Offset diffs. Where have all the real 4x4 engineers gone?

[daddylonglegs]

Way back in the dim dark ages most popular 4wds had both front and rear diffs offset to the right hand side. this system had several advantages off road. When entering deep mud for example, while the rear wheels still had good traction they would assist in pushing the front pumpkin through and therefore making clearance for the rear pumpkin to pass through with little resistance. The modern trend to centred rear diffs means that the truck has to plow 2 furrows with more chance of getting stuck. Another advantage of offset diffs is that the cross axle ramp angle is improved so there is less chance of getting hung up in deeply rutted tracks. Because the offset diffs are usually on the drivers side it is easier to line the truck up to miss large rocks and stumps etc.
Of all the modern 4x4's, I think only Landcruisers and LandRovers still have offset front and rear diffs.
Bill.

[-Scott-]

I'm guessing the real engineers are still there, but the decisions are made by the bean counters. If a centre pumpkin saves a few dollars per vehicle then the engineers are probably being instructed to do that, regardless of technical merit.

It's very rare to find a good engineer senior enough to over-ride the bean counters these days.

Scott

[TuffRR]

New 4wd's aren't built to go 4wding anymore. LandCruiser went IFS more than a year ago, putting on-road comfort ahead of off road ability. Land Rover seem to be going more in that directional also, from what I've seen the new Discovery doesn't look like anything flash.
The only manufacturer IMO who still makes new 'mainstream' 4wd's to be driven off road would be Nissan. At least they still run live axles on the Patrol and the as yet released update looks to stay the same in this department.
As long as thousands of city folk keep buying them to take the kids to school, the manufacturers will keep producing them to meet their needs.

On the upside though, this focus on comfort did introduce cup holders.

[daddylonglegs]

Don't forget the curry hooks and carpet mats !! I really don't think that Rover have had anyone on their engineering staff that really understood 4wd for over 30 years.
Bill

[bogged]

New 4wd's aren't built to go 4wding anymore. LandCruiser went IFS more than a year ago, putting on-road comfort ahead of off road ability. Land Rover seem to be going more in that directional also, from what I've seen the new Discovery doesn't look like anything flash.
The only manufacturer IMO who still makes new 'mainstream' 4wd's to be driven off road would be Nissan. At least they still run live axles on the Patrol and the as yet released update looks to stay the same in this department.
As long as thousands of city folk keep buying them to take the kids to school, the manufacturers will keep producing them to meet their needs.

On the upside though, this focus on comfort did introduce cup holders.

Bingo.. the toorak crowd are a much larger market than offroaders, probably by 50 to 1 at least...

[-Nemesis-]

LandCruiser went IFS more than a year ago,
The only manufacturer IMO who still makes new 'mainstream' 4wd's to be driven off road would be Nissan. At least they still run live axles on the Patrol and the as yet released update looks to stay the same in this department.

I thought it was the top series Cruisers? And the cheaper versions still run live front ends?
Or is it 100% IFS? The electrician at our quarry has a plain white 100 series with a live front

[Evan]

The non turbo 100 series oil burner has solid front. Not many creature comforts either.
Everything else has IFS in 100 series.

[muppet_man67]

Built for comfort? The newish defender short wheelbase couldnt be anymore uncomfortable. I had a good look at one at ULR a few months back I think it was 33" standard wheel size, no backseats. vinal floor, the handbrake was down round your ankles. I couldnt be sure but im almost certain it had off center diffs. it had center diff lock rather than viscous. Only obvious feature it was lacking was that it didnt have difflocks. instead it had traction control.

[muppet_man67]

oh yea and all this luxury for the small price of $53,000

[TuffRR]

The defender is not what would be considered a mainstream vehicle though. And if the Ford concept designs are any indication, the next model defender could be as capable as a RAV4.

[Gwagensteve]

I think that there is also a production expediency issue too - the platform can be shared with a 2WD variant that has no need for an offset diff - Hilux, et.al.

Discoveries and series two rangies would have to have the most aggressively offset rear diffs of anything.

