traffic0703
Member
Driving it again today I think the vibration may have been there a while but the flutter/low level rumble type noise is new - I am sure it wasn't there before both centre prop shaft bearings were changed.
Noise is getting worse - if you put car in neutral and coast downhill, the noise is definately still there.
Just concentrating on the noise side of things - what does it indicate that noise still present when coasting in neutral?
Noise is getting worse - if you put car in neutral and coast downhill, the noise is definately still there.
Just concentrating on the noise side of things - what does it indicate that noise still present when coasting in neutral?
traffic0703
Member
Is propshaft still turning when coasting in neutral?
Hippo
Lord Hippo
The engines revs will drop from normal, creating a different sound and less vibration.
There will be less going on in the gearbox, but some parts will still turn like the output stage.
Coasting is not good on an auto but it's a temporary attempt at trying to alter what the car is doing to see if it makes a difference.
What does it mean? It reduces the chance of it being the engine or auto causing the problem, but not totally. Reason being they have both changed what they're doing but the problem is still there.
Yer need to remove the prop shafts and VCU next which will make it 2 wheel drive. This will reduce stress in the transmission and may alter or remove the problem noise/vibration.
Unfortunately this fault needs a process of elimination to guide yer to the cause.
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Hippo
Lord Hippo
Yes.
When coasting the engine/gearbox won't be propelling the Freelander. The wheels will still be turning, which will turn the prop shafts. That's assuming everything is connected and no missing parts.
Front wheels will turn the front prop via the connection through the ird at the front. Rear wheels will turn the rear prop via the connection through the rear diff. VCU will still fight the differing prop speeds as normal.
traffic0703
Member
Thanks for the explanation. Will report back when have some info.
traffic0703
Member
Update - The prop shaft has been removed.
The vibration has now totally gone. No noise so far also however it would not make the fluttering noise yesterday when prop was still on so not sure about that bit.
I tried the gearbox manually and paid particular attention to the troublesome engine speed ranges where the vibration was most evident - 3rd gear 1500 rpm and 2nd gear 2000 rpm. All now totally smooth.
Any ideas where to go from here as I do want to get the prop shaft put back.
Thanks
The vibration has now totally gone. No noise so far also however it would not make the fluttering noise yesterday when prop was still on so not sure about that bit.
I tried the gearbox manually and paid particular attention to the troublesome engine speed ranges where the vibration was most evident - 3rd gear 1500 rpm and 2nd gear 2000 rpm. All now totally smooth.
Any ideas where to go from here as I do want to get the prop shaft put back.
Thanks
Hippo
Lord Hippo
That's good news in a way. I think the vibration is linked to the prop/VCU. I think the fluttering is from the vibration and may not always occurr.
This sort of fault isn't easy to detect. There's nothing in the ird or rear diff that would cause the noise unless someone has cut bits oft int side with an angle grinder. So they're rulled out.
That leaves the props and VCU. A similar fault has occurred before on a low number of FL's where simply loosening the rear differential to prop bolts slightly, then wiggleing the connection then bolt up again, has removed a vibration. There being a very fine oftset in the connection which causes vibrations at certain speeds or engine revs. Also removing the bolts and turning a raised rear wheel so the diff connection plate turns 180 degrees untill the bolt holes align again to the rear prop plate, then fitting bolts/tightening, has solved the problem.
It's as if a number of precise events triggers the problem vibration at certain engine revs. There will always be some vibration/harmonics but when your problem happens it's high enough to be felt.
I assume the damper on the VCU was fitted behind the vcu, on the side closer to the rear diff, if it has one fitted. Yer can run without the damper. It's there to dampen vibrations coming up the rear prop from the rear diff end of the mechanicals. LR must have detected something in order to want to fit it. The smoother running V6 models didn't need it but some of the other FL's did. Just make sure if yer have a damper it's at the rear of the VCU when the VCU is fitted.
The props are balanced separately. They shouldn't be bent unless yer given them a good whack oft road. It's hard to do but i have tried when oft road.
The 2 Half's of the vcu link together but turn separately. If the VCU hasn't been reconditioned then it will be as per factory build spec physically and spin without vibration, as there won't be any rework weld or oft centre cutting making it slightly oft wotsit when spinning on it's own, causing the vibration.
If the fluid in the VCU were to settle at the botton over time then it easily mixes around the vcu again when driving the car when the props turn at differing speeds. A VCU sat for 18 months just needs one full 360 degree rotation to overcome this to give repeatable One Wheel Up Tests of the same time for specific weight. If the fluid is too old to mix around yer get one hell of a vibration way above what your getting if it settles a bit and dun't mix around well when props turn at differing speeds. Vibration is present from low speeds and gets much worse as speed increases.
