dplotkin

My box leaks after a run (65 396). I see the exhaust manifold proximity is cooking it. It appears to have 90 weight gear oil in it, yet others suggest grease should be used. Should I suck out the oil & replace with grease? If so, what is the best way to do this and what grease should be used? Does not leak cold.

Dan

Nowhere Man

Yes you need grease not oil

dplotkin

Can I pump it in with a hand-held grease gun?

Scott Marzahl

No, you need to take the top off the box and then you will loose your lash setting, assuming it is set up correctly to begin with.

dplotkin

Why can't the oil be sucked out, or grease pumped in?

Dan

midyearvette

yes, drill out a sacrificial bolt and install a zerk fitting
remove two of the plate bolts and install the modified one and pump away
the old fluid should escape and leave room for the chassis grease through the missing bolt hole

someone may make one of these modified bolts already, im' sure others will chime in....good luck...

Powershift

You should use grease, not oil. I use GM # 12377985. Cost about $6 for a tube. Apply with a grease gun.

Paragon (and others) make a special fitting with a zerk on it that replaces one of the three steerng box bolts. You remove the forward and the center outboard cover attaching bolts and install the special zerk bolt into the forward screw hole. This allows you to both fill and vent any air. One bolt holds the top cover tight.

I prefer to raise the front wheels off the ground during the filling, and rotate then side-to-side occasionally. It helps to better distribute the new lube. It also takes any stress off the steering box with the single bolt holding things together. Fill until the new lube comes out the "CHECK LUBE" hole. The remove the zerk bolt and re-install the two bolts that were removed.

You can also make a zerk fitting with an old bolt if you desire.

The BEST solution is to remove the box and have it rebuilt and refilled with synthetic chassis lube. Then you are good for a lifetime. But for now, you can add the grease I just recommended.

Larry

JohnZ

Dan -

Nobody ever reads it, but all of the midyear Shop Manuals and Chassis Service Manuals have a chassis lubrication diagram in Section 0 that clearly shows to use chassis grease (the same stuff you use in the ball joints and tie rod ends) in the steering gear.

DansYellow66

I'm afraid you may still get some leaking after replacing the gear oil with chassis grease. Even chassis grease will separate out some oil after time and heat will only speed things up. If the pitman shaft seal is leaking gear oil it probably needs replacing.

dplotkin

allrighty then, chassis grease it is, this box was rebuilt during a comprehensive restoration not long ago, yet if Chevrolet was specifying grease while someone poured oil in it who can blame it for leaking?

Thanks for the tips; worth more than anything I paid money for today.

Dan

Tom454

I'm rebuilding my own box right now. 1970 454. I've owned the car since about 1985. The heat of the exhaust manifold melted the OEM grease and it was leaking out past the seal and running down and dripping off like gear oil. But it was grease in the box, not gear oil.

dplotkin

I'll have to remove the lube bolt & stick something in there to see what I have. Everything else on this car was done right so I imagine they put grease in it, but it looked like gear lube.

Dan

Powershift

Cars built in the 1950's used gear oil, but GM went to grease in these manual boxes during the 1960's.

Larry