I've got differential oil leaking around the drive shaft. It is a small leak that is spraying the oil from the shaft all over the gas tank and underbody. Not enough to even cause a stain on the driveway. I caught it while doing an oil change. I checked the shaft and there does not seem to be any play or looseness. Could this just be the seal or is it likely that I will need a new pinion bearing as well? How hard is this to tackle? I believe that you can replace the seal while on the vehicle but I'm not sure if there are special tools involved. Truck has 152k on it.

Thanks for the help.

the oil seal on the pinion gear has failed. i'll have to look in my FSM tonight to see how to replace it.

FYI, this is the factory service manual for a 93 toyota hilux. its instructions are probably fairly similar to what would be required to replace your pinion gear oil seal.

http://personal.utulsa.edu/~nathan-buchanan/93fsm/

You might want to check the breather to make sure it isn't plugged creating too much pressure before you tear into it.

Are you sure it's not the excess grease being flung off of the u-joints after lubing them? I know I have the flung grease ring on my truck, and after being coated with dirt, etc. you can't tell the difference by looking. Stick yer finger in it, feel it, smell it (this is not a reccommended procedure for finding out about stuff in general <img src="/forums/images/graemlins/drunk.gif" alt="" />, but I think it safely applies here).

I'm 99% sure it is differential oil. What complicates matters is that I had a transmission line blow in May and it threw tranny oil everywhere on everything from front to back. However, right above the rear u-joint there is a wide spray of thin oil. You can see the difference between this and the grease from the U-joint and other stains. I can also smell that distinct gear oil smell.

Looks like this requires some tools to remove the seal and bearing. I'm worried about that bearing because I've had a constant nagging vibration problem and It seems to be coming from the driveshaft or differential.