Xke gearbox oil pump help

I am in the middle of restoring a 1966 xke gearbox and I don’t understand how the oil pump is driven.
I just read a post that said it is driven by friction with the rear bearing. But in the parts catalog there is a pin C21309 that is supposed to drive the pump. I believe I have the pin but I am not sure where it goes.

@angelw will have the answer I’m sure

The pin you’re referring to is part of the Oil Pump Drive Sleeve. This pin locates in a keyway cut in the bore of the bronze gear to provide drive for this gear, but there is nothing other than the clamping force applied by the Companion Flange Nut that ensures that this Drive Sleeve rotates with the Main Shaft assembly.

The following picture is of the Drive Face of an original Rear Bearing, which has not been available for many years. Note the absence of any significant radius between the face and the bore of the inner race. It’s this face that the end face of the Oil Pump Drive Sleeve is clamped against. You can also note that there are signs of the Drive Sleeve having slipped on this face.

The next picture is of the typical bearing being offered by the After Market Sales brigade; note the size of the radius between the face and bore of the inner race. If you compare the size of the radius of this bearing with the contact print of the Oil Pump Drive Sleeve on the face of the correct bearing, its not hard to work out that what’s left of the annular contact band of the Drive Sleeve with the face of the bearing pictured following, is circa 1mm wide. In general terms, friction is independent of surface area, but pressure is not. Using a bearing such as that shown following, with a circa 1mm contact band between bearing face and Drive Sleeve, soon leads to deformation of the face of the Drive Sleeve, which results in a slight lessening of the clamping force applied by the Companion Flange Nut and slippage between the face of the Drive Sleeve and the face of the Rear Bearing.

What generally causes the slippage between the face of the Rear Bearing and the Drive Sleeve when the correct bearing is used, is when the unknowing tightens the Companion Flange nut and finds that the split pin hole in the Main Shaft doesn’t align with any slot in the Castellated Nut and instead of following the correct procedure of removing metal either from the inner face of the nut, or the face of the thick washer it bears against, they back the nut off until alignment with the hole in the Shaft is achieved,. This practice will guarantee slippage between the face of the Rear Bearing and the Oil Pump Drive Sleeve.



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Come on Paul, spit it out. :grinning:



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You beat me to it…:stuck_out_tongue_winking_eye:

Thanks for the help. After looking over everything I found that the pin in the drive sleeve had sheared off. I don’t understand how that happened because the gear looks to be in good condition. Will the gearbox be damaged if the oil pump isn’t working?

Depends on how far it was driven, w/o oil flow.

It’s unusual for that pin to ever give trouble, as there is stuff all load on it. The bearings that are most affected by the oil pump not working are the Drawn Cup, Needle Roller Bearing in the First Motion Shaft that the nose of the Main Shaft interfaces with and the Needle Rollers in the Lay Cluster, Lay Shaft assembly. The Lay Cluster is a big issue if the bearing surfaces get damaged, as this is a very hard to get part and expensive to repair if it can be salvaged.



Yes, is my vote.

[quote=“ejag_android, post:7, topic:434256”]
the pin in the drive sleeve had sheared off.

Looks like the pin is intact - the little piece below it looks to be a smaller diameter. Case hardened steel pins would be difficult to shear cleanly…

As I look further at what has happened I surmise that the last time this gearbox was serviced someone did not align the drive pin with the slot in the oil gear as can be seen by the dent in the bronze gear. The force of torqueing the castle nut sheared the pin. The large piece of the pin was driven out of the drive sleeve measuring .185 the smaller piece I am not sure where it came from but measures .151 so I am at a loss with that. So now I have replaced the drive pin with a spring pin and getting ready to cut it off to the right length. The oil gear has been damaged at the slot where the drive pin goes so I will look to replace it or repair it.

Yes. Getting that gear slightly off appears not difficult to do … when I rebuilt my gearbox the first time (early 90s) I did the same thing, and punched a chunk neatly out of the brass gear with the drive pin. I heard it happen so took the oil pump apart and an instrument mechanic friend did the repair - I don’t know what he used but he said it was some kind of steel reinforced epoxy (red arrow). He didn’t want to attempt a braze repair thinking it might warp the gear slightly.

I reinstalled the gear and ran with it for several years and thousands of miles with no issue. An issue I did have with the rebuild was the replacement front ball bearing, the bigger of the two in the gearbox. It wasn’t quite right and the shift lever would surge forward in third gear - an annoyance more than a practical issue but when I did the total restoration and mechanical rebuild ten years ago I took apart the gearbox and replaced the oil pump gear and front bearing with good, used items I got from @Robert_Laughton.

This gear I took a chunk out of I keep as a reminder of sometimes having more than two thumbs.

I think I am going to silver solder a small piece of brass to repair the damaged ring gear, If it warps I can get a new one on ebay for $70

Yeah, you’ll get a strong repair with silver solder with a lot less heat than brazing so warpage shouldn’t be an issue.