The possiblity of crawler gears in our chain driven transfer

[Hilux Max]

Fella's,

Thought I'd start a thread on this so we can chat about it abit and share thoughts, ideas and experiences on the matter.

As many of you know, our model hilux comes with a chain driven transfercase not a gear driven one. In older hilux's pre 1998, they had a gear driven one, which allows you the opportunity to replace gear sets to enabling you to obtain a much slower crawl ratio when offroad and in low range.

Unfortunately due to the chain driven design it has not been possible......or has it?

The alternative available at the moment are to replace differential gears to get more control and power back in low range . JT Diff's in the US offer a 4.56:1 gear ratio set of gears that are a THICK cut meaning they will fit in the 3.73:1 gear carrier that the standard hilux has. otherwise, you need to replace carriers along with the gear ratio for gear ratios over 3.9:1, like the Prado has. Or you can get the ARB locker that suits the higher ratio'd gears.
http://www.justdifferentials.com/index.php?main_page=index&cPath=22_37_484


The other option is the Inchworm Lefty, which as has been covered in threads in the past is a geared transfer case specifically built to suit the left hand output shaft (hence the name) to the front diff that current generation Toyota Pickups use. Unfortunately after having it priced by LockdUp 4x4, it would equate to $5-5,000 by the time you bring it over.
http://www.inchwormgear.com/store/product_info.php?products_id=985&osCsid=f7f02a6388f23448f81261b3df316685


Another option is adding a second transfer case, but that is similar to the option above, where you add a geared box infront of the chain driven one, along with an alluminium adaptorand has its on lever, but you need to fabricate another crosmember underneath and two new tailshafts ontop of the purchase price, slightly cheaper but pricey non the less by the time its here.
http://www.inchwormgear.com/store/product_info.php?cPath=21_89_93_109&products_id=29


Now this brings me to the point of this discussion....there must be a better and cheaper way to do this and it has been playing on my mind for ages. I found out on the darkside on the Triton Forum that a member worked out that the Triton chain driven transfer case and the one of the Pajero are identical. Along with that, this member said that he organised for a custom chain and matching gear get made up to suit the triton transfercase which would enable it to crawl in low range.

I took the contact details of the firm that did this and appropriately sent them an email inquiring about it. And the possibility of manufacturing a set for the current generation hilux, with diagrams like the one above showing them the layout of the gearset.

I also told them that the hilux transfercase is the same as the Tacoma one and that if successful, they'd have a large export market to the US as there is nothing available there such as this as of yet. Aswell as very close if not the same with the Prado and FJ Cruisers. So it should look interesting to them. The firm is Melbourne Based gear manufacturers and their name is Hardman Brothers Pty Ltd......link below -
http://www.hardmanbros.com.au/Default.aspx?AspxAutoDetectCookieSupport=1

And below is a diagram of the Hilux Transfer case gear set.


I have also sent Artic trucks an email describing the same thing after seeing an online video of their Antarctic Hilux trip Hilux Preparation and saw they were replacing the gear and chain in the transfer case. I cant find the link now, but hopefully someone will come to the party.

I will post replies from both sources and I have also posted the topic on a yank Forum to gauge interest and get ideas.

So....what do you think guys? Who would be interested if this ended up going ahead?

A gear and a 6 layer chain has gotta be cheaper than a whole transfer case assy like Inchworms......

[McSumWay]

Yes please. Under 3000 would make it doable but it should be less

[Skog07]

Max.
Changing the sprockets will cause wind up between the front and rear diff. I believe the chain drive to be 1:1 to allow both the propeller shafts to spin at the same rpm for each diff.
Changing the sprockets would be relatively easy you can purchase blank sprokets and machine them to you requirements and also chain can be bought as well.
What controls the reduction ratio in the transfer case is the planetry gears boxed in up top on the drawing. When you select low range the part# 36273 is locked giving the reduction.
The inch worm uses a geared reduction not a planetry which is easily replaced to give different ratios. Planetry gear sets arent cheap to manufacture. Think Rod may have found some Marlin crawler gears that can replace the planetry set with a lower ratio.
The only explanation I can give to the Artic truck changing of the chain and sprocket is to help adjust the ratio between the front and rear diffs. Its hard to explain but to keep optimum strength of the front diff it would be kept at say a 3.73:1 ratio, the rear may need a 5:1 for use with those 40+ inch huge tyres. By adjusting sprocket sizes in the transfer case the diff ratios could be evened out to stop windup between front and rear diff.
Cheers
Skog

[Quinny34]

So after chatting tonight Mmaaxx and after what Skog has said does this bring it back to either a lefty or similar device Or a Dif centre change.

