it with the links' pivot points too. That can make the required amount of front slip next to nothing.

 

[TeddyBoy]

All i got to say is you have less than 1 year to get this built and get all the bugs worked out. Dragging your pile out of 21 rd. aint exactly on my "wanna do again" list.

 

[FJCRAWLER]

HOLLY CRAP BATMAN !

That's going to be sweet.

Good Luck with the build.

I do have a question..... Can you use something like this?

GM 205 with PTO

 

[4xsteve]

I do have a question..... Can you use something like this?

GM 205 with PTO

While I would love a stout 205 or D300, they take up way too much space. Especially once you consider adapter plates and stuff. One of the three-speed cases, like a Stak, could work in place of my divorced duals, but they're pricey. And all of these options would have one other shortcoming [for how I want to use it]: The PTO would be off of the last case in line instead of the first. That would mean to keep the PTO moving fast I couldn't have the cases ahead of it in low range. Having a fast line speed in conjunction with fast tire speed would be more practical, but I don't have the power to do it.

Always open to ideas though, so thanks for the suggestion.

 

[4xsteve]

Mmmmmmm, Beefy!

Christmas came early!

 

[TeddyBoy]

I like these and interested in seeing how they hold up. Only issue(s) I have with this route is the requirement to re-use an old knuckle and assuming you want a spare is having to have said spare machined to fit.

So looking at the arms I assume you're full throttle into the linking the truck cuz those obviously aren't going to clear a leaf spring.

 

[4xsteve]

I like these and interested in seeing how they hold up. Only issue(s) I have with this route is the requirement to re-use an old knuckle and assuming you want a spare is having to have said spare machined to fit.

Well I have never [yet] had any issues at all with knuckles besides the studs. These arms should virtually eliminate any future issues with studs since the studs will no longer bear any of the turning forces. For that same reason, I'm not even planning to use studs; I'm planning to use my newly discovered method that came about from necessity, and originally figured just as a good trail repair primarily. (See my recent photos in the the Chat Thread)
As for spare knuckles... As previously stated, I hope to never have any more issues. But if I do, I will have my current setup that I can swap back on. My stock knuckles with Marlin Billet high-steer are still fully functional. I bought these arms with matching machined knuckles.

So looking at the arms I assume you're full throttle into the linking the truck cuz those obviously aren't going to clear a leaf spring.

Very good eye sir. Yes, I've been planning it and collecting parts for months now and she'll be coming apart sometime pretty soon (I hope) to start on the front 3-link.

 

[TeddyBoy]

For that same reason, I'm not even planning to use studs; I'm planning to use my newly discovered method that came about from necessity, and originally figured just as a good trail repair primarily. (See my recent photos in the the Chat Thread)

yeah, about that. I read it a few weeks ago but have not re-read so I'm a little fuzzy on it. First off good thinking and great trail repair skills especially given the circumstances.

Here's where I'm fuzzy, a wheel lug is pretty short compared to a knuckle stud and I wouldn't think it'd be long enough to bolt through the steering arm and still get full thread contact into the knuckle. Given your description above it sounds like you used a pair of vice grips and got them as tight as possible but would think it still left a little to be desired, That's what trail repairs are all about though.

So it got me thinking especially since I saw some longer studs over at john's a few weeks ago. Why wouldn't/couldn't you get the longer studs and thread the stud in from the inside of the knuckle and then tighten down the steering arm using a lug nut on top? More work? obviously!

Now, who in the hell carries around European versions of wheel studs? You do apparently and a damned good thing it sounds like. Why in the world did you even have these in the first place and I assume from here on you'll have a few spares in the truck.

 

[4xsteve]

yeah, about that. I read it a few weeks ago but have not re-read so I'm a little fuzzy on it. First off good thinking and great trail repair skills especially given the circumstances.

Here's where I'm fuzzy, a wheel lug is pretty short compared to a knuckle stud and I wouldn't think it'd be long enough to bolt through the steering arm and still get full thread contact into the knuckle. Given your description above it sounds like you used a pair of vice grips and got them as tight as possible but would think it still left a little to be desired, That's what trail repairs are all about though.

So it got me thinking especially since I saw some longer studs over at john's a few weeks ago. Why wouldn't/couldn't you get the longer studs and thread the stud in from the inside of the knuckle and then tighten down the steering arm using a lug nut on top? More work? obviously!

Now, who in the hell carries around European versions of wheel studs? You do apparently and a damned good thing it sounds like. Why in the world did you even have these in the first place and I assume from here on you'll have a few spares in the truck.

- Wheel lug isn't much shorter. However, that issue was compounded a little bit when I used a washer on the lug stud which shortened it's "grab depth". The washer was dual purposed: It was an attempt to compensate for the missing cone washer by its ID being tight to the stud's throat and its OD as tight to the walls of the steering arm as possible to help distribute the forces across the stud's upper and lower. It also was to purposely shorten the "grab depth" in order to keep the head high enough to be able to grab with the pliers to tighten. It worked, but the washers were metric, so not likely something anyone is gonna have laying around. Certainly not on the trail.

- Your inside-out idea is exactly what I did with my diff, if you recall from Moab. I put bolts in from the inside and bottomed them out on the inside flange. The issue is that when you tighten the nuts on the outside, if the friction gets higher at that union than at the bolt's head internally, the bolts back out rather than the nut tightening. This still bottoms out the nut and gives you the feeling in the tool that it's tight, but it's an illusion. At the first signs of vibration it'll loosen up and retightening only renews its previous state of illusion. I had to weld the bolt heads to keep them from backing out. The next issue is that the studs cannot stick out inside the knuckle very far without interfering with the Birf. That being said, knuckle studs all have 'shoulders' in the middle that'll prevent you from threading them in from underneath... unless you feel like running a die over all 8-12 [hardened] studs. One thing that could also pose a problem, but that I'm not sure about, is that I want to say the upper half of knuckle studs are a finer pitch than the lower half. In other words, trying to simply replace the cone / washer / nut assembly with a lugnut may not work.

- To your last comment, if you haven't gathered this from the preceding info, is that I was NOT on the trail when I figured this out. I did have this issue on Rubicon with the Gecko, but this instance happened on my FJ-60 while driving around locally and I was desperate to get it back together that night since I really needed the shop space the next day. No, I have never carried lug studs on the trail before, but you're damn right that I will be from now on!

The one concern I still have that I'm working on the remedy for is that I am almost certain that a knuckle set up with just these one-piece lug studs in place of the four-piece stud / cone / washer/ nut setup is that it isn't going to stay tight very long. Even with Loctite I seriously question the ability of the single bolts to remain tight after even small amounts of lateral forces from the steering arms come into play. My current idea is that I'm going to safety-wire the lugs. Haven't acted on it yet though, so I'll post up as I get into it later on.