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Layshaft Woes


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Hi chaps

I find myself back in the same position as I was in 2016 when I renewed the layshaft and lay gear with new bearings after finding the shaft chewed up and bearing broken.

This time I've caught it before any other damage other than the layshaft wearing out after 1500 miles.

Obviously the shaft is crap, and I have emailed the supplier and await their response.

As I was a newbie to Tr ownership I did not know about the uprated lay gear and wondered if it is possible to get the one I have bored out to take the extra bearing.

Any advice greatly received.

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wondered if it is possible to get the one I have bored out to take the extra bearing

It is, but you have to find a machine shop prepared to take it on and many will seek to charge more than a new double bearing shaft would cost in the first place....

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Hi chaps

I find myself back in the same position as I was in 2016 when I renewed the layshaft and lay gear with new bearings after finding the shaft chewed up and bearing broken.

This time I've caught it before any other damage other than the layshaft wearing out after 1500 miles.

Obviously the shaft is crap, and I have emailed the supplier and await their response.

As I was a newbie to Tr ownership I did not know about the uprated lay gear and wondered if it is possible to get the one I have bored out to take the extra bearing.

Any advice greatly received.

Hello

check the diameter of the axle.

He must be 20.63 mm. exactly the same as the piston pin of the TR 6. You can use it as a master. Most axes do not have the diameter and do not have the required hardness. Some of the surfaces are very rough. Deadly for a needle bearing. In the past I had such axes produced in a machine factory. Then I found a good source in the USA.

Roadster Factory.

The exact measurement of these parts helps to prevent further damage.

 

Ralf

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Hi chaps

I find myself back in the same position as I was in 2016 when I renewed the layshaft and lay gear with new bearings after finding the shaft chewed up and bearing broken.

This time I've caught it before any other damage other than the layshaft wearing out after 1500 miles.

Obviously the shaft is crap, and I have emailed the supplier and await their response.

As I was a newbie to Tr ownership I did not know about the uprated lay gear and wondered if it is possible to get the one I have bored out to take the extra bearing.

Any advice greatly received.

Hi Chris! Here is a story that you are not going to like. After 44 years of use my gear box started to whine in second, third but the whine disappeared in fourth. I spoke to ORS and Peter there told me that the lay shaft and bearings were on the way out! The common fault with the TR Gearbox? The gearbox was removed and taken apart, yes this was the problem. In the meantime I went to Moss for a new lay shaft but I had read the Roger Williams book which was printed in 20002 and it states that you must do the file test on any new bought lay shaft. So having served a tool making apprenticeship out comes one of my Sanvick files which are very hard. In the Moss shop I was able to put a flat on the edge of their new shaft!!! I told their member of staff its soft!! It s/b around 60 Rockwell C. They then said that they would test there remaining stock ,as they had a Rockwell Tester, they were all soft at 40 Rockwell C.I asked them how many they had sold from that batch and the response was 48. So are you another unsuspecting TR victim of Moss quality? So based upon that saga I sent my whole unit including the O/D to ORS for rebuild. I did learn that ORS make their own and offer the Stag mod of 3 needle rollers at £70 extra which I had done also this fault with lay shafts has gone on for years and I mean years ,certainly over 25years. Its even caught out the TR Gear Box Guru So my advice is get ORS to sort it out for you.

Good Luck.

 

Bruce.

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Thanks for all your replies I think i am learning the hard/expensive way.

I have had a response back which I'm not happy with so will contact them back and see how it goes.

 

Hi Ralf diameter checked out ok within a knats with digital verniers.

 

Bruce thanks for you response the supplier was Rimmers so maybe same batch.

 

Roger I have sent a PM back thanks.

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Thanks for all your replies I think i am learning the hard/expensive way.

I have had a response back which I'm not happy with so will contact them back and see how it goes.

 

Hi Ralf diameter checked out ok within a knats with digital verniers.

 

Bruce thanks for you response the supplier was Rimmers so maybe same batch.

 

Roger I have sent a PM back thanks.

Chris: At some point I would like to know what Rimmers response was as your photos look to be the usual fault of lack of hardening. After speaking to the TR Gear Box Guru on Sunday, I am not impressed with the method of manufacture. It is certainly not manufactured the way I was taught, for a start I would be using EN40B steel and nitride harden, in some ways its the same problem as soft cam followers? Apparently they are made from case harden steel and in the final process of centre- less grinding to size, because they are far too large on O/D they grind off the harden layer!!!! to bring them to the correct size, as per the Guru.

 

Bruce.

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Hi Bruce,

I had been told that the manufacturer had issues with distortion. So they had a balance between hardening and bending - it wasn't bent but it wasn't hardened either.

