Outer Limits 4x4 Board

I pulled my t/case with a rockhopper gear set out a few months ago (due to noises coming from the t/case) and replaced it with a spare t/case I had.

I finally got around to pulling the rockhopper t/case apart today. I pulled it apart and the intermediate gear has lost several teeth.

I bought the car about 2.5 years ago with the rockhopper t/case in it, it has front and rear lockrite diffs, 31" tyres, with the standard 1.3L and 5 speed. I did not do any heavy 4wding but it does get abused a bit on road. Did I just get unlucky or do the rockhopper gears fail pretty often?

I think they were rockhopper series 3 gears but I am not sure, is there any way I can find out?

What are my replacement options?

I am also looking at putting a 2L turbo diesel in the sierra at some stage, I expect it to have around 75kW and 200nm (1.3L is around 50kW and 100nm i think), will the standard suzuki t/case and diffs handle this?

i cant comment on your gears as i dont know. but as far as transfer strenth i have a ca18det 200hp+ in mine for 2 years and have seen any thing from turbo rotarys to v8's handleing it.
its comon to tear mounts off and occasional cracked case but the gears are pretty strong. only seen one brake gears

Ahh, the rockhopper lottery.
I don't know what the actual failure rate is, but for rockhoppers made during that period, I'd say one in five.... maybe 1 in 7 or 8.

Series three's seemed the worst. They were replaced by series 4 pretty quickly. I have heard of S4's breaking but it seems less common. Rockhopper gears have rockhopper stamped on them. As for gearing, you should be able to count the teeth and work out the low range ratio. If it's around 6:1, they're series 3.

As for replacement options, If you are planning on a diesel, I think you would want the tallest available high range. Amongst the 6:1 gears, Trail Tough have the tallest high range, but if you're not doing hard 4WDing, you might want a taller low range that also allows a taller high range to get your cruising revs down.

Steve.

steve have you had much experance with swaping gears from the lay shaft of a 1.3 ltr transfer into a 1ltr transfer and welding them together etc... i know what has to be done and have some one to weld them.
what i wont to know is, what its compared to, ie low range from ?? to ?? and compared to rockhopper s??

offroader-rama wrote:steve have you had much experance with swaping gears from the lay shaft of a 1.3 ltr transfer into a 1ltr transfer and welding them together etc... i know what has to be done and have some one to weld them.
what i wont to know is, what its compared to, ie low range from ?? to ?? and compared to rockhopper s??

http://ironbark.bendigo.latrobe.edu.au/~jeff/xfer2.htm

so by doing this it take
hi from 1.4-1 to 1.58-1
low from 2.27-1 to 4.16-1
so that is about a s2 is that right
also how does it compare with strength to after market gears??

offroader-rama wrote:so by doing this it take
hi from 1.4-1 to 1.58-1
low from 2.27-1 to 4.16-1
so that is about a s2 is that right

No, 4.16:1 is equivalent to Series 1.

Series 2 was designed and only one sample set was made. So there was only Rockhopper Series 1 and 3 produced and now Series 4.

As mentioned, Rockhopper has always been a lottery.

As mentioned, Rockhopper has always been a lottery.

Being one of the original directors of ROCKHOPPER is that one reason you got out, GRP.

Bentzook wrote:

As mentioned, Rockhopper has always been a lottery.

Being one of the original directors of ROCKHOPPER is that one reason you got out, GRP.

Apart from sh1t stirring .. whats your point ?

Bentzook wrote:

As mentioned, Rockhopper has always been a lottery.

Being one of the original directors of ROCKHOPPER is that one reason you got out, GRP.

I didn't get out of being involved with Rockhopper, without regret I handed it to BBM sometime ago.

hrmm they seem to be equivalent to rockhopper gears, gearing wise but there is no markings on the gears.

the input shaft has 27 teeth

intermediate high range gear has 59
intermediate low range gear has 21

output shaft high range gear has 47
output shaft low range gear has 59

this makes high range = (59 * 47) / (27 * 59) = 1.741

and low range = (59 * 59) / (27 * 21) = 6.14

AFAIK, this is pretty much what rockhopper series 3 is.

I think the gears were installed by a mob in Sydney about three years ago for the previous owner, GRP Auto or something like that.

I think I'll replace the gears with something similar and worry about gearing for a diesel motor down the road when I have the money to start thinking about where to get the motor and the like.

Finally, has anyone bought the trail creeper 6.5:1 gear set from Low Range Offroad over in America?

