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Which propshaft?


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#1 Ben Jordan

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Posted 31 January 2006 - 06:11 PM

After lifting the Rangie 2" and fitting the front caster correction arms, I have taken the Rangie on it's first long run today and it has developed the dreaded over run vibration. Between 40-60 and lifting off the accelerator a nasty vibration is coming from in front of the driver seat like a bearing has gone. I have put this down to the lift and caster correction arms. I have visited my local prop shaft specialist and they confirmed the UJ by the transfer box is running on its limit.

Do i?

Have them fit a (Disco 2) double cardon joint into my prop shaft for £142 + £39 for the T/box output flange?

Have them make a custom double cardon prop shaft for £222 + £39 for the T/box output flange?

Buy a Disco 2 prop shaft from Devon 4x4 for £169+vat + £39+vat for the T/box output flange? Will it fit a Borg-Warner transfer box, as I know the front prop length is different to a LT230 front prop?

Or live with it (but i probably wont because it is bad)
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#2 simonr

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Posted 31 January 2006 - 06:44 PM

I'm not convinced that double cardon joints are always the answer.

In an ideal world, the nose of both diffs should be parallel to the axis of the transfer box output flanges (Hu hu - he said Flange). It is this (or the lack of this) that tends to cause vibration (assuming your shafts are balenced and phased correctly).

You have fitted castor correction arms on the front, so there is a good chance this will be about right. Have a look at the back. I suspect it will be way off.

You can often correct the diff nose angle by fitting a couple of washers between the rear trailing arm and the chassis bush - effectively lengthening the thailing arms and lowering the diff nose.

Ironically, fitting castor correction front arms can make the vibration worse as the effect of the misallignment of the front and back can cancel out if the phasing is correct.


Si

#3 Petergg

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Posted 31 January 2006 - 06:58 PM

Hi Ben,
I had same problem with my 90 when I fitted an auto box, I got a prop for front From Here and had rear one re built in kent by J W Engineering (01322 556554), they are very good.


Peter

#4 Ben Jordan

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Posted 01 February 2006 - 05:30 AM

Hi Ben,
I had same problem with my 90 when I fitted an auto box, I got a prop for front From Here and had rear one re built in kent by J W Engineering (01322 556554), they are very good.
Peter

Hi Peter,

What am i looking for on the sellers page? Im assuming it's a propshaft but nothings jumping out?
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#5 Ben Jordan

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Posted 01 February 2006 - 06:05 AM

I'm not convinced that double cardon joints are always the answer.

In an ideal world, the nose of both diffs should be parallel to the axis of the transfer box output flanges (Hu hu - he said Flange). It is this (or the lack of this) that tends to cause vibration (assuming your shafts are balenced and phased correctly).

You have fitted castor correction arms on the front, so there is a good chance this will be about right. Have a look at the back. I suspect it will be way off.

You can often correct the diff nose angle by fitting a couple of washers between the rear trailing arm and the chassis bush - effectively lengthening the thailing arms and lowering the diff nose.

Ironically, fitting castor correction front arms can make the vibration worse as the effect of the misallignment of the front and back can cancel out if the phasing is correct.
Si

Thanks Simon, This phasing thing is like Voodoo magic to me.

It is funny that you mention rear trailing arms because i fitted a set of rear cranked trailing arms after the front caster corrected arms, but since fitting all these parts the Rangie has on really been around the block until yesterday. Anyway when fitting the rear arms i was convinced that the arms were 2" shorter than the originals and pulled the bottom of the axle forward when tightening. Is there some sort of reference point on the axle that should be parallel with the ground so i can get a spirit level on or can do something similar?
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#6 darthdicky

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Posted 01 February 2006 - 08:28 AM

Is there some sort of reference point on the axle that should be parallel with the ground so i can get a spirit level on or can do something similar?

As a quick test you could measure whether the wheelbase is 100"?

Richard
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#7 Petergg

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Posted 01 February 2006 - 08:28 AM

Hi Peter,

What am i looking for on the sellers page? Im assuming it's a propshaft but nothings jumping out?


Ben, yes a Discovery 2 prop £110.00 item no 4567518742.
Here

Peter

#8 Astro_Al

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Posted 01 February 2006 - 10:37 AM

Simonr - your comment confuses me (not too difficult...):

"I'm not convinced that double cardon joints are always the answer.

In an ideal world, the nose of both diffs should be parallel to the axis of the transfer box output flanges (Hu hu - he said Flange). It is this (or the lack of this) that tends to cause vibration (assuming your shafts are balenced and phased correctly)."

I agree with your second paragraph.

It seems kind of contradictory though - as I understand it double cardan joints are capable of working between non-parallel flange planes without inducing vibration (since they self-cancel the non-uniform rotational velocity within each joint).

