STP and Transmission: any negative experience ?

[Forddan]

Hi

Before you hate me this isn't a thread to ask about the best oil to use in the model A transmission. There are many searching this forum.

What I would like to know, is something simple.

Those, who are using 100% STP in the transmission have experience any negative point ?

Like :

have the external temperature affected the viscosity such that it was not shifting smoothly ?

Or have you experience any other issue that make your mind change, regretting the use of STP ?

Or....you got the idea.

We do not need to enter in another discussion of all the 600 W oils that can be used. I have read them almost all.

In those threads I have NOT read anyone saying something bad about using 100% STP. Because the threads were NOT pointed to get that type of comment, then here we are.

To 100% STP users:

Are you happy with the results ?

Anyone stop using it ?

Will I regret my decision of using 100% STP in my transmission?

Thank you !!!

Cheers
Forddan

[Forddan]

This is the STP I intend to use



Best !!
Forddan

[BillCNC]

I have been using it as it was cheaper than the 600w oil. About two week's ago I bought a case of the 600w and will be swapping the STP out for the 600w.

I have had ZERO negative effect's and would still use it but with this 600w lying around, ... I just want to give it a try.

Regards
Bill

[rfitzpatrick]

Boy! Don't I understand your "Disclaimer" (don't hate me) !! I'm using an ultra heavy duty oil, part number G.L. 1500 from Mikes Affordable and really like it. The next best thing -- installed their transmission dip-stick assembly -- don't have to take up my flood board to check fluid level any more --. Instructions to cutting an opening in your board is included --

I do live South Florida so this oil might not be appricated in the Northern States.

[whirnot]

Although I don't use Stop think the viscosity could be an issue in low temps. Even the 600 w is a little stiff on a cold morning in Oregon.

[rotorwrench]

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600W cylinder oil is a spec that predates modern standards for viscosity. It is still sold more for it's capability to work around steam or for old style worm gear drives. It is a straight mineral type lube that is comparable to GL1 SAE 140 gear lubricants. Any GL1 SAE 140 type lube will work in a model A transmission. STP is a viscosity builder so a person should mix it with a gear lubricant such as SAE 80 or 90 in order to get an acceptable viscosity. Straight STP is more viscous than SAE 140 gear oil and may cause stiffness in the shifting of gears. Too heavy a viscosity is almost as bad as too thin a viscosity. Another thing to consider is if you look at the advertisement in post 2 you will notice that is now has ZDDP additive. This is an EP additive that may have a detrimental effect on the phosphor bronze or brass in the transmission. This is why they used straight mineral oil in the first place. STP is designed for internal combustion engines.

[katy]

STP is not an oil, it's an additive.

[duke36]

Originally Posted by katy

STP is not an oil, it's an additive.

Yes; the closest modern gear oil found, based on inspection of an original "600W" can is 250W, such as Penrite's or Lubriplate SPO 299. These are OK for yellow metals without additives. The ZDDP additive is usually added to engine oils to increase zinc levels but could damage catalytic convertors. That's our understanding why STP discontinued the zinc- rich red bottle in the US some years ago.

[Jim/GA]

Originally Posted by duke36

Yes; the closest modern gear oil found, based on inspection of an original "600W" can is 250W, such as Penrite's or Lubriplate SPO 299. These are OK for yellow metals without additives. The ZDDP additive is usually added to engine oils to increase zinc levels but could damage catalytic convertors. That's our understanding why STP discontinued the zinc- rich red bottle in the US some years ago.

Lubriplate SPO 299 is ISO Grade 1000; they also classify it SAE Gear Oil 250 Heavy. That is quite thick. Probably too thick.

Lubriplate SPO 288, with ISO Grade 680, SAE Gear Oil 250, is closer to the original 600W. This may even be too thick for cold climates, until the transmission warms up. But if you know what's happening and adjust shifting appropriately, it's OK.

The Ford Service Bulletins mention diluting the 600W with 10% kerosene in the winter to thin it out a bit. I don't think I'd bother with that, but you can (if you are driving your A in Minnesota in the winter!). Or use the thinner Lubriplate SPO-277 (ISO 460) in winter, only in the transmission.

With an ISO Grade 680 oil in the transmission, the gears in the transmission will slow down their spinning very quickly when you step on the clutch and shift to neutral. It makes driving and shifting a pleasure. You do not need to double-clutch when going from 1st to 2nd and 2nd to 3rd gears. You only need to double-clutch when going from 3rd back down to 2nd gear at speeds above 15 MPH.

