The 2025 Calendar Voting is now live! Click here to vote!

Rear diff oil level

Talk about issues and questions specific to the FJR here.
Post Reply
CollingsBob
Contributor
Veteran
Posts: 2253
Joined: Thu Mar 08, 2018 2:19 pm
FJRModel: 2024 BMW R1300 GS
Location: Winnipeg
x 5756
x 2487

Rear diff oil level

Post by CollingsBob »

I changed the rear diff oil, filled it to almost overflowing..then drained it after a ride, measured it and found it to be 175ml...I “borrowed” one of my wifes measuring cups and refilled it with slightly over 200ml...

Should I be concerned that the rear diff was run with only 175ml in it?
User avatar
FJRoss
Veteran
Posts: 2682
Joined: Sat Apr 14, 2018 7:41 pm
FJRModel: 2011 FJR 1300
2017 BMW F700GS
Location: Fredericton NB (Canada)
x 816
x 2407

Re: Rear diff oil level

Post by FJRoss »

I wouldn't worry about it unless there was an excessive amount of metal stuck to the magnetic drain plug. More than the usual smear of black sludge. Since your bike is new, a little more than "normal" is expected anyway.
CollingsBob loved this
wheatonFJR
Contributor
I post more than I ride
Posts: 20459
Joined: Wed Jan 16, 2013 6:10 pm
FJRModel: 2013-Jwilly Special LD Delivery
Location: Travelers Rest
x 43814
x 18966

Re: Rear diff oil level

Post by wheatonFJR »

CollingsBob wrote: Mon Jul 23, 2018 12:21 am I changed the rear diff oil, filled it to almost overflowing..then drained it after a ride, measured it and found it to be 175ml...I “borrowed” one of my wifes measuring cups and refilled it with slightly over 200ml...

Should I be concerned that the rear diff was run with only 175ml in it?
Fill it to the lip. Done.

No worries. Done. Fin. End.
John d, raYzerman, and El Toro Joe loved this
boatanchor, 3rd class.
User avatar
Redfish
Veteran
Posts: 2522
Joined: Sat Oct 22, 2016 10:26 pm
FJRModel: 2014A and 2015ES
Location: Prairieville, Louisiana
x 4975
x 4909

Re: Rear diff oil level

Post by Redfish »

A couple of thoughts...

1. It's a Final Drive not a Diff. A differential is used when there are two tires and power is distributed in possibly more than one direction. But that is not useful information.

2. Are you doing this with the bike on the centerstand? That would seem obvious but I have to ask because it will have an effect.

3. Fill the drive to the bottom lip of the fill hole. Put the plug back in with a new crush washer. Forget about it until you feel like changing it again. That interval is up to you. I do mine every other oil change because I am stupid.

YMMV
PhilJet09 loved this
Never run out of real estate, traction and ideas all at the same time.
CollingsBob
Contributor
Veteran
Posts: 2253
Joined: Thu Mar 08, 2018 2:19 pm
FJRModel: 2024 BMW R1300 GS
Location: Winnipeg
x 5756
x 2487

Re: Rear diff oil level

Post by CollingsBob »

The bike is on the centrestand. There was nothing on the magnet, I’ve been changing the final drive fluid at every oil change just because oil is cheap
User avatar
raYzerman
Contributor
I post more than I ride
Posts: 9680
Joined: Mon Mar 18, 2013 10:49 am
FJRModel: 2010 Honda CBF1000FA
Location: Millgrove, Ontario, CA
x 3133
x 11597

Re: Rear diff oil level

Post by raYzerman »

Recommended interval is every 2 years... I do mine at least every year. The dark stuff is moly assembly lube, which gets less with every change. What Wheatie says, keep it simple, no need to measure anything, capacity spec is with totally dry which yours isn't. Do not rotate the wheel when filling, it will overfill and blow out the vent.
CollingsBob and wheatonFJR loved this
Keep yer stick on the ice........... (Red Green)
Duct tape can't fix stupid, but it can sure muffle the sound.
User avatar
FJRoss
Veteran
Posts: 2682
Joined: Sat Apr 14, 2018 7:41 pm
FJRModel: 2011 FJR 1300
2017 BMW F700GS
Location: Fredericton NB (Canada)
x 816
x 2407

Re: Rear diff oil level

Post by FJRoss »

The fact that your oil is coming out looking pretty much the same as it did when it went in is a pretty good indication that
1) Nothing bad has happened to your final drive
2) You are wasting oil!!

I used to do mine every second oil change (8 to 12,000 km interval for engine oil, depending on conditions and trip plans). Rear drive lube maybe twice per season now - typical season is 35,000 km or so. Still looks pretty much the same coming out as it did going in.

Note: As with the engine, capacity and the amount required to fill may differ due to "retained" fluid.

Image
CollingsBob and Redfish loved this
Post Reply