Diff Gears ???

BZINGA · 15-02-2012, 07:22 PM

Changing the diff gears in my ute is on my to do list but wondering what ratio to go .. either 3.9 or 4.11? Not much between them i realise but being an old school car owner i've had plenty of ratio's but with 3 speed auto's only so the AU being 4 speed what's peoples opinions?
Also this will throw the speedo out i'm guessing so what do i change to get it right again with the new diff centre?

Darren.

**SSD-85** · 15-02-2012, 07:26 PM

Whats the cars intended purpose? As 4.11s arent very streetable. And offer no real benefit on engines that arent extemely modified.

BZINGA · 15-02-2012, 07:40 PM

Quote:

Originally Posted by Scotty85

Whats the cars intended purpose? As 4.11s arent very streetable. And offer no real benefit on engines that arent extemely modified.

I barely drive it cause of my work truck so it's more of abit of fun streeter atm. It has extractors, cats, dumped exhaust atm .. i have another TB to put on and it will get a tune eventually but that's about it for now.

**SSD-85** · 15-02-2012, 07:48 PM

IMO, I think 3.7 or 3.9s would more than suffice.

POELWYK · 15-02-2012, 08:05 PM

i run 3.9's in my au Lots of fun to be had

) just sayin

BZINGA · 15-02-2012, 08:14 PM

Quote:

Originally Posted by Scotty85

IMO, I think 3.7 or 3.9s would more than suffice.

It runs 3.45 factory so nearly 3.5, 3.7 wouldn't be worth it i reckon ..

Quote:

Originally Posted by POELWYK

i run 3.9's in my au Lots of fun to be had

) just sayin

I'm leaning this way atm ..

StealthAu · 15-02-2012, 08:20 PM

Quote:

Originally Posted by Scotty85

Whats the cars intended purpose? As 4.11s arent very streetable. And offer no real benefit on engines that arent extemely modified.

Sorry buddy but you clearly aren't talking from experience. 4.11's are perfect for the street, just not so crash hot for highway trips. And even on a bog stock engine, they are the most bang for buck modification you can think of.

To the OP, drive your car on the highway in thrid, if it isn't too lound and you can live with less then 400km to a tank on the highway then get the 4.11's well worth it.

BZINGA · 15-02-2012, 08:27 PM

Quote:

Originally Posted by StealthAu

Sorry buddy but you clearly aren't talking from experience. 4.11's are perfect for the street, just not so crash hot for highway trips. And even on a bog stock engine, they are the most bang for buck modification you can think of.

To the OP, drive your car on the highway in thrid, if it isn't too lound and you can live with less then 400km to a tank on the highway then get the 4.11's well worth it.

Like i said earlier i don't drive it much and i'm not stressed about fuel economy .. it's just something to add for more fun

StealthAu · 15-02-2012, 08:46 PM

Cool, if you want more fun get the 4.11's. I know people who fitted 3.9's to later swap them for 4.11's. I don't know anyone who hase gone from 4.11's to 3.9's.
Doesn't really matter how much you drive it, more what you do with it. If you use it for trips away you will want some decent mufflers and sound deadener, but around town it'll keep a smile stretched across your face.

BZINGA · 15-02-2012, 09:19 PM

What about the speedo? Running 4.11's & 20" wheels would throw it out a fair bit so what needs to be changed to get it accurate again?

StealthAu · 15-02-2012, 09:28 PM

You can get an electronic speedo corrector from jaycar, you need two of them though, one between the speedo drive and the dash, and one on the wire from the dash to the ecm. Or just the one will do if you plan on getting it tuned.

Legit290 · 15-02-2012, 09:35 PM

Quote:

Originally Posted by Scotty85

Whats the cars intended purpose? As 4.11s arent very streetable. And offer no real benefit on engines that arent extemely modified.

what you talkin about Willis???

BZINGA · 15-02-2012, 09:54 PM

Quote:

Originally Posted by StealthAu

You can get an electronic speedo corrector from jaycar, you need two of them though, one between the speedo drive and the dash, and one on the wire from the dash to the ecm. Or just the one will do if you plan on getting it tuned.

Cool, i'll pop into Jaycar tomorrow since i work next door to them lol ..

**SSD-85** · 15-02-2012, 10:19 PM

Quote:

Originally Posted by StealthAu

Sorry buddy but you clearly aren't talking from experience. 4.11's are perfect for the street, just not so crash hot for highway trips. And even on a bog stock engine, they are the most bang for buck modification you can think of.

