Thread: Fabricated 4WD Diffs based on the Ford 9"

Originally Posted by uninformed

anything can be broken!

but in saying that I would think that a well built ford 9 should handle the work. I would stay away from D60 as they are heavier and lower. I think you will find that the 450 and up have D70 or even D80. Then of coarse there is other brands like corparte 14 bolt and Steriling.....

I thought wheel track was based on the vehicle the axle is to mounted to, not from???? I could well be wrong.

BTW, my opinons are only based on what I have read on Pirate4x4 etc, I have no hands on experience with F9 or D60 etc....

I just rock MD Rover and Sals

I agree, I think a F9 centre with D60 knuckles and CV's would be the best option, seems to be the best of both worlds.

The 50mm increase in wheel track in the rules appear to be in relation to the rims used and the fact the increase places additional load on the components.

It seems that if the diff / axle substitution is approved the additional 50mm track increase then applies to the new components.

if that is true, that is good news

I tried to post up some pics I have of 9" in the Isuzu section but get the message they are already posted under Diff Ratios

IIRC the F trucks with the solid front axle used a high pinion D44 front diff.
The big problem is that it goes down the wrong side of the chassis.

Originally Posted by Ancient Mariner

I tried to post up some pics I have of 9" in the Isuzu section but get the message they are already posted under Diff Ratios

When that happens, you are able to link to the already posted pics using (img)...link...(/img) Note replace the ( and ) parenthesis/brackets with [ ] square brackets

Originally Posted by CJT

...

It seems that if the diff / axle substitution is approved the additional 50mm track increase then applies to the new components.

That is the way I read the NCOP, but not how I read the QLD regs over riding parts of the NCOP.

I will have to check when I have more time, but from memory it is very clear that the 50mm increase applies to the original track, and it is out of the engineers hands to increase it further.

This is an issue for me. I'm resigned to not getting my bushie registered in QLD because of this - a lot of $$$$ in the portal axles.

When I moved to QLD, I bought with me stronger axles based on 105 series Landcruiser, with air lockers and longfield cv's, etc. These were in the bushie before I changed it to portals. I wanted to put these under my 120, and knew QLD was intending to adopt the NCOP. I didn't anticipate they would over rule that part of the NCOP.

So now I still trying to work out what to do to put stronger axles under my 120. Because of other issues, I need a strong rear end to replace the salisbury, which I can't easily use in my case (I don't particularly like it anyway). I could shorten my 105 axle but then I have to depend upon custom half shafts that can't be replaced with stock shafts that can be found almost anywhere. The other option is to get some custom wheels made with much more offset to reduce the track, but that will make my front freewheel hubs very exposed to rocks, and worsen the loads on the steering (scrub radius) and wheel bearings.

If you are right, it will make a great deal of difference to me, but I fear you are too optimistic. I look forward to being corrected.

I am not familiar with 105 axles but most diffs have a long and short axle .You cant rework the housing and use two short axles? You can educate me slightly with turbo info but wasting your time with computor talk but thanks anyway

Noel

Hi John,

Further to what Noel suggests if you are using portals could you not have the differential almost centralised. Late 1970s/80 F100 9inch 31spline (and the rarer 9 3/8inch diffs and no doubt others) have the differential quite close to the centre of the vehicle so they use two axles of the same length. This is apparently better to reduce harmonics in the rear tailshaft with the slight offset.

Not sure about the rest of your drivetrain so I suppose the only issue then is a centre drive to rear transfer case rather than an offset one. This could help you reduce the overall width increase with the portal axles. Does that make sense?

Bob