[holdenrules]

Hey all got a 1.3 in my 1.0 nt Sierra ute. what's the best gearing for it diff wise and transfer. I want to be able to do 100 comfortably with out the engine screaming. It's running 235-75-15 muddies.

[SierraDan]

4.16 transfer and 3.9 diffs would be my suggestion.

[shep]

what size tyres are on it now? i would just slap some 30s on it and leave it stock as long as it is doing less then 4000rpm at 100kph it will be ok

[mnemonix]

In the flat old Northern Territory stock might be ok, but in the real world with hills I'd be more inclined to go with something like Dan suggested.
Going from stock to 235/75's absolutely killed my highway top speed on anything but flat ground.
Your NT ratios might be sufficient but id personally want more.

[shep]

dont you blokes actually read the info provided?
he has a 1.0 driveline so has a 1.0 transfer which is a 4.16 ratio and 4.11 diffs and possibly a 4 speed as well. on stock tyres it would be spinning at over 4000rpm at 100kph.

ie he has more high range reduction then a wt sierra with a 6.5 transfer

[SierraDan]

I took note of that. That's why I suggested 3.9 diffs. And because he has muddies he obviously goes offroad so the low range reduction with the 4.16 reduction gears is better than stock low.

[holdenrules]

I put the 1.3 in it with the 5 speed. It was out of a stock 88nt. Apparently there diffs have better ratio 3.9 so I should put them in? I got the original 1 litre diff and transfer in mine still and it screams on the highway. Seems like it has really short gears when changing. I do quite a lot of highway driving and a little off road. I would rather it better for on road rather then off road. So should I put the other cars 3.9 nt diffs in mine along with its transfer or keep my transfer and just put the diffs in?

[zooky08]

You would have to put the hole diff in as the centers won't bolt straight into your 1l diff housing.

[SierraDan]

Keep te transfer. Change the diffs to 3.9/3.7.

[JrZook]

shep wrote:

has a 1.0 transfer which is a 4.16 ratio

Really?

[shep]

JrZook wrote:

shep wrote:

has a 1.0 transfer which is a 4.16 ratio

Really?

Same high range as the 4.16

[Fatzook]

shep wrote:

JrZook wrote:

shep wrote:

has a 1.0 transfer which is a 4.16 ratio

Really?

Same high range as the 4.16

Not sure why you guys are confusing reductions gears with standard lowrange cases in a thread about highway driving

The 1L case is 12% lower in high range than the 1.3L case. This will make you rev higher on the highway. (~500rpm) If you want to drop the revs on the highway, swap in the 1.3L transfer.

[shep]

Fatzook wrote:

shep wrote:

JrZook wrote:

shep wrote:

has a 1.0 transfer which is a 4.16 ratio

Really?

Same high range as the 4.16

Not sure why you guys are confusing reductions gears with standard lowrange cases in a thread about highway driving

The 1L case is 12% lower in high range than the 1.3L case. This will make you rev higher on the highway. (~500rpm) If you want to drop the revs on the highway, swap in the 1.3L transfer.

Which is why I said to put bigger tyres on it.

[holdenrules]

Thanks for your help people. I'll put the 1.3 transfer and the 3.9 complete diffs in this weekend and see how it goes.

[zukmeista]

holdenrules wrote:

Thanks for your help people. I'll put the 1.3 transfer and the 3.9 complete diffs in this weekend and see how it goes.

Just do the diffs. Leave the transfer case alone as you will need the lower gearing to compensate for the larger tyres.

[rick1970]

I have 4.1 diffs and std 1.3 transfer in my 1.3 LWB with 235/75R15's. For hwy driving, a bit lower would be good. Maybe 3.9 diffs and 4.16 transfer. Swap just the diffs 1st and leave the transfer in place like Zukmeister said.