 

Your Nitriding suggestion is the way forward surely http://www.summitglow.co.uk/processes/nitriding-nitrocarburising-treatments/

 

 

Roger

Hi Roger: Nitriding is an old process. its big advantage is the depth of hardening unlike case hardening. If there has been problems with distortion with that size of bar? it would suggest to me that it has been left in the furnace too long, in an attempt to increase the depth of hardening?

 

Bruce.

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Hi Bruce,

 

This was their last response after questioning what oil I used which was Morris Golden Film SAE40 Which states on the bottle ideal for classic gearboxes.

 

Hi Chris,

 

Whilst we are not oil technicians so can’t be sure what the difference is, the gearbox oil that we list in our catalogue and is shown in the workshop manual is Hypoid EP 90, so perhaps that may be a contributing factor? As Emily states our 12 month warranty period has long since past and we are not aware of any issues with hardening of these components.

 

Kind regards

The shaft cannot of had the correct hardening, so while they say its out of 12 months warranty how can that count when the part wasn't up to it in the first place.
Yesterday I did a test on it with a hacksaw which isn't very scientific I know and sent the photo to them, I haven't heard anything from them today.
It was only a few stokes with the small saw in the photo one handed.

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Hi Chris,

write back to them and state that Moss were made aware of this problem in the summer of 2017 or 2016 as per post #6 above and removed 48 shafts from stock.

The shafts were not heat treated - there was a manufacturing process fault. that should have been known about.

 

The oil that you use is more than adequate for the GB. The oil spec was changed to EP90 from SAE 40 probably to stop/reduce oil leaks - nobody knows.

 

Also state how many miles the shaft has done since the rebuild.

 

Roger

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Chris, I would find a local engineering m/c shop near you and ask them who has got a Rockwell Hardness Tester near to you. The hardness s/b 58 on the C scale, but looking at you demo with your hack saw. there is no chance of that? Also a point that I have never mentioned before is when the needle rollers grind there way through any sort of hardness layer, a nasty grinding paste of steel particles is being transported by the oil all round your gear box. You can imagine what that is doing to your gears and bearings etc. which means of course the whole gear box and O/D have to be fully stripped out and cleaned out. A real balls ache.

 

Bruce.

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Chris

 

Out of interest how does the layshaft receive an oil feed? Does it have a galley or does the laygear have scrolled bushes pressed in ?

 

Kevin

 

Kevin: there is a drilled hole up the middle of the shaft with an exit hole half along approx. Now I know that this is a contentious point but HP oil can take a much higher loading than engine oil except Mini engine oil so I do not know if this plays a part in longevity of the lay shaft but if you have a J type gear box its has hypoid gear tooth form, hence EP oil specified.

 

Bruce

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Now I know that this is a contentious point but HP oil can take a much higher loading than engine oil except Mini engine oil so I do not know if this plays a part in longevity of the lay shaft but if you have a J type gear box its has hypoid gear tooth form, hence EP oil specified.

 

Bruce

Just realised, it is a TR6. EP would be standard from day one.

 

Roger

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I have an old gear selector shaft from an Austin/ Morris 1300 that Ive used as a drift since about 1973 when it was changed. Ive just tried a hacksaw across it and apart from it wanting to skid over the surface Ive barely managed to mark it.

 

I know the Mk1 Cooper S had a nitrided EN40B crank but I wouldnt think this component was nitrided but its still very resilient, if its case hardened its very good.

 

Kevin

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A cheap poor manufactured component resulting in massive repair cost for the car owner.

I would be deeply ashamed if had supplied a soft layshaft to one of my customers.

Although the oil used does not have the Properties of an EP oil, a soft shaft will fail with any oil.

Good luck with the repair.

Waldi

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Roger I would happily take my hacksaw to Rimmers if it were closer not sure they would appreciate that though, when I get a chance I will fill out the parts quality for it may help others in the future.

 

I now know that the design of the lay gear bearings is not up to the task but the gearboxes must have originally performed adequately for a good milage before the layshaft was worn through the hardening, so does it mean that hardening techniques back in the day were better than now, surely as an engineering feat it can't be that hard a task. (no pun intended)

 

Chris

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Back in the day you paid good money for good Triumph or Standard parts. Providing the correct parts were used , when something was repaired subsequent parts failure was not an issue.

 

I for one, would gladly still pay good money for quality parts, unfortunately the replacement parts world has descended down to supplying lowest priced " copy parts" (as they say in HK) and in many cases I'm forced to use second hand parts because I know those available new are junk..

 

Still, forums like this help us spot the junk.

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Hello

This Laygear has run about 30,000 km. in 3 years.

Then total failure.

Diameter incorrect.

Hardness not correct.

Supplier Laygear is from Germany

Oil was changed every year.

75w / 90

Unfortunately, this is not an individual case.

 

 

Regards

Ralf

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