I have a 1988 suburban with a 350/700R4, and tons of oil splashed all over the underside. I realize it's the main seal, but my question is how to service this. Do I need to drop the tranny out? Or do I just simply remove the oil pan? I'm unsure wether it's a one or two piece seal. Thank you for your input!
Your 88' has a one-piece rear main seal. Are you sure it's the rear main seal? Did you pull off the torque converter dust cover to check for oil all over the flywheel? I find the stamp steel oil pressure gauge sender is usually the problem. If it is the rear main seal look into dropping the oil pan, tranny and of course the flywheel. The actual seal is easy to replace just hard to get to.
You are gonna have to remove the tranny and flex plate to replace the seal.
To remove the seal I drill a small hole in the center of the seal at the bottom and then run a long screw into it. it will bottom out and the seal will pop out.
Or if you are not comfortable with that just run 2 screws on opposite ends of the seal and clamp on a set of vice grips and using a pry bar pry against the vice grips and the seal will come out.
The only engine that I found that didn't like the bottoming out screw method was a Mack engine, the screw wedged between the crank and main cap and broke off.
To install the seal just use a small hammer and tap it in around the edges.
If there is a groove worn into the end of the crank a speedi sleeve will be needed to stop any future leaks.