Outer Limits 4x4 Board

got a 84 fj 60 stock with a 2f , want to put 35's or 37's on it are the
* axles
* diff centres
* transfer case & gearbox
* cv's
* drive shafts

and so on, strong enough in stock form to run these tyres ?? Or should certain things be updated straight away before they break in the scrub ??

any ideas would be great ..

Cheers ...

running 35's with all the stock equipment should be fine, even off road, although a set of crawler gears would be great.

37's with stock ratios may be pushing it a little. It will do it, but rock crawling will suck and the clutch will be worked a lot harder.

As for toughness of the factory gear, its all pretty good. Things like wear rate of CV's really depend on how hard you thrash them off road.

Oh, and you say stock? I take it you are planning on lifting the cruiser to fit the new rubber? You'll need at least 4 inches to fit 35's and probably another 2 at least to fit the 37's.

carts wrote:running 35's with all the stock equipment should be fine, even off road, although a set of crawler gears would be great.

37's with stock ratios may be pushing it a little. It will do it, but rock crawling will suck and the clutch will be worked a lot harder.

As for toughness of the factory gear, its all pretty good. Things like wear rate of CV's really depend on how hard you thrash them off road.

Oh, and you say stock? I take it you are planning on lifting the cruiser to fit the new rubber? You'll need at least 4 inches to fit 35's and probably another 2 at least to fit the 37's.

I have an Fj40 with 37's and ran it without crawlers for a while but it sucked....marks 78% reduction are awsome plus they give you a 10% reduction in heigh so its not to bad on the road

Running 37's you'll need stronger CV's. I boke 2 in 2 trips, then got some from haultech and coped in the issan trials without a breackage....except my rear axel, but it mustof had been damaged before the trials as rear axels dont break often at all.


Adam

the damage you do to your gear is far more analagous to your driving style and mechanical sympathy than the size of tyre you run. that said, any increase in tyre size will adversely alter your crawl ratio, going to 37's is a 20% change in rolling circumference over stock so your lowest ratio is 20% faster and 20% less driving force. Add to that a 37" tyre really is a dedicated off road tyre (most engineers will NOT pass them for road use) so to go to that tyre size requires $ spent on road tyres or a tow rig, and almost definitely lower ratio diffs and/or crawler gears.

the lowest ratio Marks crawler gears are only 53% lower than the stock 1.997:1 ratio, I don't know where their spastic 78% number comes from, and I have asked them about it a couple of times, they have no answers so I am forced to conclude It's a marketing fib.
Since most landcruisers' crawl ratio is only around 40:1 to start with, taking it to 60:1 with transfer crawlers then going to 37" tyres gives you a "corrected" crawl ratio of about 48:1 which is barely acceptable for rock crawling - there will still be plenty of times when you really want to go a lot slower.

on top of all that, to fit 37's you will need at least a true 3" over stock suspension lift, plus a 2" body lift or a generous chop of the guards, to fit them without lots of rubbing, so you're looking at an expensive spring lift that will reduce your available articulation, or a springover conversion, both of with are $2000+ options unless you're pretty handy with grinder and welder.

on the other hand, 35's fit well with 2" suspension and 2" body lift, don't look too "illegal", and can be engineered for road use. as Carts has said, you can turn them ok with stock gearing, but be prepared for a fuel economy shock. If you think the 2F is thirsty now, wait till you've got it turning 35's or 37's, no matter what the gearing - you'll never see the happy side of 20 litres/100km again!

food for thought anyway

cheers

Brian

Thanks very much for your input, seems without doing quite a few mods you carnt really get away with 37's,
and from what you say 35's you can get away with it so for now i think 35's will do just fine .
Cheers.

dumbdunce wrote:the lowest ratio Marks crawler gears are only 53% lower than the stock 1.997:1 ratio, I don't know where their spastic 78% number comes from, and I have asked them about it a couple of times, they have no answers so I am forced to conclude It's a marketing fib.
Since most landcruisers' crawl ratio is only around 40:1 to start with, taking it to 60:1 with transfer crawlers then going to 37" tyres gives you a "corrected" crawl ratio of about 48:1 which is barely acceptable for rock crawling - there will still be plenty of times when you really want to go a lot slower.

