Spare Triumph 1300 engine crankshaft end-float

[jagnut66]

Hi, 

I've touched on this engine in another topic, where excessive end-float / worn thrust washers was mentioned, as a possible cause for not being able to engage gears.

At the time I mentioned that, as the engine is out it was easy to get at and move the pully, to see if there was excessive movement in my spare engine.

I also noted a metallic clunk when I pulled the pully out or pushed it in, though this could be down to the fact that the engine hasn't had any oil in it for an unknown amount of time (though it still turns quite happily).

Anyway I've just taken a couple of pictures, using a tape measure as a crude form of measurement, to show how far it actually 'moves'.

I have drawn on a small green arrow, to indicate the edge of the pully, which is where I was measuring to.

The first picture shows it with the pully 'pushed in' (47mm?) the second with it 'pulled out' (48mm?).

As far as I can see there is only about 1mm difference, is this anything to worry about / do I need to replace the thrust washers or could I fit this engine (at some point if I wanted or needed to) 'as is'?

Please take a look and see what you think.

Best wishes,

Mike.

[johny]

From the manual there should be a maximum of about 0.2mm play and the clonk sound plus your measurements indicate you are far in excess of that. Saying that the engine probably isnt damaged yet but I would plan to replace the thrust bearings before the engine is used. Its an easy and relatively cheap job especially while the engine is out of the car and you can have a look at the other crank bearings, the oil pump and even cylinder bores at the same time👍

[jagnut66]

Thanks Johny, as you say, it's easier out of the car.

So does this mean I need a thrust washer of 0.8mm thickness?

Best wishes,

Mike.

[johny]

No you need to accurately measure endfloat and the thickness of the existing thrusts to calculate the size of new thrusts needed. Orrr buy all sizes and play around until you just have a smidge of play🤗

[Sandy Gibson]

You need a micrometer or a decent digital vernier to measure the amount of play accurately.  Also, if you get a selection thrust bearings, you can use one size on one side of the journal and another size on the other to obtain the best result.

Make sure to install them with the bearing surface in contact with the revolving crank!

[thescrapman]

If you can hear the movement, it is getting too much, if you can feel it, it is bad, if you can see it, too late. 😞

1mm is way too much, expect the worst.

[Pete Lewis]

whip the sump off and remove  rear main cap check what size the exiting thrust is and what it was supposed to be  

it most likely just needs a std replacement  its the rear that takes on all the clutch loads that wears 

an old thrust can be as bad as near half its orig  size 

Pete

[jagnut66]

Time to put this one on the engine stand then..........

[DanMi]

I would say that about 1mm is worn but not to the bad extent that the thrusts have fallen out, which would be multiple mm and this is when it can affect clutch action. Probably just needs a new set the same as is in there and probably new mains and big ends whilst you are at it.

 

[blubayou]

And before you take the old ones out check they have been fitted the right way round...

[Pete Lewis]

someone fitted them back to front on my 2000 its not done the crank any favours due to a wear radius on the journal you dont really want 

it happens  

Pete

[jagnut66]

As an update to this I am now at the stage where I am about to strip the bottom of the engine and replace the thrust washers & bearings. As suggested above I have purchased standard ones only -- for now.

I have also found out that you can mix and match thrust washers, if necessary, in order to get the end float measurement that is best.

Plus I have invested in a Dial Indicator Test DTI Gauge (0 - 10mm) and have got the reading below:

It hasn't travelled more indicated on the large dial, namely under one revolution, so I take it this is a reading of 3.2mm? (Set to zero first and returns to this when pully is pushed back)

Sorry, this is my first DTI gauge and I'm still learning.

Best wishes,

Mike.

[NonMember]

3.2mm would be a lot of movement.  I think I read that as 0.32mm

[johny]

Yes the little dial shows complete millimeters up to 10mm which is the full travel of the instrument...

[jagnut66]

24 minutes ago, johny said:

Yes the little dial shows complete millimeters up to 10mm which is the full travel of the instrument...

 

29 minutes ago, NonMember said:

3.2mm would be a lot of movement.  I think I read that as 0.32mm

That's a relief, so standard it is then.

Plus thanks Johny, for clarifying how the gauge reads.

Best wishes,

Mike.

[DanMi]

you will not know what size that you need until you get the old ones out, a dial gauge will not tell you if the crank has already been ground and oversized fitted. I think that gauge is reading 0.68mm (it can go both ways hence the red numbers going anticlockwise and the small gauge is about 2/3 of the way to 1mm, but that's not terminal just a bit worn. The bearings should have a mark on the back to indicate the size eg std or +0.05 so look at them before ordering new, same goes for the mains and big ends

Edited April 16, 2023 by DanMi

[johny]

It could be that or usually the DTI outer bezel can be rotated so the numbers move round. This allows you to attach the instrument in the operated position, turn the numbers so that the needle is at zero and then release whatever your measuring. Then the needle will go counter clockwise and you can read off its travel on the red numbers...

[Iain T]

1 hour ago, DanMi said:

think that gauge is reading 0.68mm

I agree. Providing the gauge has been zero'd it's reading 0.68mm.

Iain 

[johny]

All depends how Mike did it😁 If he installed the DTI, zeroed and pulled pulley forwards needle will have gone clockwise and read 0.32. However if he zeroed and pushed pulley back needle will have gone anti clockwise and could be 0.68 or 1.68 or 2.68 up to 9.68 depending on where he started...

[Iain T]

43 minutes ago, johny said:

All depends how Mike did it😁

If it was - 0.32 the small mm dial hand would be closer to zero? 

Edited April 16, 2023 by Iain T

[johny]

Yes I agree so looks like the second method I described was used and the reading depends on how many times the needle has gone round. From the first rough measurement with tape photo it could be 1.68mm....

[DanMi]

8 minutes ago, johny said:

Yes I agree so looks like the second method I described was used and the reading depends on how many times the needle has gone round. From the first rough measurement with tape photo it could be 1.68mm....

the small dial is telling you that it has gone round less than once if it was 1.68mm the small dial would be 2/3 of the way between 1 and 2

[johny]

No I was guessing that the DTI had been zeroed and then the pulley pushed in to measure its movement so the main needle would go anticlockwise and the small needle could start on say 2.

Dont forget that you cant start your measuring with the DTI plunger at fully extended. You have to start with plunger pushed in a bit against the pulley so the small dial wont be on zero. Next you turn the big dial so the needle is at zero and then move the pulley...

[johny]

Anyway Ive reread the Mikes post and he did as Ive said, installed DTI so its plunger is pushed in slightly, zeroed the needle and pulled out the pulley. His reading of 0.32 is correct as the small dial started away from its zero and has now moved by an additional 0.32....

[DanMi]

without seeing the gauge I can't tell and the exact measurement doesn't really matter here, my main point is that you need to look at the existing thrust washers / bearings as the crank may have already had a grind and they may be over-sized already