Rear End rumbles continued
Rear End rumbles continued
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Discussion

Colin Blues2

Original Poster:

2,541 posts

280 months

Monday 8th March 2004
quotequote all
And no I haven't had a curry recently...

Refer to this posting for a bit of history.

www.pistonheads.com/gassing/topic.asp?f=11&h=&t=45292

Driving the S home the other day a light metallic sound started to come from the rear end. Almost like something was hitting the exhaust.

A quick insepection under the car and twisting of driveshafts showed the the passenger side to have a bit of play. Bought the requisite parts and tools (large Torx driver for the socket set) and set too.

Removal and replacement was pretty straight forward if very messy (CV grease is revolting). Had to buy a few replacement Torx bolts from Ford, the Torx slot on the new ones is larger than the old ones so another Torx driver was required. Anyway eventually all back together.

Took it for a test drive and the noise has gone but now the rumble is worse than ever. Doesn't appear until about 80 but then gets progressivley worse. No noticeable difference when cornering, although very evident on the overrun in third. I can now also feel it through my seat. A not altogether unpleasent experience if I was after a massage chair but not what I'm looking for when driving.

Any ideas? Maybe I should have another look at the propshaft.

Current thoughts are. Check that the wheels are balanced correctly maybe the play in the driveshaft was masking a wheel out of balance but I can't explain why it is worse on the overrun.

One thing that's bothering me is the Torx bolts were very very tight to undo, yet the torque setting according to Haynes is only 30lbs/ft which doesn't seem very tight at all. I did it up a bit tighter than recommended but still not entirely happy with the setting.

Next ones are pull out the propshaft and get it reconditioned and balanced but really not looking forward to that.

Colin

S3 Kieran

968 posts

276 months

Monday 8th March 2004
quotequote all
I have similar rumbles, which gradually appear from 70mph, getting to back/chest massage state by 80mph (on a private road!)

If the hood is up, the resonance is audible too. I suspected driveshaft out of balance etc.

Peninsular took the S for a test drive and concluded that the rear diff was grumbling and would cost £400+ to refurbish, but the noise wasn't damaging. It may stay like that for years before needing sorting.

Not the end of the world, but it is bl00dy annoying, as I am frequently on private roads

I'd like to think Peninsular wouldn't get it wrong, but I may get a 2nd opinion in case all I need is some balancing!

>> Edited by S3 Kieran on Monday 8th March 09:27

Le TVR

3,097 posts

274 months

Monday 8th March 2004
quotequote all
It sounds a bit like propshaft UJs? The wear wont be even and that could explain why its worse on the overrun.

I think there is 'trick' with the rear CVs that you can simply remove them and swop each side over (you will be running on different points on the lobro joints and the play will disappear).

andyf007

863 posts

281 months

Tuesday 9th March 2004
quotequote all
Mine does it too. From experience though, start with the wheel bearings.

Andy

greenv8s

30,999 posts

307 months

Tuesday 9th March 2004
quotequote all
Did the rumbling start when you replaced the CVs? If so, it must surely be something to do with that. Is it possible one of the CV joints is fitted slightly off center on its mounting flange (due to the bolts not being exactly centered in their holes)?

Colin Blues2

Original Poster:

2,541 posts

280 months

Tuesday 9th March 2004
quotequote all
No the rumbles always been there but the vibration is defintely worse since the change.

I didn't really give much thought to centering the joint when I was bolting it up. I thought that with 6 bolts on each joint it would have been centered automatically.

What I did was put each bolt in loosely (rotating the shaft around to get to them) then nipped each one up to the appropriate torque 2 at a time with the handbrake on (releasing, turning, then reapplying the handbrake)

Is there an easy way to centre the joints on the mounting? How can I tell if it's not centred?

Thanks

Colin

Colin Blues2

Original Poster:

2,541 posts

280 months

Tuesday 9th March 2004
quotequote all
Thanks Pete you made me think about when the problem started.

I had a look under the car when I got home at the joints and if they were centered on the hub and diff flange. I couldn't detect them being off centre and I checked by holding a screwdriver aginst the trailing arm with the point just touching the edge of the joint. Turning the wheel showed no run out or variation. Same at the diff end.

