Need info on Landcruisers with Patrol Diffs...

[4stroker]

can anyone give me any info on this? ive read about it before but cant seem to find anything these days on this conversion...

mainly interested in late model utes being fitted with the beefier patrol front and rear diffs.

who does this sort of work? any links/phone numbers?

thanks, mark.

[1MadEngineer]

Just save your money!!! buy a set of longfields and some hub gears. a built toyota is stronger than anything Nissan!! and will be much cheaper!!!

apart from the Cal CVs the gq & gu are weaker than a toyota. they have no aftermarket steering upgrades, you can now buy trailgear 6shooter swivel hubs for toyotas, as well as chromo rear axles. Nissan rear axles are notoriously soft, many comp guys have to go to the H260 to get reliability.

[bj on roids]

yeah, whack in 80 series or 100 series diffs for width, and slip a GQ centre into a modded front 80 series housing. with longfield axles

nissan brakes and steering are rubbish

front diff centre is the business though!

[me3@neuralfibre.com]

yeah, whack in 80 series or 100 series diffs for width, and slip a GQ centre into a modded front 80 series housing. with longfield axles

nissan brakes and steering are rubbish

front diff centre is the business though!

Who does this mod and how much?

Thanx
Paul

[1MadEngineer]

yeah, whack in 80 series or 100 series diffs for width, and slip a GQ centre into a modded front 80 series housing. with longfield axles

nissan brakes and steering are rubbish

front diff centre is the business though!

c'mon BJ you know better than that!!!
you would be better putting a std 60 series front in it, the ctrs are every bit as strong as their nissan counterparts, except the rest of the diff is stronger!!!

[jessie928]

you can get the equivalent of longfields for the GQ-GU diff.
or retrofit the cruiser ones into them

sixshooter swivel hubs to fix a problem that the patrol ones dont have.

toyota centres are crap, especially the front.

brakes and steering are crap? heheh, just use the origional LC steering box, or the the late model brakes and box are plenty good enough

i dont see any competition ( or otherwise) patrols running any toyota running gear in them.

cheers,
Jes

[1MadEngineer]

you can get the equivalent of longfields for the GQ-GU diff.
or retrofit the cruiser ones into them

sixshooter swivel hubs to fix a problem that the patrol ones dont have.

toyota centres are crap, especially the front.

brakes and steering are crap? heheh, just use the origional LC steering box, or the the late model brakes and box are plenty good enough

i dont see any competition ( or otherwise) patrols running any toyota running gear in them.

cheers,
Jes

as i said the cal cv's are great , but you cant get high steer (decent stuff) for nissans, and the free wheeling hubs are crap ( once we upgraded to cal cv's we have blown 4 sets - as these seem to be the FUSE). Nissan diffs are very prone to bending at the knuckle/ ball neck as these are 5mm smaller in diameter than a toyota (which is a lot when they are on 55mm diameter). so its not really worth the effort because no matter what you do the equivalent toyota is more cost effective!!

[4stroker]

what would the best remedy be for a HDJ79 that keeps blowing the front diff centre? (transfer cases too!)

something to do with the pinion busting?

[jessie928]

what would the best remedy be for a HDJ79 that keeps blowing the front diff centre? (transfer cases too!)

something to do with the pinion busting?

sounds like driving style:)

actually, it mat be your pinion angle, do you have big lift?

you get plenty of air?

JEs

[DIRTY ROCK STAR]

wouldnt a solid pinion spacer be the solution??
i know with 80 series fronts they are highly recommended.

[me3@neuralfibre.com]

Is there any consensus on what exaclty the weakness is on the front diffs?

I have heard a lot of theories. Anyone care to explain and justify theirs?

Thanx
Paul

[RUFF]

Is there any consensus on what exaclty the weakness is on the front diffs?

They are simply too small for the application.

[me3@neuralfibre.com]

Is there any consensus on what exaclty the weakness is on the front diffs?

They are simply too small for the application.

Good cause I have heard

So it's not the diff housing flexing
It's not the 3rd member flexing
It's not the rotating assembly behind the ring gear flexing
It's not the bearings allowing alignment problems
It's not the crush tube in the 3rd member moving
It's not that the hypoid is being driven from the wrong side
It's not that the 1:4.3 ratio is too low resulting in a smaller pinion

It's simply that the 8" Ring is too small, depsite the hypoid being significantly stronger than the bevel geared landroveror the same? size.

That would match the failures I have seen.

Unlike the 7.5" 2 pinion in the front of the IFS the Hilux / Surf where it is a 50/50 split between crownwheel failure and side gear failure.