By streetable I mean in all public road scenarios. Which happen to include Highways.

I know plenty of folk that wouldnt tolerate 4.11 for street use & are happy with 3.45-3.9. And they aint bog stock cars.

Like the OP wanted, I offered my opinion. Based on my experience, and I dont like 4.11. My argument for their suitability on an AUs stock engine is still valid, given that you hardly put that gearing to proper & full use. Thats not to say they dont offer an "improvement" to a style of driving, its just not something id personally would do.
Id still be more than happy with whatever the OP chooses to do, because its his car. And if he's happy, thats all that matters really.

BZINGA · 15-02-2012, 10:33 PM

Quote:

Originally Posted by Scotty85

By streetable I mean in all public road scenarios. Which happen to include Highways.

I know plenty of folk that wouldnt tolerate 4.11 for street use & are happy with 3.45-3.9. And they aint bog stock cars.

Like the OP wanted, I offered my opinion. Based on my experience, and I dont like 4.11. My argument for their suitability on an AUs stock engine is still valid, given that you hardly put that gearing to proper & full use. Thats not to say they dont offer an "improvement" to a style of driving, its just not something id personally would do.
Id still be more than happy with whatever the OP chooses to do, because its his car. And if he's happy, thats all that matters really.

I can see where your coming from Scotty, i used to have fun in my old mustang that ran a 5k stally, 4.11 mini spool around the streets when people would say surely not streetable but it was very easy to drive ... The AU with it's extra gear in the auto would bring the revs down enough to still be streetable even with the stockish motor to not hurt it and still have fun driving around. Engine plans may change later but atm it's just to give it a little more poke

StealthAu · 15-02-2012, 11:04 PM

Quote:

Originally Posted by Scotty85

By streetable I mean in all public road scenarios. Which happen to include Highways.

I know plenty of folk that wouldnt tolerate 4.11 for street use & are happy with 3.45-3.9. And they aint bog stock cars.

Like the OP wanted, I offered my opinion. Based on my experience, and I dont like 4.11. My argument for their suitability on an AUs stock engine is still valid, given that you hardly put that gearing to proper & full use. Thats not to say they dont offer an "improvement" to a style of driving, its just not something id personally would do.
Id still be more than happy with whatever the OP chooses to do, because its his car. And if he's happy, thats all that matters really.

A lot of poeple wouldn't tolerate them, they are a pain on the highway. Not dangerous or ill mannered, just annoying sitting in a car at 3000rpm for an extended period.
I have no idea what you mean by putting the gears to proper & full use, would love to learn more

BZINGA · 23-02-2012, 06:16 PM

What diff do i have in my ute? a 78 or 86 series?
I got a quote from Joe at GJ Diffs in Dandenong, i've used them a few times and he gave me a quote for $1200 .. said that's the best he could do but i haven't checked anyone else yet.
$700 for new gears
$500 for new bearings, seals & labour etc

BHDOGS · 23-02-2012, 08:22 PM

There's a guy selling 4.11 ute diff gears in the for sale section for 200

BZINGA · 23-02-2012, 08:34 PM

Quote:

Originally Posted by BHDOGS

There's a guy selling 4.11 ute diff gears in the for sale section for 200

Yeah i saw that but he says it's to suit a 6cyl diff.

BHDOGS · 23-02-2012, 10:39 PM

There's a difference? That can't be right for gears surly there interchangeable?

BZINGA · 23-02-2012, 11:43 PM

Quote:

Originally Posted by BHDOGS

There's a difference? That can't be right for gears surly there interchangeable?

Apparently they run 2 types of diffs .. a 78 series & 86 series but the diff guy said you can't tell until you see the crown for the type .. All new to me, i'm used to 9" diffs lol.

MGGT RAA · 24-02-2012, 01:26 AM

i street the **** out of my 4.11s... Even on the freeway, no huge difference. Its nothing like what the people who dont have them say about them what-so-ever. Theres no difference in price, so why the hell not! ;)

BZINGA · 24-02-2012, 06:39 PM

Quote:

Originally Posted by BHDOGS

There's a guy selling 4.11 ute diff gears in the for sale section for 200

Turns out my diff is a 78 series which i found out today but looks like these sold last night