They supposedly offer a lifetime warranty for the gears with no questions asked and are a lot cheaper than the gears in Australia (especially with the current exchange rate).

i have recently bought the 4.9's from lowrange..
exchange rate has gone up recently so buy up kids
i havnt heard of any failures
want33's bought a set of the 6.5's from there recently too.

Zachius wrote: Finally, has anyone bought the trail creeper 6.5:1 gear set from Low Range Offroad over in America?

I purchased the 6.5:1's off low range off road, sean was good to deal with, they cost me $800ish about 6 months ago with express delivery (took about 4-5days) Im yet to try them out off road though, so cant comment on their performance or any warranty issues.

I read on zuwarrie about a homemade t/c kinda like rocklobster with 4.16 low range but the high range stayed the same.
Nik

Zachius wrote:Finally, has anyone bought the trail creeper 6.5:1 gear set from Low Range Offroad over in America?

They supposedly offer a lifetime warranty for the gears with no questions asked and are a lot cheaper than the gears in Australia (especially with the current exchange rate).

I got my gears from Sean at Lowrange too. 6.5:1..
They cost AU$812 delivered with a bearing kit and new layshaft. I fitted myself.
Ordered on tuesday and they were here the following monday.
Lifetime "NO Questions" Guarantee.
I've given mine an absolute thrashing for about 4 months (800km) No problems. I'm happy.

nik i asked the same thing in a sort of way click on this link

http://ironbark.bendigo.latrobe.edu.au/~jeff/xfer2.htm

Question, is there a good rule of thumb to determind what low range will work well, because before i pulled my sierra apart with the ca18det, it was pointless useing low range with the 4.11's and 29's, as it would just spool up and wheel spin.
but if i hit the same hill climb in high range second or even third and let it labour it would crawl up nicely for what it was.
but now i am runng hilux diffs with 4.3's, locked rear, LSD front, baja claws 35's.
so I'm guessing the low range would be a little more use full as the bigger tyres, lockers etc... will give me traction.
I'm considering doing the roblobster before it gets finished, but if there where a good way of working it out would save some time and money.
if i could justifie a going lower 5-1 / 7-1 ????

offroader-rama wrote:Question, is there a good rule of thumb to determind what low range will work well, because before i pulled my sierra apart with the ca18det, it was pointless useing low range with the 4.11's and 29's, as it would just spool up and wheel spin.
but if i hit the same hill climb in high range second or even third and let it labour it would crawl up nicely for what it was.
but now i am runng hilux diffs with 4.3's, locked rear, LSD front, baja claws 35's.
so I'm guessing the low range would be a little more use full as the bigger tyres, lockers etc... will give me traction.
I'm considering doing the roblobster before it gets finished, but if there where a good way of working it out would save some time and money.
if i could justifie a going lower 5-1 / 7-1 ????

not really. If you have lots of reduction boost is irrelevant- you just won't load the motor enough to build boost. But it depends on the sort of driving you want to do. I;m at 107:1 currently and even with only a 660, I can choose whether to bring it onto boost or not.

Taller gearing will load the motor and bring the boost in.

Hope that makes sense.

I'd be aiming for at least 60:1.

Steve.

well at moment i am running 30.7-1, if i do a roblobster i should get 58.8-1 does this sound right, if so then its close to 60-1 and a cheap fix.
to do better than this it'll be $1000 ++ compared $150-$250 for roblobster, as i have the parts just need the machining.

i searched for an hour to find this and its for a ca20 5sp i think there the same would very close as there interchanable

Fifth 0.838:1
Fourth 1.000:1
Third 1.308:1
Second 1.902:1
First 3.321:1
Reverse 3.382:1
(note the gap between 1st and 2nd)
that would be why i couldn't take of in 2nd also it'll give me 3100rpm at 100ks in high range.i worked it out for a 180sx (donour car) and there 2350 at 100ks but there not dragging 35's and there shaped a little better than a sierra

Ive read that link before thanks but I was reading about one that DIDNT affect high range.
I just saw marks adapters do gears for $1100 14% high range and 108%low range. Not what Im after but looks good. BBM list rockhopper $1245 not sur on specs though. Still trying to get delivered price for 6.5s from low range.
Nik

want33s wrote: I got my gears from Sean at Lowrange too. 6.5:1..
They cost AU$812 delivered with a bearing kit and new layshaft.

NIK wrote: Still trying to get delivered price for 6.5s from low range.

