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Topic: Diff refill guidance (Read 372 times) previous topic - next topic

Diff refill guidance

I just want to confirm that once I've drained my differential I simply fill from the top (not the center plug) until full. Can someone confirm I'm not under thinking this?
1987 Grand Villa ORED
2001 U320 4010

Not all that wander are lost... but I often am.

Re: Diff refill guidance

Reply #1 –
I would use the center plug just more is not better. The full level is the center plug. Also check the vent to make sure it's clear.
Bruce, Linda, and Macy
Zoey RIP 1/20/19
1999 U295 40' build #5400
2017 silver Jeep Wrangler, 1260 watts of solar on top
Moving around the country

Re: Diff refill guidance

Reply #2 –
Center plug is the level.
Peter and Frieda Morin
1999 36ft. U320 Foretravel
Build # 5436
1998 Suzuki Sidekick Sport

Re: Diff refill guidance

Reply #3 –
Got it, thanks guys
1987 Grand Villa ORED
2001 U320 4010

Not all that wander are lost... but I often am.

Re: Diff refill guidance

Reply #4 –
The full hole/proper fluid level on many differentials depends on the angle of installation.

I would suggest either verifying based on differential manufacturer's recommendation OR start by removing the "top" plug and feeling if that is the current oil level.  If not, remove the "lower" one.

Level is important, as it also lubes the axle bearings.

Brett Wolfe
EX: 1993 U240
Moderator, ForeForum 2001-
Moderator Diesel RV Club 2002-
Moderator, FMCA Forum 2009-2020
Chairman FMCA Technical Advisory Committee 2011-2020

Re: Diff refill guidance

Reply #5 –
And have the coach itself level.
96 U270 BUILD 4810
85 380SL
Drummonds TN.

Re: Diff refill guidance

Reply #6 –
I thought that my fill level hole was a little lower than the axles . Some books advise driving in circles to fill the axles and recheck through the mid level hole .

Re: Diff refill guidance

Reply #7 –
The ring gear brings the oil up and the turning of the axles drives the oil out to the wheel bearings. Just like spinning a rod with a drill motor and the fluid climbs up.
1999 40 ft. U-320 wtfe build 5563 Chuck & Lynda's "Rollin' Inn"  2030 watts solar
prev. mh's 71 GMC 5 yrs. 73 Pace Setter 1 yr. 78 Vogue 5 yrs 81 FTX 40ft all electric 18 yrs. 1996 Monaco Signature 3 yrs.
2014 Grand Cherokee Overland
Dream as if you will live forever. Live as if you will die today.  James Dean
 

Re: Diff refill guidance

Reply #8 –
I know you already did it but for someone's future reference, in my Oshkosh manual for the VC-22RD, it says to fill to carrier fill plug hole, which from the illustration appears to be about the same height as the driveshaft.
1992 Foretravel 36' Grand Villa ORED - VC22RD Chassis - 8.3 Cummins