Front propshaft phase offset

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mcapinha

mcapinha

Active Member
Posts
549
Location
Portugal
Hi.

I've replaced the UJs in my front propshaft and a mechanic friend pointed out that both prop ends should be in phase (not a LR specialized mechanic though).
I know that the shaft is balanced and took great care not to disturb it (and I took photos on how to assemble it again properly in case something happened) so I'm sure that the shaft is as it came out of the P38. As it stands, there's just a small phase offset between both ends.

Does this seem right or as someone (prior to my ownership) improperly reassembled the propshaft ?

Vehicle is a 2.5 manual DSE, tough I think the front propshaft is the same for all motors.

Thanks :)
 
mcapinha said:
Hi.

I've replaced the UJs in my front propshaft and a mechanic friend pointed out that both prop ends should be in phase (not a LR specialized mechanic though).
I know that the shaft is balanced and took great care not to disturb it (and I took photos on how to assemble it again properly in case something happened) so I'm sure that the shaft is as it came out of the P38. As it stands, there's just a small phase offset between both ends.

Does this seem right or as someone (prior to my ownership) improperly reassembled the propshaft ?

Vehicle is a 2.5 manual DSE, tough I think the front propshaft is the same for all motors.

Thanks :)
Click to expand...
I seem to remember this has been covered before, I think the UJ's should be out of phase but not sure.
 
Definitely supposed to be out of phase changed lots of these and all the props are out of phase to the degree that you cannot correct it by rotating the splines
 
Well, my mechanic friend not convinced that they are supposed to be out of line, took it apart and confirmed that there's a key spline, so the prop cannot be assembled with the ends out of phase.
This has now left me wondering because there are many threads on the internet about the shafts being assembled in the wrong way, leading to driveline vibrations. But how can this be, if they only fit in one way ?:confused:
Could it be that there's more than one version of the shafts, some being keyed and others not ?
 
They are definitely meant to be out of phase, not only have I changed loads I am an IRTE qualified engineer with over 30 years experience. If you managed to get the ujs in phase the resultant vibration at 55 will be unmanageable and damage your steering
 
Sorry, wantaquad. Maybe you misunderstood me or I failed to explain myself properly but I wasn't doubting your input on this.
What I asked about in my 2nd post was if it is usual for these propshafts to have a key spline, because I was under the impression that there wasn't one.
 
Sorry, Mcapina If jumping to conclusions was a sport I would be very fit indeed. To answer the question yep it is usual for a key spine, but as with most things it can be over come but with horrendous results.

Cheers
 
I've just bought a brand new "Hardy Spicer" propshaft. It arrived in a Britpart box with a Britpart sticker on it, and guess what, no phase offset…

The top is the genuine article, the bottom the Britpart one.

attachment.php


Do Britpart ones not have the key spline so you can adjust the phase, or do you just fit it in phase and put up with the vibration?

I'm sending it back anyway, but was just interested really.
 

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None of my front ones are. I now have 3. Not P38s, just front prop shafts.

You can't change it either, they only go in one way.

Top one is factory standard. Right hand side is just out of phase. 15 degrees or so.

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MrGorsky said:
None of mine are. I now have 3. Not P38s, just front prop shafts.

You can't change it either, they only go in one way.

Top one is factory standard. Right hand side is just out of phase. 15 degrees or so.

attachment.php
Click to expand...

Disco front props are phased P38s aren't.
 
I did read the article yes, it was very interesting. I think it did refer mostly to RRs though.

I have three genuine front prop shafts here, and they are all a tad off. Like in the picture above.

Further, the sliding joint only goes in one way so you can't adjust the phase even if you wanted to. There's what people on 't net are calling a key spline so it only goes in one way.

Land Rover probably made them like that so you can't get the offset wrong I suppose.

Either I have the only 3 out of phase P38 prop shafts in the world, or they are out of phase. At least, the genuine ones are.
 
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MrGorsky said:
I did read the article yes, it was very interesting.

However, i have three genuine front prop shafts here, and they are all a tad off. Like in the picture above.

Further, the sliding joint only goes in one way so you can't adjust the phase even if you wanted to. There's what people on 't net are calling a key spline so it only goes in one way.

Either I have the only 3 out of phase P38 prop shafts in the world, or they are out of phase. At least, the genuine ones are.
Click to expand...

I think it was done because of the angle as it switches between heights. I may be totally wrong.
 
There are a few theories around if you do a quick google.

The American Site has a plausible answer concerning castor angles, and axel orientation. Either way, it's all designed to reduce vibration.

The offset looks smaller than one key spline too (I haven't measured it, but it looks less than 22.5 degrees , so that means unless you buy genuine prop shafts you're always going to risk vibration at speed, a bit **** of Britpart.

I had a Bearmach one here before the Britpart one was sent, I wish I'd photographed that one now for comparison too.
 
MrGorsky said:
There are a few theories around if you do a quick google.

The American Site has a plausible answer concerning castor angles, and axel orientation. Either way, it's all designed to reduce vibration.

The offset looks smaller than one key spline too (I haven't measured it, but it looks less than 22.5 degrees , so that means unless you buy genuine prop shafts you're always going to risk vibration at speed, a bit **** of Britpart.

I had a Bearmach one here before the Britpart one was sent, I wish I'd photographed that one now for comparison too.
Click to expand...

That one with the broken spicer beyond repair? You're sure? Try eBay or Emmotts. Emmotts are on eBay. Very helpful if you ring.
 
MrGorsky said:
There are a few theories around if you do a quick google.

The American Site has a plausible answer concerning castor angles, and axel orientation. Either way, it's all designed to reduce vibration.

The offset looks smaller than one key spline too (I haven't measured it, but it looks less than 22.5 degrees , so that means unless you buy genuine prop shafts you're always going to risk vibration at speed, a bit **** of Britpart.

I had a Bearmach one here before the Britpart one was sent, I wish I'd photographed that one now for comparison too.
Click to expand...

Are the Britpart ones designed to go on the Disco 2 too? So no "key spline"? Can you pop them apart and twist to correct angle and reconnect? Cannot remember how many splines there are but should be easy enough to calculate angle from number of splines twisted.
 
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