Paul

[RUFF]

So it's not the diff housing flexing
It's not the 3rd member flexing
It's not the rotating assembly behind the ring gear flexing
It's not the crush tube in the 3rd member moving
It's not that the 1:4.3 ratio is too low resulting in a smaller pinion

These are all an issue and are known causes of failures in these diffs. But again most of these failures come down to the shear size of it.

The 100 series 4.3 Crown and Pinion are the weakest set up i have experianced. It appears they have used a different material on these and they break very easy.

as for the 2 reasons you gave that i deleted from the quote, Ive never heard the bearings mentioned before. And the Hypoid is being driven on the correct side in a front diff which makes them stronger than the same size R&P in the front of a hilux. But it makes them weak in reverse when all the weight is on them and this makes them exceptionally weak when trying to reverse up hill or out of a hole. Where as the same size R&P in the hilux in this situation is running on the strong side of the gear.

[me3@neuralfibre.com]

So it's not the diff housing flexing
It's not the 3rd member flexing
It's not the rotating assembly behind the ring gear flexing
It's not the crush tube in the 3rd member moving
It's not that the 1:4.3 ratio is too low resulting in a smaller pinion

These are all an issue and are known causes of failures in these diffs. But again most of these failures come down to the shear size of it.

The 100 series 4.3 Crown and Pinion are the weakest set up i have experianced. It appears they have used a different material on these and they break very easy.

as for the 2 reasons you gave that i deleted from the quote, Ive never heard the bearings mentioned before. And the Hypoid is being driven on the correct side in a front diff which makes them stronger than the same size R&P in the front of a hilux. But it makes them weak in reverse when all the weight is on them and this makes them exceptionally weak when trying to reverse up hill or out of a hole. Where as the same size R&P in the hilux in this situation is running on the strong side of the gear.

I have heard the comment "right" and "wrong" side of a hypoid for drive quite a few times, and understand that they are stronger in one direction than the other.

Where I am confused is to what this means. I thought it was the tooth profile, but I take it that it is something else. Daddylonglegs spoke ages ago about changes to the rover diffs to make them stronger in the reverse direction, but I never saw details.

I also know that a hypoid (toyota) runs high or low, whereas the bevel geared rovers run central to the input. The theory on McNamaras page is that the hypoid allows for each tooth to be longer for the same size R&P, resulting in a stronger gear.

SO

Can you explain how a hypoid and / or bevel gear is directional in it's strength?

(and then to get really cool, we'll get DBongard to explain the centre gears in the timed air lockers that are cut with some magic profile that nearly defies the laws of physics to make them stronger)

Thanx
Paul

[RUFF]

Can you explain how a hypoid and / or bevel gear is directional in it's strength?

I could but im really not interested in helping you write more opinionated stories for your website.

[me3@neuralfibre.com]

Can you explain how a hypoid and / or bevel gear is directional in it's strength?

I could but im really not interested in helping you write more opinionated stories for your website.

Or in helping anyone else learn either I see.
Thanx Ruff

Paul

[The Fish]

Wally (80UTE on here) does a Nissan centre and the rest Toyota front end for 80/100 series and possibly 78/79 series. They are super strong and haven't heard of any breaking other than a CV in his ute when he was lauching up an enbankment with the Big Block on song! He's probably done 10-15 of the conversions, some for guys on here, and they seem to be the way to go. It's not a cheap conversion but once you've avoided breaking a front diff 2-3 times it starts being cost effective.

[RUFF]

Can you explain how a hypoid and / or bevel gear is directional in it's strength?

I could but im really not interested in helping you write more opinionated stories for your website.

Or in helping anyone else learn either I see.
Thanx Ruff

Paul

Sorry Paul i will attempt to explain it.

Im no engineer but these are my thoughts on why they are weaker one way more so than the other. Also this is easy to explain in person. I may struggle to explain it here.

With a Hypoid(actually also with the Bevel but its not as noticable) cut gear one side of the Curve of the cut pulls the gears together making them mesh nice and tight(strong side). But the opposite side will try and push the gear appart making the crown wheel or pinion flex depending on which is weaker. This in turn gives the C&P less surface contact area as well as stressing the surface due to the flexing and once loaded up excessivly failure is iminant.

Bevel cut gears can be strong too it just depends on the application. I think in extreme conditions in a diff centre is not a great application. They are close to being as strong forward as they are in reverse as the pinion hits almost directly in the centre of the gear as opposed to across one edge in a hypoid(the hypoid is designed this way to get more gear contact or possibly explained as better mesh). This is why a Bevel cut diff centre can easily be mistaken for a high pinion to the untrained eye as the pinion is a lot higher(generally centred) than a Hypoid. But this also means there is very little gear Mesh which makes them weaker in design.

