Car violently jolts when not under load

[FridgeFreezer]

I'm sure someone (possibly @TSD) had a GKN application note on correct phasing of props, and/or it was in the RAVE manual with specific instructions.

I'm sure the front is some odd number of splines out of phase and the rear is more "normal" maybe 90deg?

[TSD]

I do remember a paper that covered the reasoning and calculations, I just can't find it

I think the prop phasing was originally in a Range Rover Classic manual, possibly around the US launch. As said already, front prop only, pretty sure it was offset by two splines, but I can't recall if it was advanced or retarded, or if it even matters.

Not all props have the same number of splines of course, so even that isn't much help. I found an out of phase prop on the rear is very noticeable, because on the overrun it rattles the handbrake drum over the backlash in the rear diff at certain speeds.

[hurbie]

if you have a original front propshaft , give it a really good clean , there are arrows on both sides of the slider to help with assembly 🙂 

(and the 110 is out of phase as stated earlier, (only the front))

 

[uninformed]

Given the 90, 110, 127, 130 and D1 all share the RRC suspension geometry and basic driveline set up, it should not be too hard to understand they all run out of phase front prop shafts. 
 

the only caveat is I’m having a mental block and can’t remember if Tdci Defender went DC prop shaft? 

[landroversforever]

6 minutes ago, uninformed said:

the only caveat is I’m having a mental block and can’t remember if Tdci Defender went DC prop shaft? 

I want to say they stuck with a normal one, but that they're a wider angle.

[Snagger]

On 1/18/2023 at 4:03 PM, FridgeFreezer said:

I'm sure someone (possibly @TSD) had a GKN application note on correct phasing of props, and/or it was in the RAVE manual with specific instructions.

I'm sure the front is some odd number of splines out of phase and the rear is more "normal" maybe 90deg?

I remember there was a formula based on deflection angles and prop length for calculating the phasing.  I’ll see what I can find.

This, in the mean time, goes into a lot of the physics of prop shafts and the mathematics is quite involved.  https://www.elbe-group.de/incaches/uploads/construction_e.pdf

[Snagger]

1 hour ago, uninformed said:

Given the 90, 110, 127, 130 and D1 all share the RRC suspension geometry and basic driveline set up, it should not be too hard to understand they all run out of phase front prop shafts. 
 

the only caveat is I’m having a mental block and can’t remember if Tdci Defender went DC prop shaft? 

I don’t no so, and certainly don’t recall seeing one on my wife’s.  Discovery II and I think the P38 did.  TDCI props were perhaps different in length to earlier Defender, but similar construction.

[Snagger]

On 1/18/2023 at 6:32 AM, uninformed said:

A DC does not increase articulation, in fact they have a limit that is less than a wide angle traditional uni joint.

 

Proper DC has the DC with the majority of angle change from flange to shaft and the standard uni end should be only 1 degree. 
 

The Internet will say zero degrees for the standard uni end, but you want at least 1* so the needle rollers get turned . At zero they won’t and can brinell.

 

Strictly true.  The output from a DC is uniform as the second UJ within the DC cancels out the impulses from the first, so the standard coupling at the other end should be as straight as possible to avoid inducing there.  But as you say, a perfectly straight rear couple could theoretically result in lubrication failure and brinelling.  In practice, axle wrap from torque applications from driving and general suspension articulation should prevent that from happening; it should only be an issue on fixed geometry applications.

[elbekko]

14 minutes ago, Snagger said:

I don’t no so, and certainly don’t recall seeing one on my wife’s.  Discovery II and I think the P38 did.  TDCI props were perhaps different in length to earlier Defender, but similar construction.

D2 yes, P38 no.

[TSD]

24 minutes ago, Snagger said:

Strictly true.  The output from a DC is uniform as the second UJ within the DC cancels out the impulses from the first, so the standard coupling at the other end should be as straight as possible to avoid inducing there.  But as you say, a perfectly straight rear couple could theoretically result in lubrication failure and brinelling.  In practice, axle wrap from torque applications from driving and general suspension articulation should prevent that from happening; it should only be an issue on fixed geometry applications.

I had exactly this problem with a DC prop on the front of 1Bex at one time. Had a new vibration, but no noticeable movement in any of the UJs. When I dropped the front prop, the single UJ was almost solid. At that time I was doing a lot of high speed road miles and no off-road at all. The front prop was close to a straight shot into the diff at that time.

[ThreePointFive]

2 hours ago, Snagger said:

 TDCI props were perhaps different in length to earlier Defender, but similar construction.

I read about this on Gwynne Lewis's site while looking at refurb Vs upgrade. It sounds like they really had to work to fit the TDCI in there and it resulted in some sub optimal compromises having to be made.

Though I look forward to finding out that's wrong, as with everything else I've said on this thread. 😬

[Snagger]

54 minutes ago, ThreePointFive said:

I read about this on Gwynne Lewis's site while looking at refurb Vs upgrade. It sounds like they really had to work to fit the TDCI in there and it resulted in some sub optimal compromises having to be made.

Though I look forward to finding out that's wrong, as with everything else I've said on this thread. 😬

Yes, the engine had to be mounted higher, so the gear box axis is inclines (not helpful for prop geometry) and is part of why the bonnet bump had to be so tall.