Dave M

I have an oil leak from what appears to be where the driveshaft enters the differential. Can anyone tell me what is needed to go about fixing this? Is there a gasket/seal in there to replace or do the u-joints act as gaskets? I'm not familiar with end of an f-body!

jewbacca

iTrader: (5)

Pinion seal. Looks like a perfect time for a gear swap!

Dave M

I suspect gears were already done, but I can't know for sure. They have a whine to them when decelerating just like my old 'bird did after I did gears in it.

ahritchie

iTrader: (1)

You should be able to figure it out by noting your RPM at a certain speed in top gear, say 60mph cruise....that and if it does nasty burnouts with little effort!

Dave M

I don't have stock sized tires on the car, and I don't know if the computer has been reprogrammed to compensate for the change in speedo, so I don't know how accurate either of those methods would be.

jewbacca

iTrader: (5)

With your tire size you should be able to calculate what your current gear set it. There are quite a few calculators out there.

ahritchie

iTrader: (1)

Is it 6spd or auto? Auto would almost certainly have a PCM tuned for the gears, besides, you can get a friend to pace you or visa versa at a set upon agreed speed in something stock; or like 95% of people these days just use a portable GPS, they all tell you exact speed....even my iphone will do that. Most people have a smart phone or a least know someone who does.

Dave M

It's a 6 speed. I've used GPS apps on my phone to check and at highway speeds the speedo seems to read ~2 mph high. The rear tires are 315/35r17 and the fronts are 275/40.

ahritchie

iTrader: (1)

Those rears are the exact same diameter as the stock ones; 275/40/17 or 245/50/16, the 35 series sidewall makes up it; I also have the 315/35/17 on my car. Mine runs 2100 rpm at 70mph in a cruise in 6th with 4.10's....when it had stock 3.42's it turned about 1600-1700 RPM at that same speed. Given that, you should easily figure out what yours has.

Dave M

Thanks, I'll double check the rpm next time I'm out.

Dave M

What's involved in replacing the pinion seal. Any writeups out there on it?