Community Forums

sevenmacs · 09-26-2021, 03:54 PM

Just returned from first trip in new 2021 fleetwood Bouunder V8. 3 hrs drive in climbing hard passes west of Denver on I 70. Upon arrival I discovered a small amount of differential fluid has come out of vent tube rearend was cool at that time as we had been there awhile. I checked level and it was a little over full, fluid running out of plug. I didn't let it all run out probably should have, and will do not that i'm home. On return trip again over hard passes at high allitude , and 90 degree temp. I checked again upon arriving home. This time a very small amount, a light coating of 6" on frame channel below vent. The other issue I'mm concerned about is the differential was too hot to keep my hand on it, but not too hot that I couldn't touch it. Didn't know if this is normal to be that hot in 90 degree temp and hard driving, as I've never checked. After sitting an 1/2 hour it was 140 degrees, by temp. scanner. The metal under coach was hot as well but not as hot as rearend. Concerned because of the recall on the rearends, dealer said mine was checked and fluid was only low a very small amount. Whats a normal temp ?

Mark Kovalsky · 09-26-2021, 04:32 PM

In 90°F weather climbing grades, temperatures approaching 300°F are not unusual.

The fluid was coming out of the vent because it's overfilled.

donr103 · 09-26-2021, 04:46 PM

At least you are thinking about it... 90% dont even do that.. but this very reason if you plan on keeping coach for long time... to change diff oil.. some go as far as adding temp gauge on diff.. I just goggle it.. and said it depends on what gears and load you pull... so 150 to 300.. if mine goes above 220.. you bet I will do oil change on diff.. I have different rv.. but it uses diff.. I also plan to add larger diff cover and gauge next.. there are many diff cover choices and many make oil changes easier.. with drain bolt.. mine current one does not have one..
SO keep diff oil change.. I would not go by sealed for life time.. or 100,000 mile.. I would go by use.. big mountains and heavy loads in hot temps.. every yr change diff oil.. at least every 2 to 5yrs.. good luck and keep us posted

GypsyR · 09-26-2021, 07:47 PM

What Mark said above basically. Know that on highly stressed rearends like in racecars they even have oil cooler setups for them. Not seeing race duty ours aren't going to run quite that hot. Too hot to keep your hand on is right about normal on most vehicles from what I've seen/felt over the years on stuff coming straight in off the road.

sevenmacs · 09-26-2021, 08:16 PM

Thanks for the replies, it helps greatly. After posting I did goggle it and found info on OTR trucks. The feedback from members here is very comforting confirmation of what I goggled and is based on people with real life experiene with issues.. This forum has been great for sorting out the issues with a new MH, of which mine has had a few. Thanks again !

arcaguy · 09-26-2021, 08:17 PM

If you had overheated the rear end there would probably be a gawd awful smell coming from the rear end and smoke coming from the vent. Since this is not the case I think you're fine. 140 is not a high temp for a rear end oil it doesn't start to burn until 350 to 400 deg and synthetic up to 500 deg so I think you're in safe territory. Here's a link to the information: https://waynesgarage.com/tips/more-tip/synthetic-oils
I know it's talking about engine oils but in many, many ways there aren't a lot if differences between engine and differential oil. Heck, Harley-Davidson uses the same oil in both the engine and transmission.

AKIQPilot · 10-01-2021, 01:16 PM

I have a Workhorse 24k chassis, 30k GCWR, Dana 130. I check my diff temp at every fuel stop. It's one of about a dozen things I shoot the temp of while refueling. We run around pretty well loaded and pulling a Wrangler. For reference, I typically scale somewhere between 28,600lbs and 29,000lbs.

First time I shot the diff temp we were not pulling the Wrangler and scaling around 22.6k. Diff temp was 185f at the hottest part of the pinion snout. I thought this was very high and kinda freaked out. A semi was refueling a couple spots over so I shot the temp of his diff and it was about the same, 190f.

After basically 5 years of monitoring the differential temperature both loaded and not quite loaded, I've seen it as high as 210f and as low as 180f. If I'm refueling and another motorhome pulls in I will often ask if I can take a temp reading of their diff. Lots of them are F53 chassis coaches. 180f-200f is the average temp I will see on a 24k chassis coach. I've shot plenty of semi diffs and have seen them as high as 250f just after they pulled in.

Note: The pumpkin temp is considerably lower than the pinion snout. I rarely see more than 160f on the pumpkin. I always shoot the pinion snout because that is typically where the most heat is.

GypsyR · 10-01-2021, 05:12 PM

Nice! I've got an IR gun lingering around in a toolbox drawer. It has been my habit to put a hand on each tire at stops when I can. With the gun I can check front hubs, pinion, AND tires without getting a hand dirt. Plus maybe finally get a little use out of that thing.

AKIQPilot · 10-01-2021, 06:58 PM

Quote:

Originally Posted by GypsyR

Nice! I've got an IR gun lingering around in a toolbox drawer. It has been my habit to put a hand on each tire at stops when I can. With the gun I can check front hubs, pinion, AND tires without getting a hand dirt. Plus maybe finally get a little use out of that thing.

Our coach has a driver side door with a nice pocket in the door where I keep the IR gun. After I get the fuel flowing I grab the gun and take a quick shot of every tire, hub and brake rotor on the coach and toad. I shoot the pinion, center diff pumpkin and cats. If it was a long steep pull I will reach under and take a close shot of each ujoint. I may shoot the tranny pan on occasion if I was working the coach harder than normal.

I start at the driver side front tire and work all the way back on that side then all the way back to the front on the passenger side. Takes maybe 2 minutes total. I don't record the temperatures but I've done it so much I know what normal looks like so I can easily tell if a temperature is not within the range I am expecting. It's just something I do while waiting for meter to reach $100 and shut off.