Randiego

36 Plymouth P2 Transmission Issue

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NAPA has GL-1 (i.e., straight mineral oil) available by order in either SAE 90 or SAE 140, BUT you may have to buy a 5-gallon pail as a minimum quantity.

 

My 1948 Jeepster's owner's manual is very explicit that only "straight mineral oil" (i.e., Gl-1 although that designation did not exist in 1948) be used in the transmission and overdrive, and that "hypoid" or "extreme pressure" gear oil be used in the differential.  Accordingly, I use GL-1 in the trans and OD, and GL-4 in the diff.  I use the same two products in my synchro 1934 & 1936 Pierces.

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I bought 5 gallons of gl1 from Napa several years ago. I understand that everyone agrees that it's the closest to oem spec oil to run in our old transmissions. However when i use it i notice more grinding and hard shifts then I have with a modern multigrade hypoid and non hypoid lube. I've been running 85-90 wt gl 4 and 5 in my transmissions now for 22 years now and have yet to see any deterioration to the brass synchros in the transmissions. Maybe I don't let the cars sit idle enough?

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Guys,

 

A lot of response to my inquiry.  After talking to two other Plymouth owners here in San DIego area and one in San Clemente, they told me that the new oils/greases are not as thick as the lubricants of yesteryear.   They all use DIFFERENT products.   

 

I picked up two quarts of Sta-Lube Hypoid SAE 140 Gear Oil.  It is an API/GL-4.  Product part no. SL24228.  Sta Lube is owned by CRC Industries  out of Westminster, PA.   Not as thick as what Gary L uses in his Model T and the 37 Buick but I was told that it will give excellent results.  Worth a shot.  

 

So I will drain my transmission20180119_190337.thumb.jpg.a6b0054030a80567ac37d3b571f1532c.jpg tomorrow and install the Sta-Lube.  I will report back with the results.  Hopefully, it will do the trick.  We will see.

 

Randy

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17 hours ago, Randiego said:

they told me that the new oils/greases are not as thick as the lubricants of yesteryear.   They all use DIFFERENT products.

On what basis? Did they look at comparable products? Frankly, I don't believe it and would like to see evidence.

 

They all use different products as would be expected, but also there is very little knowledge about oil in the car fraternity.

 

You would be better to drain it with a hot transmission, because, of course, the oil will be less viscous and more will drain out in the same amount of time.

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They all use different products as would be expected, but also there is very little knowledge about oil in the car fraternity.

 

Did you read the S K article ?  That is a car fraternity for sure.

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