I think that the biggest goal for 4WD design now is low NVH. Even in sierras, the differences between a 1.0 litre (82-84) and a coiler (95-99) are incredible - soooo much time was put into NVH reduction, and it works - a coiler is far more refined.

I thinl we just have to accept that we (four wheel drivers) are a very small part of the market now, and that sooner or later will will mak the new stuff work. I still recall when the 80 series was launched all the old skool cruiser guys saying how they would never ever ever own one of those plastic sissy stoopid over complex blah blah blah cars, and now they all love their 80's, and now reckon they will never own an IFS car.

I empathise though bill.... there doesn't seem to be much common sense around anymore.... except for those curry hooks

[J Top]

I remember back in 72 when Rangies went up from $7200 nz to$7500 nz
and every one said no-one will buy those to use off road.
Times change
J Top

[muppet_man67]

Whats NVH??

[daddylonglegs]

NvH Noise Vibration Harshness.

[muppet_man67]

The defender is not what would be considered a mainstream vehicle though. And if the Ford concept designs are any indication, the next model defender could be as capable as a RAV4.

Yea good point. Whilst talking to the salesman at ULR Apparantly if you ever want a classic rover nows the time as overseas legal presures are forcing them to phase out the Chassis. image 4bys with nowhere to attatch the bull bar lol

[-Nemesis-]

Soon the world will be over obsessed with "cross over" vehicles that struggle crossing over a speed hump, but do 0-100 in 6 seconds and have a "high driving position."
Whilst the rest of us will be driving "old" 4WD's that will probably be outlawed by people who can't even drive like Carr.

[landy_man]

Built for comfort? The newish defender short wheelbase couldnt be anymore uncomfortable. I had a good look at one at ULR a few months back I think it was 33" standard wheel size, no backseats. vinal floor, the handbrake was down round your ankles. I couldnt be sure but im almost certain it had off center diffs. it had center diff lock rather than viscous. Only obvious feature it was lacking was that it didnt have difflocks. instead it had traction control.

so did you actually drive one....
if you did you might have found that they are not as uncomfortable as they look... they do have no right arm room... but besides that... on a long distance trip you don't feel tired or sore after

[muppet_man67]

no I didnt drive one. the back seats in the longwheel base wernt to flash though.

[landy_man]

no I didnt drive one. the back seats in the longwheel base wernt to flash though.

......... you were talking about the 90 which only has front seats..... i agree on the rear 110 seats being pathetic.... but you can't come on here and say the 90 is uncomfortable if you have not driven one........

did you even sit in one

oh and by the way... the SWB or 90 is only new in Oz... has been available in the rest of the world since the series 1 - albeit an 88

[Gwagensteve]

whats NVH?

Drive a WT before you bag a coiler!!!!

[bj on roids]

Way back in the dim dark ages most popular 4wds had both front and rear diffs offset to the right hand side. this system had several advantages off road. When entering deep mud for example, while the rear wheels still had good traction they would assist in pushing the front pumpkin through and therefore making clearance for the rear pumpkin to pass through with little resistance. The modern trend to centred rear diffs means that the truck has to plow 2 furrows with more chance of getting stuck. Another advantage of offset diffs is that the cross axle ramp angle is improved so there is less chance of getting hung up in deeply rutted tracks. Because the offset diffs are usually on the drivers side it is easier to line the truck up to miss large rocks and stumps etc.
Of all the modern 4x4's, I think only Landcruisers and LandRovers still have offset front and rear diffs.
Bill.

I don't quite get the topic, unless it is just a chance for everybody to whinge.

There is one important benefit that I think you missed too. I also don't think there is any difference between teh offset on a cruiser and a rover, they both seem to have a very similar length shortside axle. anyways, there is still people putting offset diffs under offroad vehicles, in fact if you look at the trend in the states then, you will notice on some the pumpkin is jammed hard against the tyre (particularly Tiny/scrapper, and copies of same.)

