Thread: Td5 Roational 'rattly' noise

Thanks all for your help in diagnosing and fixing this problem.

Here's a bit of a summary for those who may be in the same boat.

Kayes D2a Td5 started making a 'rattly rotational sound' which was diagnosed as a broken harmonic balancer/crankshaft pulley (thanks to justinc) which I am told is fairly common in TD5's at >200K Km's.

The crankshaft pulley and harmonic balancer are two separate pieces bolted together. What had happened to ours was that two of the three cast lugs on the rubber mounted centre of the pulley had broken so the harmonic balancer was just hanging on with one lug and this is what was making the noise.



These two parts are usually bolted together with three 10.9 grade High Tensile bolts.

What Kaye did mention later was that she thought her car was a bit 'noisier' than it used to be. This may have been a clue to the pulley/balancer failing, so I guess if you reckon you're Td5 is a bit noisier than usual this would be a good thing to check.

After removing the viscous fan and the drive belt and feeling/rotating the various pulleys it was obvious that the pulley/balancer was broken.

This link here (courtesy of alien)

www.discovery2.co.uk / Crankshaft pulley* / TV damper replacement

gives a very good description of what's involved to repair.

The parts required are LHG100580 damper TV assy, ERR5992 seal and LYG101190 bolt. In Australia not much change out of $1000 depending on where you buy.

What is also needed is a method of holding the crankshaft still whilst the retaining bolt is removed. As this is done up to 460 Nm (330 ft lbs) it is a major exercise.

I made a tool very similiar to that in the UK thread to hold the pulley whilst removing the bolt. The same tool is also used when replacing the pulley.



I used a 300mm length of 50mm X 8mm angle with a 'socket' welded to it to take a 1 metre length of High Tensile 'Z' bar (can't successfully weld HT bar without seriously weakening it). This method was to allow me to use additional bar(s) for greater leverage if neccessary.

Unfortunately I couldn't use this tool to hold the broken pulley as two of the three bolt holes were broken. What I did was rest a socket extension on the LHS chassis rail with a 24mm socket on the pulley bolt so I could use the starter motor to undo the bolt. Before I could do this I had to stop the engine from starting when the starter motor turned. The mental vision of the engine running with a socket and bar connected doesn't bear thinking about .

Removing relay R9 in the engine bay fuse/relay box stopped the engine firing with the starter motor turning. The marker pen is in the R9 position with the relay removed.



On the fourth hit of the starter the bolt loosened with an almighty 'CRAAK' which did my blood pressure no good at all. The pulley was very easy to remove from the end of the crankshaft, no taper and no key just slides off quite easily.

The old seal was a bit fiddly to jag out with a pair of screwdrivers as there's not much room between it and the radiator but OK in the end. The new one tapped in quite easily.

I separated the pulley/harmonic balancer and with a splash of oil on the new pulley seal surface fitted it to the end of the crankshaft and loosely tightened. I put plenty of anti sieze/lubricant on thread and bolt/washer surfaces.

The next problem is how to get 460 Nm/330 ft lb of torque on the bolt.
Your normal 1/2" drive tension wrench won't come near this.

There's a couple of options.

1/. Build an extension (torque multiplier) for your existing tension wrench
2/. Buy a suitable 3/4" drive tension wrench
3/. (And don't laugh), Hang two 20 litre jerry cans of water on a piece of rope via a pulley attached to a bar 1 metre from a socket on the crankshaft bolt.

A good link for a torque multiplier (again thanks to alien) is here.

Torque Wrench extensions

After making one of these I looked on eBay and found this

TENSION WRENCH 3/4 DRIVE 120 - 600 FT/LBS REVERSABLE RATCHET HEAD CHROME FINISH | eBay

and decided it was good value as I could also use it on the OKA.



I didn't get around to trying option 3, but 46 Kg @ 1 metre gives pretty much 460 Nm of torque.

Here's the final assembly/setup



Here's another shot



There's a piece of ply between the radiator and the engine which is recommended by me as it saved the radiator from damage when the socket drove forward when removing the bolt.

There was no Loctite on the pulley bolt that was removed so I put none on the replacement but there was plenty on the 3 bolts holding the harmonic balancer to the pulley, I used high strength 'red' Loctite here and didn't skimp'. These are done up to 80 Nm/59 ft lb.

Easy peasy from here, new fan belt, refit viscous fan with plenty of anti sieze on the thread, replace plastic covers and wonder why car won't start, until I remember to refit R9.

Deano

Great stuff Deano, a difficult job tackled, with ease

JC