If the dif centres still allow the front locker to work due to being thick cut, and possibly installed for around $1800 then I'd be favouring this option. It would reset the auto back for me also...

Is there any Australian suppliers of these gears??? Skog, your in the trade so to speak... is there anyone you know of who would do these or have them made up?

[Skog07]

Quinny.
I only really think the only achievable option is a ratio change for front and rear diff.
If you have a look at the way the newhilux transfer case is set up the whole drive train is inline. There are no lay shafts for reduction gears. When you shift from 2H to 4H the splines lock in on the sprocket and engage the front drive via chain. Giving you 4H. Next is N on the shift which disengages the gearbox completely from the driveline. Front and rear diffs are still locked in together but are disconnected from the gearbox. ie auto/manual the sun gear is locked onto the mainshaft. When you push it forward into 4L this locks the outer gear on the planetry set giving the reduction ratio of 2.25:1. Its fairly simple compact and robust design. Unfortunately hard to tweak with ratios due to the design of planetry gears. It would be hard to modify the transfer case reduction gear and bloody expensive as well. The only real option would be a replacement planetry set which would mean pulling apart the transfer case and replacing it with an aftermarket part. Think Rod may have found something to do the job think it was Marlin crawler gears if they do make a system to fit into the hilux transfer case???
If you wanted to research getting specialty gears made up you could try Newvale Enginnering Pty. Ltd. and also if you are looking into trying adjusting the chain and sprockets ratios you could try Tsubaki Australia. Pty. Ltd.. I think for all the screwing around though you'd just be far better off just changing the diff ratios. This would make high range 4wd and 2wd more practical as well
Cheers
Skog

[Hilux Max]

I agree that changing the diff ratios is the best thing to do to bring it all back and in some cases working better than a stock hilux would be in low range....I was just hoping to get some feedback on the possibility of doing this.

If it is not doable well so be it, atleast we'll all now... but if you dont ask and inquire you never will know.

JT Diffs are the way to go, I was just hoping there might be a cheaper route to go.......

you guys understand yeah?

[tgibbo]

Forget about the Lefty for a moment and think about what you want to achieve, with some reduction gears. Once you put in a low rang gear set in a T/case your low range may be too low in some situations so you can’t get the momentum up (eg maybe on a slippery muddy road).

Some people put in a second transfer case that gives them two sets of low range selectors in the drive chain. This gives them a bigger range of reduction gear sets so Low-Low will give you double the low gearing and High-Low will give you the same gearing as stock. Have a look at this picture and look at the available gearing options that something like the KLUNE gives you (3 low ranges!)



The purpose of the Lefty is to allow us to use an older gearbox on our trucks and swap the output shaft over to the left hand side. Why do we want to do that? Because then we can put in a low range gear set from the old Hilux and optionally mate up with another set of reduction gears (so we have the dual transfer, twin stick setup).

For my mind, I like the idea of the dual transfer case setup as that means you can leave the low range gearing as stock until you really want to crawl over big obstacles.

The Klune is a much simpler way to deal with the dual transfer case setup and there are no issues with clocking the case or the shaft on the wrong side. As it has a cylindrical case and a cable shifter, it is much simpler to mate up between the gearbox and the existing transfer case.

Yes; you still need to deal with altering drive shaft lengths and relocating the cross member. The link below shows the price of a Klune kist as being $2,695 which is highly competitive with the Lefty. Note that the Klune is also sold mated to an Atlas T/case which is regarded as the best solution on the market.

Here is one of the links I found when I researched this previously which quotes a price for the Klune.
http://128.83.80.200/TACO/whycrawl.html

There was also a bit of a shootout in technical terms on TTORA I read between Inchworm Gear and Marlin Crawler I think which indicated the reduction was occurring at different places in the drive chain due to th edifferent way bits of other gera boxes are bolted together to solve the problem.. One of them multiplied torque loads in a bad place and broke stuff because of it. I can’t remember which one it was. But in any case Klune was not doing this as the reduction all happened in a strong set of planetary gears in front of the t/case. I'll try and find it.