If this is true, how is a double-cardan jointed shaft not a good solution to the problem? :huh:

Cheers, Al. :)

#9 Brett

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Posted 01 February 2006 - 10:46 AM

Ben,

I've got a spare TX box flange.If you want it, send me a pm.

Regards
Brett

Edited to add:

All of this waffling about pinion angles & whether fitting a DC shaft works is all well & good but I HAVE had the vibration problem & it IS cured by fitting a DC shaft. B)
1984 Ninety with a few mods
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#10 robhybrid

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Posted 01 February 2006 - 10:48 AM

In my opinion double caradon joint works great if the joint at the other end of the shaft is running virtually straight i.e. diff nose pointing up towards the transfer box.
If the diff nose is running parallel with the ground and hence along the same plane as the transfer box then the double caradon joint may not (should not) fix the problem.

The prop useually has 2 uj's so that one cancells out the other.

Made any sence? Or just confused the mater further?
I'm an Engineer. Why leave it alone, when I can REALLY screw it up?

There is no mechanical problem so difficult that it can't be solved by brute strength and ignorance.

#11 Bush65

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Posted 01 February 2006 - 10:59 AM

Radius arms cause the diff pinion to change angle so that that it is approximately in line with the front drive shaft.

To compensate the uni-joints are approximately 45 degrees out of phase.

When you fit castor correction radius arms, you change the angle of the diff pinion, which causes the driveshaft vibration.

With a double cardin joint driveshaft, the diff pinion should be aligned with the driveshaft ie. no (or only small) change in angle of the front uni-joint.

As above, castor correction radius arms stu$$ up the alignment of the pinion, causing vibrations in driveshafts with double cardin joints.

IMHO castor correction arms are a waste of money.

The best way to correct castor is to rotate the swivel housings.

Some cator correction info for rangies here

John
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#12 Michele

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Posted 01 February 2006 - 11:03 AM

Guess who'll give it a try...?
B)





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#13 Astro_Al

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Posted 01 February 2006 - 11:10 AM

In my opinion double caradon joint works great if the joint at the other end of the shaft is running virtually straight i.e. diff nose pointing up towards the transfer box.
If the diff nose is running parallel with the ground and hence along the same plane as the transfer box then the double caradon joint may not (should not) fix the problem.

The prop useually has 2 uj's so that one cancells out the other.

Made any sence? Or just confused the mater further?


Rob - I agree, but what you describe is a nominal case where the propshaft can just be a standard one and the flange faces are in parallel planes. (2nd sentence).

The reason your first sentence makes sense is that if you point the diff nose at the transfer box output flange (actually, slightly offset from this ideally to allow room for the DC joint, I suppose), only one end of the propshaft needs a DC joint. The diff end, during normal use, has no odd angle to correct - the propshaft is along the same axis as the diff pinion. It is the TXbox end which has an uneven angle to be corrected by a DC shaft.

Raising the angle of your diff like this can lead to pinion oiling issues, I'm not sure how robust Rover diffs are to this problem.

Besides, if you are going to go to the trouble of rotating the diff, why not rotate it back to a nominal position to keep castor angle etc and then you can keep the regular UJ propshaft?

Al.

#14 Ben Jordan

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Posted 01 February 2006 - 04:54 PM

Ben, yes a Discovery 2 prop £110.00 item no 4567518742.
Here

Peter

I did see that but did not have a clue as to what it was. Does anybody have a picture of it from a parts book?
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#15 Ben Jordan

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Posted 01 February 2006 - 04:58 PM

As a quick test you could measure whether the wheelbase is 100"?

Richard

I have measured the wheelbase and it is 100"
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#16 Ben Jordan

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Posted 01 February 2006 - 05:01 PM

Ben,

I've got a spare TX box flange.If you want it, send me a pm.

Regards
Brett

Brett, PM sent.
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#17 Petergg

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Posted 01 February 2006 - 05:04 PM

I did see that but did not have a clue as to what it was. Does anybody have a picture of it from a parts book?

Posted Image

Just like this one. The Auto one is 15mm longer, than Manual.

Peter

#18 Ben Jordan

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Posted 01 February 2006 - 05:07 PM

Will the Disco 2 prop fit onto my Borg-Warner transfer box? As Iím sure the front prop with this t/box is a different length to the rest?
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#19 Ben Jordan

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Posted 01 February 2006 - 05:10 PM

Ben, yes a Discovery 2 prop £110.00 item no 4567518742.
Here

Peter

Pete, Do you know if these props are new or second hand? I have contacted the seller but no reply yet.
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#20 Petergg

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Posted 01 February 2006 - 05:27 PM

Pete, Do you know if these props are new or second hand? I have contacted the seller but no reply yet.



They are s/h the one I had was in 1st class condition. How long a prop do you want in normal sitting position? I can measure mine if you want.

Peter




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