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Balance of Prop


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Still feeling up beat following The Malvern show over the weekend.

I think 96 TR6s in the enclosed arena. Close on to 1 car for every 1000 made.

Plenty more 6s parked outside; ever spec and colour known to man.

 

Anyway. Still investigating the heavy vibration on the car.

I read this morning in the TR6 brown bible the following.

 

Removal of Propellor Prop shaft.

1. Place the car on stands.

2. Remove exhaust.

3. Mark for reassembly the relationship of the gearbox driving flange to

the universal joint flange and remove the four nuts.

 

Now when I removed the gear box over last winter, i did not mark up the flange.

I just rebolted the flange to flange afterwards.

 

Does this critically change the balance of the prop if not religned up a specific way?

 

John

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Still feeling up beat following The Malvern show over the weekend.

I think 96 TR6s in the enclosed arena. Close on to 1 car for every 1000 made.

Plenty more 6s parked outside; ever spec and colour known to man.

 

Anyway. Still investigating the heavy vibration on the car.

I read this morning in the TR6 brown bible the following.

 

Removal of Propellor Prop shaft.

1. Place the car on stands.

2. Remove exhaust.

3. Mark for reassembly the relationship of the gearbox driving flange to

the universal joint flange and remove the four nuts.

 

Now when I removed the gear box over last winter, i did not mark up the flange.

I just rebolted the flange to flange afterwards.

 

Does this critically change the balance of the prop if not religned up a specific way?

 

John

With the off set of the bolt holes it will go one of two ways thats all so its 50/50, try it the other way round. You could try the old hose clip trick as a balancer. Attach hose clip around the prop opposite to the balance weight that is already there (small plate welded to the side of the main body of the prop) and try it up the road and then keep moving it round until the vibration lessens or take it off and send it off for a complete rebalance.

Stuart

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With the off set of the bolt holes it will go one of two ways thats all so its 50/50, try it the other way round. You could try the old hose clip trick as a balancer. Attach hose clip around the prop opposite to the balance weight that is already there (small plate welded to the side of the main body of the prop) and try it up the road and then keep moving it round until the vibration lessens or take it off and send it off for a complete rebalance.

Stuart

 

John, Stuart,

To amplify stuart's description;

TWO jubilee clips are needed.

You are using the screw mechanism as a counter weight, and by itself, one is far too much.

Mount them on the prop shaft with the screws opposite to each other.

They will then balance and have no effect on the shaft.

Mark their positions, with paint, or Typpex.

Move ONE, and test drive; if worse, move it the other way.

Then move the other, likewise.

Continue to shift the clips until balance is acheived.

 

To be honest, this process is either a wonderful excuse for driving your TR about, or a pain in the ............

It may be better to have the shaftworkshop blananced.

 

John.

 

PS Did you just unbiolt form the gearbox, or remove the shaft entirely.

One end gives two choices, two ends gives four.

One will be dreadful, two so-so, one perfect! J.

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I did only remove from the gear box end.

When I married then up again after , I did so without a care as

to the correct positioning. In fact I was unaware that It made a difference.

 

When you say there are two positions, are we talking 90 deg out either way

as the alternative, as apposed to 180 deg being the same as the start off position;

if that makes sense?

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I did only remove from the gear box end.

When I married then up again after , I did so without a care as

to the correct positioning. In fact I was unaware that It made a difference.

 

When you say there are two positions, are we talking 90 deg out either way

as the alternative, as apposed to 180 deg being the same as the start off position;

if that makes sense?

Its 180 degrees as the prop flange will only marry two ways.

Stuart.

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John

 

Just curious but does the vibration come in at all speeds or just certain ones? I ask because I started feeling what potentially was prop vibration on my 6 on the way back from Malvern, but only above an indicated 80.............(I know, don't drive it at that speed :rolleyes: ) My prop has been off in the past but as I didn't do it, I've no way of knowing whether it went back again correctly.

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Bob

The vibration comes in at 50mph ish and gets increasingly worse.

People tell me this tends more to be a wheel problem speed, but the wheels have just been re-balanced.

I suspect the prop first of all because it was detatched over the winter and i paid no attention how it

went back together.

 

John

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Correct John.

The 4 holes do not form a square,so only 2 possible positions to fit it!

It is very possible that when you re-connected it,that the 2 flanges havent seated down in the recess correctly,this will cause a bad vibration.

Also make sure your nuts and bolts are all the same size,and fitted from the same side as an odd one could cause it as well!!

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The power of the forum

 

I may be getting some where now.

