hmmmm now I'm really confused ! why is it that people say when draining the thicker oil out of the diff, its better to have the diff warm so the oil flows out better ? according to this theory the oil is thinnest at cold temp.

I always thought oil is thick when its cold and gets thinner when it heats up ?

 

Im no mechanic but i really dont think it is necessary to warm the oil before draining. Mine drained fine.... Maybe wait an extra 10 min??

 

i think you need to reread what you just said and then reevaluate the theory.

 

A given oil is thinner when warm ... but if one oil is rated 75W-140 and another is a 80W-90 or straight 90 ... then at cooler temps, the 75-140 will be thinner.

As the oil heats up, the 75W-140 will retain more of its resistance to flow (viscosity) and be thicker at operating temps.

pilotb777_300, it's hard to say how well a previously owned car was cared for. People will get the engine oil changed but neglect the diff or the tranny for 50,000-100,000 miles in some cars.

It's also hard to say what level of noise is normal. When I first got my 2005, I was amazed how mechanical the car sounded ... despite having only 15,000 miles on the clock. I began calling my '06 Civic my 'electric car' because it was so smooth and silent by comparison.

Most all of the mechanical noise went away when I changed the tranny and the diff fluids ... I suspect most of it was coming from the diff. With the top up and everything off, I can still hear a faint, tinny, whine coming from the rear of the car ... could be the diff, could be the rear brakes gently dragging in the disc. I'm not sure which. Gear oil is Chevron 80W-90 with less than 1,000 miles on it.

 

Is mobil 1 75w-90 gear oil fine for cold temps?

 

Yes.

 

I can't find a 24mm anywhere in the stores that has a 6 pt. I'm assuming that you can't use a 12 pt. The guy at sears says it could be a specialty thing and I will probably have to purchase it online.

 

You should be able to use a 12pt. My 23mm is a 12 point and worked just fine.

 

I wonder what the margin for error is?

My shop manual states .78 qt as required. Of course getting my car perfectly level is not possible. My driveway is simply not level. With a 2-3 degree bias to the rear I changed my fluid.

I pumped until it began leaking and pumped a little more. Between the remaining amount in the container, fluid still in the pump and the small amount that dripped out before I put the fill cap on I would estimate .85 to .90 qt is in my diff.

Since there was some flow when I first undid the fill bolt, I tried to duplicate this flow level while in my driveway. The first fill was done on a lift that was approximately level, with the standard method of fill till spill method being used.

I wonder if I'll have problems?

What gets me is why there isn't just 1 QT required and a 'high low' check allowed?

 

I read that it can round your bolt and that is something I don't want to do.