Foretravel Owners' Forum

Foretravel Motorhome Forums => Foretravel Tech Talk => Topic started by: prevostart on September 03, 2011, 01:41:02 pm

Title: Re: Rear Axle Fluid Change?
Post by: prevostart on September 03, 2011, 01:41:02 pm
I thought I would check the fluid in the diff. after they changed the seals it was low enough where I had to reach my finger down
about 1/2 to 3/4 of inch down to touch fluid.  I checked the owners manual and it said it is a Rockwell diff. RS21-145 and it uses 85w140  GL-5  Hypoid fluid  ,  And says  it takes  32 pints and penciled in next to it says 1.7 Gallons or 7 Quarts , Doesn't make since I drained out 3 gallons and it was a little low. The book says to change yearly, I'm sure that is heavy use.  Art
Title: Re: Rear Axle Fluid Change?
Post by: wolfe10 on September 03, 2011, 01:47:09 pm
Many axles have more than one fill hole, with the correct one determined by the angle of installation of the rear axle.

Some manuals suggest using a certain fill hole up to a certain angle of installation, then shifting to the other hole.  Others suggest correct oil level is to the hole that comes closest to the centerline of the axle tubes.

You might give James Triana a call at Foretravel 800 955-6226.  If you would, post his answer-- and if it applies to other Foretravel models.
Title: Re: Rear Axle Fluid Change?
Post by: prevostart on September 03, 2011, 03:06:02 pm
Brett: The more I read it now makes sense ,The book says 32 pints which is 4 gallons, I drained a little over 3 gallons and it was
low. Here are some pictures.
Title: Re: Rear Axle Fluid Change?
Post by: Rick on September 03, 2011, 08:03:43 pm
see this post

Rear axle oil change instructions (http://www.foreforums.com/index.php?topic=11038.msg57918#msg57918)
Title: Re: Rear Axle Fluid Change?
Post by: prevostart on September 03, 2011, 10:57:19 pm
Rick: Great explanation I did everything close to that but I didn't use Synthetic, My book said to use 85w-140 API GL-5 gear lube so that's what I used .
Title: Re: Re: Rear Axle Fluid Change?
Post by: amos.harrison on September 04, 2011, 03:26:45 pm
I change my rear axle fluid every 25,000 miles.  Once a year seems excessive to me unless you're driving a whole lot of miles-like an over the road 18 wheeler.
Title: Re: Rear Axle Fluid Change?
Post by: Barry & Cindy on September 06, 2011, 11:23:05 pm
We use synthetic 85w140 gear lube and change it every 3-4 years. Full is a little below fill plug hole.
Title: Re: Rear Axle Fluid Change?
Post by: prevostart on September 10, 2011, 11:57:54 am
The book doesn't say to use synthetic , Is it really necessary to use synthetic? Since I changed it already with regular.
    Art 
Title: Re: Rear Axle Fluid Change?
Post by: P. Wyatt Sabourin on September 10, 2011, 01:08:21 pm
Converting to full synthetic fluids in your coach will reduce the rolling resistance and fuel consumption.
Some folks on this site have posted convincing comparisons of fuel consumption with and without synthetics.

ont I will look at the oil in the differential by dipping my little finger. If water is present (tan colour), or dirty (black), I change it. I see no real need to change it before 25,000 miles.

I convertered to full synthetics, even the chassis grease, and front wheel bearings in February this year.
Title: Re: Rear Axle Fluid Change?
Post by: John Haygarth on September 10, 2011, 04:47:14 pm
I also use full synthetic but Amsoil make and the grease and the Allison. The previous owner used it all too so I carried on and have read enough to convince me it is a top grade lubricant. I also use their  external  filter systems too.
John
Title: Re: Re: Rear Axle Fluid Change?
Post by: Pierce & Gaylie Stewart on September 10, 2011, 06:58:27 pm
I have been an Amsoil fan for years. I had a '70 Kawasaki 500 that was really fast but fouled plugs with any in town riding. Took a couple of miles to clean it out and the 750 Hondas were gone by that time. Changing to synthetics was magic. Smoke was 95% gone and it never even missed let alone fouling it's plugs after the change over. Hondas 750s were road kill after that.

Still have my old Suzuki PE250. Has done the Barstow to Vegas race twice with lots of back road/trails riding between. Used nothing but Amsoil and the cylinder head has never been off.

