Hilux 4x4 Forum

Well, with my previous project being complete, I suddenly felt a vacuum as I have been used to grafting in the garage on something to keep the brain ticking over , so I decided that I will investigate the installation of a Marlin Crawler ( http://www.marlincrawler.com) additional reduction transfer box on my Hilux.

I have often found 1st gear low range a bit fast when driving over really rocky patches and wished I could go slower.

After reading Simon's (Syron Conversions) article http://www.hilux4x4.co.za/simon/marlin_ ... /index.php I decided to have a look. Marlin Crawler are having a year end special pricing until end December so that interested me immediatley

I did some browsing of the parts I'll need, and after much time piecing it all together in my head, I've figured out how it all works, and what I'll need.

You basically need the MC07 kit, speedo extension, 23 spline rear replacement shaft and output shaft (recommended as stronger to deal with the extra torque) and some other bits which I must still clarify.
I aquired a full spare G52 gearbox that I'll use as the donor box for the transfer case.

With the help of the instructions from the Marlin Crawler site ( http://www.marlincrawler.com/tech/guide ... taller-old ) I decided to strip out the transfer case from my spare gearbox to see what goes on inside.

I have never opened a gearbox before , so here goes. Hopefully I learn something

Here is the donor gearbox (G52) and transfer case (RF1A - Gear Driven forward shift with 2.28:1 reduction ratio and 21 spline input shaft - Can be identified by the 7 bolt rear cover )
I then drained the all the oil from the gearbox and transfer case and removed the rear output flange.
I then removed the rear 4WD gear cover
Then I slid off the speedo gear, oil slinger, bearing etc from the output shaft
Stripped some more parts...

I then split the transfer case from the main gearbox
Then, I split the transfer case from the rear 4WD section
Here is the transfer box output side view, followed by the input side view
Here is the main output shaft and gear removed. Next job is to remove the gear from this shaft, so it can be re-used with the adaptor.

I will try to finalise what I need to get from the USA next week, and the prices. Looks about $ 450 for the parts, but I'm sure the shipping will be the killer :wth:

what transmission does your truck have?
are u going to convert the crawl box to a top shift setup?
if u have any questions about reassembly, let me know, ive assembled over 10 of these.

Hey Andrew, looks like your hilux is going to be a machine of note when it's completed one day...
You really need to get a hobby, like opening a hilux workshop!
Enjoy all the same, look forward to reading this article, and thanks for the front diff redo, have just finished mine, really satisfying work.

Hey Philip, my Hilux has the same transmission as the one I'm stripping above. As far as I can tell, it's a G52.

Trans Date Range 1st 2nd 3rd 4th 5th Rev T/Case
G52 1984-86 3.928 2.333 1.451 1.000 0.851 4.743 Gear

Output Spline T/C Shift Notes
21-spline Forward 25.5" long, 80x20mm open-face input bearing

I plan to forward/remote shift the first crawl box, and I'll have to top shift the rear transfer box. Just got to find out what I need to be able to do this.

Is dual stick top shift for the rear box the only option, or can you top shift in the conventional "J" pattern?

Bandit wrote:Hey Andrew, looks like your hilux is going to be a machine of note when it's completed one day...
You really need to get a hobby, like opening a hilux workshop!
Enjoy all the same, look forward to reading this article, and thanks for the front diff redo, have just finished mine, really satisfying work.

Glad you found it useful

here is a good write up on the forward shift to top shift conversion.
http://www.4x4wire.com/toyota/tech/topshifter/
and u can keep a single shifter with the j pattern in the top shift setup on the rear transfercase.
ive done some searching, and all of the top shift conversion kits are for the crawl box only. to convert the rear t-case to top shift, u will need both shift rods , base plate, low/high range shift fork.

here are some of the kits availible

http://www.marlincrawler.com/hardware-t ... -crawl-box
http://www.marlincrawler.com/transfer-c ... t-aluminum

http://www.inchwormgear.com/store/produ ... 7908e62e05

here is the best deal, and a compleate kit with everything u need
Kit B

http://www.trail-gear.com/top-shift-con ... -kits.html

Great links, thanks

Andrew,

Do yourself a favour and give Ronald a call tomorrow. I think he has a 23 spline output lying in his workshop (he ordered two 21 spline shafts and got a 23 spline by mistake). He's also just done a top shift conversion to his crawler box. I recall him mentioning something about not being happy with the shift rails that he got sent and ended up modifying the old ones.

