Offroad-Express

LET THE STUPID QUESTIONS BEGIN!

*Overseas alot of hard out offroaders are using Unimog or Volvo portal axels in their rigs (lucky buggers). Does anyone know if anyone has ever tried or succeeded in making their own portal axels? Out of a normal beam axel let’s say for example: a landcruiser beam axle. If this could/has been done would it be certifiable?

*I'm just curious are dual gearboxes (like in DeRanged's Lemon build) or dual transfers (like in Rokhounds Toyota surf) certifiable?

*I know there are A.N.D.R.A rules about rollcages, what I'm curious about is are there some rules like that for a tube frame 4wd buggy? And are there rules as to which metals are allowed to be used to make that tube frame buggy? I.e. the tube frame cannot be made of aluminium. I also want to know the answer to those two questions for getting a vehicle certed for the road.

*A few weeks back when Matt (Toyota surf) was fangin it up the river banks in the waipara I noticed that even though he was in 4wd the back wheels were spinning a lot faster than the front, all the weight transfer was at the back and the front wheels were no use what so ever, is this because a Toyota surf does not have a center diff lock (transfer lock)? Is this the same as an open wheel diff? When one wheel loses traction the other wheel gets no drive? So in Matt’s case everything attached to the rear drive shaft had no traction and so the front drive shaft got no drive?

hope that's not too confusing, I guess what I'm saying is if a Jeep Cherokee (full time 4wd and center diff lock) and a Toyota surf (part time 4wd and no center diff lock) both with auto locker diffs front and rear were climbing that same slope the Jeep Cherokee would have more traction (because the front wheels are travelling at the same speed as the rear wheels) than the Toyota surf?

*My understanding of auto lockers is that they are locked unless an external force puts pressure on them to unlock or ratchet (driveline wind up when turning a corner on tarmac) this got me thinking, if they are locked when the wheel is travelling forwards and unlocked when the wheel gets a force on it going backwards, then if you are offroad, driving forwards with auto lockers front and rear (all four wheels turning at the same speed) and you need to reverse does that unlock your auto lockers? And essentially turn you diffs into open wheel diffs while in reverse? (only two wheels turning at the same speed)

Well that's it for now, any answers will be much appreciated (soothe my overactive mind)

MULLET

*A few weeks back when Matt (Toyota surf) was fangin it up the river banks in the waipara I noticed that even though he was in 4wd the back wheels were spinning a lot faster than the front, all the weight transfer was at the back and the front wheels were no use what so ever, is this because a Toyota surf does not have a center diff lock (transfer lock)? Is this the same as an open wheel diff? When one wheel loses traction the other wheel gets no drive? So in Matt’s case everything attached to the rear drive shaft had no traction and so the front drive shaft got no drive?

hope that's not too confusing, I guess what I'm saying is if a Jeep Cherokee (full time 4wd and center diff lock) and a Toyota surf (part time 4wd and no center diff lock) both with auto locker diffs front and rear were climbing that same slope the Jeep Cherokee would have more traction (because the front wheels are travelling at the same speed as the rear wheels) than the Toyota surf?

It could have been he didnt have it in 4wd if neither of the front wheels wernt moving. his surf is part time 4wd which means its two wheel drive to the back wheels when 4wd lever isnt engaged and 4wheel drive when engaged(no diff at all in the centre).
With normal open diffs the power will goto the wheel that has no weight on it(per axle on part time systems, per axle and between axles on fulltime systems), this is why you see one spiinng up fast and one stationary(which is what you might have been looking at).

With mats surf in 4wd one front wheel will spin up and one will stop in very uneven terrain (in that case there was a hole on the left side of that climb making the right wheel stop while the left spun up) and there was drive still to the rear wheels. He has a limited slip diff in there so traction to both rear wheels is assured depending on the condition of the lsd. with a locker in the front or rear no matter how much a wheel spins up the other side has the same amount of drive and should be spinning the same amount whether on the ground or in the air(turning is another story- unlcoking etc).
The jeep with its fulltime 4wd and centre diff locked is exactly the same as mats when engaged in 4wd. mats 4wd is either on or off, that is, the front wheels have drive equal to the rear wheels or not at all. the jeep on the other hand is the same with the centre diff locked but when unlocked allows the front to turn slower than the rear or not at all, ie when one wheel spins all the power from remaining three wheels goes to this wheel with no weight on it - hence why you should always lock that centre diff when 4wding.

hope that helps a bit.

Mike

gomulletgo wrote:LET THE STUPID QUESTIONS BEGIN!

*Overseas alot of hard out offroaders are using Unimog or Volvo portal axels in their rigs (lucky buggers). Does anyone know if anyone has ever tried or succeeded in making their own portal axels? Out of a normal beam axel let’s say for example: a landcruiser beam axle. If this could/has been done would it be certifiable?

Had a bit of discussion about portals the other week in this thread

http://www.offroadexpress.co.nz/modules ... c&start=15

Bit of work involved but anything within reason is possible. From that thread was this link to a guy from aussie who built his own portals using various LR/RR bits, very interesting read

http://forums.lr4x4.com/index.php?s=eb7 ... =6428&st=0