67 p-30 with a 4 speed manual - The 1947 - Present Chevrolet & GMC Truck Message Board Network

heritagewraith · 10-08-2018, 10:10 PM

What is the correct fluid or oil for the transmission???

**HO455** · 10-08-2018, 10:25 PM

Assuming it still has the SM420 in it here is the lube recommendation from Novak. If you find that it has had a new transmission swapped in then the link to Novak should be able to help with IDing what you have.

"When filling your 420 with gear oil, we recommend that you select a conventional mineral oil or a para-synthetic in lieu of a full synthetic oil. Properly assembled manual gearboxes do not have the thermal strains seen by combustion engines or hypoid gears. Synthetic fluid in these gearboxes, while not harmful, is probably an economic waste.

Hypoid gear oil is sulphurized higher than transmission oil and can be mildly corrosive to the non-ferrous alloys used for synchros, bushings and thrust washers in these transmissions.

An 80W-90, API-GL5 or MT-1 rated fluid is very good. Some claim faster shifts from using a 50W engine oil in their transmission and we do not consider this to be contraindicated unless you operate your vehicle in a very warm environment."

http://www.novak-adapt.com/knowledge...s/manual/sm420

P.S. Welcome Aboard.

**LockDoc** · 10-08-2018, 10:26 PM

-
Check this thread out.....

http://67-72chevytrucks.com/vboard/s...d.php?t=160507

LockDoc

**'68OrangeSunshine** · 10-09-2018, 01:29 AM

A couple of things. The SM420 is physically shorter that the SM465, so it may take less than the 8 pints [US Standard -- not Imperial] specified in the '68 manual. One US Gallon is 3.8 Liters, for our international viewers.
Also GL/4 is recommended for transmissions with bronze synchronizer gears. GL/5 is specified for limited slip [positraction] differentials.

10-08-2018, 10:10 PM	#1
heritagewraith Registered User Join Date: Mar 2017 Location: Spokane Wa Posts: 28	67 p-30 with a 4 speed manual What is the correct fluid or oil for the transmission???

10-08-2018, 10:25 PM	#2
HO455 Post Whore Join Date: Feb 2016 Location: Portland Oregon Posts: 11,393	Re: 67 p-30 with a 4 speed manual Assuming it still has the SM420 in it here is the lube recommendation from Novak. If you find that it has had a new transmission swapped in then the link to Novak should be able to help with IDing what you have. "When filling your 420 with gear oil, we recommend that you select a conventional mineral oil or a para-synthetic in lieu of a full synthetic oil. Properly assembled manual gearboxes do not have the thermal strains seen by combustion engines or hypoid gears. Synthetic fluid in these gearboxes, while not harmful, is probably an economic waste. Hypoid gear oil is sulphurized higher than transmission oil and can be mildly corrosive to the non-ferrous alloys used for synchros, bushings and thrust washers in these transmissions. An 80W-90, API-GL5 or MT-1 rated fluid is very good. Some claim faster shifts from using a 50W engine oil in their transmission and we do not consider this to be contraindicated unless you operate your vehicle in a very warm environment." http://www.novak-adapt.com/knowledge...s/manual/sm420 P.S. Welcome Aboard. __________________ Thanks to Bob and Jeanie and everyone else at Superior Performance for all their great help. RIP Bob Parks. 1967 Burban (the WMB),1988 S10 Blazer (the Stink10 II),1969 GTO (the Goat), 1970 Javelin, 1952 F2 Ford OHC six 4X4, 29 Model A, 72 Firebird (the DBP Bird). 85 Alfa Romeo If it breaks I didn't want it in the first place The WMB repair thread http://67-72chevytrucks.com/vboard/s...d.php?t=698377

10-08-2018, 10:26 PM	#3
LockDoc The Older Generation Join Date: Aug 2006 Location: Montezuma, Iowa Posts: 25,815	Re: 67 p-30 with a 4 speed manual - Check this thread out..... http://67-72chevytrucks.com/vboard/s...d.php?t=160507 LockDoc __________________ Leon Locksmith, Specializing In Antique Trucks, Automobiles, & Motorcycles (My Dually Pickup Project Thread) http://67-72chevytrucks.com/vboard/s...d.php?t=829820 -

10-09-2018, 01:29 AM	#4
'68OrangeSunshine Senior Member Join Date: Feb 2002 Location: Tucson, AZ USA Posts: 7,512	Re: 67 p-30 with a 4 speed manual A couple of things. The SM420 is physically shorter that the SM465, so it may take less than the 8 pints [US Standard -- not Imperial] specified in the '68 manual. One US Gallon is 3.8 Liters, for our international viewers. Also GL/4 is recommended for transmissions with bronze synchronizer gears. GL/5 is specified for limited slip [positraction] differentials. __________________ Every 25 years I like to rebuild that 292, whether it needs it or not.



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