hellride

So I had a new diff put in under warranty and just did a fluid change to Redline 75w90 after 500 miles. The diff fluid that came out had a lot of metal in it and the plug had a good amount of metal paste on the magnet. Check the pics.

My question is this, it only took about a quart and a half to fill back up. I'm wondering if somehow all the fluid didn't come out upon draining, possible due to me using rhino ramps and backing up on them to get under the car for the change. Would the angle of the car ramps from the front end being higher than the rear cause some of the old fluid to get caught up in the pumpkin? Thanx

MN_V

iTrader: (5)

1.5qt is about what mine drained

punishmentcycle

iTrader: (6)

you should always warm the fluids your draining. wether it be engine oil,trans or diff. warm fuild flows better than cold and will drain faster and more completely. always take a 10 minute drive to get everything moving then change em

hellride

I drove about ten miles on the highway before pulling I the garage. Fluid was warm and light.
It's funny that it only drained 1.5 quarts when the Cadillac FAQ page says you need 3 quarts for a diff fluid change. Actually one page says 3, another says 2 plus 4oz diff additive.
I'm not using diff additive due to the viscosity properties of the redline supposedly not needing it.

shadyLS6

After my breakin mileage, I didnt have anywhere near that amount of sludge attached to the magnet. Based on that wear i would change it again after another 500mi and see what it looked like. also i did my diff fluid change on rhino ramps as well and i used over 2qts unitll it spilled out the top..

9t8z28

iTrader: (19)

Yes the angle will prevent you from getting all of the fluid out.
The metal residue is normal. You are breaking in the gears that are meshing together.
IF there is metal in the fluid, pick it out and take a picture and post up

hellride

If the ramps do limit fluid drainage, that's a good tip for others out there.
Also, when I called my dealer asking when they recommend a fluid change, he said that they don't, after break in. I told him I'd get back to him with info on what my fluid and mag plug looked like after I did mine. I'm sure he'll be interested in seeing this.
This reminds me of when I bought my first brand new ford truck. They have you come in at 500 to change all fluids i.e. the new diff fluid.

etcts-v

The official capacity for the diff is 2.7 pints or 1.35 quarts so it sounds like that's about right. Both times I changed my fluid is was about 1.5 quarts.

http://www.amsoil.com/mygarage/vehic...CADILLAC+CTS+S

9t8z28

iTrader: (19)

The dealer already lost money replacing it under warranty so he lied about it needing to be changed after break-in

rand49er

Have done my diff twice. First time, it took 44 oz the second time it took 42 oz.

Just FYI.

hellride

Thanks guys for clearing up the capacity issue. Seems like I'm ok for now then.
It's also interesting how Amsoil recommends adding the limited slip lube $oz additive from gm part no.1052358 and redline says you dont need it. Any opinions there?

odthetruth

iTrader: (4)

This.

And be prepared for that diff fluid smell. Normally smells like ***, IMO. LOL

JDB

iTrader: (2)

I use Redline 75w90 in my rear diff with no additive. It has it already. Redline makes a "NS" version that has no slip additives.

FWIW, this was after using GM DEXRON LS gear oil that the dealer put in with the gen IV diff that was replaced under CPO warranty. This fluid also has the slip additive in it.

My diff is silent. Probably have 25k miles on it and a few track days.

Capacity is definitely under 2qts.