Kirkham diff

[rsk289]

Apologies for the late reply - David has been way above and beyond just 'helpful' in his response to my problem and very generous offer regarding fixing the diff.

First off - following David's advice, which he sent personally to me, hence my missing it on this forum - I started by draining the diff oil. This was to level, and perfectly clean without even that light grey dust you find on the tip of the drain plug. It looked like fresh honey. Thinking about it, I reasoned that it was unlikely that a failed component would make a hard, rotational metallic noise inside a diff that's full of nice, clean oil. Grinding or grumbling, yes, but this was almost like that noise you get when there's a stone behind a dustshield. So I pulled the NS hub to check the rear wheel bearing.

The retaining bolt into the stub axle had backed off half a turn, taking the tabwasher with it. This was just enough to take the pressure off the bearing inner race and spacer pack, and one of the bearing inner races had just started to turn on the stub axle. Hence the noise. I'd only driven it about 50 yards like this, so after careful dismantling and measurement of the interference fit (still 1.5thou) I cleaned everything up and reassembled with new seals, this time using a spot or two of Loctite bearing adhesive on the shaft for good measure. I found that polishing the topside of the new tabwasher, and the 'land' on the underside of the stub axle bolt stopped the tabwasher from picking up and twisting during assembly, and got the bolt to around 120lb/ft before knocking the tabs over which I think should be OK - it's not a race car and gets driven carefully.

There is a bit of lateral movement on the output shafts as David describes. At the roadside, I was making decisions with the car on the Cobra's Shelley jack with my hand pushed in from the side. I could only reach so far along the driveshaft, which may have increased the movement I could feel - I don't know. With the car on the lift back home, I could move the output flanges themselves and from what David has said I think these are within tolerance. With everything reassembled, a test drive has not thrown up any further noises or problems.

I don't, therefore, see this as in any way down to KMS. I apologise to David if this has cast any doubt on the quality of his product - but on the other side, to my mind this episode has demonstrated the absolutely excellent quality of his after-sales service. Thank you, David, it is really appreciated.

Roger