Synthetic Gear Oil

[Model A Ron]

Ok so what gear oil do you use and what weight? Synthetic or non-synthetic? From what I have read about the vendors 600W oil is about the same as 140w.

Do you use the same gear oil for steering box, trans, and rear end?

I just got my car so I plan on changing them all in the near future but I cannot decide on 140w or 250w. People say 250w makes for smoother shifts in the trans and helps with engine braking but I would like to hear from people who have used both.

Thanks
Ron

[Bob Bidonde]

I run SAE 75W140 synthetic gear oil in the transmissions and differentials of my Model A's. I have been doing this for many years (thousands of miles) without any issues. This gear oil withstands the high heat and large forces of modern car differentials, so it is superb for Model A's and AA's.

[Model A Ron]

Does anyone know who carries the 250W oil? Also if you used it does it make for smoother shifts? Still working on my 3 to 2 shift so that's why I am interested in 250W.

[Kurt in NJ]

A place that sells industrial lubricants--- I got a pail of shell Omaha 680, -- 600W steam cylinder oil is listed for use with steam engines, and worm gears, then there's the 600 series of gear lubricants, listed uses are spur gears and bevel gears, this is what I got

[Ruth]

Originally Posted by Model A Ron

Does anyone know who carries the 250W oil? Also if you used it does it make for smoother shifts? Still working on my 3 to 2 shift so that's why I am interested in 250W.

Restoration Supply Company, they carry Penrite SAE 250 https://restorationstuff.com/shop/#fb0=27

[Ruth]

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Here is a good oil chart posted by someone in the past (sorry, I don't recall who).

[alexiskai]

Mike's carries ISO 1500 oil, which is the same viscosity as the 250. I've used it and it seemed fine.

[Patrick L.]

I really don't a difference between 250 and 140.

I use them in all 3 places.

I just add to the steering box. The transmitter oil gets changed more often than the rear end just in case it happens to get some grease in it.

I usually grease and adjust things once a year.

[Y-Blockhead]

Originally Posted by alexiskai

Mike's carries ISO 1500 oil, which is the same viscosity as the 250. I've used it and it seemed fine.

I tried Mike's GL 1500 oil and was not too thrilled with it. Even in Southern California I found it extremely difficult to shift, especially on cold mornings.

It seemed OK in the rear end, just not the trans. I just recently drained it out of the rear end.

[alexiskai]

Originally Posted by Y-Blockhead

I tried Mike's GL 1500 oil and was not too thrilled with it. Even in Southern California I found it extremely difficult to shift, especially on cold mornings.

Huh, interesting. I had no trouble shifting, but I don't think I've run it on a cold morning recently. What did you switch to?

[Y-Blockhead]

Originally Posted by alexiskai

Huh, interesting. I had no trouble shifting, but I don't think I've run it on a cold morning recently. What did you switch to?

Right now I have Lucas SAE 85W-140 in the trans, Mitchell and rear end. I chose this weight because Mitchell calls for SAE 80w-140 and I thought it would make my life easier to have the same oil in all three. So far working good. Lucas is OK for use with GL4 and GL5 applications.

[jb-ob]

Ron,

First, I've tried all the different slimes & tars listed above. They are the least of your concerns. As a new Model A owner, change the engine oil and check the level on the trans & rear axle. If they are wet. drive the car.

Smooth shifting is a function of two variables.

First is outside temperature. Close to 30 degrees, you are not shifting into any gear for the first mile using 250W gear oil. In 1932 and 5 million Model As later, Ford recommended 140w for the trans & rear.

Is your clutch pedal free play correctly adjusted ?

Second variable, YOU !

The Model A with straight cut trans gears is not your ol' four speed fully syncro Camero transmission. No winding out the gears before pounding into the next. Model A owner's manual suggests shifting from 1st to 2nd at 8 mph, second to third at 15 mph. This is where you begin to find your car's shifting sweet spots with out grinding gears.

