Oil Pump

[Eric Worpe]

There's an article in Totally T Type 2 issue 61 August 2020 which looks at the circlip problems. The groove for the circlip was found to be too shallow in the replacement drive shafts.
However, over-stretching of the circlip when being installed was suggested as a contributory factor to circlip failures.
Try https://ttypes.org/xpag-oil-pump-circlip-replacement/

[Mark McCombs]

As there is no gasket at the oil pump top cover to body joint, I am thinking a thin brush coating of permatex sealer?

[SteveW]

You shouldn't be putting anything on it. It has to be metal to metal in order to get the end float of the gears right. If the face is not perfectly flat the cap should be skimmed. You can check end float by putting a flat edge across the top of the gears in the body and then using feeler gauges to measure.

[jddevel]

Managed to get the old clip to fit with a "bit of filing". However then found that two teeth on the new drive gear "caught" on the pump base. Little more filing and drive shaft now turns smoothly. Concern is obviously that the new gear was fractionally not as it should be. Being optimistic that the gear is still balanced.

[jddevel]

Have filed the groove and the original clip now fits. Did however actually have to file down a minute portion of the bottom of two of of the drive gear teeth which was "catching" on the base of the casting. Hope being an optimistic it`s not now to much out of balance.

[Mark McCombs]

Was this the new version of the gear and shaft with the pinned gear?

What I noticed on that version was the the helix gear cut extends into the collar underneath it, whereas the original had a plain collar without the gear cuts. I suspect you were catching on several of those cuts in the collar.

I also noticed that the bottom of the pump shaft housing is not a finished area; As the gear is pulling inward in operation, there would have been a clearance at the pump housing base and the bottom of the shaft collar so the inside of the collar wouldn't be riding against it.

[jddevel]

Mark, Only changed the gears as drive shaft etc good. It was only 2 teeth on the drive gear that were "catching" on the housing base.
Steve W. watching the John Twist video on this he suggested that a "minute" amount of sealer around the very edge of the top would not cause a problem

[Eric Worpe]

This topic was the subject of an article in Totally t type Issue 61 August 2020. Part of the problem in currently available replacement parts was the inadequate depth of the groove for the circlip.
See https://ttypes.org/xpag-oil-pump-circlip-replacement/