Diff Strength

[Cory]

Hey,

My overlander replica is fitted with Holden diffs, and from what ive seen the originals where fitted with DANA 60 and 44 diffs,

So Im wondering how a holden 10bolt diff compares to the DANA 60 and 44 diffs, and what sort of torque would I need to break the 10 bolt diff?

Thanks

Cory

[Gwagensteve]

Is your car a dark red /purpleish panelvan with a 253? A one time member of the Zook club in melbourne here had one with a 253, trimatic and 10bolts front and rear.- I think the front was some sort of odd custom thing (only saw it at night and the owner didn't have it for long)

I guess it depends on how hard you are on it, but generally, 10 bolts are not considered as strong as a D44. A 35" tyre limit is the general consensus in the US. Also, if they are "holden" 10 bolts, I am guessing they have prettly tall gears in them. The car I went in certainly had very tall gearing.

A 10 bolt is WAAY weaker than a D60, however, I thought that Overlanders had 44's front and rear. Saw an ad in a mid 80's 4x4australia (I think) from wen arthur hayward was retiring/cleaning out his shed and he was selling a couple of 60's, so maybe some if them had 60's.

Personally, It light be easier to build it with landcruiser or patrol stuff than try and emulate an overlander with 44's/60's. These will be pretty expensive to build in australia.

[daddylonglegs]

When I was rebuilding diffs at Jack Mcnamara years ago I saw lots of Holden Salisbury 10 bolt diffs with pinion failure. even many of the ones that came in just for new bearings had hailine cracks radiating frm the pinion centre out to the teeth roots, so if reliability is what you want forget these and go for either GqGu Nissan or 80 series Cruiser assemblies.
Bill.

[Cory]

My car is a yellow wagon with a 253, trimatic and 10bolts front and rear.- The front is custom, 10 bolt diff with Landcruiser outer bits, and cut down holden leaf's, so it might have been made by the same guy.

This car does have very tall gears, the D60's where for sale in a kit from Arthur Hayward in an add from a Bushdriver mag from 84 (it came with the car)

Why would 44s/60s be so expensive?

If going to a complete landcruiser diff I suppose the only difference would be its width, and the shafts, how strong are the Landcruiser diffs? Would they compare to 60?


daddylonglegs: As your experienced with holden diffs do you reckon it would be cost efficient to beef up the holden diff to what a landcruiser diff could handle?

thanks guys

Cory

[daddylonglegs]

Cory, I think the 10 bolt failures I described were more a production problem with heat treatment or gear cutting than a design fault, so unless GMH has addressed the issue in the 15 years since I last rebuilt a Holden diff, then there isn't much you can do.
Landcruiser diffs are easily strong enough. They have very similar size ring and pinion to a D60. Nissan diffs are also very strong and may suit you better because the rear diff is centred.
Bill.

[Cory]

thanks daddylonglegs, my front diff actually sits to one side, and I have a nine inch laying round here, would their be any problem with using a landcruiser front diff and 9inch rear? provided they had the same ratio?

Thanks

Cory

[daddylonglegs]

No problem with the 9" in back Corey, but unless built up with aftermarket bits, ie nodular iron housing, steel top hat if limited slip, and solid pinion bearing spacer, the 9 inch is overated and not as strong overall as a Nissan or Toy.
Bill.

[CRUSHU]

No problem with the 9" in back Corey, but unless built up with aftermarket bits, ie nodular iron housing, steel top hat if limited slip, and solid pinion bearing spacer, the 9 inch is overated and not as strong overall as a Nissan or Toy.
Bill.

I find that a strange comment to make, as my brother has a drag car, capri, with over 600hp. it has a 6200rpm stall convertor with trans brake. it has 32" x 13" wide slicks.
it runs a standard falcon housing, single rib non nodular carrier, and a thin wall 35 spline spool with standard size bearings. it had aftermarket 4.8 gears, not pro gears. it does have an aftermarket alloy pinion support.
i agree with the lsd hat, and solid pinion spacer. although most 9" in the 4x4 application would run a spool (mini or full) or a automatic locker of some kind, lockright or detroit.
its strange, but i have not seen any other diffs in the drag racing scene, from a vehicle, other than hilux diffs in old 6 cyl lightweight dragsters, or dana 60's in old school prostockers. now a gq diff is only $500 or so, a lot cheaper than a 9". im sure this would have filtered thru to the diff and chassis builders.

[big red]

No problem with the 9" in back Corey, but unless built up with aftermarket bits, ie nodular iron housing, steel top hat if limited slip, and solid pinion bearing spacer, the 9 inch is overated and not as strong overall as a Nissan or Toy.
Bill.

