Vibration - Propshaft?

[Rangi246]

Hi All

Our car has a vibration at 50-60mph that's driving me completely nuts!!! I'm hoping someone here can give me some suggestions before I get really fed up and sell it - that's almost where I'm at!

Its a 1965 Vitesse 1600 with an 1850 Dolomite J type overdrive gearbox. So far I have balanced the flywheel and clutch, replaced the halfshaft UJ's, replaced the front and rear wheel bearings, had the diff professionally rebuilt with new bearings and seals, rebuilt the brakes (front and rear) replaced the propshaft UJ's and had the propshaft professionally balanced.  

On Saturday we went for a run to visit some friends and the vibration seemed minimal so I didn't think much of it at the time. The car sat for about an hour and a half and then we proceeded to drive home. As soon as I hit the motorway and the speed came up to about 50mph, the vibration felt like the car was going to shake itself to bits (I'm talking REALLY bad here). It felt like it was coming from the centre of the car and could be felt through the driver and passengers seats and it was especially bad through the gear lever. Its definitely the worst its ever been!!! I had to slow down to about 30mph for it to cease. When we left the house, the diff and gearbox would have been cold and warmed up over the drive. Would the heat build up from the diff and gearbox make any difference to it?

After much swearing and cursing, I removed the propshaft and am going to run the car and test the gearbox at 55mph while stationary to try and eliminate the front end. I doubt it's the gearbox or anything in the rear end as its all been replaced/rebuilt.

I don't think the propshaft is a Vitesse one either. It has the sliding spline at the front and I can't detect any play in it - but that doesn't mean its not there. Would a brand new propshaft work? With new UJ's and balanced up? This is all I can think of trying now.

Mark    

[Nick Jones]

Sounds familiar........

The only way I've ever been to get my Vitesse vibration free was to balance it on the car with two jubilee clips.  That included (over quite a few years) different gearboxes (even a Toyota one), different diffs, different propshafts (including a specially made one for the Toyota box which was balanced twice), different driveshafts, different wheels.  I've also messed about with gearbox mounts to change the driveline angles. The only things that made any difference were all to do with the propshaft, and the only cure was the on-car balance.  I have no idea why.

Good luck!

Nick

[esxefi]

unless you have tried already you could try fitting the prop with the sliding spline at the diff end.

triumph props seem to have a life of their own, as nick says.

there is a current thread about vibration and countless others in the archive.

I would suggest getting a second opinion on the prop balance somewhere else unless you are confident about it from the start.

I had an imbalance some years back and took it back to the guy who provided it(it was a hybrid prop)who assured me it was fine.

anyhoo the vibration was still there so I sent it to a place in west London(name escapes me at the mo')they said was out of balance.returned it and it was fine after that.

also are you sure it is a driveline vibration?

there is a distinct difference in frequency from a wheel and a prop one(this being caused by the diff ratio)
but from what you say it sounds like driveline :-/

[Rangi246]

I didnt think of turning the prop around.

Ive just checked the sliding spline. As it slides, it has a minute amount of play left and right when twisted, about 1mm in total.

Is this an acceptable amount or is it pretty worn?

[marktheherald]

Check that you haven't got a damaged tyre... I had a bulge in an inner sidewall that gave this effect.

[Pete Lewis]

when we got the Vit6 in 2003 it had all sorts of vibrations from previous mal practices

like your we balanced crank and changed everything  clutch,replaced the oiless gearbox, new diff drive shaft uj and uncle tom cobbley and all. and the vibro growl  stayed around the 55-60 ., you could drive through it if you could stand the noise,

the orig prop telescope was competely stuffed , realy slack ,  new propshaft made at local recoprop, ,all the same

so after chasing this for  ages and doing everything twice you learn ......stick to the simpleze

in the end it was the dreaded float on the shaft UJ's that made the most improvement , you must have absolutely NO lift or float in these cups,  thicker clips can be sourced and you can fit these on the car , may nly need one or two

just make sure they are fully located as if they pop out   there's a lot of expleatives .

Pete

[thescrapman]

7902 wrote:

I didnt think of turning the prop around.

Ive just checked the sliding spline. As it slides, it has a minute amount of play left and right when twisted, about 1mm in total.

Is this an acceptable amount or is it pretty worn?

1mm is a bit knackered.

try it the other way round, it may be better.

Cheers

[Nick Jones]

1mm is a bit knackered as Colin says, though not necessarily the cause of your troubles.  I've found that knackered splines tend to show up as a worsening vibration when you are coasting on neutral throttle and diminishing (to an extent) under acceleration or over-run.

