Dread Rear Freeze plug replacement

Copyright (C) 2017 by padgett, all rights reserved


Note: Weasle words: This is a limited experience. And while it can be done this way there is a question of whether it should be done like this. If one freeze plug is leaking, more may follow and the best advice is to pull the engine and replace all. I prefer brass plugs.


So one of the freeze plugs on my '90 Reatta started leaking. Now there are two 1.5" freeze plugs on each side of the block (front and rear if mounted transversely). The fronts on a Reatta are not to bad, just remove the radiator then unbolt and move either the starter or the AC compressor far enough for access.

At the rear there is a different issue: the transmission.

Note: While this could be done on jackstands I have a lift and could raise the car about three feet off the ground. This made using a creeper possible and a difficult job easier.

While you can see the freeze plug, It is about six inches up and the gap between the transmission and the oil pan is only about an inch wide. Just to complicate things the plug is only about 30 degrees from vertical.

OTOH, while I have everything needed to pull the engine, it is a royal pain and might be possible to remove the radiator, take everything loose and swing the engine a few inches forward but in that case might as well just pull the engine and get the small ones on the flywheel side as well.

Getting 2 it

First needed as much clearance as possible so after raising the car about three feet in the air I pulled the oil filter and pan. (note: lift is now in a different place (is mobile) so can close door).

OK I tried a lot of things that did not work (see Edison) such as using a very long screwdriver to try to flip it, screw and pry bar, etc. and spent days without any movement atol.

What did finally work was to drill a succession of larger holes (started using an electric screw driver, 1/16" drill to start, and a LOT of extensions). Have a bucket ready as the block will drain unless already empty. More if you did not drain the radiator first. Then began trying to pry it out. (note bend in shaft). Pan and oil filter have been removed.

Didn't work.

Then tried an assortment of hooks that came with my slide hammer but could not really get enough movement.

Finally went to the local hardware store and bought a 6" (longest they had, 8" or 10" would be better) 3/8" carriage bolt and ground/filed the head into a hook, then tapped the same size as my slide hammer adapter(M10-1.0 YMMV).

After ka-banging for the better part of 20 minutes (my arm hurts thinking about it) coupled with occational beating on the bottom lip with a very long screwdriver, what was left of the freeze plug finally popped out (on right side of jpg).

Did think about cutting the edge of the freeze plug with a dremel but was concerned about possibly scoring the block. Important to be careful to avoid that.

Reached up and was able to clean some trash out of the block at the freeze plug hole, may have contributed to the problem or may have been a '90 issue (had a '90 Bonneville with the same drivetrain that was a new car when I received it and lived in Central Florida (no rust) all its life. Shortly before the millenia I had to have all of the freeze plugs replaced). As to the new freeze plug, there was no way I could feel confident about pressing a new one in place so used a 1 1/2" Dorman rubber freeze plug. Expensive but have never had an issue. Could pop in and use an offset wrench to tighten until firm.

Next I replaced the oil pan (used some axle grease to hold in place then used trouble light after enough bolts to hold it to make sure gasket was still in place (bright blue so easy to see). Spec is 120 in-lbs/10 ft-lbs. New oil (Mobil 1 10w-30 high milage, 5 quart jug - since cleaned out the oil pan it needed all), Filter (PF-47 with 5 holes), long life antifreeze, and distilled water (gallon is 88c at wally world).

Have driven about 100 miles now with no leaks.

And there you have it. Not the factory approved method but worked and did not need to pull the engine. It can be done this way but you really, really, REALLY have to want to.

Caveat y'all.

Copyright (C) 2017 by padgett, all rights reserved

This page was written using Windows 10 Notepad. Some habits die hard.
All photos taken locally. I have never been very good at graphcs.