Technical question: missing oil seal?

[john h]

I have removed the half-shafts on my 165 to replace the brake backing plates. Whilst doing this I noticed evidence of a slight oil leak, so I was paying attention to the seals.

Haynes shows an inner and outer oil seal at the wheel bearing:



My axle has an outer seal, and a channel for the inner seal, but the inner seal is missing.






So is it a simple case of a seal missed during a bearing change? Looking at the Skandix parts site, this service instruction is given:

"Installation Information Volvo 140 70-, 164 70-, P1800E, P1800ES:
The wheel bearing runs under differential oil and is only pre-greased during installation to prevent dry running. Do not use the inner radial oil seal. It is only supplied in the kit to be used at the 200/700 Series."



Annoyingly, they don't say why the exact same bearing should have both seals fitted on a 200, yet not the inner seal on a very similar 100 axle.

IPD sells an inner oil seal which is current on their site and listed as correct for a 1973 164. So the Skandix instruction to delete the inner seal is clearly is not universally accepted practice.



Also, although grease from my bearing has all been washed/absorbed by axle oil, there are traces of grease in the groove between the axle tube and the end piece. This supports my view that my axle originally had a greased wheel bearing with seals both sides.

On the basis of my leak, and the evidence of the axle being designed to have two oil seals, I am strongly leaning towards refitting an inner seal.

But if anyone can explain the rationale of the Skandix instructions, I would be keen to hear and understand it.

Thanks

John