Changing brakes on my pickup this weekend.  Rotors are built into the hubs, so had to replace the whole thing.  So I'm repacking the bearings while I have the hubs off and I noticed that the old grease was a dark greenish-black color and the new grease I was using was a lighter brown color.  Is that just a brand difference, or did I use the wrong stuff?

It varies from mfg to mfg you just need to make sure the grease is rated for high temp or it will boil and sling out.

BTW marine axel grease is green while many others are red or brown. I have seen high temp axel grease in all of these colors.

Quoted: Changing brakes on my pickup this weekend.  Rotors are built into the hubs, so had to replace the whole thing.  So I'm repacking the bearings while I have the hubs off and I noticed that the old grease was a dark greenish-black color and the new grease I was using was a lighter brown color.  Is that just a brand difference, or did I use the wrong stuff?

There's temperature and seal compatibility to worry about.  Axle grease should be high temp grease.  

Synthetic grease will go to about twice the temp than petroleum-based grease.  Generally though, synthetic grease and petroleum grease aren't compatible with the same seal materials, so they shouldn't be mixed.  I doubt whatever you have will have or need synthetic grease.

It's a 2001 F-150, so nothing exotic.  The grease I used was from my grease gun, but I bought it years ago and have no idea what it actually is.  I know it's not "moly" and it's not "white lithium" and it came from the automotive dept. at the store.  

You should be fine, but you do know you can open your grease gun and look at the tube without making too much of a mess, don't ya?

Quoted: It's a 2001 F-150, so nothing exotic.  The grease I used was from my grease gun, but I bought it years ago and have no idea what it actually is.  I know it's not "moly" and it's not "white lithium" and it came from the automotive dept. at the store.

If it was from your grease gun, odds are it was "chassis grease".  This is a low temp grease used for slip joints, U-joints, ball joints, etc.

What you want for your wheel bearings in disk brake applications is "high temp wheel bearing grease".

It is a very long chain grease compared to chassis grease.  And it feels sticky when rubbed between your fingers, chassis grease feels...greasy.

You didn't hurt anything, but you need to remove, clean and repack your wheel bearings with the proper grease as soon as you can.

I must be getting old. I thought Axl Grease was the front man for Guns & Roses.

Quoted: Quoted: It's a 2001 F-150, so nothing exotic.  The grease I used was from my grease gun, but I bought it years ago and have no idea what it actually is.  I know it's not "moly" and it's not "white lithium" and it came from the automotive dept. at the store.   If it was from your grease gun, odds are it was "chassis grease".  This is a low temp grease used for slip joints, U-joints, ball joints, etc. What you want for your wheel bearings in disk brake applications is "high temp wheel bearing grease". It is a very long chain grease compared to chassis grease.  And it feels sticky when rubbed between your fingers, chassis grease feels...greasy. You didn't hurt anything, but you need to remove, clean and repack your wheel bearings with the proper grease as soon as you can.

You need to remove the incorrect grease and put in the heavy-duty hi-temp disc brake grease ASAP.

I have never heard of synthetic grease having seal issues. I have used moblie one synthetic on everything from wheel bearings to u-joints, tie rod ends and ball joints. Never had a problem. All out of the big tube they sell for grease guns.

While you're at the auto parts store getting the correct hi-temp WB grease you sould buy new seals (if you don't have them already).

Pennzoil does make a multi-purpose grease that comes in cartridges that you can use for wheel bearings on trailers and older non-disc brake equipped cars/trucks.

When I was pricing the rotors I asked the guy at the parts store if the axle grease was different than what was in my grease gun and he said "nope, same stuff".  I asked again when I picked up the rotors and the guy (different guy) said "grease is grease".  I guess when I get home tonight I'll have to pull the tube and see what's in the gun.  If it says "high temp" on it I'm OK?  

The metal flange on the seals did deform a bit, but the rubber parts looked OK.  

You should always replace the seals when repacking wheel bearings. A leaking seal will contaminate the brake pads. I'm not aware of any cartridge type multi-purpose chassis grease that's suitable for disc brake applications.

I make sure what I buy says Bearing Grease so I know I get the right stuff. I use the tube grease for all other lubrication.

Just because.

Mobil 1 Synthetic Grease is an NLGI No. 2 supreme performance grease that combines a polyalphaolefin (PAO) synthetic base fluid with a lithium complex soap thickener. The wax-free nature of the synthetic base fluid, together with its low coefficient of traction compared with mineral oils, provide excellent low temperature pumpability, very low starting and running torque, and can reduce operating temperatures in the load zone of rolling element bearings. Because of its low traction properties, the PAO base also offers the potential for energy savings through improved efficiency. The thickener system provides a high dropping point, while additives impart optimum extreme-pressure properties and excellent resistance to water wash, and outstanding protection against rust and corrosion. Mobil 1 Synthetic Grease has excellent structural stability and low-temperature pumpability, making it an outstanding automotive grease.

Based on its outstanding performance capabilities, Mobil 1 Synthetic Grease is recommended for a wide range of automotive applications, but especially where any of the following operational conditions occur: high loads, moisture or condensation, high temperature exposure and low temperature start-up.

Features

Advantages and Potential Benefits
All-round excellent performance features (detailed below)
Multi-purpose automotive service for reduced inventory requirements
Operating range of -40ºC to +180ºC
Excellent low temperature start-up
Outstanding service life even under the most arduous conditions
Excellent resistance to rust and corrosion
Excellent all-weather bearing protection
Outstanding structural stability
Outstanding grease life, even in high shear environments
Excellent wear protection under heavy loads and good shock loading protection
Superb protection of greased engine parts providing long life and avoiding unexpected malfunction or breakage
Excellent resistance to water wash
Maintains excellent performance and protection even in the wettest conditions

Applications

Disc brake wheel bearings
Ball and steering joints
Universal joints

So in moblie 1's case, grease is grease.

ar-wrench and jmarkma were right.  I pulled the tube out of the grease gun and it wasn't TOO messy.  And it was indeed "multi-purpose chassis grease... for wheel bearings (non disc brakes) ...".  (But the small-print patter on the back said '...recommended for...high tempeartures..."?)

I found three brands of high-temp grease at the store that did say "recommended for disc brakes" on them.  (The two that indicated color were red, and the tube I could open was a bright shop-rag red. )

So I'll be repacking the bearings this weekend.  I already drove it 120 miles with the wrong grease, but about 90-100 miles of that was highway with no braking and I'm pretty easy on the brakes (got 105,000 on the original brakes and the pads would still be OK if the rotors weren't rusting through) so I don't think I burned it all out.  <crosses fingers>

Next question:  Should I get a tube of the red stuff for the grease gun and use it for everything, or should I get a tub of it and stick with the brown stuff for the grease gun?