69 posi rear axle

[Jim M.]

I was thinking today that maybe it would be a good idea to change out the fluid in the posi traction rear end and the the tranny fluid. However, looking at the rear axle it appears to me that there is no drain plug and if that is correct, I'm guessing the back plate must be removed and to do that, it looks like the rear leaf spring also needs to come out. Hope I'm wrong because that sounds like a real PIA just to replace the fluid.

[Paul D.]

Re: 69 posi rear axle

Jim,
Most people use a suction gun to pull out the old gear lube. Be sure to use proper lube. I like to use the GM lube and additive, but I am sure there are others that work well also. Chip.

[Joe L.]

Re: 69 posi rear axle

I was thinking today that maybe it would be a good idea to change out the fluid in the posi traction rear end and the the tranny fluid. However, looking at the rear axle it appears to me that there is no drain plug and if that is correct, I'm guessing the back plate must be removed and to do that, it looks like the rear leaf spring also needs to come out. Hope I'm wrong because that sounds like a real PIA just to replace the fluid.

Jim-----


DO NOT loosen the cover bolts to drain the fluid. If you do, you're very likely to have a leak at the cover-to-carrier interface thereafter.

[Chuck G.]

Re: 69 posi rear axle

As Paul said, you need a "slurp gun" or suction gun. They look like HUGE medical syringes.

The metal bodies are about 3" diameter and 12" long. On one end, where a needle would go in a medical syringe, is a 8-10" length of tubing.

You remove the square plug, put the tubing end in, and suck the fluid out. Adding fluid is the reverse process.

You can use this tool for both the transmission and rear end. It's a VERY handy tool to have.

Chuck

[Edward M.]

Re: 69 posi rear axle

I concur with the above "slurp" gun idea. Harbor Freight (and others) has them. They are cheap. They sort of look like grease guns.

My recommendation is to put in two bottles (they are small) of GM posi-addative, they fil to capacity with quality gear oil. Get the GM stuff, not the stuff they sell at the parts stores.

Then you get to go out to the parking lots and do a bunch of figure 8s.

[Jim M.]

Re: 69 posi rear axle

Thanks everyone for your comments. Hadn't thought about sucking the oil out the fill hole, a much better solution. I'll take a look/see this weekend for one of those in my town. Sounds like a good project for a rainy weekend in the Northwest.

[Chuck G.]

Re: 69 posi rear axle

Corvette dealers and Corvette shops will usually have electrically powered "suction pumps" to suck the fluid out.

Us "backyard" mechanics get to use the "manual" pump.

That 80-90 wt. gear oil smells great too.

Chuck

[Edward J.]

Re: 69 posi rear axle

Jim, one quick note, the colder it is the thicker the 80w90 oil is, if possiable drive the car to try and warm-up the fluid , other wise the suction pump will take longer.

[John H.]

Re: 69 posi rear axle

Jim -

It's a LOT easier to get to if you remove the right rear wheel.

[Richard R.]

Re: 69 posi rear axle

What type of a wrench do you use to get the plug out?
Do they make square sockets? I tried a wrench but their is on room to turn it. Any suggestions would be appreciated.

[Dick W.]

Re: 69 posi rear axle

What type of a wrench do you use to get the plug out?
Do they make square sockets? I tried a wrench but their is on room to turn it. Any suggestions would be appreciated.

8 point socket works well

[John H.]

Re: 69 posi rear axle

8 point socket works well

Sears has them (Craftsman).

[Richard R.]

Re: 69 posi rear axle

Thanks guy's, your are such a great help!

Rich