If it were mine i would visually:
Check the props look ok.
Check the universal joints on the props look ok and move ok.
Check the vcu looks ok and the damper if fitted isn't loose. Check it looks central to the shaft going through the VCU.
Put it all back on the FL.
It wouldn't surprise me if the problem vibration then disappeared. Reason being the connection would be slightly different in alignment. Prop plate to diff plate that is. Same for prop to ird connection. Try it and see how yer get on. Some will laugh but it has solved the strangest of vibrations int past on other hippo's.
If that dun't solve it I would disconnect the prop from the VCU spine, turn the prop say 45 degrees, then put them both together again. Again this shouldn't make a difference but if the prop or VCU is very very slightly out of balance on it's own (it's own weight central to the centre line through itself), then it sometimes solves a vibration such as yer have. Mad i know and it shouldn't happen but our hippo's are special and int past on ere it has solved the strangest of vibrations.
This sort of fault isn't easy to detect. There's nothing in the ird or rear diff that would cause the noise unless someone has cut bits oft int side with an angle grinder. So they're rulled out.
That leaves the props and VCU. A similar fault has occurred before on a low number of FL's where simply loosening the rear differential to prop bolts slightly, then wiggleing the connection then bolt up again, has removed a vibration. There being a very fine oftset in the connection which causes vibrations at certain speeds or engine revs. Also removing the bolts and turning a raised rear wheel so the diff connection plate turns 180 degrees untill the bolt holes align again to the rear prop plate, then fitting bolts/tightening, has solved the problem.
It's as if a number of precise events triggers the problem vibration at certain engine revs. There will always be some vibration/harmonics but when your problem happens it's high enough to be felt.
I assume the damper on the VCU was fitted behind the vcu, on the side closer to the rear diff, if it has one fitted. Yer can run without the damper. It's there to dampen vibrations coming up the rear prop from the rear diff end of the mechanicals. LR must have detected something in order to want to fit it. The smoother running V6 models didn't need it but some of the other FL's did. Just make sure if yer have a damper it's at the rear of the VCU when the VCU is fitted.
The props are balanced separately. They shouldn't be bent unless yer given them a good whack oft road. It's hard to do but i have tried when oft road.
The 2 Half's of the vcu link together but turn separately. If the VCU hasn't been reconditioned then it will be as per factory build spec physically and spin without vibration, as there won't be any rework weld or oft centre cutting making it slightly oft wotsit when spinning on it's own, causing the vibration.
If the fluid in the VCU were to settle at the botton over time then it easily mixes around the vcu again when driving the car when the props turn at differing speeds. A VCU sat for 18 months just needs one full 360 degree rotation to overcome this to give repeatable One Wheel Up Tests of the same time for specific weight. If the fluid is too old to mix around yer get one hell of a vibration way above what your getting if it settles a bit and dun't mix around well when props turn at differing speeds. Vibration is present from low speeds and gets much worse as speed increases.
If it were mine i would visually:
Check the props look ok.
Check the universal joints on the props look ok and move ok.
Check the vcu looks ok and the damper if fitted isn't loose. Check it looks central to the shaft going through the VCU.
Put it all back on the FL.
It wouldn't surprise me if the problem vibration then disappeared. Reason being the connection would be slightly different in alignment. Prop plate to diff plate that is. Same for prop to ird connection. Try it and see how yer get on. Some will laugh but it has solved the strangest of vibrations int past on other hippo's.
If that dun't solve it I would disconnect the prop from the VCU spine, turn the prop say 45 degrees, then put them both together again. Again this shouldn't make a difference but if the prop or VCU is very very slightly out of balance on it's own (it's own weight central to the centre line through itself), then it sometimes solves a vibration such as yer have. Mad i know and it shouldn't happen but our hippo's are special and int past on ere it has solved the strangest of vibrations.
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traffic0703
Member
many thanks for this reply.
Will be passing it all onto the mechanic that is doing the car for me and will post back asap
Will be passing it all onto the mechanic that is doing the car for me and will post back asap
traffic0703
Member
Yes I did, sorry thought I had updated thread. The cause was one of the small joints in the propshaft. There was just slight play in it. I think you call it universal joint. Before this problem occurred, we had failure of the central bracket which holds prop shaft up. Maybe that weakened the joint. I hope this helps you.
andyfreelandy
Well-Known Member
Is it only when the torque converter has locked? So rev counter is steady with speedo? If so could be same problem I have with a worn TC clutch. I put some anti shudder additive in which has improved but not eliminated the problem.
javars
Active Member
Thanks for that. Mine started after the front prop was replaced. Vcu and bearings less than 6mths old
