Parts quality AND Materials???

[John Bracher]

So today, I started to begin reassembly of my failed TR6 clutch.

Using new parts from Moss, I found the following :-

1. The new/replacement cross shaft bushes seem to be a worse fit on the shaft than the old ones!!!!

I can probably only finally verify this by fitting the new ones, probably wrecking the old ones in the process??

 

2. The new/replacement Bronze bearing carrier is a REALLY tight fit on the gearbox extension.

I am not sure it will even turn easily once fully on??!!??

To me, it needs a couple of thou skimmed out of the bore to make it a 'slide fit'.

 

3. The material of this new 'Bronze' carrier is REALLY 'yellow' compared to the old (sadly, quite knackered) one.

I have photographed the 2 side by side to try and show the difference.

I cleaned up a small area on the old one with 1500 w&d paper to show the material colour (difficult to photograph well!)

The old one is 'Pinky/Orange', the new one is 'Yellow'.

Can anyone advise if the new one is actually Bronze, or in fact Brass???

 

4. It has cutoff saw marks on one end, from where the material was trimmed down from the stock bar before turning.

When I was an apprentice engineer, this part would have been rejected, and probably your head slapped for trying to pass it as 'correct to drawing'!!!

 

Any suggestions gratefully received..........

 

[SuzanneH]

Don’t use it in your TR the material is  too soft. This item is designed for Saloon cars not TRs. Hope this helps.

[BlueTR3A-5EKT]

Hmmmm!

I do not know what material they have used for that repro but it would be worth asking the question.   If too soft it will bell at each end in service, causing it to rock on the cast iron snout.

Ask them to fit the carrier on a new snout from their stock.   If it fits ok then either their snouts are undersize or your old one has got bigger in service (ooo matron)

  That end machining for the price earns a throw back at the supplier.

 

Here is a comparison of materials in the bronze range and some of their properties.   Perhaps PB1 is what your original is made from

https://www.leedsbronze.co.uk/materials.html

Edited November 28, 2021 by BlueTR3A-5EKT

[PXC]

Those cut-off marks very poor. It looks to me like in an attempt to save material, the maker has cut off so short that he hasn’t had enough material left to machine the piece cleanly to length across its whole width.  

[Z320]

Hi John,

this cut marks looks not very nice, but this surface causes noting, so I see no problem here.

But the carrier must be bronze and slide easy on the „tube extension“ of the gearbox.

If not bronze the two pins of the fork will dig in the material. Yellow very likely is only brass.

In my opinion you better not let the carrier spin, a roll pin avoids this. Original a „dent“ was also used, we discussed this some time ago.

Roger showed a „LOVELY“ photo, but I can’t help with that, I hope he will join this thread.

Ciao, Marco

 

Edited November 29, 2021 by Z320

[SuzanneH]

Roger says, he believes Reviington sell the correct item.

[brian -r]

John

Maybe speak to Tom at TR Enterprises they supplied and fitted the correct parts to my TR6 clutch after a certain "specialist " wrecked it.

Fitting doggy parts will make it dangerous to drive in traffic as I found out

Brian

 

[RobH]

I should think doggy parts would make it a complete bitch Brian. 

(sorry)

[Kevo_6]

John, I had similar problems with the  new carrier (Steel in my case) and bearing a few years back causing a sticky clutch, had the gearbox out a couple of times and then finally I bought the bronze carrier and uprated bearing and shaft bushes which I doubled up from Revingtons. The clutch plate and Cover was from Moss. This has been no problem for the last 5 or 6 years.

[brian -r]

2 hours ago, RobH said:

I should think doggy parts would make it a complete bitch Brian. 

(sorry)

Too right Rob sent me barking mad

A bit like this laptop does.

[stillp]

5 hours ago, RobH said:

I should think doggy parts would make it a complete bitch Brian. 

(sorry)

Depends which bits of the dog!

[Z320]

I found it, see here „all“ informations, I hope this helps you.

Ciao, Marco

 

 

[John Bracher]

On 11/29/2021 at 7:11 PM, Z320 said:

I found it, see here „all“ informations, I hope this helps you.

Ciao, Marco

 

 

Thanks Marco.

[Nobbysr]

On 11/28/2021 at 7:41 PM, John Bracher said:

So today, I started to begin reassembly of my failed TR6 clutch.

Using new parts from Moss, I found the following :-

1. The new/replacement cross shaft bushes seem to be a worse fit on the shaft than the old ones!!!!

I can probably only finally verify this by fitting the new ones, probably wrecking the old ones in the process??

 

2. The new/replacement Bronze bearing carrier is a REALLY tight fit on the gearbox extension.

I am not sure it will even turn easily once fully on??!!??

To me, it needs a couple of thou skimmed out of the bore to make it a 'slide fit'.

 

3. The material of this new 'Bronze' carrier is REALLY 'yellow' compared to the old (sadly, quite knackered) one.

I have photographed the 2 side by side to try and show the difference.

I cleaned up a small area on the old one with 1500 w&d paper to show the material colour (difficult to photograph well!)

The old one is 'Pinky/Orange', the new one is 'Yellow'.

Can anyone advise if the new one is actually Bronze, or in fact Brass???

 

4. It has cutoff saw marks on one end, from where the material was trimmed down from the stock bar before turning.

When I was an apprentice engineer, this part would have been rejected, and probably your head slapped for trying to pass it as 'correct to drawing'!!!