Both the Hypoid and the Beval have a Curved gear cut. This does 2 things. One it reduces gear noise as they slide across each other rather then over each other in a straight cut situation. The other is they offer more gear contact or mesh which adds to their strength.

A straight cut gear set is prob the ultimate in strength in both directions(although the Hypoid and Beval are prob still stronger in one direction) but is generally very noisy soi this is why its not commonly used as a diff centre in a motor vehicle.

Again these are my opinions based on my personal experiances in many failures of Both Hilux, 75/78/79/80/100 series cruisers and Range Rover diffs.

[bj on roids]

you can get the equivalent of longfields for the GQ-GU diff.
or retrofit the cruiser ones into them

sixshooter swivel hubs to fix a problem that the patrol ones dont have.

toyota centres are crap, especially the front.

brakes and steering are crap? heheh, just use the origional LC steering box, or the the late model brakes and box are plenty good enough

i dont see any competition ( or otherwise) patrols running any toyota running gear in them.

cheers,
Jes

lets get started on crap panhard rod setup,

crap radius arms

they are pretty ordinary overall... just pull the front centre!!

[bj on roids]

any competent 4x4 shop could install the nissan centre into the toyota axle housing..

[The Fish]

any competent 4x4 shop could install the nissan centre into the toyota axle housing..

Having been involved in the R&D of the conversion that Wally does I can say there is quite a bit involved especially when you want to use the strongest parts available. There wouldn't be many 4x4 shops I would trust with this sort of conversion and good workmanship.

[80UTE]

My theory on why the late Toyota fron diff gears s**t them selves is

1. The OEM gears are made from some sort of hard cheese, i know guys that have located some early high pinion front diff centres out of Bundera's and have lasted much longer hense they are made from better material and heat treating process.

2. The amboid gear mesh on the front centre ( hi-pinion ) pushes the crown wheel and the thrust ( axis is above centreline of crownwheel ) pushes the pinion against the larger pinion bearing and better supports the gear reducing flex. ( Forward direction )

3. In reverse direction the pinion gear pulls the crownwheel around this thrust pulls the pinion, the thrust is all taken on the pinion flange , pinion nut and smaller pinion bearing. Any movement/stretch leaves the pinion unsupported the gear mesh opens up and mesh rides up the gear tooth to the tip of the tooth and this contributes to the gear tooth failure. A solid bearing spacer helps this situation as the bearings can be solidly preloaded and less movement is benificial. I have been making solid bearing spacer's on Toyota front and rear diffs for the past 20 years as the 40/60/75 wear running the front diff in the weak direction but due the the larger size the gears survived.

4. The std open carrier does not support the crown wheel as well as a full carrier like the ARB this helps in reducing flex at the gear mesh.

5. But the main reason is the gears are just to small for a full size 4X4. It was dissapoing they upgraded the axles, C/V's, Brakes and let the good package down with the small gear set.

Ive made in access of 25 front ends for 78's/80's/100's in the past 10 years and was a success for each owner. Ive built fronts with this combination for some comp cars using Longfields and they have not had a failure to date. I had drivers bend housings but due to excessive impacts but that cant be avoided when constucting a housing.

To sum up fitting the complete Nissan front axle into a Toyota have problems with pumpkin and chassis clearance as the RHS ( short side ) is conciderable shorter than the Toyota axle and the longe side longer pushes the diff centre to the RHS when axle is centred in the chassis. Nissans have problems with FWH and wheel bearings to close together to deal with as well. The Nissan/ARB centre with Toyota outers and custom housing gives a combination of the best components from both manufactures and all parts are easily obtained if spares are reqired.

Wally

[me3@neuralfibre.com]

My theory on why the late Toyota fron diff gears s**t them selves is

1. The OEM gears are made from some sort of hard cheese, i know guys that have located some early high pinion front diff centres out of Bundera's and have lasted much longer hense i say made from better material and heat treating process.

2

Wally

Are any aftermarket sets significantly better? The diff guy I spoke to reckoned they were worse, but I'm interested in everyone's experiences.

Paul

[bj on roids]

any competent 4x4 shop could install the nissan centre into the toyota axle housing..

Having been involved in the R&D of the conversion that Wally does I can say there is quite a bit involved especially when you want to use the strongest parts available. There wouldn't be many 4x4 shops I would trust with this sort of conversion and good workmanship.

