Spare Triumph 1300 engine crankshaft end-float

[johny]

Plus as I found you dont know how much the existing thrusts have worn. If for example he has standard size but unworn ones then he needs only one 5 thou oversize thrust. However if theyre standards but worn then just replacing like for like might be sufficient...

[johny]

To the job properly you need a micrometer to measure up what youve got otherwise you have to put in known size new thrusts, measure the float and then if incorrect buy what you need...

[DanMi]

29 minutes ago, johny said:

Plus as I found you dont know how much the existing thrusts have worn. If for example he has standard size but unworn ones then he needs only one 5 thou oversize thrust. However if theyre standards but worn then just replacing like for like might be sufficient...

It does not matter how much the thrust washers have worn, they are bin fodder. In my opinion if the same size (new)as existing does not bring within spec then get it to a machine shop for a grind to the next oversize, I would not mess with trying different sized thrust washers as if the crank itself has worn then the bearing surface may well be not perfect so it won't last long

[johny]

Wow big difference in cost there! Im not sure even when crank was new standard size thrusts were always used as it depends on the block machining as well. Of course you have to inspect the bearing surfaces but if ok Ive got no problem using oversize thrusts...

[DanMi]

14 minutes ago, johny said:

Wow big difference in cost there! Im not sure even when crank was new standard size thrusts were always used as it depends on the block machining as well. Of course you have to inspect the bearing surfaces but if ok Ive got no problem using oversize thrusts...

agreed but if the crank was ground for a  standard and a plus 0.005 then that is what would come out and what I would replace. if replacing like for like  ( I did not mention standard or otherwise) does not bring within spec then I would get it to a machine shop, I guess there is always a trade off between cost and longevity. I also have no issue using oversized thrusts if that is what the crank/block is machined for, but I wouldn't do it to accommodate a worn crank/block

[johny]

The trouble is I dont think you can know what the block was originally as the castings were all over the place in those days so they just machined em and then fitted what ever thrust was needed to get within tolerance. Believe there used to be even thicker thrust sizes available originally but no longer...

[johny]

In fact I reckon to lose 5 thou off a crank would require a huge mileage with numerous thrust changes or some kind of seizure. As the first is unlikely I would just confirm the crank thrust surface condition and fit the required size bearings...

[DanMi]

21 minutes ago, johny said:

In fact I reckon to lose 5 thou off a crank would require a huge mileage with numerous thrust changes or some kind of seizure. As the first is unlikely I would just confirm the crank thrust surface condition and fit the required size bearings...

which should be exactly the same as the ones that came out which is what I have been saying, just look at the size info on the existing thrust washers and buy the same, if then the endfloat is too great the crank is worn , which is not likely here as endfloat is not terrible. Or am I being stupid and they are not stamped with any oversize as big ends and mains are

[PeteH]

Hi

Ref; Thrust Clearances, I have this from the Haynes Manual for the Herald:-

The Thrust Clearance would appear to be extremely tight, a Mere 4 to 6 Thousand of an inch. Suggesting that the clearances shown by the DTI, are well out of specification? (5 Thou; is 0.127mm)(0.2mm is 0.00787402")(0.32mm would be 0.01259843)(0.68mm = 0.02677165) Or so my Calculator would have it.?

EDIT:- Just realised that is for the 1147 Engine. But the float for the 13/60. is still quoted at only 0.0042 to 0.0085". (0.11 to 0.216mm).

I supose to be fair, assuming the wearing face was acceptable (undamaged) it is probable the replacement of the Thrust with new thrust bearings of the same thickness should bring it back within acceptable tolerance?.

Pete

Edited April 17, 2023 by PeteH

[johny]

9 hours ago, DanMi said:

which should be exactly the same as the ones that came out which is what I have been saying, just look at the size info on the existing thrust washers and buy the same, if then the endfloat is too great the crank is worn , which is not likely here as endfloat is not terrible. Or am I being stupid and they are not stamped with any oversize as big ends and mains are

Its just that so much has been changed over the years by POs you dont really know what the original size thrusts were☹️ Not even sure all after market thrusts come stamped...

[jagnut66]

When I have the sump off and it dismantled I will check what sizes were last fitted and aim to replace like for like. 

I will then recheck the end float.

I will also get back to you (update this post) to let you know....

Best wishes,

Mike.

[jagnut66]

Hi, 

Okay, I had ordered standard sized bearings and thrust washers. 

Happily I'm glad I did now.

My micrometre showed that the existing ones were only slightly smaller than the new standard ones, the main wear being on the thrust washers themselves and the rear mains, one half of which was through to the copper(?). 

Anyway, all are now replaced, torqued up and I have a tight engine.

I now don't appear to have any fore and aft movement, previously caused by the worn thrust washers.

However, some 'you-tubers' seem to recommend a little bit of play but (as far as I am aware) my standard bearings are the smallest size anyway? Are they? And should I really be worried?

The above not withstanding, all things being equal I shall now put the covers back on with replacement gaskets where necessary...................