I have just removed the tunnel guard to get to the front UJ on the prop.

 

It is shot to pieces. Wobbling around like a good'un.

 

Also I can see a clear engraved line on the overdrive flange which corresponds

180 deg with a line on the UJ flange. dooooowwwww :huh:

 

Hoping over the weekend to get the prop out and check the other end UJ + splines.

 

My only worry now is that I could potentially have damaged the new bearing I put

in the overdrive over last winter; although the overdrive flange seems solid.

Then there is the bearing in the diff.

 

Although it is not yet fully resolved, thanks to all your comments that have led

me in what seems to be the right direction.

 

Luckily picked up two new UJs at Malvern. Funny that.

 

John

Edited by JOHN'S TR6
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going of on a tangent here I know my 6 has developed a vibration when slowing down(not under braking) it`s nice and smooth under acceleration and braking I`ve not investigated yet has anyone got any ideas before i go and strip half the car before realsing I didn`t need to do all that !!!

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Just as an after though; my new UJs have grease nipplies.

My current ujs do not.

If my prop is atall balanced, will the introduction of the nipples throw the balance out?

 

Also I can see a small nut on the end of the prop. May this be to detatch the two parts of the

splines so that i can grease? I don't think i currently have grease nipples on the prop.

 

John

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Hi John.

 

Am glad youve found the problem!

Fix this first and try it before worrying about the o/d and diff bearings as they may well be ok!

The nipples shouldnt affect the balance as they are quite close to the center of the turning axis,however make sure they dont catch on the prop when its turned.

Do them slowly and carefully as a popped out roller bearing will knacker it in weeks if its not noticed!

OH ****!!!

Its thunder,lightening and torrential rain here and ive got to take the TR to a studio in town for a photoshoot!

 

Better go,and get there early,as it will no doubt need a bit of a clean up on arrival!

 

cheers dave

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I have just removed the tunnel guard to get to the front UJ on the prop.

It is shot to pieces. Wobbling around like a good'un.

As I said on 10 July in your topic about Vibration at 50mph - vibration on acceleration = front uj.

To which I would add - vibration on the overrun = rear uj.

 

I'm puzzled about scribing a line across the flange - I've never done that on any car - surely it can make no difference, provided the prop is balanced?

And on cars where there is a rubber boot on the prop splines - eg my Landy - I've put the hose clips on any whichway without (apparent) detriment. In future, I'll be careful to oppose them. As you say, the power of the forum.

 

Ivor

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Ivor

 

You did say it may be the front UJ.

When I got the front flange off it was clearly marked with a very

accurate line and a centre punch line. There was also also the same on

the over drive flange. I had married these up 180 deg to each other previously.

Having said all this the flange looks symetrical.

No such marks on the rear of the prop or the

diff flange though :blink:

 

John

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You did say it may be the front UJ.

The trouble is, so many equally credible people say it may be this or it may be that... :unsure:

What's appreciated however, is taking the trouble to report back on the outcome, from which we all learn. Not everyone bothers.

Thankyou.

 

Ivor

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  • 8 years later...

Propshaft can not be removed upwards.

Exhaust must be removed and both flanges stripped.

Than rear end upwards over/besides the diff and front

fiddeling under gearbox to the front.

 

If joints are changed balance might be lost.

 

Vibrations between 80 and 90 Km/h are indicated

to wheel / driveshaft imbalance.

These vibrations come back at higher speed.

Our TRs are very sensitive to that and steel wheels

are only centered by the bolts what is not perfect

 

Wire wheels must be rebalanced from time to time.

When lifted off and refitted I found an imbalance of

30 grams quite often.

 

I bought a Hofman SD-10 finish balancer to balance

wheels at the car. Normally not affordable in these days

the tire shops want to get rid of that equipment and sometimes

they are a bargain. With some space in the garage well spent money!

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  • 2 weeks later...
  • 5 weeks later...

Whether you replaced the prop shaft into its original orientation or not shouldn't affect the balance of your drivetrain - it's not as though the crank, transmission and prop were balanced as a unit at the factory. As long as the prop itself is balanced, then its orientation shouldn't matter (as others have said, it'll only go on one of two ways). Interestingly, when I took my prop in for balancing (I was in the middle of a frame-off, so I had the prop balanced and the flywheel refaced while I was in there), the guy said that the yokes were "off" (i.e., not aligned correctly) - he cut one off and rewelded it in the correct alignment (can't remember what the actual issue was, but I didn't notice any real difference between before and after)

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