Clutch Thrust/Release/Throwout Bearing Part Numbers

[fatboyoz]

Hi All,
Thought I would start a new topic to bring all of the clutch release bearing, part numbers together with an easily searched heading.
I will start by refering to Rohan's list:

"The number 408504 hand written on the box is I believe the SKF bearing equivalent number to the RHP and FKC 6W - 1 3/8 number thats printed on the box. I have a NOS FKC one in a box exactly the same. The list below is the numbers I have tracked down. These all had plastic inner sleeves of various colours except the FAG and I believe the SKF ones which were brass like the cheap new no name ones. My no name bearings dont have that 405804 number etched on the face

Original Manufacturer Number
Ford 105E7580
Ford 105E7580B
RHP 6W 1 3/8
FAG 508458
Timken 1375
FKC 6W 1 3/8
SKF 408504

cheers
Rohan."
Referenced here:
viewtopic.php?f=37&t=47142&start=15


One number that Rohan mentions above; 405804 is also mentioned by TeeJay back in 2007:
"Hi. Anyone got any comments re the fit of a new Clutch Thrust Bearing?

I have a new bearing and when I came to fit it to the carrier, it was a loose fit.
The Workshop Manual states that it has an interference fit.

Should I fit this, or try to locate a correct interference one, if I can locate one?

It was purchased from CN, but I understand that PM also has a batch of loose bearings.
I assume that they have come from the same Manufacturer.

My guess is that the interference fit on the shoulder is to ensure that the bearing race rotates only, so am I right to think that being loose, the whole bearing could rotate on the carrier, which would damage the carrier?"

Thanks for any replies.
Attachments
Clutch Thrust Bearing.jpg
https://lotuselan.net/lel/2650/1/Clutch ... earing.jpg


So, it would appear that bearing 405804 is similar in looks, but, where the correct bearing is an interference fit on the bearing carrier, this bearing is 0.002" too big and will not do the job. As Miked quoted a couple of days ago: "All the right numbers but not necessarily in the right order as Eric Morcambe would say."
viewtopic.php?f=37&t=47142

I have recently bought a couple of SKF 408504 from 123Bearing:
https://www.123bearing.eu/bearing-408504FX-SKF.php
Not cheap, but a quality bearing.
I will add, that my original bearing was made by a company called Pollard, England, 6/W 1 3/8.
Cheers,
Colin. (Have to do something during these Covid restrictions).

[2cams70]

You actually don't need to restrict yourself to using the early flat face release bearing and can use the later round face bearing instead. Use a spacer together with the round face bearing and make sure you use a matching pressure plate with bare springs without the thrust pad. I believe the 5 speed Elans and the later RS escorts used the 8.5" pressure plate without the thrust pad.

https://www.burtonpower.com/clutch-rele ... d3259.html

[mbell]

I believe the 5 speed Elans and the later RS escorts used the 8.5" pressure plate without the thrust pad.

The 5 speed uses:
- 8.5" plate
- round face bearing
- pressure plate without thrust pad

[2cams70]

The 5 speed uses:
- 8.5" plate
- round face bearing
- pressure plate with thrust pad

Are you sure?? Round face bearing should be used with clutch pressure plate without thrust pad. See link below.

https://qedmotorsport.co.uk/product/clu ... ion-helix/

[mbell]

Your right, no thrust pad for 5 speed. I am obviously overdue an engine removal job to refresh my memory....

Edited my original post to avoid confusion.

[RichardHawkins]

My understanding of the flat ring attached to the pressure plate is that it was a carryover from a time when a release bearing was made from carbon or graphite, and required a smooth flat surface. My old Morris 1000 1963 had a carbon thrust onto a flat ring, and so did my 1968 Elan when I first took the clutch apart. I think if you were to look at a more recent vehicle you would find a curved face thrust bearing working directly on the pressure plate fingers.

Given how difficult it is to replace a thrust bearing on our cars I think it well worth the effort to find the correct item from a reputable manufacturer.

Pollard was a predecessor to Ransome Hoffman and Pollard which became RHP, and I think then absorbed by NSK.

Hope this helps

Richard Hawkins

[2cams70]

Given how difficult it is to replace a thrust bearing on our cars I think it well worth the effort to find the correct item from a reputable manufacturer.

In the parts manual for the later RS Escorts which used exactly the same bellhousing, transmission and clutch fork as the Elan you will find a change in part number for these parts when they changed the bearing design to the round face type. If it works in an Escort there should be no reason why they wouldn't work in an Elan. No doubt it is an improved design compared to the earlier flat face bearing.

[rgh0]

Given how difficult it is to replace a thrust bearing on our cars I think it well worth the effort to find the correct item from a reputable manufacturer.

In the parts manual for the later RS Escorts which used exactly the same bellhousing, transmission and clutch fork as the Elan you will find a change in part number for these parts when they changed the bearing design to the round face type. If it works in an Escort there should be no reason why they wouldn't work in an Elan. No doubt it is an improved design compared to the earlier flat face bearing.

The Plus 2 5 speed used the same later design pressure plate and round nose bearing with a longer carrier for the bearing and the same pivot pin and arm. I don't think the later design is superior but it is probably cheaper. I find the ends of the diaphram spring arms that bear directly on the round nosed bearing face wear on the later design. I have stuck with the earlier design on my Elan so far despite the bearings for the later design being more easily available.

cheers
Rohan

[2cams70]

I don't think the later design is superior but it is probably cheaper. I find the ends of the diaphram spring arms that bear directly on the round nosed bearing face wear on the later design.

My experience with the early design is that diaphragm finger wear is no better or worse than the later design. You just can't see it in the early design because it's hidden by the thrust pad! If you look carefully though underneath where the pad contacts the finger you most certainly will find evidence of wear.

It's not unusual in Automotive engineering for later designs to be both cheaper and better - you can have both you know! Certainly eliminating the thrust pad reduces the number of components that can possibly go wrong and the round nose bearing design is what's commonly used on modern vehicles.

Usually by the time the diaphragm spring fingers are worn the rest of the clutch is well beyond it's use by date so it becomes a moot point in any case.