4:6 dif ratio's

[UTEGQ]

hey guys,
Can you all tel me the good and bad things that swaping my 4:1's to 4:6's. I'm running 35's. would it knock up on hills quicker so i'd be going down gears, would i be rideing my clutch too much when doing tricky slow rocky 4wding.
all info appreciated cheers

[vanbox]

4.6 will assist the fact you have bigger tires.

you will accelerate quicker, but rev harder for the same speed.

While not exact, 4.6 is arguably the closest ratio for 35's.

I have 4.6 in my GU ute with 35's which I may change back to 4.1 as I am putting a new motor in and it might like a lower ratio. Not sure til I drive it.

Your clutch will definitely thankyou for it. And you will be slower in low range.

[turbo gu]

I would run 4.3s not 4.6s on 35's if you want to do any sort of long distance road driving!
I have had both in a GU wagon and very happy with 4.3s over the 4.6s

[young pup]

i was thinking of putting in 4.6's, then i got told my truck will rev too high on the road ( i have a tb42), then i got told to put in 4.3's because its a good inbetween ratio that illiminates the sluggish feeling but still keeps the revs at a good rate... then some one else tells me that im wasteing my money putting in 4.3's beacause your gain is hardly noticeable...


so im in the same boat people are telling me mixed things... im leaning towards 4.3's as mine is a daily driver on 35's and i do like to do lots of trips...

[shw337]

i went for 4.1's to 4.6's is wasome offroad and revs around 2200(giv or take a smidg) at 100.
have been tryin to go back to 4.3's but no one will swap..

[A.J.]

Same here, I've got 4.3s and I'm very happy with them! Speedo is spot on too!

(TD42 aftermarket turbo on 35"s)

[GQsh0rty]

Ive had 4.3 and now have 4.6's
prefer the 4.6's havent even noticed my revs changing and have run 35's on both. 5th gears just keeps pulling up any hills on the road and low range you crawl

[Screwy]

I had 4.1s and 35s with no transfer gearing my my GQ shorty for ages.
Its a TD42 after market turbo....

When on 4.1s i was under powered, had far less ability to tow weight up hills and due to this my exhaust temps ran warmer cause the motor worked harder....
Offroad my clutch hated me and cause me much trouble.....
At 110kms an hour my motor ran warm after awhile and i was sitting at about 2100 RPM i believe

I put 4.6s in recently and all i can say is, wow what a difference...

My acceleration is MUCH better, I have the power i should up hills, my exhaust temps run cooler up hill and while towing....
Even at 110, while i rev MUCH higher at about 2600 RPM ( so not so good for long distance road kms for fuel issues ) My motor actually likes running at the higher RPM on the high way more, my exhaust temps are way lower ( about 100 degrees ) at the same speed and the motor isnt struggling to hold that speed like it previously used to.....

Not to mention offroad a massive difference in low range, i still run too high in low range but its much more manageable on my clutch now.

I would never go past 4.6s for a truck you only tend to use around town and to go to and from 4x4 tracks and on weekends.... etc

But if you want something in the middle cause you tend to do more road and highway kms then offroad then 4.3s would be the go and put some reduction gearing in your transfer to help you offroad....

Screwy

[young pup]

what ratio do you guys recommend for carby tb42? i can get two complete 4.3 diffs for 700 bucks or two complete 4.6 diffs for 990 bucks... nissan wants $1250 for just rear ring and pinion..

i really cant afford to make a wrong choice

[Screwy]

what sort of driving do you do???

on 4.6s your carbi TB42 will be even worse on fuel down the highway.... better offroad and better acceleration and towing abilities....

If you dont do huge kms in it and do a fair amount of offroad work 4.6s are the choice.....

[young pup]

it is my everyday driver aswell as my play truck... but ye i plan on doing a few trips to hit up some tracks...

will 4.3's make a noticeable difference? southern diffs told me ill only gain an extra 200 revs?

[Screwy]

it is my everyday driver aswell as my play truck... but ye i plan on doing a few trips to hit up some tracks...

will 4.3's make a noticeable difference? southern diffs told me ill only gain an extra 200 revs?

very very marginal.

4.6s at 100kms make about 500 rpm difference so generally you can assume its about 100 rpm per 0.1 gear change..... 4.1 to 4.6 about 500 rpm. 4.1 to 4.3 about 200 rpm.....

Your offroad ability will be an unnoticable difference, and your on road ability will only be marginal, will stop it feeling quite so sluggish up hills but you may not even notice a difference.

If you do highway kms and are set on diff gears 4.3s are better, but you will still need transfer gears offroad and your speedo will still be out by alot...

4.6s also almost brang my speedo back to correct.... its only about 5kms out ot my GPS at 100km/h now. was like 20km out before.

