Ram Rear Diff Fluid Change

[IdaD]

I just changed out the rear diff fluid on my Ram at 20k miles. Why on earth did Ram not put a drain plug on the rear diff cover? It turned a 10 minute job into an hour job having to take all those bolts out. Still a very easy DIY maintenance item but I may look into an aftermarket cover with a drain in it the next time I change the fluid out.

I do think the first change is the most critical one because there should be less grinding now that the gears are broken in.

[BenK]

Automotive differentials is one of the toughest applications for any gear box

Several thousand foot pounds of torque and very, very little or small
amount of lube...

Properly designed gearing will have the gear faces NOT go metal to metal,
but we all know it does go metal to metal too often...they why of that
magnet in there (or at least the better designed ones do)

The lube is supposed to have enough film strength to have the gear faces
ride on that film during 'normal' usage (to specifications)

Even one of the best magnets will NOT capture all or enough of the metal
floating in the lube...so getting as much (every last drop) out during
a flush is important

I like the diff's that have a drain plug on the bottom of the pumpkin,
but for off roading...it will get wacked off...so either pull the rear
cover or live with the drain plug higher to leave some lube left in there

Suggest loosening all the cover bolts and the bottom ones a bit more
than the ones on top...pry the bottom to break the seal and leave
your pry bar (screw driver) in there to hold it open...draining into
the catch pan

I normally go do something else on the vehicle while it drains this way

Then remove the cover and replace the gasket...or just retighten the
bolts if you have an O-ring or glued one side of the gasket like I do

ALWAYS use the best synthetic and highest weight lube listed in your
manual's lube page.

If no friction clutches in there, use one of the metal lube additives.
I like Molybdenum Disulfide powder and NOTE IF CLUTCHES in there, this
will ruin the friction material...as it is too slippery. Use the cheaper
stuff with a larger particulate size here

[IdaD]

Bedlam wrote:
Don't the GM and Ram use the same AAM axle?

Yep, the 11.5". Different diff covers though. I think the LSD setup is different too or at least I recall seeing somewhere that some GM guys would swap in the Ram setup.

[Bedlam]

Don't the GM and Ram use the same AAM axle?

[Charlie_D_]

Bigfoot affair wrote:
All my GM HD's, 2001, 03, 12 and 15 have had drain plugs on the bottom of the diff housing. No need to remove the cover 😉

As do the 2006 and 2013.

[romore]

Trackrig wrote:
Because it saves them 50 cents or less per vehicle..........

When I bought my 1983 Chevy truck, they tried to stop putting spare tires on them that year. They wanted $230 for a spare tire as an extra. Luckily that bright idea didn't last long.

Bill

My dad's 65 GMC came with a rim but no tire, theory was if customer wanted to upgrade he/she would buy a spare to match. Dad wasn't impressed.

[bpounds]

spoon059 wrote:
I used a siphon to pump out the old fluid, that was simple. Getting the new fluid in was a pain in the neck! Next time I will simply remove the diff cover to drain and pump the new fluid in... much easier!

I assume you mean suction, not siphon.

The same tool I use to suck out the old fluid, can be used to pump in the new.

[spoon059]

I used a siphon to pump out the old fluid, that was simple. Getting the new fluid in was a pain in the neck! Next time I will simply remove the diff cover to drain and pump the new fluid in... much easier!

[dodge_guy]

R&R the cover on the ground shouldn't take longer than 20-25 minutes. And that includes filling it up!

[ScottG]

It isn't really any trouble. The gasket (o Ring) is reusable and I just zip the bolts off and on with my electric drill. The screws bottom out when tight.
Easy peezy.

[bpounds]

Drain plug or not, if you want to do a first rate job, you remove the cover.

If you just want to git'r done, you can suck the fluid out of the fill hole. The tool is cheap. And it gets as much of the fluid out as would a drain plug. If you have a lube shop do the job, that's what they are going to do. And that is why you might want to do the job yourself, but if you are not going to go to the extra work to remove the cover, might as well just have a lube shop do it.

And for full disclosure, I've done it both ways, depending on the situation. And none of my vehicles have ever had a plug.

[Cummins12V98]

I have a MagHytec I took off my 11 Dually from what I have been told it will not fit the RAM with real air ride. I had no issue removing the bolts and letting mine drain thoroughly and wiping out the inside and bolting the cover back on and re filling. I do like the fill plug has a gasket as does the cover, both re usable. I like to see the condition of the gears especially on the first change.

[Bigfoot_affair]

All my GM HD's, 2001, 03, 12 and 15 have had drain plugs on the bottom of the diff housing. No need to remove the cover 😉

[azrving]

.

[Bedlam]

If I have to go to the trouble of removing the pan or cover once, I will either tap in a drain or replace the part with one that has a drain. I even use easy open plugs on my off-road toys instead of repeatedly removing the drain plug since I change fluids often in them.

Knowing you will be doing this often, spending a little to make maintenance easier makes sense whether doing this on your own vehicles or for a fleet.

On the flip side of this, removing the cover allows you to do a visual inspection you cannot do with a drain plug. Maybe there is a reason for removing the cover?

[Old-Biscuit]

Shortly after purchasing our truck I was roaming around a local swap meet and spied a Mag-Hytec Diff Cover for $125 (Brand new $250)

O-ring on face, on magnetic drain lug, on dipstick and has a port for temp sending probe.

Had it for 1st oil change so just had them swap covers.

Makes changing fluid easy and very easy to fill to proper level PLUS added oil quantity and cooling fins.