Nick

[Pete Lewis]

most manuals show telescope at the rear , cant see it makes much difference

Pete

[Nick Jones]

peterhlewis wrote:

most manuals show telescope at the rear , cant see it makes much difference

Pete

Makes it easier to access the grease nipple - that is all.

Nick

[Dazman1360]

I would also try rotating the prop 180 degrees at the gearbox flange, then if no better at the diff flange, then again at the Gearbox flange so you have tried all 4 combinations. No idea why this can make a difference, but it can.

[RobPearce]

7017 wrote:

I would also try rotating the prop 180 degrees at the gearbox flange, then if no better at the diff flange, then again at the Gearbox flange so you have tried all 4 combinations. No idea why this can make a difference, but it can.

It can make a difference for the same reason that balancing on the car works better - namely that a small imbalance in the prop, if correctly aligned, can compensate for a small imbalance in the shaft it attaches to. And, for the purposes of this point, slight off-centre of the flanges can be treated as an imbalance.

[Pete Lewis]

and always make sure the mating coupling surfaces are free of any aged  bruising or anything to stop them running true
even a wad of paint can upset the runouts

Pete

[Rangi246]

Thanks for your help. I put a new prop on and tested the car. The vibration is a little better but still not good. I removed the prop and decided to test the gearbox on a hunch.

Turns out the vibration is coming from the j type overdrive. As soon as its engaged it vibrates badly. I've removed the gearbox as I suspect the od needs pulling.

I havent done an od before and am thinking the bearings need replacing but is there anything else that it could be?

Mark

[esxefi]

unless you are confident in tackling an OD I would advise that you hand it to someone who knows them inside out.
they are quite complex and require special tools to set up properly plus you should get a guarantee or warranty for a refurb'd unit.

if it is as you suspect just a bearing it shouldn't cost so much.

but on the flip side they are pretty robust and most problems are oil pressure activation related.

there are a few good people who will deal with it for you.

mike papworth is one as well as Canley classics and a handful of other traders.

I have no dealings myself but they all have good recommendations :)

might be worth providing your g/box too.

[Nick Jones]

Vaguely remember that it is possible for OD units to be assembled with their gears incorrectly "timed" (there are marks that are meant to be aligned when the planetary gearset is assembled).  Vibration is one of the possible consequences of this being wrong.

Otherwise it will probably just be a case of replacing bearings.  Does it leak oil from the output shaft?

Nick

[Rangi246]

It didn't leak oil from the back when the drive flange was on. As soon as I took it off it leaked out though, quite badly. Is this a sign the bearing is a bit stuffed?

Any idea where the marks are on the planetary gear and how they line up? I've had a look and there a some notches on the inside of the cogs.

Mark

[Nick Jones]

No, it will leak with the flange removed.

This may help re gear alignment though note this is an A-type OD

http://www.tonydrews.com/Overdrive/A-type%20OD%20manual.pdf  (page 16)

Nick

[Pete Lewis]

D type

the planet  hub has very small etched dots/marks, the very edge of one of  the 3 gears teeth have another etched line maybe a dot, not easy to find

these are aligned so all 3 gears have the same contact load , or you end up with 1 loaded and 2 sort of free wheeling

so all 3 need setting  to this best running  condition or you can make good vibrations.

and dont sneeze when re assembling,  

to get the main shaft back in easy without fafing about with the splines , use two big drivers to lever open the cross bars against their springs this allows the whole shaft spline set up to just pop on easy

Pete

[Rangi246]

Thanks for your help.

I've disassembled the OD and there are no broken gear teeth, circlips or scoring anywhere. In fact I suspect the previous owner has had the OD off before as its got all new O rings, annulus looks like new, cone clutch appears fully reconditioned and the bearings are new as well. I can't find any play in the rear annulus bearing but did find a bit in the sun gear and bearing (sideways play). I'll replace the clutch and sun gear bearings and see if that makes a difference. I also noticed that previous owner has used a fully sealed bearing at the back of the annulus?

I'll also have another look at the planet gears again and see if I can spot the etched marks. The Buckeye website says they don't need lining up on a J type overdrive???

  

[Rangi246]

Looked at the planet gear again, there are definately no etched marks on the gears anywhere. I can see two notches inside each gear wheel on opposite sides (there are two of them).

[Pete Lewis]

there should be a line runs outwards from the 3  spindle ends,  right on the  side /tip edge of the planets is a  small etched marker

may have to really clean the edges to see these  they are shown in all the manuals but take a bit of finding under the oil and staining

Pete