And cross my fingers...................

One thing, the metal cover over the front mains bolts appears to two wooden plugs either side of it, these are supplied new in my gasket set but do I need to change them?

They don't appear to have been damaged by the removal of said cover.

So far I have left them undisturbed and in place, are they likely to be an issue if left or not?

Thanks to all for your help thus far by the way.

Best wishes,

Mike.

[johny]

The manual gives the recommended minimum endfloat figure and you shouldnt go tighter than this as theres a risk of seizure due to insufficient oil flow (oil flow is necessary not just for lubricating moving surfaces but also taking away heat).

If you really cant detect any movement then its possible to remove metal from the back (steel face) of the thrust washers by carefully rubbing them on abrasive sheet laid on a flat surface to get the correct clearance...

[johny]

The other alternative is to use one of the old thrust washers if in good condition and only slightly smaller than the new one. In the end I would prefer to have slightly too much clearance than under spec....

[jagnut66]

Just now, johny said:

The other alternative is to use one of the old thrust washers if in good condition and only slightly smaller than the new one. In the end I would prefer to have slightly too much clearance than under spec....

That sounds like a good idea. The end float will still be less than it was, with the added benefit of my having a good spare standard sized thrust washer.

I will try this and report back.

Best wishes,

Mike.

[johny]

You could put the thicker one on the front side of the crank so that it runs slightly pushed backwards more and so the clutch travel is less when operated....

[jagnut66]

4 hours ago, johny said:

front side of the crank

To confirm, by 'front' side, do I understand you correctly by thinking you mean looking towards the front of the engine, as opposed to the flywheel side (which I would take to mean the back)?

Best wishes,

Mike.

[johny]

Sorry I was getting confused, you can put the thickest thrust in the rear position ie nearest the back of the car. Its a minor point but this is the side that wears the fastest as it takes the load when the clutch is pressed plus should give the best clutch operation...

[jagnut66]

3 hours ago, johny said:

Sorry I was getting confused, you can put the thickest thrust in the rear position ie nearest the back of the car. Its a minor point but this is the side that wears the fastest as it takes the load when the clutch is pressed plus should give the best clutch operation...

Thanks Johny.

[jagnut66]

Right, the front thrust washer has been swapped out for the best of the two used ones, this one definitely has more 'slop' around it but, apart from being slightly worn, it has no pitting or other damage..... unlike the other.......

For those interested I thought I'd post up some pictures of the main and big end bearings I have now replaced. At first glance it appeared that only the rear mains wear showing signs of wear....

However, I decided I'd clean the oily sludge off them, before taking pictures for your perusal, to find they weren't as 'unworn' as I first thought.....

And whilst one of the two thrust washers was only slightly worn (if after all this it successfully fires up and works well in the Herald I will still have to keep an ear, as opposed to an eye 😉, on it), the other was almost worn flat on the side with the oilway notch in it, worse still it was badly pitted (poor manufacturing quality standards?), so this ones a bin job for sure.....

Best wishes,

Mike.

 

[johny]

yes you just caught those in time - a bit longer and the crank gets damaged so a regrind is necessary.

Ive found pitting on thrusts and not sure what causes it. What end float have you got now?

[jagnut66]

I will let you know but it must be better than it was....

Thanks and best wishes,

Mike.

[johny]

Certainly replacing thrusts makes you realise why its not a good idea to ride the clutch😁

[jagnut66]

Well the 1300 engine went in today. The hardest part was reattaching the mounting rubbers onto their respective towers. They came attached to the engine and look in good condition, so I've reused them and therefore left them attached.

In retrospect it may have been better to employ a trick I use with Morris Minor engines, with one rubber attached to the engine and the opposite one attached to its tower, though with Minors the mounts tower itself is detachable too (bolts in place), which makes things really simple.

As always with this type of project I have discovered parts I don't have and need, so an order has been placed and I will get on with what I can in the meanwhile.....

One that has caught me out though (apart from the air filter housing which I've put a request out for in the parts wanted section) is the coolant return pipe along the side of the engine, it will not undo from the outlet on the side of the engine.

It turns so far then just jams up. I could try and force it but I'll break it in the process, so I've simply done it back up and left it attached to the 1200 engine. I hope it doesn't leak now..... 

Which means I also need a replacement return pipe for the 1300 engine, as it didn't come with one attached.

I hope after all this the blessed thing works! 😄

Best wishes,

Mike.

 

Edited May 29, 2023 by jagnut66

[Colin Lindsay]

The coolant pipe has two screw-connections, the large adaptor into the water pump housing and the smaller pipe-sized nut into the adaptor. I'm assuming the smaller one round the pipe is the one that spins? It's probably rusted up from years of use and will require heat and gentle force to remove. Hopefully you haven't dislodged the olive so that it starts to weep. The parts are all available if required, but the manufacture of some of the replacement pipes can be a bit off - mine was a gentle curve, more of an angle than a curve meaning that the rear bracket went nowhere near the head stud it was meant to attach to.