Do you use one or two springs??

[paisesmediterraneos]

 

Hello, I am David from Spain, I have a 1.6 k roadsport.

 I was reading at the club web the John Vine's tutorial about the clutch bearing preload.

How many of you are using the double spring at the clutch pedal??, is this a thing that the most of you use to do??, I have only one spring at the clutch pedal (as the car came from factory), will I damage my clutch bearing if I continue like this??.

 

Regards, David.

[Wrightpayne]

I’ve never had a bearing fail (they start squealing) but I’ve done the extra spring modification anyway.

It is interesting that the bearing is fitted in 1000s of Fords without problem but many Caterham owners have had failures - what is the reason?? 

For the cost and effort involved it was an easy decision for me!

Ian

[SLR No.77]

Never seen a need to do the mod. Not had a bearing fail in 20 years of Caterham ownership.

Stu.

[Paul Richards]

The problem can occur on a 7 because of lack of use. Bearing gets damp then stands for a few weeks getting rusty. Muck and rust build up and can cause a problem. Daily use prevents this. 

[John Vine]

It is interesting that the bearing is fitted in 1000s of Fords without problem but many Caterham owners have had failures - what is the reason?? 

Well, the basic reason is lack of sufficient pre-load on the CRB in the Caterham application.  In the equivalent Ford application (the Sierra), the required pre-load is applied by a quadrant mechanism on the clutch pedal that keeps the cable at the correct tension.  My two-spring mod is a way to replicate the Sierra design, and to implement the pre-load (80-120N) that the CRB manufacturer (INA) says is essential.

I have only one spring at the clutch pedal (as the car came from factory), will I damage my clutch bearing if I continue like this??

I assume the spring you have is the one between the clutch pedal and the back of the pedal box?  This spring will typically provide only around 15-20N of pre-load.  As far as I can tell, its main (only?) purpose is to prevent the cable detaching from the clutch fork.

Whether you end up with CRB problems depends on a number of factors, including how much you use the car, how frequently you change gear, at what engine speed you change gear, and whether you tend to "ride" the clutch pedal by using it as a rest for your left foot.  Note that clutch-riding (if not excessive) is probably a good thing from the pre-load point of view!

Personally, I'd recommend that you fit the extra springs.  I fitted mine after my car suffered two premature CRB failures.  This was around 15 years ago, and the car is still running on the same CRB that I fitted when I applied the mod.

If you need any help with this, just send me a Private Message.

JV