Amsoil is not in the budget for our 6V-92 but feel Delo 100 does the job well. Conventional oils fill the bill for most any application, especially our light duty RV use. Yes, I believe synthetics are are better but don't feel any component's lifespan is compromised by using modern conventional lubricants. Bottom line: Tough enough paying over $4/gallon for diesel and then a whopping bill for gallons of synthetic engine oil. I know you don't have to change as often but I don't like to go over a year with any engine oil without changing. Rear axle lubricant is another story as it rarely requires changing. Many Detroit autos don't even have a drain plug for the rear axle.

Synthetics have an advantage for turbocharged engines as the turbos are prone to "coking" up due to heat soak with conventional oil if operators fail to idle the engine for a couple of minutes to cool it after an extended hard pull. Synthetics totally eliminate the problem. So, when you get to the top of those long grades, don't shut it down until engine/trans temps are down. 800-1000 RPM fast idle will bring all temps down in a couple of minutes. Even a good idea if running synthetics.

Title: Re: Rear Axle Fluid Change?
Post by: John Haygarth on September 10, 2011, 07:57:03 pm
should anyone want to use Amsoil I would be willing to sell it too them for a 10% over my cost (I am a  Prefferred Customer) and it makes a biggish difference in the cost of it. I would just use your address for shipping and then you send me a chq. I would e-mail you a copy of bill + ship. I will give you a quote before order.
John
Title: Re: Re: Rear Axle Fluid Change?
Post by: Dave Head on September 10, 2011, 11:48:50 pm
OOHH - another triple fan.... I had a 73 and later on a 72 350 triple. I would trash RD 400s all day long (mainly because I was crazy...). Somethin cool about a wheelie in all 5 gears leaning all the way over the front tire. I put 4 rim locks on the back tire (road racing tire) to keep from ripping out the tubes - then it would strip chain tensioners! I went up one heat range and went to synthetics... Later on I graduated to a Kaw 1000 bored out with a hot set of cams. The frame couldn't contain the torque of the engine and it would try to flip you at the oddest moments - like in the middle of an apex. Affectionately known as the 'widowmaker'...

I still miss my Suzuki 250 X6 Hustler...
Title: Re: Re: Rear Axle Fluid Change?
Post by: PatC on September 11, 2011, 10:55:25 am
Converting to full synthetic fluids in your coach will reduce the rolling resistance and fuel consumption.
I converted to full synthetic  85w140  GL-5 in the rear differential last year after doing a lot of research.  From everything I read, it all indicated you can extend your differential lube changes, and that the differential will run cooler, but doubted you would reduce fuel consumption.  My thought is that the mpg is so low to begin with, that percentages are next to impossible to see, except over the long term.  But there is nothing wrong in increasing you MPG by 1% or 2%.  The advantage of synthetics is that they handle heat better and last longer than dino products.  That is a big plus in my book.
Title: Re: Re: Rear Axle Fluid Change?
Post by: Pierce & Gaylie Stewart on September 12, 2011, 10:58:59 am
Years ago, we changed a DeTomaso Pantera's transaxle to Amsoil. It had a dash trans temp gauge and was 17 degrees cooler after the change. Must translate to a little better MPG.

Dave,

As I remember the X6 had 6 speeds and was a real rocket. Only 250cc but just flew. It really started the age of the superbike.

I missed a shift with my 500, broke a piston right at the piston pin and the center rod went out through the case. Kawasaki pulled a engineering crew off their submarine work to design the engine. Super easy to work on with just hand tools. I replaced the pistons with forged dykes ring type with ports done also. Put mag wheels with disc brakes on and 16" inch racing tires front and back. They were so sticky that I bent the forks just cranking hard on the brakes on flat road. A corvette with foot wide rear tires came up from LA looking for me. We went out to Montecito and found a long straight road. I had clip ons and still had to lean flat forward to keep the front end down. I let him go first but was able to lean the bike a bit and pull in front of him as I shifted into second gear. Perhaps two seconds at the most. I asked him if he got a bad start but no takers for a second run. He had been running in the 12's but light years away from  a 10 second superbike. Great engine but frame flexed badly.

FYI: Two cycle bikes have engines that turn the opposite direction from 4 cycle bikes. They use gears instead of chains to the transmission so the engine goes the opposite direction from the gearbox. They always try to pick up a front wheel coming off the line, just the opposite from 4 cycles.