Defender 90 TD5 Single Axle Rolling Brake Test Lets have this chat

Should defender 90 td5s be tested on a single axle rolling rig.

I know its been said before but i want to get to the bottom of it.

The MOT testers say yeah yeah its fine then many just say hell no you cant do that but what does the engineering of the defenders transmission say?

The 90 TD5 has a centre differential which sends drive to either the front or rear axle whichever one has the least resistance gets the drive.

So are we right in saying that you can test the defender td5 on a rolling single axle because the centre diff will allow that axle to rotate freely not sending drive to the axle that is in contact with the ground?
And obviously its done at very low speeds.

I know on older models you should remove the prop shaft to the axle your testing but the newer td5 has that lockable centre diff doesnt it?

All 90/110/Defender have the same centre diff arrangements (excepting some very very early 110 models).

If it's low speed it's fine, the plate in your car says up to I think 5mph or thereabouts? If they want to do a test at a higher speed then they need to use the Tapeley meter on a road test.

lr say not to , spinning a center diff like that would entail is not wise,

What are the effects of testing it in this way? I mean surely you could end up in a worser off situation say if you got stuck in a field where again just one axle was getting the power? I mean obviously then you would lock the diff but wouldnt this be more harmful than a lower speed rolling rig?

How do you have your defender brake tested?

The sticker on the cover in front of the gear lever says it's OK to test on a "single axle roller rig" up to 5mph.
So if Land Rover say it's OK, then surely it is?

Yeah thats what i was thinking but theres more people out there saying no you cant do that youll shatter your diff etc etc.

You can do it, but only up to 5mph. Like the sticker says.

The shattering the centre diff thing comes from when people are off-road without diff lock in and one axle looses traction, then they boot it which causes the gears in the centre diff to spin faster than they are happy with and they can go bang (something to do with lack of sufficient lubrication for a high differential of output shaft speed or the like I believe).

This is the LT230's Achilles heel and is the reason why it says on the very same sticker to engage the diff lock if you are likely to lose traction - i.e. before you get stuck. Funnily enough Land Rover know how their own vehicle works and as such if you follow their instructions you don't put the centre diff under undue load.

Sambora8080 said:

What are the effects of testing it in this way? I mean surely you could end up in a worser off situation say if you got stuck in a field where again just one axle was getting the power? I mean obviously then you would lock the diff but wouldnt this be more harmful than a lower speed rolling rig?

How do you have your defender brake tested?

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Sambora8080 said:

Yeah thats what i was thinking but theres more people out there saying no you cant do that youll shatter your diff etc etc.

Click to expand...

Where I get my Ninety done, they don't put it in the brake tester. Been to the same place for years, they never have. Mainly because they are concerned that my locking diffs would break the tester, I think!
All they do is take it up the road at the end of the test, check that the brakes stop it, and don't pull to one side. Quite adequate for the requirements of the regs. according to them. They have been testing about twenty years, think they must know!

And the other side of the coin,my 90 had its 21st MOT at the same place a couple of weeks ago and brake test was done on the single axle roller as usual.Test is done at very low speed a lot less than 5 mph no problem.The center diff has no strain on it in this situation.

If in doubt, we always do a decelerometer test on the road at work.

Mine's always been road-tested. Last place I went to the tester produced a very ancient-looking decelelerometer and went up and down the road a few times. The plate in mine says a single axle roller is allowable up to 5mph. Above that, disconnect the prop to the stationary axle and lock the diff.

I think some MOT stations will just test all 4x4s on the road to avoid any accidental damage to the transmission or claims as such.

I have been advised that you can test on a single axle unit, however only if the wheels rotate in different directions, there is a name for this type of single axle roller but I've forgotten it.

Surely that's just going to cause the same stresses but in the axle diff.