[daddylonglegs]

Yes BJ, this thread did vere off topic somewhat, but you get that.
The guys in the states that are starting to use offset diffs again are privateers who have finally caught on. not mainstream vehicle manufacturers who seem to have forgotten how to design proper off road vehicles. The most capable truck I ever built was a Landrover with dual wheels front and back. the inner wheels were 7.50's the outers Q78 Swampers. The drastically offset Dana 60 diffs were virtually inside the inner duals, so it was nearly impossible to get hung up on the diffs.
Bill.

[bj on roids]

Yes BJ, this thread did vere off topic somewhat, but you get that.
The guys in the states that are starting to use offset diffs again are privateers who have finally caught on. not mainstream vehicle manufacturers who seem to have forgotten how to design proper off road vehicles. The most capable truck I ever built was a Landrover with dual wheels front and back. the inner wheels were 7.50's the outers Q78 Swampers. The drastically offset Dana 60 diffs were virtually inside the inner duals, so it was nearly impossible to get hung up on the diffs.
Bill.

\

Bill, you make a very good point, it is clear, you have a vast knowledge of four wheel drives and their workings, it is also clear that you have many years of experience in driving, and building, which is quite admirable really.

Also, Bill, I understand what you are saying about mainstream manufacturing. I am going to stick up for the mainstream manufacturers, and say, that the people buying the new cars are determining what WE the 4x4 community will drive in the future, therefore the manufacturers are meeting the demand, people want IFS, the companies will make it. Its a capital system, they are private companies, I will staunchly defend there actions, and decisions to manufacture and sell the vehicles that are quieter, lower, safer, have less un-sprung weight, and greater steering and braking control, in on and offroad environments. A lot of these favourable qualities come with independant suspension. It also has its place in racing, and off road driving, not necessarily rock crawling, always, but a deserved place non the less.

As a percentage of the market, I hate to say it, but at this time, and for the forseeable future, we are an insignificant few, who, while hating the new cars, will remain brand loyal, as they will seem to be "best of a bad bunch" and will continue to purchase our chosen brands, regardless of the offroad capability. From a sales perspective, many of us will never purchase a new car, but keep the used sales ticking over, and for the time being there is plenty of vehicles to satisfy us, the offroad enthusiasts, the builders and the wheelers.

Having said that, down the track the market may call for a limited production run, for a special offroad vehicle, a retro-cruiser or landie, that will sort of impress the enthusiasts and sell to the both markets, almost like the monaro, or the Brock commodores, the Jeep Rubicon and so on.

Anyways, enough of all of that, lets see the pictures of your landrover, the way you described it "Dana 60 diffs" seemed to suggest it had a Dana 60 front, and rear, that is something I would really like to see pictures of!

How drastically offset was your Dana 60? Was it stock series landrover? if so I would not call that drastically offset. In my mind, drastically offset is something like this. (see attached picture)

From simply looking back, even in "the dim dark ages" I see that many vehicle manufacturers simply copied off each other.

LandCruiser copied LandRover, in terms of offset diffs. Except Landcruiser increased the axle size, diff size and strength.

Hilux have had a centred rear forever, GQ drivelines are simply a copy, but roughly 50% bigger in the transfer case and bigger in the axles and diff centres.

This trend continues, only now, we have Independant suspension, cleaner motors, and, of course the mod cons. I love cup holders and centre consoles and on-board DVD players, and map holders and takeaway hooks, handles evrywhere, storage pockets up the wazoo, and so on, that new vehicles have. They ride nicer, handle better and fare quite well offroad.

When it comes to competition, it is a different story, it is all about custom offroad vehicles, buggies, and the like, and that is where the future lies for most of us (the rockcrawlers, mud pluggers, desert racers, and importantly your type as the builders)

One last thing, I see you complaining about the new vehicles and this and that, and yet, you took a series landy, modified it to the point that landrover would deny its existence, to make it more capable for you personally. I would challenge that a man of your ability and talent could take a brand new land rover/range rover and turn it into an unstoppable offroad machine with a similar amount of work that has gone into your current four wheel drive, why then, are the current vehicles a bad thing?