Here is another link for you
http://www.high-impact.net/dual_transfer_cases.htm

quote from old page that rod put up, i think this is the best option as you can put the shifter where ever you want, the only problem would be is it shifts the transfer case back so the shifter will be in the glove box,

[Quinny34]

Skog07, Sorry mate... my last sentence was not clear... I meant the dif centres... Do you know any Aussie suppliers of dif centres....

mmaaxx, Dont be sorry, the only dumb question is a question not asked or the age old "does my arse look big in this?"....

If we can find a good supplier in Oz then we may get at least 1/2 dozen of us for a group buy.... If we need to get from the US... we may be able to save on shipping etc...

[rodw]

Geez guys, I have forgotten what I found now. From memory the shootout clearly favoured one over the other. I think there might be a link from one of the manufacturers to the shootout.

The trouble I have got is like the idea of doing the right thing and sometimes it is more expensive this way. Tgibbo has summed up the right way to do this. The Klune wins hands down if it can be adapted to our truck. It is also mated with the Atlas Tcase in one package which is more compact again.

Regearing the Suzukis was a big thing and one thing that came out of that was that it was not a good idea to regear at the t/case so far up the drive chain (maybe for the reasons mentioned in the shootout). The Sierras had a gear set that gave you a reduction in both High and Low range so you could fix your big tyres in High Range and do the crawling at the one time by simply changing the t/case gears. However, the feeling from the smart fellas on the forums was that you should do your diffs first and then worry about crawler gears.

I have done a bit of work on building a table of suitable gear sets for different tyre sizes and sent it to Max. Hopefully, he can get some part numbers etc to flesh it out and then I will post up some details.

Anyway, my thinking is that the current tyres I bought will last me till the end of warranty at which time it might be worth looking at going to 255/85 R16's and at that time regear and install ARB lockers to both axles to save the cost of the carriers. For me, only after that would I be lookng at fititng crawler gears.

On an aside, the information about the technical details of our truck has mushroomed recently, I think we need to establish a new Forum controlled by the Moderators called the New Hilux Bible where we can post a summary of our findings on topics like this so we don't have to wade through stuff again and again. but we need to do a bit of planning before we rush in and create the new forum.

[tasibrett]

I'am happy with my highway gears, a transfer case mod would be the only way to go for me.

[rodw]

Thought we better have a picture of the Klune


See here http://www.high-impact.net/transmission ... ochure.htm

How simple is that to add a dual t/case?

The Klune/Atlas Combo


http://www.high-impact.net/transmission ... 0Combo.htm

[rodw]

I'am happy with my highway gears, a transfer case mod would be the only way to go for me.

I can understand this if you are still running the 31's on your profile. I went from 31's to 32's on Friday. I think it becomes more of an issue at large tyre sizes. Personally, I think the Hilux is designed for 31's, not the tiny 29's they put on.

[Drew]

I too would be interested in this. Am looking at changing the diff ratios now thru installing lockers. I cant get over how high the standard gearing is in our new tucks compared with my 99mod, and for those of us with larger diamiter tyres it just makes the problem worse. my 33's for instance it seems to die off the line in highrange 2 or 4 before it takes off. Makes for good fuel economy though i suppose lol

I have been looking into the idear of the 2nd transfer case as well. A lot of my patrol driving mates have done this with it on an air actuator so with just the flick of a switch you can have crawler gears but still have the stock lowrange for when you need that momentum like tigbbo said. Would definatly be somthing worth looking into maxx good post

[Skog07]

Quinny.
Was going to edit the post I miss read the last sentence....
I could ask Cliffy at Newvale Enginnering to look into making sets up for those want them. But the problem is he would possibly need a stock pinion and crown wheel from each diff to duplicate them. Then a custom ratio could be devised and cut into the blanks. He may even need both complete diff assemblys to get his dimensions? Im sure that it would be fairly pricey to say the least.. The more you make obvioulsy the cheaper it would be, being a prototype as well you may run into trouble with custom cuts as well. I dont know alot about gear cutting, its a science in itself in the trade.

