• Hi Guest!
    You can help ensure that British Car Forum (BCF) continues to provide a great place to engage in the British car hobby! If you find BCF a beneficial community, please consider supporting our efforts with a subscription.
    There are some perks with a member upgrade!
    **Upgrade Now**
    (PS: Subscribers don't see this gawd-aweful banner
Tips
Tips

Throwout bearing: roller or carbon?

Share this page

TulsaFred

TulsaFred

Jedi Warrior
Country flag
Offline
The carbon face throwout bearing strikes me as a really bad design. I see that Colin Dodd sells a hand made roller bearing on ebay for $125 plus $18 shipping. Pricey. He says that the modern repro carbon face "bearings" are of poor quality compared to the originals, and that they may only last 6 weeks!

Who has used the repro carbon throwouts, and what has been your experience on their longevity?

Is the roller bearing worth it?

https://www.ebay.com/itm/Austin-Hea...A-clutch-roller-release-bearing-/181638163103

Fred
 
Last edited:
Fred,
I would use whatever prevents me from having to pull the engine and transmission prematurely. I don't know about the quality of the new carbon TOBs, but if the roller is an upgrade that's what I would do.
Rut
 
Probably right, Rut. Unfortunately, I've got a new carbon face TOB fitted, and was going to marry the trans and engine this weekend. Ordering a roller bearing from Australia will likely take a few weeks, which is a long delay on the project.

If others have had a reasonable experience with the carbon bearings it may be worth the risk to keep the project moving.

Fred
 
Fred,
Ill be dealing with this in the near future so I did a little more research on Google looking at MM, classic Minis, as well as Midgets and Sprites. The general consensus is that the carbon bearing lasts as long as the roller if you treat it right and the clutch fork is not worn. One of the sites mentioned Peter May so I'll post that link.
Rut
https://www.petermayengineering.co.uk/specialistProducts.htm#5.6
 
I've always used carbon in all my cars (including current race car). It's never really been an issue.
 
Of course (for those in the know - namely people here), it's important to not depress the clutch when sitting idle. I've had to tell my wife this. With that in mind, I find they last a good length of time (though I agree that a "bearing" type would be nice).
 
I guess I'll just go with the carbon bearing I've already got fitted.
 
A couple things...

The ones to watch out for are the ones secured by a roll pin. I don't know if anyone is still making them that way, but I detail on my page on the subject, as do I show and detail Colin's roller bearing. The main issue with the roller bearing is that unlike gearboxes where the roller release bearing travels in a straight line against the clutch fingers, the BMC design travels in an arc. I think Colin may have dealt with that issue with the friction surface mated to his roller bearing, but I don't think any of the others made are that way.

https://gerardsgarage.com/Garage/Tech/TO_Bearings/tobearings.htm
 
One bonus with the roller T.O. is the ability to set a lower idle RPM. The friction between the Clutch arms and the Carbon T.O. is gone.
 
i had my worn bearing replaced with a regular carbon one and just about three months later it was already shot. went with the roller bearing from the source in australia. another source in the UK makes them but my mechanic got a response from the Australian place first so we went with that. it seems great to me. i wanted a picture of the one that only lasted a few months but it got tossed too soon. whoever is making them is not doing a good job at all and i'd advise anyone to steer clear of them. there's no excuse for a new part to crap out so quickly. for a couple of days i was hearing odd random ticking sounds and then one evening the clutch gave some crunchy feedback and within blocks it felt like i barely had a clutch at all. it just crumbled.
 
Back
Top