Screwy

[young pup]

would 4.6's be bearable for long distance? i used to drive a 2.8 hilux and it reved pretty high down the highway.

im just tossing up wheather i could tolerate 4.6's down the highway or not

[Screwy]

would 4.6's be bearable for long distance? i used to drive a 2.8 hilux and it reved pretty high down the highway.

im just tossing up wheather i could tolerate 4.6's down the highway or not

only you can answer that..... its the only draw back of them

[young pup]

i was afraid you would say that.. i wish there was an in between 4.3 and 4.6 diff ratio

[351ciofgrunt]

Go 4.6

Your low range will thank you for it.

[turbo gu]

Go 4.6

Your low range will thank you for it.

If you that worried about low range put transfer gears in!

4.3 to 4.6s aren't really going too make that much difference to low range!!

I would go 4.3s and save for transfer gears. Best set up in my mind.

What you need to do is work out were you cars sits at comfortable in the rpm range at 100km/h and choose the gears that will put you in that rpm range in 5th gear.

[SIM79]

I would go 4.3s and save for transfer gears. Best set up in my mind.

x2 4.3s Thats what I am going to when my 35s arrive.

[5inchgq]

what about 4.3's with 33's and TD42t ?

[young pup]

What you need to do is work out were you cars sits at comfortable in the rpm range at 100km/h and choose the gears that will put you in that rpm range in 5th gear.

thats a good idea, ill try that tomorrow... first week of my patrol on the road fuel costs are going to kill me on apprenticeship wages far out.

[Glennb]

what about 4.3's with 33's and TD42t ?

your revs should be around the 2352. Im going 4.6s with 33s but I have a 4.5 petrol auto, so it will be reving around the pefect rev range of 2070 @100kph

[turbo gu]

what about 4.3's with 33's and TD42t ?

your revs should be around the 2352. Im going 4.6s with 33s but I have a 4.5 petrol auto, so it will be reving around the pefect rev range of 2070 @100kph

thats a big jump from 3.9s to 4.6s for 33s!!! i think your calcs might be out by a bit!!! i reckon it would be over 3000rpm

[Screwy]

what about 4.3's with 33's and TD42t ?

your revs should be around the 2352. Im going 4.6s with 33s but I have a 4.5 petrol auto, so it will be reving around the pefect rev range of 2070 @100kph

thats a big jump from 3.9s to 4.6s for 33s!!! i think your calcs might be out by a bit!!! i reckon it would be over 3000rpm

The calcs wont be right......

Mine on 4.1s and 35s was 2100 rpm at 100k approx
mine now on 4.6s and 35s is 2600 rpm at 100k approx.

If your going from 3.9s to 4.1s id guess based on my results a 700 rpm change and your only going 33's not even 35's which will make it even worse......

for a 3.9 ratio truck on 33's, you need to go 4.3s not 4.6s

[Glennb]

Gu turbo, I will re check my calculation but going from 1725rpm @ 100kph to over 3000 is a huge jump, mine is an auto with a final gear ratio of .694 not .850 like the manuals.

screwy, from the calculator I used your 4.11 calculation earlier seems closer to the speed at 100kph and the 4.6 calculation was done at 110kph.(I used .850 5 gear final ratio and 34.8" for tyre)

Currently my GU 4.5 AUTO revs at 1725rpm in OD at 100kph on 32.8" tyres which is close to what the calculator has estimated too, around 30rpm off.
figures I get on calculator
100kph-3.9diff-.694 final trans ratio-32.8" tyres=1746rpm
100kph-4.36 diff-.694 final trans ratio-32.8" tyres=1952rpm
100kph-4.62 diff-.694 final trans ratio-32.8" tyres=2069rpm

I used this calculator
http://izook.com/gearcalc.htm
I maybe doing something wrong and happy for anyone to correct me and if you have an auto and have different figure please let me know cos its alot of money to stuff up.

[zookimal]

Sounds about right.

4.6 is about 118% of the original 3.9
4.3 is about 110% of the original 3.9

[Glennb]

cool

has anybody who has an auto put 4.3 or 4.6s in their truck. Is there any negative effects with the auto?
Cheers

[Jake GQ..]

i got 4.6 put in my gq about two weeks aga i am running 36 peds it is awsom it pulls like it has 31s

[OGJON]

hey ppl I'm picking up my '98 GU 4.5L Auto this week from the dealer
is it correct that it should have 3.9 difs as standard?
It currently has 2" lift on 31" A/T's I'm wanting to run 33" muds for off road & do transfer gears as well, which diff ratio should I change them to?
Will be our daily driver & weekend off roader as well as our touring rig.

would I be right in thinking 4.3 diff gears be the ones to get?

I'm in Newcastle nsw anyone recommend where to get the diff gears?
& approx how much $$?

[shannonpacher1]

i got 4.6's...never look back!

[boost is good]

cool

has anybody who has an auto put 4.3 or 4.6s in their truck. Is there any negative effects with the auto?
Cheers

running 4.3 gears & 33" tyres on my tb42 auto GQ .. better acceleration, better economy, runs slightly cooler and doesnt jump back gears at the slightest hill

in short no