 

Any suggestions gratefully received..........

 

yep when i was an apprentice a beating would have followed that finish 

[John Bracher]

Almost a shame that ethos doesn't still apply..........

After the initial shock, things would improve!!

[RogerH]

Hi John,

if you haven't fitted the bearing carrier yet then do look at the link that Marco(Z320 ) posted.

The carrier supplied by Moss and Rimmers are for Saloon cars that have the slipper pads on the fork pins. These spread the load.

For the TR cars you need the harder (more expensive) dark gold Phosphor bronze carrier that help resist the digging of the fork pins.

Although the bearing is designed not to spin it ould actually be an advantage to allow it to as this would put the fork pin reaction contact area in a different place on each actuation.

Roger

[stuart]

39 minutes ago, RogerH said:

Although the bearing is designed not to spin it would actually be an advantage to allow it to as this would put the fork pin reaction contact area in a different place on each actuation.

Roger

I prefer them to spin, if they come with the small dowel pin I remove it or if they have the pinched section I get it machined out.

Stuart.

[Ralph Whitaker]

For my sins, I was an apprentice at RHP bearings in Ferrybridge in the early 70s, clutch release bearings were our main product and were original equipment for a lot of British car manufacturers. One thing I do remember was that the main cause of wear on a clutch bearing was the initial start up. You imagine taking your car up to max revs and then hitting the clutch to change up, as the release bearing made contact with the cover the bearing was subjected to zero to 4000 rpm or more, in a fraction of a second, causing the balls in the bearing to slip until they caught up. It was found that by keeping the release bearing in light contact with the clutch at all times the life of the bearings was increased enormously. Subsequent clutch designs allowed for this, usually by doing away with a pull off spring, and having a light spring in the slave cylinder which kept the piston out and automatically kept the clutch adjusted, ie; no free play and the bearing in light contact.

Looking at the parts books, 4cyl cars were all fitted with pull off springs between the operating arm and the slave cylinder bracket, 6 cyl cars  did not have this spring, but at the same time were fitted with the pin in the bearing carrier to stop it rotating. I am assuming that was because now the release bearing was meant to be in permanent contact with the later type clutch cover.

Anyway, just an observation,

Ralph

[BlueTR3A-5EKT]

3 hours ago, Ralph Whitaker said:

For my sins, I was an apprentice at RHP bearings in Ferrybridge in the early 70s, clutch release bearings were our main product and were original equipment for a lot of British car manufacturers. One thing I do remember was that the main cause of wear on a clutch bearing was the initial start up. You imagine taking your car up to max revs and then hitting the clutch to change up, as the release bearing made contact with the cover the bearing was subjected to zero to 4000 rpm or more, in a fraction of a second, causing the balls in the bearing to slip until they caught up. It was found that by keeping the release bearing in light contact with the clutch at all times the life of the bearings was increased enormously. Subsequent clutch designs allowed for this, usually by doing away with a pull off spring, and having a light spring in the slave cylinder which kept the piston out and automatically kept the clutch adjusted, ie; no free play and the bearing in light contact.

Looking at the parts books, 4cyl cars were all fitted with pull off springs between the operating arm and the slave cylinder bracket, 6 cyl cars  did not have this spring, but at the same time were fitted with the pin in the bearing carrier to stop it rotating. I am assuming that was because now the release bearing was meant to be in permanent contact with the later type clutch cover.

Anyway, just an observation,

Ralph

Good observation    Having the bearing continually running makes very good sense.

My only addition is that the clutch slave pull off spring was deleted when the clutch type changed from 3 fingered spring type to diaphragm type. (TR4A). The release bearing operating/contact face shape changed from flat to curved also with the clutch type change. The release bearing carrier grew in length too.

Edited December 30, 2021 by BlueTR3A-5EKT

[RogerH]

Hi Ralph,

That is a nice observation.

 the 4A is the exception.  It does not have the pull off spring.  Although I do have one fitted to my 4A.

 

Roger

[Lebro]

Well that has got me thinking, should I remove the spring from my slave cylinder ? (I do have a diaphram clutch)

Bob

[stuart]

31 minutes ago, Lebro said:

Well that has got me thinking, should I remove the spring from my slave cylinder ? (I do have a diaphram clutch)

Bob

Ive had one fitted for 26yrs at least with no problems so I wouldnt worry.

Stuart.

[BlueTR3A-5EKT]

2 hours ago, Lebro said:

Well that has got me thinking, should I remove the spring from my slave cylinder ? (I do have a diaphram clutch)

Bob

Have you got an anti spin pin fitted in the carrier?   If not then leave it alone.   I am in the same boat as you Bob.  Diaphragm clutch and a slave release pull off spring. I have no idea if the carrier has the anti spin pin fitted so am leaving well alone.

[ntc]

Maybe something to do with the thickness of the front of the gearbox 

[Lebro]

4 hours ago, BlueTR3A-5EKT said:

Have you got an anti spin pin fitted in the carrier?   If not then leave it alone.   I am in the same boat as you Bob.  Diaphragm clutch and a slave release pull off spring. I have no idea if the carrier has the anti spin pin fitted so am leaving well alone.

To be honest I don't know if the pin is there or not. Although the box was out & re-built a year ago, the bearing seemed fine, so I just put it back in without examining it in detail. It came from the TR shop along the "GT6" cover & driven plate.

Bob