Yep I read that and how much Jaffa paid but dosnt the exchange rate change? If I can get them for that I will put in my order next week but I dont want to order anf find out its over $1000 it would be easier to get it local.
Nik

NIK i doubt there is any thing that wont effect high range doing what it says in the link takes high form 1.4 - 1.58 so its 0.18 of a difference where as range goes from 2.274- 4.16 almost doubling low range


STEVE crawl Vs boost, its easy to say you choose to bring in boost but when does your boost come in from memory mine is about 3500rpm, lets say i let the clutch out at 1500rpm,to go climb a rock, that only give me 2000rpm to play with, which is very little, result it wanted to wheel spin before. but thats all here say now, as i have now got hopefully sh#t lods of traction and flex so even if it did boost a little, its only going to push the car rather than wheel spin.
hence asking if there was fomuler that i could use to help work it out, its all good to try and acheive 100-1 crawl, but if that means it takes me 3 gear changes to get to 20ks, then whats the point, but i like the idea of 60-1 thats what the roblobster will give me.

NIK, yes the exchange rate does change daily but not by much.
Lowrange offroad list their 6.5:1 gearset at US$475. At todays exchange rate that is only AU$534.94.. Postage will add another US$100 or so.
Your total will be around AU$647.56... waaaay under what you would pay in Australia.. I got a bearing and gasket kit with mine and it was still only AU$812 delivered. Go for it before the exchange rate slips again.

http://www.gocurrency.com/v2/dorate.php ... te=Convert

the 6.5 from low range seem pretty good , with my 35 claws 4.88 hilux diffs locked the gearing is spot on for crawling in 1st and 2nd and 3rd for hill climbs ,

id go the 6.5's again if i was building another one , sean is real good to deal with , and very fast frieght , just don't go over $1000aus but if just buying the gear set it will be under that with postage by a long way .

cheers Jai

Thanks I didnt know how to convert it but Sean posted a link for me .
WAY under the cost of buying local but good for me!
Nik

IF i was to go over the $1000 mark, what extra costs is there. as in is it just worth getting a few things for other people and paying the tax, as opposed to paying frieght on more items?? for example=== for a $2200 purchuse how much extra will i pay.

offroader-rama wrote: STEVE crawl Vs boost, its easy to say you choose to bring in boost but when does your boost come in from memory mine is about 3500rpm, lets say i let the clutch out at 1500rpm,to go climb a rock, that only give me 2000rpm to play with, which is very little,

I think your misunderstanding the benefit of gearing. I can run right to the rev limiter without bringing boost in.... If the engine doesn't have any load on it. The taller the gearing, the more load you will put on the motor, and the more easily it will build boost and you'll be dealing with the traction problems.

but if that means it takes me 3 gear changes to get to 20ks, then whats the point, but i like the idea of 60-1 thats what the roblobster will give me.

Well, 60:1 might be fine for your application. Yes, I spend a lot of time in 4th low, (which is good for about 20-30kph) but once I am in 4th I can build boost without having traction problems. That's part of the point of deep gearing - I can choose to idle through an obstacle, pick the speed up a bit without calling in boost and loosing control of traction, or go up a couple of gears and get on it to build wheelspeed.

Hope that makes sense.

for the record, my boost threshold is about 3000 rpm. (don't have a tach, but that's what the same turbo does on a twincam version of the 660.)

PS I wouldn't stuff around with making your own rocklobster. IMHO that was only an option when commercial gears weren't available.

Steve.

"steve" PS I wouldn't stuff around with making your own rocklobster. IMHO that was only an option when commercial gears weren't available.

i apreciate you opion steve
i want to get a tranfer brace form roctoy, but he dosent think it will fit the 1ltr transfer what shift light etc... i was under the impression they where the same case as 1.3ltr, different internals, i know the early 1ltr is far smaller am i correct or not if i go to a 1.3 ltr transfer over my ltr then i loose my hand brake etc but gain bigger flange for hilux shafts any suggestions here, to help fit all together with crawler gears being a major concern i dont think i want to go as low as 6-1 i think > 4-1 - >5-1 max which is way a roblobster is so apealing as i hit most things faily hard any way but which tranfer to start with i have all three earely 1tr, late 1ltr, 1.3ltr

ive been looking at this topic and i have gotten in contact with lowrange now waiting 4 a reply. now i was getting the 6.5.1 gears and the gasket/ bearing rebuild kit. all up $615 but without the US postage. so i am yet to c how much that will be. but i am sooo excited. just gotta concentrate...