DUMBDUNCE:

Dude, you keep bringing up these numbers as though they are some personal crusade

And what do you mean by "barely acceptable for rock crawling" ? I have 38s and the marks gears and it is ideal for rock crawling ! It is what my rig does.

Have you driven a rig on 37s or 38s wuth the gears ? Or are you basing your assumptions on 'numbers' ?

I dont want to sound like I am trying to hammer you, but you keep scaring people away from Marks gears If you have a problem with them - fine. But I get the feeling you dont have them and never have. It seem like you have issue with their marketing.

Come for a drive one weekend and see how they go

HEY CHARGER:

I have 60 series diffs, axles, transfer case, gearbox and cvs. With a V8 and 38" tyres I have yet to break stuff - it may be due to how I drive my rig -but thats not to say it doesnt cop a hammering

Gears would certainly take a lot of strain off stuff like your clutch

Shorty40 wrote:
DUMBDUNCE:

Dude, you keep bringing up these numbers as though they are some personal crusade

it is a bit of a crusade. I don't like people being fibbed to. I just want to know *why* they claim that number.

And what do you mean by "barely acceptable for rock crawling" ? I have 38s and the marks gears and it is ideal for rock crawling ! It is what my rig does.

you also have a topless 40 series a V8 engine! a 500kg+ heavier 60 with a 2F with the gears will struggle.

Have you driven a rig on 37s or 38s wuth the gears ? Or are you basing your assumptions on 'numbers' ?

I have driven a HZJ75 with gears and 36's, and found it to be barely acceptable for true crawling. it will only be worse with a heavier truck on bigger tyres. The numbers - torque, power, rpm, mass, speed don't lie.

I dont want to sound like I am trying to hammer you, but you keep scaring people away from Marks gears If you have a problem with them - fine. But I get the feeling you dont have them and never have. It seem like you have issue with their marketing.

It's not my intention to scare people away from Mark's gears and I think they are a great product, they make a massive improvement over the factory low range of landcruisers, they are bulletproof strong, and they are reasonably easy to install - I just really want Marks to come clean about the ratios intead of fibbing to their customers - so you are spot on, my mission is against their *marketing*, not the product itself. I have installed abot ten sets of marks gears in patrols and landcruisers, and driven most of those vehicles for testing, on and/or off the road. I have never personally owned a set because I have never owned a vehicle in which they would be a worthwhile investment*, but if I had a 60 or 40 they would be high on my list.


* spending 3k + for cruiser crawler for the 80 (and the 80 is dead at the moment anyway) is ridiculous. In the bundera, you get 4.88:1 diffs and 2.3:1 low range factory, spending $2k for a 30% reduction is not a good investment either.

Sorry dumbdance i meant 68% reduction have a look at the marks toyota crawler page about half way down

http://www.marks4wd.com/lc-extra-low-tc-gears.htm

wasn't the weakest link for most cruisers the axles ?n please dont say the crawler gears a shit ive just invested in themhopefully 1st trial sunday

every thing should be pritty strong and hold up gearsing will be your only drama but nothing u cant fix

MY45 wrote:Sorry dumbdance i meant 68% reduction have a look at the marks toyota crawler page about half way down

http://www.marks4wd.com/lc-extra-low-tc-gears.htm

whatever marks clains them to be, it's misleading.

Tidy42 wrote:wasn't the weakest link for most cruisers the axles ?n please dont say the crawler gears a shit ive just invested in themhopefully 1st trial sunday

th weakest link in early cruiser axles (to 1989) is the CV joints, the rest is pretty strong but it is possible to break the crownwheel and pinion gears if you try. The crawler gears are very strong, you are highly unlikely to break them.

dumbdunce wrote: but it is possible to break the crownwheel and pinion gears if you try.

mmmmm....Monty

carts wrote:

dumbdunce wrote: but it is possible to break the crownwheel and pinion gears if you try.

mmmmm....Monty

that wasn't monty's fault - one of his carrier bearings collapsed and the backlash went way out of spec, combined with the detroit it was only a matter of time!