I'll be watching this topic closely

Great to see you embarking on another Technical Lux Project Andrew

Great text and peekchaz

Looking forward to the next chapter

As you can see, the title of this project changed a bit. After battling with Marlin Crawler in the USA to just get simple answers, I got fed up with their customer service and contacted Ronald (Dieseldog) as per Jonathan's (Toybox) advice.

He brings in the Trail Gear (http://www.trail-gear.com) range. I have dealt with Trail Gear on the internet, and they actually get back to you when you make an enquiry!! They have everything I need, especially the forward shift to top shift conversion kit for the rear transfer case which Marlin Crawler no longer sells.

I had a long conversation with Ronald this morning, and he was really helpful. Lets see where we go from here !

The Trail Gear goodies look really good! Even the rock sliders look good... I'm beginning to get seriously jealous... one of my 4x4 buddies, Craig, has a 'crawler gears' type mod on his lux, Allan did it... using 2 toyota transfer cases... his lux is an awesome offroad monster... running 35" tyres and an EFi'd 4Y... only problem with his mod is the ratio/gearing is not selectable, but Craig does fine with it just like that!

mr b

OK, so I made up my mind, quickly

I have ordered the following from Ronald:

QTY: PART NO: DESCRIPTION:
1........... 100006-1-K..........Trail-Creeper Dual Case Kit, 23-Spline
1........... 105001-1-K..........Trail-Creeper 4.70 T-Case Gears, 23-Spline
1........... 100122-1-K..........Top Shift Conversion Kit C
1........... 120005-1-K..........T-Case Crossmember, 4cyl, 1984-1995
1........... 182501................Rubber Shift Knob, 2.28
4........... 100069-1.............Transfer Case Shift Detent Spring, Heavy Duty
1........... 107510-1-K..........Twin Stick Shift Boot Kit
Now I just have to wait for the parts...

RustyRod wrote:The Trail Gear goodies look really good! Even the rock sliders look good... I'm beginning to get seriously jealous... one of my 4x4 buddies, Craig, has a 'crawler gears' type mod on his lux, Allan did it... using 2 toyota transfer cases... his lux is an awesome offroad monster... running 35" tyres and an EFi'd 4Y... only problem with his mod is the ratio/gearing is not selectable, but Craig does fine with it just like that!

mr b

Bretton, I have to do something, you have EFi

Andrew, just enlighten me here a little .... with that setup, would you still have an H4 option, or would it be just L4 and Crawl-4?

Andy, to borrow another pic from another forum,
Setup is:

Gearbox - 2.28:1 Front Crawl box - 4.7 rear transfer box and 4WD section.

Front Crawl box has:
Gear selector Hi/Lo for selecting 1:1 or 2.28:1 ratio
Rear Transfer box has:
Gear selector Hi/Lo for selecting 1:1 or 4.7:1 ratio
Gear selector for selecting 2WD/4WD

A total of 3 gear sticks + your normal gearbox stick for 5 speed.

You do not loose your high range and can run like this:

Front Crawl box 1:1 then Rear Transfer box 1:1 = normal 5 speed high range.
Front Crawl box 2.28:1 then Rear Transfer box 1:1 = 5 speed low range range.
Front Crawl box 1:1 then Rear Transfer box 4.7:1 = 5 speed extra low range.
Front Crawl box 2.28:1 then Rear Transfer box 4.7:1 = 5 speed super duper low range.

Total of 20 forward gears, and 4 reverse combinations

My setup will look similar to this pic, except that my front crawl box will remain a forward shift box (the front box here is top shifted).

Rear box will look like the pic.

Thanks .... enlightened! So then you'll only need to cut one more hole in the tunnel for the rear sticks?
The lower gearing could also come in handy with surfaces that would cause you to loose traction because of too much torque . Pity the existing X-fer box did'nt have another low gearing option. :D

Yip, only one hole to cut. It will end up looking like Simon's Marlin Crawler mod below,
You can just put 4.7:1 gears in the existing transfer box, which is much cheaper, but then you have normal H4, or very slow L4, no intermediate ratios. 3rd and 4th gear aren't as strong as 1st and 2nd, and you'll end up riding in 4th L4 in some cases which could potentially lead to gear damage.