Hence the term "competent"

[bj on roids]

Nissan front axle into a Toyota have problems with pumpkin and chassis clearance as the RHS ( short side ) is conciderable shorter than the Toyota axle and the longe side longer pushes the diff centre to the RHS when axle is centred in the chassis. Nissans have problems with FWH and wheel bearings to close together to deal with as well. The Nissan/ARB centre with Toyota outers and custom housing gives a combination of the best components from both manufactures and all parts are easily obtained if spares are reqired.

Good answer

[1MadEngineer]

My theory on why the late Toyota fron diff gears s**t them selves is

1. The OEM gears are made from some sort of hard cheese, i know guys that have located some early high pinion front diff centres out of Bundera's and have lasted much longer hense they are made from better material and heat treating process.

2. The amboid gear mesh on the front centre ( hi-pinion ) pushes the crown wheel and the thrust ( axis is above centreline of crownwheel ) pushes the pinion against the larger pinion bearing and better supports the gear reducing flex. ( Forward direction )

3. In reverse direction the pinion gear pulls the crownwheel around this thrust pulls the pinion, the thrust is all taken on the pinion flange , pinion nut and smaller pinion bearing. Any movement/stretch leaves the pinion unsupported the gear mesh opens up and mesh rides up the gear tooth to the tip of the tooth and this contributes to the gear tooth failure. A solid bearing spacer helps this situation as the bearings can be solidly preloaded and less movement is benificial. I have been making solid bearing spacer's on Toyota front and rear diffs for the past 20 years as the 40/60/75 wear running the front diff in the weak direction but due the the larger size the gears survived.

4. The std open carrier does not support the crown wheel as well as a full carrier like the ARB this helps in reducing flex at the gear mesh.

5. But the main reason is the gears are just to small for a full size 4X4. It was dissapoing they upgraded the axles, C/V's, Brakes and let the good package down with the small gear set.

Ive made in access of 25 front ends for 78's/80's/100's in the past 10 years and was a success for each owner. Ive built fronts with this combination for some comp cars using Longfields and they have not had a failure to date. I had drivers bend housings but due to excessive impacts but that cant be avoided when constucting a housing.

To sum up fitting the complete Nissan front axle into a Toyota have problems with pumpkin and chassis clearance as the RHS ( short side ) is conciderable shorter than the Toyota axle and the longe side longer pushes the diff centre to the RHS when axle is centred in the chassis. Nissans have problems with FWH and wheel bearings to close together to deal with as well. The Nissan/ARB centre with Toyota outers and custom housing gives a combination of the best components from both manufactures and all parts are easily obtained if spares are reqired.

Wally

Can you please explain to me why you consider the nissan H233 center to be better than the toyota 9.5" ring gears. I am curious to hear you opion as from my own personal experience, i see quite a few H233 pinion failures. I know you have commented on using nissan centers in the fronts of "comp" rigs, i am curious to know how many are running 30spline chromoly longs, and how many have destroyed hub flanges or hubs with chromo hub gears. As Ruff will atest, a well built 60 series front will generally destroy a hub flange or upgraded locking hub waaaaaaay before destroying a diff center (out of shear power input - not just shockloading). I am very curious as one of the cars i compete with is a GQ running CAL cv's and so far it has destroyed a front center and 4 locking hubs - way before the cv's are likely to fail.

[98lux]

Can you explain how a hypoid and / or bevel gear is directional in it's strength?

I could but im really not interested in helping you write more opinionated stories for your website.

Or in helping anyone else learn either I see.
Thanx Ruff

Paul

With a Hypoid(actually also with the Bevel but its not as noticable) cut gear one side of the Curve of the cut pulls the gears together making them mesh nice and tight(strong side). But the opposite side will try and push the gear appart making the crown wheel or pinion flex depending on which is weaker. This in turn gives the C&P less surface contact area as well as stressing the surface due to the flexing and once loaded up excessivly failure is iminant.

That makes perfect sence to me, some thing i never thought about.

[80UTE]

My theory on why the late Toyota fron diff gears s**t them selves is

1. The OEM gears are made from some sort of hard cheese, i know guys that have located some early high pinion front diff centres out of Bundera's and have lasted much longer hense they are made from better material and heat treating process.