MANY Model A transmissions have been filled in the past with "modern" gear oil that is way too thin (like SAE 90 or SAE 140 oil). This was mostly done out of ignorance of what viscosity the original oil was, and the guys used what they had on hand. They did not have an SAE 250 oil (probably didn't even know it existed!). As soon as you do that, the shifting problems begin. You have to double-clutch on every shift because the gears spin too fast for too long, so they clash when you shift. Thus began the old wive's tale that you had to double-clutch a Model A all the time. Not so.

Answering the Original Poster's question, STP is not a stand-alone lubricant, it is a thickener additive. It is not intended (per the manufacturer) to be the only thing you put in a gearbox. They say add 10% STP to your manual transmission oil. Sure, running straight STP may work OK, but why do that when the proper ISO 680 (SAE 250) gear oil is available?

YMMV.

[M2M]

Originally Posted by Jim/TX/GA

Lubriplate SPO 299 is ISO Grade 1000; they also classify it SAE Gear Oil 250 Heavy. That is quite thick. Probably too thick.

Lubriplate SPO 288, with ISO Grade 680, SAE Gear Oil 250, is closer to the original 600W. This may even be too thick for cold climates, until the transmission warms up. But if you know what's happening and adjust shifting appropriately, it's OK.

The Ford Service Bulletins mention diluting the 600W with 10% kerosene in the winter to thin it out a bit. I don't think I'd bother with that, but you can (if you are driving your A in Minnesota in the winter!). Or use the thinner Lubriplate SPO-277 (ISO 460) in winter, only in the transmission.

With an ISO Grade 680 oil in the transmission, the gears in the transmission will slow down their spinning very quickly when you step on the clutch and shift to neutral. It makes driving and shifting a pleasure. You do not need to double-clutch when going from 1st to 2nd and 2nd to 3rd gears. You only need to double-clutch when going from 3rd back down to 2nd gear at speeds above 15 MPH.

MANY Model A transmissions have been filled in the past with "modern" gear oil that is way too thin (like SAE 90 or SAE 140 oil). This was mostly done out of ignorance of what viscosity the original oil was, and the guys used what they had on hand. They did not have an SAE 250 oil (probably didn't even know it existed!). As soon as you do that, the shifting problems begin. You have to double-clutch on every shift because the gears spin too fast for too long, so they clash when you shift. Thus began the old wive's tale that you had to double-clutch a Model A all the time. Not so.

Answering the Original Poster's question, STP is not a stand-alone lubricant, it is a thickener additive. It is not intended (per the manufacturer) to be the only thing you put in a gearbox. They say add 10% STP to your manual transmission oil. Sure, running straight STP may work OK, but why do that when the proper ISO 680 (SAE 250) gear oil is available?

YMMV.

Very good information here and you're spot on by asking why use STP when you can buy proper gear oil to suit the car.

I think you're probably correct that real 600w (not the fake stuff the suppliers sell) was thicker than SAE 140. Note that there was a SAE 190 standard for gear oil, and it's still available:

https://www.amsoil.com/lit/databulletins/g2498.pdf

(this Amsoil is good but expensive)

Penrite Transoil 250 is a better way to go than STP but I don't like that a full spec sheet doesn't exist (such as the spec sheet on the Amsoil 190 and 250 SAE in the link just above)...fair-dinkum oil makers provide full specs unless they're selling low quality stuff. We don't know the pour point for Penrite Transoil 250 but my guess is it's around freezing.

Lubriplate SPO 288 spec sheet is here:

https://www.lubriplate.com/Lubriplat...s.pdf?ext=.pdf

Non-synthetic Lubriplate and Penrite are good, but the Amsoil synthetic clearly outperforms them.

For a few dollars more than Lubriplate SPO 288 and Penrite Transoil 250, but cheaper than Amsoil, you can buy high quality full synthetic ISO grade 680 gear oil that's yellow metal friendly and with a pour point of -30F. The problem is often these oils are only available in 5 gallon pale size or larger but I've found a couple of companies that sell it in gallon jugs for a fair price for the quality you get.

[Forddan]

Originally Posted by katy

STP is not an oil, it's an additive.

Katy

Isn't a car oil made of "mineral oil and petroleum distillates " ?

I am asking because I just don't know.