you are gonna love the dual ultamints, thats what i have in my 1985 toyota with 4.37 axle gears
what axle gears do u have, and what size tires?
u might want to also upgrade your front axle shafts (birfs) all of the added torque will bust them real qiuck.
i broke 9 birfs on 33's in one year

I'm running 4.88:1 axles with 33"'s

if u dont get the front tires in a bind, u shouldnt have too many problems.
im running the same setup with 37' wrangler mtr's on stock birfs. only broke 1 so far in my 1990 4runner
my 1985 hilux has longfield super axles, 30 spline chromoly birfs. with chromoly hub gears.

chromoly

Do you mean 'Chrome alloy'? :D

Sifu-Lux wrote:Yip, only one hole to cut. It will end up looking like Simon's Marlin Crawler mod below,

243217686b44901ef33f8e3ed6eec6a7706b5f0959885577c0c43b6c.jpg

You can just put 4.7:1 gears in the existing transfer box, which is much cheaper, but then you have normal H4, or very slow L4, no intermediate ratios. 3rd and 4th gear aren't as strong as 1st and 2nd, and you'll end up riding in 4th L4 in some cases which could potentially lead to gear damage.

Well that shelves the centre console project I had in mind (for now anyway). Andrew, I'm sure you will but keep a tally of the costs involved.

For the moment I think I will stay with electricity it is not complicated

Mud Dog wrote:

chromoly

Do you mean 'Chrome alloy'? :D

Andy, it is chromoly, this was the material to have your BMX frame made from when I was a laaitjie.

41xx steel is a family of high-strength low-alloy steels (HSLA), as specified by the Society of Automotive Engineers (SAE). Alloying elements include chromium and molybdenum, and as a result these materials are often referred to as chromoly steel or CRMO. They have an excellent strength to weight ratio, are easily welded and are considerably stronger and harder than standard 1020 steel.

While these grades of steel do contain chromium, it is not in great enough quantities to provide the corrosion resistance found in stainless steel.

Examples of applications for 4130 include structural tubing, bicycle frames, AK-47 receivers, clutch and flywheel components, and roll cages. They are also used in aircraft and therefore 41xx grade structural tubing is sometimes referred to as "aircraft tubing".

We live and learn! Thanks Andrew

Since I got a nice pair of snap ring pliers from SWAMBO for Christmas, I decided to work off the Christmas over-indulgence this evening and carry on stripping the donor transfer case. I ended up buying a pair of 90 deg jaw ones as well since they were "only" R 145 ea
Here is the transfer case stripped of all the internal gears etc.
With all the parts stripped, I needed to get the get the low speed gear off the main shaft as it will be re-used with the adaptor kit. To remove the gear, you first need to remove the 6208N bearing from the shaft.

I supported the bearing on two 8mm steel plates on top of my wood vice and then tapped out the main shaft with a nylon hammer. It came out quite easily, so a press was not needed.
I then re-assembled all the parts I will not need again for this project. They will be my spares
Shown below are all the parts that will be re-used once my Trail Gear adaptor kit arrives. I am going to bead blast the transfer case housing to clean it up when I am back at work.
I am also playing with the idea of re-using the 4WD indicator switch on the front case, but tapping the blank hole on the opposite side and installing it there so it can be used as an indicator switch for the crawl box to show if it's in low range. I will have to grind a cam slot into the high/low shift rod to activate the switch. Will have to see how hard the material is.

On Xmas day!! .... Now that's dedication!!!

And I thought I was the only guy who lost his marbles and will do things like that on x-mas day

Andrew :!: :!: You still married Or are you sleeping in the garage

Looking good man :!:

After I thought I would need to buy a speedo cable extension due to the transfer case moving backwards, I was advised that it is not necessary, and that the speedo cable can be re-routed to allow extra slack.

I re-routed the cable this afternoon, and did gain a bit more length. Whether this will be enough, I'll have to see.
I also removed the front output flange from my spare 4WD transfer case which I will re-use on the rear output as I will probably go the route of removing the center bearing altogether and install a lengthened front propshaft in reverse with the double cardan joint.

Here you can see the difference between the front and rear transfer case output flanges. Different diameters and bolt hole PCD's.
I also ordered two new flange nuts and two new transfer case drain plugs from Toyota today.

Is there a difference in the diameter of the front and rear output shafts, or is the rear just stepped down at the splines? With a carrier bearing on the rear prop there would obviously be less stress on the rear output shaft .... smaller bearing would suffice. If it is smaller then you would have to machine the casing out to accept a bigger bearing.

