Thread: Td5 harmonic vibration

i'm stumped too with mine so far. i'm going to have a better look at the exhaust system incase it is blocked up. i was hoping that perhaps one of the sensors was playing up, but nanocom never gets any readings that seem iffy. so i'm not sure that i'll get any joy out of that.

the DC(double cardan) joint is the 2 uni joints on the front driveshaft. the ones that join to the transfer case. i'm quite certain that if you're having the same thing as me, this wont be the problem. check it for any freeplay in the uni's themselves. the output shaft from the transfer case may have a bit of slack in it though. apparently this is normal and ok, unless it's weeping oil.

Yours sounds identical to mine, I dont think it will be the DC joint (now you have explained what it is). Mine is even noticable at idle although very very slight. I dont think anyone else would notice it but I have driven a few TD5's and can tell the difference.

I need to slip on a new prop doughnut soon cos I've just noticed some monor splits in it but nothing to severe. The new mount should arrive in about ten days so that should give me an answer one way or another.

Duncan

Hi . Is it noise or actual vibration ? As I posted earlier I had a harmonic noise in my D2 Td5 and it was from a loose heat shield on top of the muffler Its worth a look see . Cheers George

George

This is a definate vibration and not a noise. No problems when coasting but a slight vibration on over run, say in 2nd and 3rd (auto). I found the old thread some time back re the hole in the bottom of the engine mount saying that the internal rubber should be visable about 10mm ABOVE the hole. The rubber on mine is sitting on the hole with zero clearance. Bottomed out. It will probably be at the stage where its almost being forced through the hole soon.

I think if I had never driven any other TD5's I would never have known. When I ordered my new mount the other day from the uk dealer (Armstrong Massey ask for Dave. Cheaper than buying one here given the power of our $) he said that they don't sell many. I think that can be explained that they are spoilt by miles of tarmac and used as Chelsea Taxi's on the school run. We however have the joy of coragations and towing, Mines been chipped as well so that may have added to the stress. Also the alloy top mount has a distinct shine where its been in contact with the rubber of the mount.

The passenger side has the 10mm clearance and no shine on the underside of the mount. Incidently in doing a few google searches I have noticed that the mount part number has changed three times over the years. The latest number is KKB 500750.

In reading this back I've almost convinced myself that this is the fault and the cause of the vibration. I'll know in a week or so.

Duncan

Originally Posted by porgey

I had an annoying harmonic rattle .Traced it to a loose heat shield atop the centre Muffler Cheers George

Thanks Porgey, I checked mine after reading your post & sure enough two of the holes in the shield where damaged & the shield floating. All fixed with 2 washers & now reduced vibrations.

Another thing I looked at was re-tentioning the transfer case mounts. I developed a violent driveline vibration from 95-110kph after having the engine mounts replaced by a LR specialist. They reported that one of the mounts was extremely difficult to fit, afterwards I noticed the rubber part of the transfer case mount was quite twisted so I backed the nuts off both mounts (the transmission & transfer case moved as I did this then retightened the nuts. After a test drive the vibration was still around but not nearly as much. I might do this again as I think there was severe alignment issues created by replacing engine mounts.

Well, I got fed up with waiting for my new cheaper mount to arrive from the UK so got one local. After getting told by TRS that it was unlikley to cure the problem I bolted the new one on. Simon I hope your reading this! It's made a world of difference. The whole drive line has totally smoothed out. Still a very slight vibration around 110kmh but I know that's a rear wheel balance.

My UK order is still on the slow boat delivery and its paid for so I'll end up with that eventually. I'll post its arrival on here just incase anyone is looking for one in the future at a discounted price. They are a bit of a ball ache to fit when lying on your back but I was happy sweating over it when I saw the results. Money well spent and thanks to whoever posted the initial story on here way back identifying the problem (sorry cant remember who it was).

Rover are on their third part number for this item now. The latest is KKB500750 if it helps and is about $196.

Hi Duncan,

good to hear you got to the bottom of it.....can you please explain what I should look for when looking at the mount (from above or below)..

This may be my issue but want to check what I should be seeing, measuring etc..

Cheers
Caine

I replaced both mounts in the end but that only slightly changed the drone. I replaced the exhaust hangers but no difference. I replaced the main muffler with a big straight-through one as it sounded hollow when tapped and seemed to rattle at revs but no improvement. I spotted the harmonic balancer moving around a little at idle so removed that and the engine vibration and cabin drone is greatly reduced. But as I've only driven the vehicle in 30 minute stints, the jury is still out but in a few days I'll be doing a couple of full-day drives so will know exactly what the effect is. If it is a big improvement then maybe I'll replace the HB ($600), but I can't see why I should go to the trouble of replacing the pulley as well.

I wonder about my exhaust flexible joint. Its the later bellows type and the bellows are fully extended, seemingly against an internal stop, which I don't know is normal or not. I can easily lift the lower section but its solid when I try to pull it down. I've tried bending the mounts to get the exhaust higher but can make such little difference that I cannot get the weight off the flex joint. Even if I could, I'm sure the twist of the engine under load would negate anything I might achieve. With the engine idling, I can lift the lower flange of the joint and this removes the idle vibration totally. However as the price of a new engine pipe c/w cat is ridiculous I'm not about to replace it on spec.