All synchro transmission Layshaft Question

Opon disassembly to do a quick reseal on my '66 E gearbox, I decided to insert a dummy shaft and remove the layshaft to check it for wear. It’s surprisingly good with only 45,000 miles, but does have enough wear I want to replace it.

Moss offers a standard shaft for $69.00 but sng has a uprated one for $169.00. My instinct says get the upraded part. My question is: Is it worth the extra $$$ ?

If uprated means the shaft is harder, I would definitely do it for my all-synchro


Denis Welch sells an uprated one

Hello Tim,
That’s considerable wear for 45K miles, but its common to see wear in that area (1st Gear / Reverse Idler Gear)

I always have a chuckle when I see reference to Uprated associated to this shaft. There was a change in material mentioned in Jaguar dispatches, early in the production of the S3 car, but apart from the material and Heat Treatment, not much more can be done to “Uprate” this shaft.

The great majority of gearbox parts, including shafts such as your Lay Shaft example, are made using EN36A, or on less common occasions, the slightly stronger EN39B. Both of these are Case Hardening Steels that if the manufacturer has any pride in the components they make, should be double heat treated (Core Refined and Case Hardened).

This is a relatively simple shaft to manufacture with the tolerance easy to maintain. Accordingly, rather than advertise an Uprated part, it would be more accurate to list the two varieties as Poorly or Normally made.

Most Heat Treatment plants will be obliging and perform a hardness test on your shaft (its quick and simple). As you intend replacing the shaft, the test can be made in any area along the shaft. If your shaft is case hardened, the test should indicate a hardness circa 60RHC. On a new shaft, the test can be made in either of the areas that locate in the walls of the Gearbox Housing.




Maybe “uprated” in this case means not defective from day one? This the new shaft the previous rebuilder installed in mine that went all of 200 miles. I’m not sure which vendor it was purchased from but I’m both annoyed that it was supplied like this, as well as used like this.

Wow! I ordered the supposed uprated one from SNG Barratt. They have good customer service compared to moss. Plus the moss one is likely made in china. I would like to find a rear cover as my cover has two cracks. I can stop drill the cracks and put some Marine JB weld on the area.

The second post from Douglass shows the link to Dennis Welch Motorsport a supplier who has them.

Funny… not funny.


Since I’m not really in the business of this stuff, I don’t see directly the amount of craptastic parts there are, but reading on here anout the amount of junk that people get, and pay good money for, is just astounding to me.