Andy, I am trying to understand your question, but here's a pic of what I plan to do. Same as Simoan Morris, and pic courtesy of his Marlin Crawler conversion.

I do understand all that Andrew, but the two flanges you show above have different internal diameters (possibly a different no of splines as well) ..... my question was therefore, are the out-put shafts the same diameter for the front as for the back, or is the shaft for the smaller i/d flange stepped down at the splines?

Mud Dog wrote:I do understand all that Andrew, but the two flanges you show above have different internal diameters (possibly a different no of splines as well) ..... my question was therefore, are the out-put shafts the same diameter for the front as for the back, or is the shaft for the smaller i/d flange stepped down at the splines?

Ah ha! Well clarified dear sir The flanges are interchangeable. The internal splines are the same. Only the flanges mating face diameters and hole PCD's are different, because a UJ is used at the back and a cardan joint (CV) at the front in standard setup.

Oh, I just looked at the pic again and I see your confusion :? The flange on the left still has the washer in place from under the nut, making the ID look smaller

Thanks for "un-confusing" me ...

OK, so back at work this week This does have some advantages though I prepared the donor parts and taped off the areas I want to keep protected when I get them bead blasted tomorrow.
I ordered new transfer case output flange nuts and new oil drain plugs from Toyota. The nuts and plugs arrived yesterday, but the parts guy ordered me filler plugs for the t/case instead of drain plugs with the magnet in :x

So, stuff it, I decided to make my own, as the filler plugs are a lot cheaper than the mag drain plugs. I got some Neodymium rare earth magnets today (10mm OD x 5mm thick). The filler plugs have a 10mm ID recess, which I drilled out to 10.5mm. Roughed up the inside, sanded the magnet surface and glued them in with metal epoxy. All done in 15 minutes !

These magnets are flippin strong for their size. I could pick up my BIG shifting spanner with one . Should suck all the metal out the oil enol.

The Trail Gear parts from Ronald were shipped from the USA just before Christmas, so hopefully will be here in the next 2 weeks.

Bead blasted all the donor parts today. They look like new now

just a bit of input.
for the twin shift, don't forget to leave out the inter lock pin.

as for those heavy duty springs, try one before you put the cases in the truck!!
My wife could not shift hers at all, even with both hands.
I could pick up the transfercase by the shifter and it would not shift.

I ended up taking the stock springs and streching them about 1/4 inch.

for your floor hole make a saddle out of a piece of tin. to cover a much larger hole then the twin shift boot.
mount the twin shift boot to your saddle the the saddle to the floor.

the hole for the twin shift. only cutting that hole in the floor has to be perfect.
or you will hit the floor pan with the shifters as the drive train moves around.

also chain down your motor mounts.
I used 3 chain links and just bolted it to the steel on each side of the rubber mount.

I made a new front drive shaft out of receiver hitch square tube.
had the rear made with the thickest tube they had.

if you have any questions I run two of these trucks.

oh yeh, here is the write up for part of it.
all of this was done in a gravel drive way.

viewtopic.php?f=92&t=6705

oh, one more thing.
I stuck with the 21 spline because there are so many out there that in case of failure I can just grab anouther case and stick it in there.

save your old drive shafts just in case of failure, that way you can toss in a single case and still get it home.

Cool, thanks for the tips. If I get the parts this month I'll probably start in February when I'm back from Germany. Can't wait :)

OK, so on with the show. My parts finally arrived end January just before I had to go to Germany, so I spent the whole time wishing I was back :roll:

I must say, a very comprehensive kit of parts, nuts, bolts, seals and gaskets etc. Here are some pics of what I got
All the nuts, bolts, seals etc, and top shift conversion kit
Here's the adaptor, very well made and machined
and the 4.7:1 gear set for the rear transfer box

Also got a whole selection of gearknobs for the twin stick conversion kit and front crawl box high low selector. This is how they come, made from good quality rubber
But, these look a bit boring and you can't really see the lettering so easily, especially when you have 4 gear sticks in the vehicle

So, I painted the inlay to make it stand out better

Hey Andrew, glad you've finally got your mitts on the goodies, was wondering how your project was going

Full steam ahead nou

I was wondering when you were going to pick up on this thread again! Glad to see your parts arrived .... will be watching out for the progress reports!

Last night I built the crawl box up into the adaptor. I won't go into all the details of assembly here, but Trail Gear's web site had excellent instructions and video clips if you are interested.