Master that and then find your favorite flavor of the month gear lube.

[Synchro909]

By my experience, a light weight oil like 140 will make shifting without a crunch difficult when it is hot. Even selecting 1st gear at a stop take a lonnng time, then a crunch. It is simply not thick enough to slow the gears for a silent change. I like the idea of the extra "slipperyness" of an EP oil but not the difficulty of changing. I've tried adding thickeners to that oil without success. I is OK till things get hot, then it's back to crunchy changes. As a matter of fact, I have just drained it all out of the cog box and replaced it with my usual Transoil 250. Just over 100 miles the next day and all was back to the wonderful normal. No more experimentation for me!

[jb-ob]

Synchro,
From how you describe 'crunchy' I'm wondering about your clutch adjustment and idle speed ??
Just because factory 'new' was 1 inch free play, 80 years later a slight bit less couldn't hurt ?
No air leaks & a tight throttle shaft makes for a nice low idle speed between shifts.

But you knew all that ..............

[Synchro909]

Originally Posted by jb-ob

Synchro,
From how you describe 'crunchy' I'm wondering about your clutch adjustment and idle speed ??
Just because factory 'new' was 1 inch free play, 80 years later a slight bit less couldn't hurt ?
No air leaks & a tight throttle shaft makes for a nice low idle speed between shifts.

But you knew all that ..............

jb-ob, thanks for the reply but all was well before I changed the oil to the lighter one and all well again after I changed back so I think all of those things are OK.
Before I changed the oil for the second time. I checked the clutch and made it just under 1" freeplay. Idle is slow and steady.

[Model A Ron]

Originally Posted by Synchro909

By my experience, a light weight oil like 140 will make shifting without a crunch difficult when it is hot. Even selecting 1st gear at a stop take a lonnng time, then a crunch. It is simply not thick enough to slow the gears for a silent change. I like the idea of the extra "slipperyness" of an EP oil but not the difficulty of changing. I've tried adding thickeners to that oil without success. I is OK till things get hot, then it's back to crunchy changes. As a matter of fact, I have just drained it all out of the cog box and replaced it with my usual Transoil 250. Just over 100 miles the next day and all was back to the wonderful normal. No more experimentation for me!

I have driven manual transmissions all my life but just got a Model A. The crunch is something I do not like at all and it seems to come into play as the gear oil heats up. Also I find my 3 to 2 shifts crunch as the oil heats up.....interesting that I had no issue with the 3 to 2 shift with a cold gear box. I think I am going to change the car over to 250w oil. I live in Carolina so outside temp should not be a problem.....and if it does get cold I will not be driving my Phaeton so it sounds like a win win for me.
Ron

[Bob Bidonde]

Automotive gear oils are especially formulated. Unless the oil is formulated for gears, I would not use it. Gear oil should have:

• Extreme-pressure and anti-wear agents;
  
• Pour-point depressants to improve low-temperature performance;
• Rust and corrosion inhibitors to protect internal components;
  
• Oxidation inhibitors to reduce the deteriorating effects of heat, increasing the oil’s service life;
• Viscosity index improvers to allow a lubricant to operate over a broader temperature range;
• Anti-foam agents suppress foaming tendency and dissipate entrapped air;
• Friction modifiers - The required degree of friction-reduction can vary significantly between different pieces of equipment in drivetrain applications. In some cases, friction modifiers may be required to obtain the desired results.

[Model A Ron]

So has anyone used the stuff below? Is it any good for a Model A?

LUCAS SYNTHETIC SAE 250 RACING GEAR OIL

[Ruth]

Originally Posted by Model A Ron

So has anyone used the stuff below? Is it any good for a Model A?

LUCAS SYNTHETIC SAE 250 RACING GEAR OIL

FWIW it states on the container "Not Recommended for Passenger Car Use" so use at your own risk.

[Model A Ron]

Tis may be a stupid question but is gear oil offered between 140w and 250w? Maybe a 200w would be a good option if offered.....just asking

Ron