rocky diffs

[cookiemonster]

what diff ratios do rockys come with and are they interchangeable?

[BundyRumandCoke]

The diesels are 3.3636. I dont know for sure what the petrols are, about 5.???, or maybe thats the Feroza. Anyway, AFAIK, the diff centres are not interchangable.

[RockyF75]

Where there any other ratio rocky diffs?

Cause i rang a wrecker today bout a new rear and the bloke said they have a rocky rear, year model unknown but he said the ration is 378 or 379 . 3.78379. maybe? I'm confused? He just said 378379, no points or nething, so i dunno whether it was 3.78 or 3.79 - OR- 3.78379... if that makes sense

[BabyGodzillaGTi-R]

I thought diesels are 3.3 and petrols 3.9?
That's according to the workshop manual.

And from this forum that's where i heard that u can plonk a 5.2 from a F10 and a 4.8 from a F20 Daihatsu apparently.
Sigh i want 4.8s........

[Spartacus]

And from this forum that's where i heard that u can plonk a 5.2 from a F10 and a 4.8 from a F20 Daihatsu apparently.
Sigh i want 4.8s........

ahha

[RockyF75]

BUMPITYD BUMP

NEED to know rather urgent, like, before tomorra, are the rocky ute rear diffs the same as the rocky wagons? I know they're sprung ova but are the center's interchangable? Same ratio's? This is all for a diesel BTW. The wagon's a F75 and i need to stick the F77 diff in it. I will start reading thru the manual now, but would be easier if sum1 just knew it

[tabrocky]

RockyF70, from what I have heard/read the F77 is same ratio as the F75 etc but uses different wheel bearings (roller bearings rather than ball bearings). Also my mate has got one and Im pretty sure its Spring Under at the rear, like the wagons... could be wrong though.
As far as overall width, mounting points etc... im not sure.

From a genuine daihatsu brocure on the rocky, it states the Diesel ratio as 3.909 and the Petrol as 3.363.
Now i might be wrong, but I reckon this brocure is arse-about.
I think the Diesel is the 3.363. It makes more sense this way because you'd expect the petrol to rev higher at 100km/hr say... than the diesel cos the petrol has more poke in the top end, where as the diesel is lower reving.

Anyone move or second this motion???....

Cheers.

[RockyF75]

Tabrocky, I stopped being lazy and checked the manual, the F70, F75 and F77 diesel's r 3.363 ratio.

What year model's your mates ute? Cause I know my mates got one and its SPOA rear , so I just assumed they all were. There's no way that petrol ratio's right, cant be higher than the diesel According to the wrecker I went to the one's he had were 5. something , which brings me to my great revelation... if anyone wants to a build a stricly offroad rocky, who say's you can't have crawl ratio's - Just get petrol diffs .. prolly have a top speed of about 60 though ... but i'm not sure if they guy know exactly what he's on about. In the manual it doesn't have a listing for petrol or diesel. Just say's F70, F75,F77....and I thought there were petrol F75's... which leads me to think both petrol and diesel's are the same ratio

+ one other thing that makes me think the wrecker was a bit off, is the Rocky diffs center's he had hangin up on the shelf where all pull out centers like a hilux or sumthing, but all 6-7 Rocky's i've looked at have a one piece diff housing, so you can't just pull out the centre without pulling the diff innards (pinion, gears etc etc) to bits
Do feroza's have a pull out center? This guy's really confused me now what the heck where those diff centers off???

[tabrocky]

RockyF70, My mates ute is an '89 model. Could have look at it last night to confirm SPOA/SPUA but i forgot... Sorry.
I will say that I dont know cos I don't want to leed you astray...

I dont think the petrol ratios could be 5.xxx. That seems much to high. I would say the 3.909 figure I got from the brocure is correct.
If it was 5.xx then if my F75 does about 2850rpm at 100km/hr, then the petrol (assuming the same gearbox) would be doing about 4200rpm which seems a bit to much and... not so economical me thinks.

All rocky live axels are Sailsbury style (pressed metal cover plate), not banjo style like hilux/cruiser/patrol where the pinion and centre is removed as a coomplete assembly.
If memory serves, I reckon the rear axel of the Feroza is banjo style (not the same as rocky)... so he may be trying to sell you one of those.

Also all petrol rockys are refered to as F8x (ie F85, F83 ?) as far as I know.
I cant see any reason why you couldn't fit the crown and pinon from a petrol rocky into a diesel as physically from the outside the diff's are identical. The only thing I can see stopping you is if they differ radically on the inside (ie different number of bolts in the crown wheel, axel splines).
Again I'm not 100% sure about this so I cant say for certain yes or no.

Hope this helps
Cheers.

[RockyF75]

Thanks tab, that part about salisbury/banjo diff now confirms my suspicion that;

a) the wrecker was stoned
b) the wrecker has no idea about daihatsu's (even though its a daihatsu wrecker)
or c) Both a and b - I'm going with this one

Just checked a feroza manual, they have 5.285 (F300's), and they have banjo style too. Sum great daihatsu wrecker i went too , doesn't know his rocky's from is feroza's.

[tabrocky]

Common problem.
Not many wreckers care much about Daihatsu's these days. And if they do it's only cos they know parts are rare so they can charge an arm and a leg for them...

Chasing an A/C thermo fan for mine at the mo. Best price so far is $55... not to bad but I havent seen the condition or how many k's on the vehicle its off.

Good luck with yours anyway.

Cheers.

[RockyF75]

Common problem.
Not many wreckers care much about Daihatsu's these days. And if they do it's only cos they know parts are rare so they can charge an arm and a leg for them...

This is from a daihatsu/zuki wrecker... and they seem to have been in business for quite a while too dunno how. Your right the arm and leg, I rang one other wrecker about the rear diff.... $660 yeah, it costs $550 to get mine rebuilt .

Whats worse is when I bought my rocky the guy had another perfectly good one there too, bit more rust and no rego, only wanted $500 for it but i had no where to keep it... if i had of known the parts situation, i woulda made the room sumhow

[BabyGodzillaGTi-R]

Why dont u find an F20 Daihatsu then?

[RockyF75]

Why dont u find an F20 Daihatsu then?

Didn't know they had the same diff

And as if they'd be easier to find anyways

[tabrocky]

This is from a daihatsu/zuki wrecker... and they seem to have been in business for quite a while too dunno how.

There is a simmilar Daihatsu/Suzuki wrecker hear in adelaide and I wouldn't touch them with a 10ft barge pole. Ridiculous prices.
Like i said before, if they know what there selling, be prepared to morgage the house...

In the words of a good aussie movie "Tell'em there dream'n"