C70: Manual gearbox oil refill

[C70mmy]

Hi everyone,

I lost a fair amount of gearbox oil when removing the drivers side drive shaft, I now plan to do a manual gearbox oil change - not just a top up.

Accessing the drain plus is ok, not too hard but how on earth do you get the remove the refill plug? The gearbox/engine mount blocks access completely.

I’m thinking of supporting the gearbox from underneath and totally removing the mount in order to gain easy access to the plug.

Am I missing something or is this the only way to do it? Thanks 🙏

(Manual 5-speed)

[amazondean]

The best way is to remove a sensor which is located on top of the gearbox. It is much more accessible, but you will need a smallish funnel! The proper refill plug is sometimes so tight you just can't move it, even when reasonably accessed by removing items, as I think it is brass.

The sensor is much easier to undo as you can get a socket over it from above, once you have disconnected the wiring. If you look at the gearbox from above, you can see the sensor. You might need to remove the air filter housing, but not sure. Its been a while since I did mine

[PNuT]

The proper way to fill your gearbox is via the proper filling hole which you access via the passenger side wheel arch, you fill to that level.

[Cookeh]

Originally Posted by PNuT

The proper way to fill your gearbox is via the proper filling hole which you access via the passenger side wheel arch, you fill to that level.

Absolutely this. Access really isnt that bad for the proper drain hole. Sensor option isnt a bad idea but will make it harder to get the correct volume of replacement fluid in.

The following is for a V70 but the same applies, hopefully the pictures and directions help:

https://www.pelicanparts.com/techart..._Replacing.htm

This one also covers the procedure well:

https://www.matthewsvolvosite.com/fo...ic.php?t=58312

[Spawned66]

Anyone know what size the compression washers needed?

[StatusRed]

I was going to flush and refill the gearbox oil as a bit of maintenance when I first got my C70 then saw the fill plug and was like.. nope I do not see how the hell you can get a socket on that, so just left it alone :P

[amazondean]

Quite right to use the correct filler plug where possible, but its not like draining an automatic transmission, where only part of the fluid is removed. Almost all the oil will be removed on a manual transmission. when you drain the fluid out you just have to put the recommended amount back in, which I believe is 2.1 litres and away you go. You wont be far off correct.

[volvo again]

Tip...I learned years ago to always remove the filler plug before draining...ask me how I know !!!

[4x4]

Originally Posted by Spawned66

Anyone know what size the compression washers needed?

18.3mm internal hole size

[C70mmy]

Thanks everyone for their replies.

StatusRed is correct, there is no way removing the refill plug as an easy option.

Thanks for both links Cookeh, but the C70 (perhaps the convertible for structural reasons...?) is different to both the pictures/guides. There is no way at all to access that drain bolt via the wheel arch.

Please see the two images attached, mine clearly has a gearbox mount obstructing access vs the other image of a guy reaching in with a tool.

Thanks!