2008 E-450 Differential identification

Axle code will be on the VIN label in the driver's door jamb. I don't have a chart for recent E-series codes, but the general pattern is a two-digit number for open differential, a letter and a single number for Limited Slip.

ScottG wrote:
Use any synthetic oil that's rated for both.
FWIW, it will do no harm to put additive in a non-LSD diff.

+1 the fluid is not that different is it? Just use the heavier stuff and you are fine.

2008 OEM LS has enough wear that it probably barely works and will not chatter or need the friction modifier additive.

j-d wrote:
Ford DOES show Limited Slip available on E-Series, and it's something I would be willing to pay for as an option on a new RV. I don't think I'd pay to retrofit one.

X2.

I checked my E450's differential several years ago and it's of course not Limited Slip. :( I did not order my RV but if I had, I would have ordered it with Limited Slip.

I've had GM's equivalent of Limited Slip on my 4WD pickup (which I drive in 2WD most of the time) and really like it. For instance, it makes it possible to not have to shift into 4WD just to come up the steep driveway to hour home in wet conditions. We also have switchable traction control that locks up the rear differential on our 2002 2WD family sedan and it easily comes up our wet driveway with no problems. As far back as 1972, I even ordered a brand new 3/4 ton Dodge van - that we converted into a camper - with a lockup rear differential for added traction off paved roads.

I would really like it on our small Class C for extra insurance when driving off paved roads.

Block both front wheels so the vehicle can't move. Jack up the rear axle till both rear tires are off the ground. Put jack stands under the rear axle and then make sure the trans is in neutral and the emergency brake off. Now go to one side of the rear tires and give a turn while watching the other side rear tires. If the both turn the same direction then you have limited slip, if they turn in opposite direction than you do not have limited slip but have an open differential.

See if this helps.
Ford DOES show Limited Slip available on E-Series, and it's something I would be willing to pay for as an option on a new RV. I don't think I'd pay to retrofit one.

You should not normally need to ever replace the differential oil. Ford says its good for life, or every 150,000 for EMS use.

Do be sure to use full synthetic if you do have to replace it. Otherwise, you are suppose to change it every 5,000 using conventional.

Use any synthetic oil that's rated for both.
FWIW, it will do no harm to put additive in a non-LSD diff.

I put Royal Purple Synthetic in mine. Works in either one.

It's unlikely that it's a limited slip, but you'll know for sure once you pull the cover off to drain it. If you get the code off the tag, you can probably google it up to find out in advance.