I found the o-rings on simplybearings.co.uk who have a simple page where you put in all of the dimensions and find the product. I ordered both of the o-rings that you suggested, getting five of each o-ring because it was only a few pence more...

FNL is flanged housing designation from SKF. TFL is the size of the double lip seal that goes in it. Little bit confused with the lettering/number on the seal, but It may be a place to start and ring an SKF place. Dont know why I bother, but...

Actually, having given this some more thought, I’m talking rubbish. You can see that the lip seal is installed into the shift motor the ‘wrong way round’ i.e. the front of the seal first, because it’s there to prevent the transfer box fluid...

I think that many users never select low range during their entire period of ownership, so the lip seal, which is designed as a rotating seal, ends up as a static seal. (The same reasoning also applies to the rotary potentiometer in the shift...

The O-ring seal is a bit ‘belt and braces’ because the lead screw has a lip seal which should prevent any fluid escaping. So, you may need to have a look at this seal too. New Venture Gear was an American company, so I don’t know if the...

A crunching sound when moving the lever into Park is usually a sign of something disconnected downstream of the transmission output. It’s caused by the parking pawl ratcheting on the park lock gear, even though the park lock gear should be...

…and does the gear position displayed on the instrument panel correspond exactly with the position of the gear lever i.e. D in D, N in N, R in R & P in P? Phil

I admire your optimism. So, to recap, the car made the ‘big bang’ when accelerating in a forward gear. It will still engage and drive forwards but, since it made the noise, it will no longer engage or drive in reverse. Is that correct? Phil