As you may remember from a previous post I’m getting my former daily ‘71 Chevelle back on the road this spring. Since it’s 100 miles away (almost exactly, it’s like 100.some from my apartment) work can really only happen on weekends, and yesterday I finally got started.

First, jack up the car

Nothing too exciting this time around - I changed the oil (replaced the 1000mile/4 year old oil that was sitting in it with wal-mart’s cheapest - when all the works is done I’ll change it again with good oil and a new filter) and tightened up a leaky lower radiator hose clamp.

The main endeavour was the transmission service - at 100k miles the Powerglide was getting a little weird going into gear, and it felt like the torque converter was full of jam. I can rebuild it, but I’d rather not, so a sorta-good fluid service was carried out.

Drain came out without issue, and the pan came off too easily (the torque spec on the bolts is only 8ft-lb but they should not have been that easy to get out). The fluid was, uh,

Maroon is the new red


fluid. Also very thick, yes it was cold but this was moving like 50wt. I had a suspicion I may be the first person to ever actually drop the pan, since it sure doesn’t look like the previous owner ever really serviced this transmission.

Like I mentioned, the pan bolts came out easily enough and I dropped the pan, and it was, uh,


dirty. Not only was there a good 3/32" of metallic/clutchy sludge on the bottom of the pan, there was also what looked like 1/4" long rectangular pencil lead everywhere, which after a moment of thought I realized would be the edges of the gears from the gearset. Laying in the pan. Some visible in the above picture near the top right.

Definitely hadn’t been removed in the past 45 years; that’s the sort of wear that would happen in the first 100 miles, not after 100,000 (car has 100,057 for reference).

Quite a bit of elbow grease went into removing the old cork gasket (which fortunately stuck to the pan, not the trans housing) and removing the incredible amount of stuff from the pan.


RIP Can of Brakleen

I also changed the filter, which was pretty well caked in the same sort of metallic/clutch slop and another dozen gear-edges. I took a picture of the valve body/filter, but being on my back under a car using a 4+ year old phone, it didn’t really come out very well.

After reinstalling the pan and filling the trans back up, I went for a short drive around my dad’s property (totally didn’t go on the roads in an unregistered, uninsured car... nooope...) to run it through all the gears and let the fresh fluid pump around.


The car went into gear a little bit better, shifted fairly well, etc. Brought it back in and pulled up on some ramps, to drain out the fluid from the pan. It was a bit redder (no picture, sorry). After putting a fresh fill in, back off the ramps and for another short loop.

The car went into gear a little bit better, shifted fairly well, etc. Brought it back and pulled in front of the garage to wash it for the first time in 4+ years.


Washing was uneventful, as washing is, but it was dirty enough that it honestly could use washed again to get the last layer of crud off. I’ll probably give it a quick coat of wax soon, though this is the last it will be driving around for quite a while.

After the wash and some time to dry, I pulled the back back onto the ramps to drain the transmission fluid. It was redder than before (funny how that works). I filled it back up with a final fill of fresh Dex/Merc and a bottle of “Lucas Transmission Conditioner” which worked out to having put 2.25 gallons of fresh fluid in, though some of that would have been drained back out.


Backing off the ramps went as usual, but when I went to pull forward into the workspace after I moved them, something strange happened...

“Drive” engaged with serious authority, and I actually had to push harder on the [manual drum] brakes to not lunge forward. I take this as a good sign. While I could have continued the drain/fill/drive cycle for another several gallons of fluid to get it all clean, at this point the fresh stuff in there, with the Lucas crap, should be enough to keep it happy and from getting any worse in the does-weird-things category. It also feels much less like the torque converter is filled with honey, which is good.

I had intended to change the oil in the axle, however after verifying that I could get the fill plug out of the side of the diff, I decided there wasn’t room to pour the oil directly from the jug into it (something I’ve been able to do on other vehicles) so I’ll take an appropriate pump next time.


What’s Next

Next time I work on the car (might be this coming Saturday, but I’m not certain; my sister is moving that morning so time may be short) I’ll change that axle oil, remove what’s left of the old exhaust pipes, and attempt to begin removal of the factory manifolds (sprayed the bolts with Kroil before leaving yesterday).

Have a good week, Oppo!