Transmision and Rear End Fluid question.

I used straight STP for my trans. and rear end for the last two years, no problems, shifts good, I did go back to 600w this year, I read some where that STP alone should not be used as a lub, I cant tell the diff. they both work well.
 
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It was recommended to use straight STP as a gear lube in one of the model A magazines several years ago. I took it for gospel and put it in my 31 tudor. STP seemed to work fine at first but after several years I noticed that our sedan didn't shift nearly as well as our other model A's. I decided to replace the STP with the 600W offered by Snyders and see if it would make any difference. I removed both plugs from the transmission and after an hour or more, not one drop of the STP had drained out. I ended up using the heat gun on the transmission for 30 minutes or more before it liqufied enough to mostly drain out. After pouring in the Snyders 600W The gears shifted the way that they should.

STP is mostly a viscosity booster (thickener) . If used straight as a gear lube, after a few years it thickens. It has been said that some model A vendors make their own gear lube by mixing 140 weight and STP and call it 600W . I have used the mix lube with no problems but had problems with straight STP after a period of time.

Some make a big deal about gear lube and buy large quanities of certain brands of gear lube that they believe is closest to what Ford used in the day. I agree with Timothy Kelly, 600W doesn't mean 600 weight but was the part number. The actual weight of the gear oil that Ford used was closer to 250 weight. I understand that Snyders Gear lube is 250 weight and that is what I now use.

I've owned model A's since the spring of 1960 . As a teenager with a part time job after school, I didn't have a lot of money to pay shipping on some unheard of gear lube. I used 140-90 weight gear lube that I could get locally. I had good results and never a problem. I didn't start using the model A vendor 600W untill sometime after 1978 and never felt a difference.

Just to add a note. When adding lube to the transmission or backend , stop pouring at about an inch below the level of the fill plug. This practice will help keep gear lube off the brake lining and be less likely to leak.
 
Back in the 50,s,when useing an A as a daily driver, I used 140 gear lube for trans in summer & 90 oil in winter.I used 90 lube in rear end all year round.At -20* or more,the 140 would be so stiff it was easy to stall the engine & hard to change gears.
 
billybronco1 said:
Seems most places only sell a multi grade like 90-140 is that what you used and mixed half with STP
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Yes, most places sell only multi-grade like 90-140 but not all. Why not spend ten or fifteen dollars extra to have the correct oil shipped to you? I think if STP was designed for trans and rearends STP would promote it for that...they don't.

I don't understand why people decide to experiment or cut corners for the sake of $10.
 
If I could run down to my local store and buy it I would do it but I can not find this stuff any where and shipping from Australia is not cost effective
 
When this forumn said Lucas Hub oil was great I put it in 2 cars, am I the only one still happy with it? or waiting for trouble? sure cured my grinding.
 
I have the Lucas Hub Oil in my car. I am well satisfied with it. It shifts easily on the upshift and downshift. The ****** is pretty stiff at first on cold days but it will shift ok if I shift at a lower speed. After a mile it warms up and shifts easily again.
 
Timothy Kelly said:
With all due respect, I disagree with the above statement regarding oil viscosity.

The viscosity of the above identified oils is generally in the range of 200 to 250 weight oil. Oil in this weight range is quite thick and can be tough to pour in cold weather. I am not sure that anyone manufactures "600 or 680 weight" oil. If they did, it would be like peanut butter.

Typical manual transmission oil today is often found in the 85-140 weight range.

Transmission oil, at the time Model A Ford's were being produced, was known as "600W" where the 600W was the PART NUMBER, not the WEIGHT of the oil. The weight of that oil was in the 200 to 250 range, just as is the modern 680 oils.
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Your correct Tim, The 680 weight is an ISO Viscosity which is approximately 140 plus SAE Viscosity
 

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RonC said:
Your correct Tim, The 680 weight is an ISO Viscosity which is approximately 140 plus SAE Viscosity
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Those flow charts are very general in nature and misleading. Look up specific lubricants and you will find just that. Look at the viscosity at 40 degrees Celsius as that is the closest to our operating temps. ISO 680 is actually a little heavier than SAE 250. Ford changed to SAE 250 in 1932 except in sub-freezing temperatures.
 
I use
lucas hub oil in my ******, much, much better "feel" than Mac's 600w that I ran a year with. The Lucas has been in now for 6 mo. It does foam up some in hot weather so the slick feel will fade a bit when really hot but I'm very happy with it. The 600w I had was a foamy slimy mess when I drained it. The car had been sitting for several days too. I think there is a difference in 600w the different suppliers are selling, I know some that are very happy with what they got. I'm not recommending or arguing anything, just my 2 cents.
 
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