Wide angle prop fitment direction

[neilly]

Hello All,

May seem a strange question, here is the crux of the situation.

I was greasing up my props as you do, looking at the rear prop and noticed it was out of phase. It is a wide angle DA6353. Which afaik should be in phase. Have done a lot of searching on here and others and decided to investigate.

Just for fun, I removed it and checked , it was 3 splines out of alignment with the arrows marked on the outer case. Never had any real vibration issues, But it still seemed weird.

I reassembled it in line with the arrows and refitted to the vehicle, there is no noticeable difference that I can tell.

But then as I refitted it, I wondered if a wide angle prop has a direction it should be fitted, does the outer spline sleeve section go towards either the transfer box or the rear diff? which leaves the main mass of the prop ( inner spline drive) in the opposite direction. It is fitted as it came off.

Cheers

 

[zeaphod]

I could be wrong, but I think the outer section should be at the gearbox end. I'm pretty sure mine have always been fitted that way. There would be a bit less mass moving at the axle end that way, and at the rear the seal would have some protection from the larger diameter.

 

[jamesmartin]

wide angle or standard front needs to be out of phase ,its a double carden that should be in phase for front prop, it doesnt matter which way round prop fits but its better with slide nearest diff, ie water will run out

 

[neilly]

Cheers JM,

Yes I understood the front is always out of phase, But this was the rear which is a wide angle the PO had fitted out of phase.

Cheers

 

[Brown]

wide angle or standard front needs to be out of phase ,its a double carden that should be in phase for front prop, it doesnt matter which way round prop fits but its better with slide nearest diff, ie water will run out

Yes, I've always thought that. It makes sense to fit them so the female part of the splined section is pointing downwards to keep the water out. But you almost always see them fitted with the splines nearest the gearbox. Anyway, I'm pleased to see my idle thoughts backed up by someone as experienced as James.

 

[jamesmartin]

Cheers JM,

Yes I understood the front is always out of phase, But this was the rear which is a wide angle the PO had fitted out of phase.

Cheers

my bad

 

[neilly]

Cheers Gents,

As mine was 3 splines out but is now back to being in line and I cannot feel any difference then as long as it continues i shall leave it as it is. Also with the direction set up so that water will run out of it, if it ever got around all the grease I have pumped into it.

Cheers

 

[lynall]

Always fitted mine in line with each other, series and coilers, I have read of some models having them oit of phase for some reason, cant remember what it was mind!
Trucks are always in phase, I have seen people fit the slider out of line and theres been no long term issues.

 

[Kwakerman]

Always fitted mine in line with each other, series and coilers, I have read of some models having them oit of phase for some reason, cant remember what it was mind!
Trucks are always in phase, I have seen people fit the slider out of line and theres been no long term issues.

The reason the phasing is different on the front prop is due to the angle that the UJ's have to work through (more angle on the front prop than the rear). It gives a more even / smooth power transmission (less 'cogging'). Its the same basic reason that CV's are used in vehicles (rather than UJ's) where power is transmitted to the 'steering' (road) wheels as they have to articulate as the vehicle turns a corner. Even though both ends of a propshaft rotate at the same speed there are torsional impulses induced by the UJ when it is working at an angle, a CV eliminates that effect, however CV's cost a lot more to make hence they are only used where needed.