Max.
It would be really nice to get a low range that actually works with larger dia tyres and also save my clutch a bit. Ive held of on the front locker thus far and thinking of going to a front Prado ARB airlocker with 3.9:1 or 4.1:1 gears fitted front and rear. Would really work well on 32 inch tyre. 4.5:1 would be nice but would possibly need a 6 speed Prado box to make it behave on the freeway nicely with an extra overdrive. probably spent a lazy $6000 grand in that last paragraph.

Tiggbo.
I do agree if the lowrange is to low it does become inpractical. The inchworm ratios of the top of my head were. 2.5:1, 4:1 and 5.7:1. but it was fixed. The 5.7:1 is over double the std reduction. And as you said when you need momentum you may be shifting from second gear to fifth to get up something. And if you went back to 4 high the jump between low and high would too great.

Rod.
That Klune system looks like it has a few sets of planetry gears inside and pulling the stick locks the outer ring gear into position giving the ratio. It would push the transfer case shifter back somewhat though.


All I want from mine is to bring it back to stock gearing on 32" rubber or slightly lower so with the clutch fully released it is slightly slower than wind in speed on the winch in 1st gear low 4.
Cheers
Skog

[tgibbo]

i didnt actuly say any of that rod did in the other crawler tread i just cut it out to show another option

[rodw]

Rod.
That Klune system looks like it has a few sets of planetry gears inside and pulling the stick locks the outer ring gear into position giving the ratio. It would push the transfer case shifter back somewhat though.

Cheers
Skog

Quite right skog. The Klune is 6.5" long and probably needs an adapter which adds another inch. Hopefully, the existing tcase linkages culd be extended to keep the low range stick in the factory position.

There are adjustments required to the drive shafts and the rear with the centre bearing might be problematic. Might be worth going to a one piece shaft. I think drive shafts might be another area of black art in your world mate. Easy to shorten/lengthen, but will it work and avoid harmonic frequencies?

[Hilux Max]

Guys,

geez, this thread took of real quick....good to see everyones input.....after talking with Quinny, and Rod last night and this morning, and looking into the setup abit more, Rod made me realise that my idea of changing the chain and the associated gear was incorrect, aswell as Skogs explanation of how the chain works at a 1:1 ratio.....

what we are really looking at is the ring gear that slides over the planetary gears at the front of the transfer gear set. A seen below in an updated diagram.....


The low range lever slides the ring gear over the planetary gears selecting the low range. So therefore, if we wanted to modify the transfer case for a better low range, we would need a new planetary gear set along with the selector ring gear......almost looks like the job and work invovled would be to big to be practical....

Thou it does help me understand now how the Klune works.....with several planetary gear sets in the unit, the lever would be selecting the appropriate one that you need, giving you way more options for various Low Range Ratios...am I correct in the explanation Rod? Skog?

So Rod, whats the pricing on a Klune unit? It mounts infront of the standard transfercase yeah? so you would still be looking at an adaptor, transfercase crossmember and tailshafts........

diff gears is looking more and more attractive and the way to go after studying all the options here.

Thanks once again for all your inputs fella's.

[Bull]

I talked to Marks; they told me it's not worth designing anything for it yet. They're going to wait until the new Hilux is older and more people want to mod them. I'm doing the diff gears in the meantime.

[Hilux Max]

Bull, I just spoke to mark Adapters too, and they told me that Snake racing is selling diff gears for the hilux.

So I just gave them a call and spoke to Ryan. He confirmed that they are selling diff gears in lots of different ratios, and their website has not been updated yet with them.

He asked me to send him an email so when he has time he can list everything for me, which Ill post back up here.

By the sound of it, they do not have the thick cut gears that I mentioned earlier from JT Diffs in the states, so if you want to regear, you'll need to replace the front gear carrier which will be another 300bux ontop of the set of gears fro the front, or if you already have a front locker, you'll have to replace it with one to suit the Prado and the higher ratio gears.

cheers,

[Bull]

Well I dunno now. I've got a trutrac sitting in a box on the back seat but I havn't ordered the new R & P yet. I was going to let the local diff specialist supply and fit the new ratios when he fits the trutrac. I guess I'll wait and see.