The problem is us, we want something unique, something different and this cannot be supplied, due to problems with other people not wanting exactly what we want, and constructing each vehicle individually certainly is not cost effective, nor would you or I pay the money it is worth, so we decide to build it ourselves. So the problem is us. Vehicles have come a long way since Henry Ford first said: "They can have any colour, as long as its black" Any person, can purcahse a new vehicle right now, and tick all sorts of boxes, from performance and stereo options, to wheel and tyre combinations, personalised plates, seats, paint jobs, trim design, and so on. Clearly vehicle manufacturers are evolving to meet the demands and needs of the mainstream market, and this is where a business should position itself to maximise sales, and ultimately pay dividends for shareholders.

[dave]

Jesus BJ you know how to write

[antt]

so true bj

in 20 years there mightn't be any solid axle vehicles for sale anymore. hell, they man not even have a chassis anymore. but i'm sure that people everywhere will come up with ways to bolt these late model bodies and drivetrains, onto a chassis fitted with solid axles, or even develop link setups the bolt straight to the body.

[bj on roids]

In all the cliffs notes, I forgot to attach the picture.

Just to re-state my point, I think landcruisers and landrovers have offset diffs and this is good to a point, I think when custom building soemthing it can be taken to the next level, this picture shows a different degree of the next level.

How cool is this, the shortsiude axle would be 5" long.

[bj on roids]

so true bj

in 20 years there mightn't be any solid axle vehicles for sale anymore. hell, they man not even have a chassis anymore. but i'm sure that people everywhere will come up with ways to bolt these late model bodies and drivetrains, onto a chassis fitted with solid axles, or even develop link setups the bolt straight to the body.

jeep wagons already have a monocoque setup with solid axles attached to it.

all we really want from late model vehicles is high power, lightweight motors!

[bj on roids]

better picture

Custom diffs and so on are a lot better than off the factory.

Check this out, 35 spline, shaved, nd flipped 9" that didn't come off any big factory!

[XterraGuy]

One thing that a centered diff offers is simplicity. You've got just one axle shaft to deal with instead of unique left and right. Strength is equal, you only need one spare, and the maker saves a few bucks by not having to spec, build, stock, and otherwise deal with two separate items.

[daddylonglegs]

Thanks BJ and others, you make some very valid and interesting points. I am runnung short on prepaid internet hours so I will try to be brief today.
I doubt that once a system has been discontinued on mainstream production, that the manufacturers could once in a while fire up the production line to build a limited number of specialist vehicles. usually ,due to space considerations the tooling is sold off for scrap.
I doubt very much that I would be able to take many of the current crop of 4wd's and produce a vehicle with the kind of allround offroad ability that I personally want . I would have to change or re-engineer too many components which would sort of defeat the purpose of spending all that money on a late vehicle in the first place. Yes I know I have changed almost everything on my LandRover, but in most cases I have merely exchanged each components for stronger ones. I haven't really re-invented the wheel. The LandRover with Dana 60's and duall wheels front and rear no longer exists in that guise. Although the vehicle was successful
in that it acheived the desired results, I was unable to convince any RTA
approved engineer to even consider inspecting it and after getting put off the road by the TOG twice in 2 years I decided it wasn't worth the hassle.
I swapped to rangeRover axles and Portal hubs and there are a couple of photos of the truck in the Rover forum in the "Another Rangey on Volvo's" thread. BTW BJ The diff offset was the same as a 110. not so drastic with single wheels but with duals with a n inner track width of 39 inches the diff was similar to that photo of the 9 inch. Right up against the tire.
I made up the Dana60 front end from a Dodge 114 pickup rear axle, cut down with series3 Rover swivel assemblies, CV's and special inner shafts. I fitted Rover Salisbury R&P and 4 pinion carrier to it. Photos do exist of the vehicle in this form but they are not digital, and they belong to other people because I have never been able to hang on to a camera for more than five minutes without dropping it in a mud hole or running over it.

Bill.