Stick with Dino!!!!!
muncie 4 speed
Melting Slicks
Joined: Mar 2005
Posts: 2,838
Likes: 10
From: Austin TX
Most would recomend a conventional lube for your Muncie. Valvoline 80w-90 has an MT-1 sub-spec said to good for the yellow parts,..synchros, etc. Plus, it's no secret a syn will leak before a conventional/mineral lube.
FWIW
FWIW
Melting Slicks
Joined: Feb 2004
Posts: 2,040
Likes: 105
From: State of Confusion!!!
2018 C2 of Year Winner
Le Mans Master
Joined: Mar 2004
Posts: 7,493
Likes: 1,502
From: Little Rock AR
I think I have some left over from when I tried it. You can have it for the cost of postage if you want it. 
The tranny made a little more noise after I switched to the Royal Purple and it leaked more. I drained it out, changed the output shaft seal and put some straight 90wt GL-4 rated lube in it. I will not try that synthetic lube again in a Muncie.
That synthetic gear oil is supposed to be bad for the old school brass blocker rings so why jack with it? 
-Mark.
The tranny made a little more noise after I switched to the Royal Purple and it leaked more. I drained it out, changed the output shaft seal and put some straight 90wt GL-4 rated lube in it. I will not try that synthetic lube again in a Muncie.
That synthetic gear oil is supposed to be bad for the old school brass blocker rings so why jack with it? -Mark.
Safety Car
Joined: Oct 2000
Posts: 3,547
Likes: 12
From: Carbondale Pa.
I think I have some left over from when I tried it. You can have it for the cost of postage if you want it.
The tranny made a little more noise after I switched to the Royal Purple and it leaked more. I drained it out, changed the output shaft seal and put some straight 90wt GL-4 rated lube in it. I will not try that synthetic lube again in a Muncie. That synthetic gear oil is supposed to be bad for the old school brass blocker rings so why jack with it?
-Mark.
The tranny made a little more noise after I switched to the Royal Purple and it leaked more. I drained it out, changed the output shaft seal and put some straight 90wt GL-4 rated lube in it. I will not try that synthetic lube again in a Muncie.
That synthetic gear oil is supposed to be bad for the old school brass blocker rings so why jack with it? -Mark.
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Intermediate
Joined: Sep 2007
Posts: 34
Likes: 0
little less than 2 qts. of the 80-90 stuff. Fill it to about 1/2 inch below the plug. Use a pipe cleaner or a q-tip as a dip stick and you can get it pretty much where it supposed to be, we're not talkin' space shuttle here.
Le Mans Master
Joined: Oct 2007
Posts: 7,453
Likes: 976
From: RI, Now Franklin/Nashville TN
Sorry guys but Mobil 1 gear oil in my 4 spd for 20 years! No leaks and much easier shifting when cold! Synthetic oil is dino oil that is reformulated so that all the molecules are the sames size with a more robust additive package. I have run Mobil 1 15W-50 Racing in the engine and in the differential as well since 1985 with zero issues and no leaks.
Melting Slicks
Joined: Mar 2005
Posts: 2,838
Likes: 10
From: Austin TX
Give George Sollish a call. He's the chief engineer at Autogear which is selling the new beefed up Muncies. Ask him what he thinks of synthetics and Muncie transmissions:
www.autogear.net
www.autogear.net
