67 427/435- 4 spd Muncie lube.

[Richard S.]

I'd like to change the transmission oil in the Muncie 4 speed.....I don't know what is in there now. Could someone please recommend what I should buy. The car is not driven hard or too often. Thanks for the help.

[George Romano]

Re: 67 427/435- 4 spd Muncie lube.

I use Pennzoil 80W90 gear lube.

George

[Joe Pennington]

Re: 67 427/435- 4 spd Muncie lube.

When I installed a rebuilt Muncie in my vette a couple of years ago. I put in GL5 gear oil in it, all I could find. It wasn't shifting smoothly and was making some gear noise 1st through 3rd and some noise in 4th when de-accel. that I contributed to the fresh rebuilt, figuring it would get better after some breakin miles. Never improved, so when I found some GL4 at O'Reilly's I changed it out. Big improvement.

[Mike M.]

Re: 67 427/435- 4 spd Muncie lube.

i like Mobile synthetic gear oil. only draw back is greater tendency to leak. super slippery though. mike

[Lawrence S.]

Re: 67 427/435- 4 spd Muncie lube.

Mobil 1 80 90 gear lube is what I would suggest.

[Todd H 26112]

Re: 67 427/435- 4 spd Muncie lube.

I agree w/ Joe on the API GL-4. A good multiweight 75W-90 or 80W-90 or even 85W-90 GL-4 is ideally suited for most any manual transmission. The Redline MT90 (75W90) GL-4 is popularly recomended though there are other options. You may have to scrounge a bit to find a GL-4.

Any modern synthetic lubricant will have no greater propensity for leaking than a conventional oil of the same weight. This is even less likely to be an issue w/ a fresh rebuild or overhaul.

Other things to consider... if a fresh rebuild included new synchros and or gears or other metal parts - might not be a bad idea to do an early oil change, say around 1000 miles, to remove any initial metal flecks from new parts. Don't know about originality or exactly when they appeared but simple magnetic drain plugs can also be handy for collecting metal if that's an option.