Google " STP MSDS" and will pop up a pdf file with this data on it :

60-100% mineral oil-petroleum distillates
< 5% Calcium long-chain Alkylphenate Sulfide

[katy]

[QUOTE=Forddan;1760872]Katy

Isn't a car oil made of "mineral oil and petroleum distillates " ?

I am asking because I just don't know.

Google " STP MSDS" and will pop up a pdf file with this data on it :

60-100% mineral oil-petroleum distillates
< 5% Calcium long-chain Alkylphenate Sulfide

You're correct, STP is a type of oil, but it's not sold as an oil it's sold as an additive.

[BILL WILLIAMSON]

Just use 140 W gear oil & learn to shift your gears properly!!!
Bill W.

[mhsprecher]

I use the tranny oil from Bratton's.

FWIW, last weekend on a drive to a cars and coffee, I was crashing gears like crazy. Once it warmed up, I was fine. It was not really cold, just cool and I thought that either: 1. I couldn't shift anymore or 2. my trans was out of oil. I drive it a lot and never really noticed the extent of the crashing before.

[WHN]

We have been using STP in the transmission and rear end for years.

Shifts nicely, no leaks, changes just like the old 600w oil.

I would recommend. I do understand your beginning comment. Enjoy.

[Joe K]

When did they start putting brass components into Model A transmissions?

I can't think of a one.

STP now 100% and about 30 years. No adverse effects. Of course I don't drive cross country in the car. And I have noticed STP is a little "slow" at first when its below freezing - but so was the 600W.

I may be corrected, but STP in my estimation is probably the "original" synthetic oil - engineered for consistency of viscosity no matter the temperature. That is their selling point as it "holds up" and augments a thinner lubricant.

I believe I have STP in my John Deere 110 tractor - which has a lot of commonality with the Model A transmission - straight cut gears, no synchros. But John Deere wanted all of outdoors and my first born child for the quart of JD branded gear oil for this application. But JD is like that. What the market (and market ignorance) will bear.

Tranny (both of them) still going strong.

Joe K

[F.M.]

Originally Posted by Joe K

When did they start putting brass components into Model A transmissions?

I can't think of a one.

STP now 100% and about 30 years. No adverse effects. Of course I don't drive cross country in the car. And I have noticed STP is a little "slow" at first when its below freezing - but so was the 600W.

I may be corrected, but STP in my estimation is probably the "original" synthetic oil - engineered for consistency of viscosity no matter the temperature. That is their selling point as it "holds up" and augments a thinner lubricant.

I believe I have STP in my John Deere 110 tractor - which has a lot of commonality with the Model A transmission - straight cut gears, no synchros. But John Deere wanted all of outdoors and my first born child for the quart of JD branded gear oil for this application. But JD is like that. What the market (and market ignorance) will bear.

Tranny (both of them) still going strong.

Joe K

Hi, On The Early Cluster Gear at each end, Brass/Bronze.. Until 1929

[Joe K]

Originally Posted by F.M.

Hi, On The Early Cluster Gear at each end, Brass/Bronze.. Until 1929

Hah! You got me there. March 1929 no gots.

Ah well, each to their own. Those who buy Cadillac NEVER regret the decision. Those who bought Yugo now wish they had bought TWO.

Back then they needed it. Not so much now except as investment.

Joe K

[Terry, NJ]

Dan (Fordan) that looks like a very nice Tudor! Good Luck with her! The next gear lube I want to mention is Lucas Hub Oil, which is great for beginners, It won't leak out, It will stiffen up the tranny. So stiff in the winter you may find shifting difficult. The stuff is hard to find, lotta dealers don't have it. You can usually find it in truckstops. For your steering box, try John Deere Cornhead grease. Do not put a grease fitting on the box and pump it up till it's full! "Normal" greases will not run down into the gears. The gears will cavitate and just make a hole in the grease and never get on the teeth where the grease can do it's job. Cornhead grease never gets solid enough to not lube the gears. You'll wonder if it's grease or a heavy oil. $3 a tube at the JD dealership. Type in JD Cornhead grease and JD has a lot of info about it. Not for transmissions though. One more semi solution to the shifting problem is to park on a slope (with the left side down) And fill the transmission with just a little more oil. This gives the gears more liquid resistance. Just a little more, don't try to fill the case. Till you learn to shift, then get that extra oil out of here. Good Luck!
Terry

[Forddan]

Originally Posted by F.M.

Hi, On The Early Cluster Gear at each end, Brass/Bronze.. Until 1929

Mine is from January 1929. Can I be relax about this aspect ?

Thanks
Daniel