However whilst I was under there I had a think and then I noticed the clips I had used to secure the gaiters. I had used jubilee clips and I wondered if the extra weight of the screw was throwing the shaft out of balance. So I took them off and replaced them with tie wraps.

Seems to have done the trick, it's certainly better now and much like before I replaced the joints. I shall take the car in tomorrow and get the wheel balance checked too though.

Colin

andyf007

863 posts

281 months

Wednesday 10th March 2004
quotequote all
Jubilee clips will do it. Back in the good old days we used to use them to balance prop shafts. Scary really, car's rear on axle stands, one guy in the car to rev the engine and engage and disengage the drive, while another (usually me) lay underneath to make the adjustments

Andy

Colin Blues2

Original Poster:

2,541 posts

280 months

Thursday 11th March 2004
quotequote all
Andy

Well wheels now balanced but I'm still getting vibration so I think more under car investigation is called for.

I'll check the wheel bearings and propshaft but if they are still as solid as the last time, I'm wondering if the the problem is the new joints themselves. I still have the old ones so I'm contemplating putting the old ones back on as a test to see.

Colin

Colin Blues2

Original Poster:

2,541 posts

280 months

Thursday 11th March 2004
quotequote all
Aha..

Further crawling and prodding has revealed the front UJ on the propshaft is worn. Doesn't help that the grease nipple is missing (there's just a hole where the nipple should be).

I've removed the exhaust and undone the bolts on the diff flange but I can't seem to manouver the propshaft far enough back to disengage the front from the gearbox. The back won't drop down enough to allow me to slide it out the back (ooer missus) due to the cross member there. Am I missing something or do I have to drop the diff as well? Can I get away with just loosening the mounts and jacking the diff up or dropping it down slightly? I don't fancy trying to manhandle that diff from underneath! According to the bible I should be able to remove the exhaust drop the back end of the prop down and slide it out.

Colin

andyf007

863 posts

281 months

Friday 12th March 2004
quotequote all
Fairly sure that you have to drop the diff and take the prop shaft back, up and over the top of the diff to get it out of the gearbox. You could use a trolley jack under the diff to ease maneouvering, but get the car up to a good height on some axle stands first.

Andy

Colin Blues2

Original Poster:

2,541 posts

280 months

Friday 12th March 2004
quotequote all
Thanks. It's already on ramps at the front and axle stands at the back, but I'll take it up as high as I can on the axle stands this weekend.

I take it I can just loosen the mounts rather than having to disconnect the driveshafts and taking it right out?

Colin

Colin Blues2

Original Poster:

2,541 posts

280 months

Tuesday 23rd March 2004
quotequote all
Finally got all the parts after several abortive attempts from local suppliers then called DG who shipped it the next day.

Think I've discovered what the light pinging sound was......

......the needle rollers falling out of the cup they were all missing from one of the cups when I took it off.

Anyway all re-fitted (twice cos I'm a plonker and assembled the propshaft without lining up the marks on the joints). Things are a lot better now although still getting a slight vibration at about 100 (private road of course). So looking for a propshaft balancing service that won't take weeks to get it back to me as I've not really driven the S for 2 weeks and I've got withdrawal symptoms.

One thing I have noticed during my hours under the car is that the diff isn't central in the chassis. Can't decide if this is a design feature to make room for the fuel lines or a problem. Can't see anyway of moving it sideways but the front is definitely over to the drivers side of the car. Anyone noticed this?

Colin

Colin Blues2

Original Poster:

2,541 posts

280 months

Thursday 25th March 2004
quotequote all
Just spent the best £21.15 to date. Took the propshaft off on Tuesday night dropped it off at a propshaft specialist for balancing on Wednesday lunchtime. Picked it up today and re-fitted it tonight.

Hey presto no vibration and also I do believe the rumbles from the rear end have reduced if not disappeared. Certainly they are not as noticeable as before.

If anyone is looking for a somewhere to get their propshaft balanced (they also do full reconditioning) then I can recommend this place.

Propshaft Services
Central Way North Feltham Trading Estate
Feltham Middlesex
TW14 0RX

Tel: 020 8844 2265

Just of the A312 on the trading estate opposite Tesco's.

Stupid grin back in place and the weather forecast this weekend looks good as well..