[mrw82]

Weighing up my options in a WT diff swap.

Current setup is 1 litre, 5 speed gearbox, 4.16 transfer gears (s1's), and 4.55 diff gears. Currently 5th gear at 100 it sits on 4000rpm. But to keep it simple, in 4th gear (1:1 ratio) it does 5000rpm at 100km/h.
This gearing works perfectly for my needs. On road drivability is great, off road crawl is perfect for what I drive.

Now, my options are:
Maintain current transfer gearing and fit 4.6 diff gears from LROR

Fit 3.7 or 3.9 diff gears and change the transfer gears to get the right gearing again So question being what transfer gears would work best with each ratio to get back to (or close to) 5000rpm in 4th gear?

[Matthew]

http://www.4lo.com/4LoCalc.htm

[masterA]

mrw82 wrote:

This gearing works perfectly for my needs.

Why change if it's perfect for you now?!

As an example, I've got 4.11 diffs with 5spd box.....4.9 reduction on 31's and at 100km/h it sits just over 3,500rpm and at 110km/h it sits at 4,000rpm

The best part about it is that the speedo is SPOT ON for 60km/h to 100km/h

[neofitou]

I would say he must have 1l Diffs with LJ RP, but wants WT diffs that they dont fit into. Thats why.

Why do you want to swap from 1L diffs? are they broken or something?

If you do change to WT diffs I would leave whatever is in them (3.7s) and change the TC gears.
Another option while your at it to change the TC case to a Wide track one, this way your all 1.3 from the front of the gearbox and there will be no adapteryness or smaller 1L driveshafts etc, selling all the 1L stuff.
I had 5sp>6.5s>3.9s>31s. was a tad overgeared but perfect for me and would have suited the GTI engine well if I had got around to fitting it.

[royce]

Matthew wrote:

http://www.4lo.com/4LoCalc.htm

Quickly off this link (becuase nobody else seems to have read the post)

if I asusmed 1:1 trans gearing for both, 4.16 transfer and 4.55 diff, I get 18.928
6.5 transfer and 3.7 diffs, 24.05
5.2 and 3.7 19.24

so some series 2 and WT diffs would work out close, is that cheaper than a aset of 4.6 gears from a few vits though?

NFI what those combos would do in high range though, I wiped my memory of sierra ratios years ago

[Matthew]

I was working on the basis of "teach a man to gear"

In this case it would be best for the op to use the "Find RPM" calculator.

[royce]

Matthew wrote:

I was working on the basis of "teach a man to gear"

In this case it would be best for the op to use the "Find RPM" calculator.

wasnt bagging you, you were helpful

[Matthew]

All good mate, didn't think you were.

[Jackson]

I worked mine out ages ago, and you didn't mention your tyre size so can't really say what will work for you.

This gear calculator is good.
http://www.grimmjeeper.com/metric_gears.html

Here is all the high range ratios for different gears.


And I think 5th is about 0.875.

With a 1ltr --> 5 speed box --> 6.5's --> 3.9's --> 30's. I was looking at about 4000 in 5th and 4600 in 4th to do 100.

[mrw82]

Thanks for the responses guys. Jackson that gear calculator is brilliant, so easy to use and clear to see the variations. I've seen that ratio chart before but couldn't find it. I'll be downloading and saving it this time.

It definitely answers my questions. From what I've now worked out (and Jackson's calculations confirm) 6.5s in the transfer case will drop the revs at 100km/h from 5000 to 4600 which is too much of a change for my liking, and then I end up with low range gearing which is too low, the other transfer ratios were no good either.
So it looks like leaving the transfer case alone and just playing with the diffs is my best option. Low range diff gears are 4.57 (not 4.6 like I originally thought, minor difference anyway)

As for the questions of why, I have 1 litre (narrow track) diffs and want to go to wide track diffs. I currently run wheel spacers and whilst I've had no trouble from them I'd like to get rid of them. Eventually I want to get airlockers, which I can not do on 1 litre diffs.


1 more question for those in the know, is the spline on the diff pinion shaft the same for 1 litre and 1.3, Will I be able to install 1 litre flanges to the WT diff?

[Jackson]

I was told the spline on the pinion is not the same.

You can change the yoke on your tail shaft at the uni joint to WT ones by using two of the caps of a 1.3 uni joint (they are the same size but have a different circlip arrangement). Thats what I did. Or you could look at getting a WT tail shaft extended.

Is there a Vitara ring and pinion you can use? There is 4.66 ones or something?

[mrw82]

I was aware of doing a half and half uni, just hoping I didn't have to.

Yes vitara 4.6r&p would work, but I remember tanshi having a lot of trouble trying to track some down. And for the price of $189usd per diff from low range i'd be happier knowing that what I'm putting in isn't already half flogged out.

[Scrawny]

mrw82 wrote:

I was aware of doing a half and half uni, just hoping I didn't have to.

What's the issue with running a half/half? They take the same uni so it's easy enough to carry a spare

[mrw82]

I guess its not a big issue and what I'll end up doing. And one uni of each type will do the unis at both diffs, so its no extra cost. I was just hoping 1 litre flange would fit, to keep it simple more than anything.

[just_cruizin]

if the 1lt flange is the same as the NT flange you could sway the WT pinion flanges for NT and use those, I'd gladly sway some.

[Jackson]

My 1ltr flanges were a different size to 1.3 NT. Type 3 may be different or something?