I find that a strange comment to make, as my brother has a drag car, capri, with over 600hp. it has a 6200rpm stall convertor with trans brake. it has 32" x 13" wide slicks.
it runs a standard falcon housing, single rib non nodular carrier, and a thin wall 35 spline spool with standard size bearings. it had aftermarket 4.8 gears, not pro gears. it does have an aftermarket alloy pinion support.
i agree with the lsd hat, and solid pinion spacer. although most 9" in the 4x4 application would run a spool (mini or full) or a automatic locker of some kind, lockright or detroit.
its strange, but i have not seen any other diffs in the drag racing scene, from a vehicle, other than hilux diffs in old 6 cyl lightweight dragsters, or dana 60's in old school prostockers. now a gq diff is only $500 or so, a lot cheaper than a 9". im sure this would have filtered thru to the diff and chassis builders.

i'd be thinking the ratios dont suit and/or the weight is too much

[CRUSHU]

No problem with the 9" in back Corey, but unless built up with aftermarket bits, ie nodular iron housing, steel top hat if limited slip, and solid pinion bearing spacer, the 9 inch is overated and not as strong overall as a Nissan or Toy.
Bill.

I find that a strange comment to make, as my brother has a drag car, capri, with over 600hp. it has a 6200rpm stall convertor with trans brake. it has 32" x 13" wide slicks.
it runs a standard falcon housing, single rib non nodular carrier, and a thin wall 35 spline spool with standard size bearings. it had aftermarket 4.8 gears, not pro gears. it does have an aftermarket alloy pinion support.
i agree with the lsd hat, and solid pinion spacer. although most 9" in the 4x4 application would run a spool (mini or full) or a automatic locker of some kind, lockright or detroit.
its strange, but i have not seen any other diffs in the drag racing scene, from a vehicle, other than hilux diffs in old 6 cyl lightweight dragsters, or dana 60's in old school prostockers. now a gq diff is only $500 or so, a lot cheaper than a 9". im sure this would have filtered thru to the diff and chassis builders.

i'd be thinking the ratios dont suit and/or the weight is too much

4.11 4.3 and 4.6 are the most common drag racing ratios. they would also weigh similar.

[Gwagensteve]

I have though simiilar stuff In relation to airlocker diffs over the years - they are the perfect street/strip diff, and low and behold, Martin Donnon in Zoom has just done an article on fitting selectable lockers to drag cars.

Don't forget that many rotary and 4cyl drag cars run Hilux rear diffs.

I can think of two reasons why the drag scene doesn't use 4WD diffs:

often 5 on 5.5 or 6 stud patterns

And low availability of lightweight heavy duty parts such as spools. The drag scene always revolved around the 9" after some 40 years of motorsport support. Why reinvent the wheel? (pardon the pun )

The 10bolt set up you describe sounds pretty similar to the one I saw.

Personally, I would go with GQ diffs for the overlander project. I don't think it is feasible to beef a 10 bolt to match their strength.

I would leave the 9" to the drag boys. I can se little advantage to use it as there will be some cost involved to get it to match whatever is inthe front, and on top of everything else, the pinion in VERY low and easy to damage in a 9"

[daddylonglegs]

Surprisingly the standard 9 inch diff, in spite of its reputation among the hotrod and race set is the only diff in the world I am aware of that has a shitty old grey iron housing. you have to pay quite a lot for a nodular iron housing , if you can find one. A mate of mine with 9 inch diffs front and rear in a 6 cylinder Valiant powered Landrover blew his rear diff to pieces with the pinion gear and part of the grey iron housing dangling on the end of the propshaft after attempting to climb a simple 2 foot high bank.
He is a diff specialist with Jack McNamaras and now runs a Dana 6o/Salisbury in the rear. But I will stick to the Nissan or Toyota recommendation.

Bill.

[Cory]

thanks guys

DANA diffs are off my list , 9 inch is virtually off my list..

Salisbury is still there cause its what I already have and I have 2 spares,

What kind of Patrol/Landcruiser diffs would you use and what sort of weight am I looking at? I dont mind my current 3.36 ratio but something higher wouldnt hurt.

Cory

[daddylonglegs]

I dont know the actual weights, but either Nissan or Toy axle assemblies would be lighter than the original Overlanders Dana 60 rear and possibly lighter than the front dana44.
Most common ratios are 4.1's .

[turps]

If you where to goto GQ diffs ratios are
3.9 - more commonly found in Mavericks
4.1 - Most common, fitted to both petrol and diesel's 4.2lt
4.3 - 3lt petrol patrol
4.6 - 2.8td

So if your where only after something abit lower the 3.9ratio would be perfect and cheap to get genuin 2nd ones, as most people who fit bigger tyres try to get something lower.

Nissan fronts are off-set to the drivers side and I think is a high pinion. Rear diff is centered.

[Jmcdonald]

Hi there,

I just wanted to back up the recomendations and add to the nissan GQ side of things all 4.2 diesel's from 88 to the mid 90's have got 3.9 ratios and are common enough to get, also the nissan GQ/GU diffs are far stronger than the toyota diff's and 9 inches availble in australia. The rear's are very strong with very large axcels but if you are looking for a super strong diff that you will never brake and is cheap "providing you have a mate who can import it for you" get a 14 bolt disk brake converted rear diff 4.11 from the states around $600 AU fully rebuilt about as strong as you can get with out going up to Rockwells 2.5 tone diffs :> Match this with a 4.11 GQ front diff and you could do this for under $2000.

Cheers,

Jeff.

Just remeber weaker diffs will cost you more in the long run :>