2. The amboid gear mesh on the front centre ( hi-pinion ) pushes the crown wheel and the thrust ( axis is above centreline of crownwheel ) pushes the pinion against the larger pinion bearing and better supports the gear reducing flex. ( Forward direction )

3. In reverse direction the pinion gear pulls the crownwheel around this thrust pulls the pinion, the thrust is all taken on the pinion flange , pinion nut and smaller pinion bearing. Any movement/stretch leaves the pinion unsupported the gear mesh opens up and mesh rides up the gear tooth to the tip of the tooth and this contributes to the gear tooth failure. A solid bearing spacer helps this situation as the bearings can be solidly preloaded and less movement is benificial. I have been making solid bearing spacer's on Toyota front and rear diffs for the past 20 years as the 40/60/75 wear running the front diff in the weak direction but due the the larger size the gears survived.

4. The std open carrier does not support the crown wheel as well as a full carrier like the ARB this helps in reducing flex at the gear mesh.

5. But the main reason is the gears are just to small for a full size 4X4. It was dissapoing they upgraded the axles, C/V's, Brakes and let the good package down with the small gear set.

Ive made in access of 25 front ends for 78's/80's/100's in the past 10 years and was a success for each owner. Ive built fronts with this combination for some comp cars using Longfields and they have not had a failure to date. I had drivers bend housings but due to excessive impacts but that cant be avoided when constucting a housing.

To sum up fitting the complete Nissan front axle into a Toyota have problems with pumpkin and chassis clearance as the RHS ( short side ) is conciderable shorter than the Toyota axle and the longe side longer pushes the diff centre to the RHS when axle is centred in the chassis. Nissans have problems with FWH and wheel bearings to close together to deal with as well. The Nissan/ARB centre with Toyota outers and custom housing gives a combination of the best components from both manufactures and all parts are easily obtained if spares are reqired.

Wally

Can you please explain to me why you consider the nissan H233 center to be better than the toyota 9.5" ring gears. I am curious to hear you opion as from my own personal experience, i see quite a few H233 pinion failures. I know you have commented on using nissan centers in the fronts of "comp" rigs, i am curious to know how many are running 30spline chromoly longs, and how many have destroyed hub flanges or hubs with chromo hub gears. As Ruff will atest, a well built 60 series front will generally destroy a hub flange or upgraded locking hub waaaaaaay before destroying a diff center (out of shear power input - not just shockloading). I am very curious as one of the cars i compete with is a GQ running CAL cv's and so far it has destroyed a front center and 4 locking hubs - way before the cv's are likely to fail.

When looking for the alternative for the 80 front centre i built a front axle with a Toyota 9.5" centre in the front but the chassis shape and panard mount required the front mounted track rod to very low to allow for clearance when the the diff was on the bump stops. The other problem was the was excessive angle difference between the panard rod and the drag link causing excessive bump steer so it was cut up and thrown in the bin. For the steering geomerty to work required the track rod to be behind the axle and because of this a Hi-pinion centre is required to give clearance for the trackrod. This is why the Nissan Centre was selected for this combination and added significant strength just because of its increased size of the gears.
Having worked at ARB 20 years ago and my job was operating the CNC machines that made the locker components i observed when checking components to the drawings that most locker's at that time were made to the two locker mechanism envelope sizes. The main lockers manufactured at that time were Hilux, Cruiser, Nissan Patrol, Range Rover, Pajero ETC and the Cruiser and Patrol shared many of the same components like Clutch Ring, Spider Gears, Cross Shafts and Actuator Piston like wise the Hilux, Pajero and Range Rover shared similar parts.
The side gears are very similar ie gear teeth, lockring teeth and spigot diametres are the same, what differed was the lengh of the spigot the internal spline ( to match the axle spline ) . With a slight modification to the lenght of the spigot Toyota side gears ( 33mm 30 spline ) can be fitted into Nissan ARB locker so the Toyota axles can be used and that how the Longfields can be used with the Nissan front center
On comp trucks i set them up to 80 drive plates with 10mm 100 series studs collets and dowels to address this area.
When i supply a gear set i only use genuine Nissan gears sets as they set up far better than the aftermarket items ( gear mesh ) i also have a prefered mesh pattern that i like to achieve and set up the backlash and bearing preload for maximum strength. On high HP applications i recomend limiting the ratio to 4.375:1 so the pinion size/teeth count does not compromise required strength.

This is how and why i came up with the final combination that works and it took a lot of prototypes and testing before the final combination was proven

Wally.

[me3@neuralfibre.com]

My theory on why the late Toyota fron diff gears gh HP applications i recomend limiting the ratio to 4.375:1 so the pinion size/teeth count does not compromise required strength.

This is how and why i came up with the final combination that works and it took a lot of prototypes and testing before the final combination was proven

Wally.

Excellent explenation. I say a big thank you.

Paul