Runng Paj in permanent 4h mode

Post by **Ian Sharpe** » Fri May 23, 2003 6:26 pm

Hi guys,

I had a drive of my mates Toy just recently & was impressed by its road holding ability & handling. Its full time 4wd.

I can get the same effect by running my super select in 4h mode but wondered what would be the longer term problems from this if any.

More fuel useage, more front tire wear, more front end wear?? what do you guys reckon. I thought maybe not a bad idea since I dont use my Paj as a daily driver now.

cheers

Post by **redrocket** » Fri May 23, 2003 7:11 pm

What advantages to you forsee in doing this other than added traction in "low" traction conditions? Would this minor advantage weigh up against the disadvantage of increased wear and fuel usage?

Post by **Ian Sharpe** » Sat May 24, 2003 7:21 am

Well as I said I reckon that having the fron t wheels driving in 4h gives much better road holding & handling even in high traction conditions.

Post by **pajpwr** » Sat May 24, 2003 9:20 pm

Ian Sharpe wrote:Well as I said I reckon that having the fron t wheels driving in 4h gives much better road holding & handling even in high traction conditions.

Agreed, which is why I won't run a front locker. Arguably, there is reduced stress all round as 50% torque (or so) goes to the front.

I'd like to see how much less fuel is used. I doubt it would be significant.

My usage is 2WD, but as soon as I drive on wet roads, or dirt, or at high speed, I move into 4H unlocked.

Post by **redrocket** » Sun May 25, 2003 12:42 am

pajpwr wrote:
My usage is 2WD, but as soon as I drive on wet roads, or dirt, or at high speed, I move into 4H unlocked.

I personally prefer the drift style of driving i get when in 2h on dirt roads, especially with my right foot booted against the firewall. :finger:

Post by **Bitsamissin** » Sun May 25, 2003 10:37 am

True Ian, that in 4H (centre diff unlocked) that the handling is way better specially on twisty mountain roads.
I only ever used this function once or twice to see the difference.
Having manual hubs and a front auto-locker I have lost this function now but it doesn't bother me at all.
I would say you would use more fuel maybe 5% or so running in this mode permanently. When I fitted manual hubs I noticed better fuel economy when I had the 31"s.
Also the design of the t/case provides just enough slippage to prevent wind up when in 4H but I really don't know the long term effects of driving permanently in this mode. There will certainly be more wear and tear but to what extent ?? CV's, front diff, t/case centre diff and viscous coupling would all be working full time.
I personally wouldn't do it because I think it's not designed that way only for the odd occassion when extra traction is required. There is also the issue of speed and some were concerned about the ability to drive over 100km/h in this mode, it was a big topic on Trail Talk some time back.
My personal opinion is that you may end up cooking the viscous coupling and possibly the centre diff.

Post by **Ian Sharpe** » Sun May 25, 2003 5:21 pm

good points Frank,
BTW any new from ARB re front locker, I had an email some time back from Greg saying "soon there will be an announcment"

Have you had any further contact??

cheers

Post by **Grantw** » Mon May 26, 2003 6:55 am

Sooooonnnnn.....

Post by **Bitsamissin** » Mon May 26, 2003 6:47 pm

No Ian haven't heard anything more.
Through a contact I did hear that the engineer who was working on this project resigned and left a few weeks ago. This may set things back a bit ??
The other engineer (who I know reads this forum) will be snowed under coz of this but I believe he is a breathtakingly gifted locker engineer and no doubt will come through with the goods !!!
Do you think that was a good crawl job :roll:

Post by **pajpwr** » Tue May 27, 2003 8:28 pm

Does the Paj have a centre diff, or a viscous coupling? Why would it need both?

Post by **Bitsamissin** » Tue May 27, 2003 10:12 pm

Rob, it has both I'll post some pics tomorrow of them.
Centre diff for drive without t/case wind up and the viscous coupling for the 50:50 torque split.

Post by **Bitsamissin** » Wed May 28, 2003 6:20 pm

OK here is a pic of the super select centre diff (left) and the viscous coupling (right).

Post by **pajpwr** » Wed May 28, 2003 8:24 pm

Thanks Frank. So a pure centre diff wouldn't be 50/50? I expect the VC would also need to be locked or bypassed too, then?

That must mean most constant 4WD vehicles have a VC as well as a C/D.

I never knew that, and I know one mechanic that doesn't either, because I asked and he couldn't explain!

Post by **Bitsamissin** » Wed May 28, 2003 9:26 pm

Yes I'm sure they do.
When you lock the centre diff the VC is also locked out.
I think how it works is that you have a nominal amount of drive to the front but if the rear starts to loose traction the VC starts to lock up towards that 50:50 torque distribution.
The Gen 3 has a 33:67 torque distribution capability which further limits power loss through wheelspin.

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Runng Paj in permanent 4h mode

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