First I had to weld a piece of key stock onto the existing high low shift rod so the high low gear stick cannot slip out.
Then I assembled the existing 2.28:1 gearset from the donor transfer case onto the adaptor.
Closed up the box and installed the shift rod into the shift fork, all done
So now I need to make some time to start stripping the Hilux's transfer box and prop shafts. will have to dodge SWAMBO a bit...

Hey Andrew
I've seen cars with Articulated Steering -
and now you going for Articulated Gearing -

Are you going to employ a permant gear changer coz you got to keep at least one hand on the steering and I doubt you have 4 arms

a little spray paint on the inside of your rear case will show you IF or where to clearance it.
also don't grind to much off the oil valley's on the sides, just a bit will do it.

I used two transfer case mounts to hold them down, also so you are not putting all that force on just four bolts tapped in to the aluminum case.

tail gear makes some really nice transfer case and motor mounts.

I have to ask. how much was shipping??

pretty odd to "talk" to some one on the other side of the world about doing the same thing I did in my drive way here in South Dakota, USA.

the other thing that I will do on my next over haul of the trucks.
I will cut out the center hump from my truck and a slightly larger center hump from a donner truck so I can remove the whole thing for service.
from up under the radio back to where I can reach the rear transfer case drive shaft mount. And maybe over so I can get at the front drive shaft.

ps, before you pull your transfer case use some card board or paper and mark your shift hole that you have now.
then set it over your dual case set up to figure out where to cut the rear hole.
also my twin shifters hit the floor of the truck when the motor flexed around.

so I cut some thick rubber, (inner tube) mounted that to the floor and mounted the twin stick shift boot set up to that.

Thanks for the input, I was going to use some marking blue to check the clearancing area, I guess spraypaint would work too.

I will use two transfer case mounts, my original, and a used donor one from the crawler box original transmission. I bought a Trail Gear replacement dual transfer case cross member as well which takes 2 mounts
Not sure about the shipping cost, bought it through a local importer. I would guess about US$ 1000

1000 for all of it.. or just for shipping... :wth:

No, JUST the shipping !! I did a quick calc now, $1028 parts, ~$800 shipping

Eina, maar die regte goed kos altyd geld, jy sal nie spyt wees nie

OUCH.
but I guess that is not to bad for half way around the world.
where do you guys post up pictures of your runs?

ps how do I read what is in the above post?

I am so mono lingual...

missouriman wrote:OUCH.
but I guess that is not to bad for half way around the world.
where do you guys post up pictures of your runs?

ps how do I read what is in the above post?

I am so mono lingual...

The guys post pics directly in the topic or otherwise they provide a link to something like 'Photobucket'

Eina, maar die regte goed kos altyd geld, jy sal nie spyt wees nie

Translation
"Ouch, but the rightt stuff always costs more. you won' be sorry. "

This afternoon I started work on stripping the Hilux. First up was to remove the interior seats and vinyl mats so it will be easy to work when I need to cut the floor pan for the extra gear sticks.
With that done, I removed the front and rear prop shafts, then put a jack under the transmission to support it. Next to be removed was the cross member. The original one is quite light compared to the heavy steel plate that will replace it. I will have to find some other things to remove to compensate for the weight gain :shifty:

Next, drained the oil from the transfer case, disconnected the 4WD switch wiring, speedo cable and removed the Low range gear stick.
I then lowered the transmission on the jack as low as I could so I could get access to the two top bolts which hold the transfer case to the transmission.
This is a really tight fit and you only get about one click of movement on the socket ratchet. Luckily all the bolts came loose easily. For the middle two bolts you need a universal joint on your socket to get access to the bolt heads.
With the bolts removed, I tapped the transfer case a few times with a rubber mallet to seperate it from the transmission.
I then lay on my creeper with a piece of wood on my stomach and pulled the transfer case and 4WD section off and onto my stomach and slid out from under the Hilux to see SWAMBO staring at me with that :wth: expression. "You just drove it this morning, so why is it now in pieces "
And finally the transfer case out and ready to have surgery tomorrow... 5 hours well spent

Nice going Andrew, keep up the good work on this thread!

Very nice thread Andrew! Soon you'l have to start thinking of publishing all your ideas and upgrades!
How does the title "Hilux Upgrades for Dummies" sound for your fisrt book??

Looking good Andrew cant wait to see it all finnished!!!