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Diff Gear Ratio's

Posted: Wed Jun 11, 2008 1:21 pm
by g35me
Is it possible to get away with 4.11 front diff and 4.10 rear diff ratios on a constant 4wd with centre diff lock (i.e 80 series)?

Posted: Wed Jun 11, 2008 1:23 pm
by ISUZUROVER
Yes. that difference is probably less than the variation in tyre diameter front-rear.

Posted: Wed Jun 11, 2008 3:19 pm
by dank
i think redneck had something similar going on with his rangy.

check out diff gears companies from the states. It might be cheaper to import a new set. Make sure to shop around though. try getting them from an western us state to reduce shipping. USPS is cheaper than UPS, but UPS more realiable with tracking numbers etc....

Posted: Wed Jun 11, 2008 3:29 pm
by dogbreath_48
dank wrote:i think redneck had something similar going on with his rangy.

check out diff gears companies from the states. It might be cheaper to import a new set. Make sure to shop around though. try getting them from an western us state to reduce shipping. USPS is cheaper than UPS, but UPS more realiable with tracking numbers etc....
Someone like locktup4x4.com.au could get them from the states for you, hassle free. I assume you're planning on running an older diff in the rear?

Posted: Wed Jun 11, 2008 5:13 pm
by want33s
4.10:1 = 41 crownwheel teeth divided by 10 pinion teeth

4.11:1 = 37 divided by 9.

I don't think I'd try and match these two in a FULL TIME 4wd.
Part time would be OK I'd reckon.
Jas.







http://www.difflap.com.au/ratios/s-y.htm

Posted: Thu Jun 12, 2008 7:20 am
by Ruffy
want33s wrote:4.10:1 = 41 crownwheel teeth divided by 10 pinion teeth

4.11:1 = 37 divided by 9.

I don't think I'd try and match these two in a FULL TIME 4wd.
Part time would be OK I'd reckon.
Jas.







http://www.difflap.com.au/ratios/s-y.htm
X2. I wouldn't recommend it on a constant.

Posted: Thu Jun 12, 2008 8:19 am
by g35me
This guy says he has sold heaps of them:

http://cgi.ebay.com.au/TOYOTA-LANDCRUIS ... dZViewItem

I went down to pick them up as they sell these out of a workshop in Tyabb and when I got it home and realised the ratio was wrong I rang them and suddenly it was double the price for the 4.10 ratio so I would have to pay the difference, hmmm something fishy going on.

Then the guy who runs the workshop spoke to me and said he puts them into 80 series all the time and you can get away with a 10% difference in ratios and that is only 1% so there is no problems.

I then spoke to the owner and said I would fit them but if anything bad happens they have to replace them with the correct ratios and all the labour for free which he agreed (on the phone, reality may be a little different).

Posted: Thu Jun 12, 2008 10:24 am
by Ruffy
g35me wrote:Then the guy who runs the workshop spoke to me and said he puts them into 80 series all the time and you can get away with a 10% difference in ratios and that is only 1% so there is no problems.
:shock: I'd be curious to know how long the centre diff lasts when you're doing lots of highway work. It'd have to be working overtime to compensate.

Posted: Thu Jun 12, 2008 10:49 am
by g35me
The centre diff lock in an 80 is only engaged when offroad, not with normal highway use.

Posted: Thu Jun 12, 2008 11:04 am
by PacMan
Hi g35me,

have a look to that: http://www.outerlimits4x4.com/phpBB2/vi ... p?t=130440

Greetings
Chris

Posted: Thu Jun 12, 2008 12:13 pm
by g35me
PacMan wrote:Hi g35me,

have a look to that: http://www.outerlimits4x4.com/phpBB2/vi ... p?t=130440

Greetings
Chris
Thats a bugger

Posted: Thu Jun 12, 2008 12:25 pm
by Ruffy
g35me wrote:The centre diff lock in an 80 is only engaged when offroad, not with normal highway use.
That's exactly my point... the diff will be working the whole time as it's not locked.

Posted: Thu Jun 12, 2008 5:08 pm
by RED60
g35me wrote:
Then the guy who runs the workshop spoke to me and said he puts them into 80 series all the time and you can get away with a 10% difference in ratios and that is only 1% so there is no problems.

I then spoke to the owner and said I would fit them but if anything bad happens they have to replace them with the correct ratios and all the labour for free which he agreed (on the phone, reality may be a little different).
It's only 0.25%. I personally don't think it would be a problem, especially if only engaged offroad...

Posted: Thu Jun 12, 2008 11:00 pm
by g35me
I couldnt help it so i went and bought a new diff to take out the correct gears set. Anyone want to buy a brand new set of 4.11's :)

Posted: Fri Jun 13, 2008 7:12 am
by Ruffy
RED60 wrote:It's only 0.25%. I personally don't think it would be a problem, especially if only engaged offroad...
It's constant 4wd

Posted: Fri Jun 13, 2008 10:29 am
by Tiny
Ruffy wrote:
RED60 wrote:It's only 0.25%. I personally don't think it would be a problem, especially if only engaged offroad...
It's constant 4wd
yes, but to allow constant 4wd there is a diff fitted in the drive line meaning the poer is transfered to the the front or the rear, what ever has the least resistence, it is only locking the front and rear together when the difflock is engaged for offroad use

Posted: Fri Jun 13, 2008 1:01 pm
by HSV Rangie