gear oil

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mopardude318

mopardude318

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I've searched, everyone has mixed reviews with little information provided, making things confusing. Hoping to make a centralized thread on where everyone can post what they use and why not to use another...So, what do yall use? Synthetic or not? What viscosities? Of course, each manufacture has many different viscosities available....I've heard to stay with a GL4 rating, not a GL5 because those have friction modifiers which are not good....thoughs/opinions?

-Valvoline 80/90 gear oil?
-Pennzoil syncromesh
-GM syncromesh
-Redline 75/140
-Royal Purple 75/90
-Standard type F trans oil
-Lucas 80/90
-straight Type F trans fluid
 
If it is a fresh rebuild, flroyal purPle full syn is what it gets, otherwise it standard 80-90w (was using this in all my 4 speed till they were rebuilt and switched to royal purple full syn).
 
My tranny shifts really nice with straight ATF. But I worry about that poor clusterpin, so I run some 75/90 in it,for her. 50/50 still shifts ok. Sorry,I never paid attention to the GL rating. She's got 125,000 Miles on her and still going strong.
 
Syncromesh for me too. 9 years, same tranny. Nice shifting and always powershift the 1-2 throw at the track. Never had one issue.

I probably just friggin jinxed myself.........
 
Just saw. This thread. I only use GL6 oil in my trans and diffs. 75/140 for the diff and 75/90 for the gear box. While the test is obsolete the oil is not. The real issue is that the GL6 test was a mother bear to pass so when the need dropped off, most oil companies just went to the GL5 rating.

A quality GL6 oil only has one issue and it's not brass. Because brass has a sticky feel to it, and because the factories wanted to cut back on how many lubricants they had to buy and store, they started using linings on and different materials for the syncros. An example would be an early 90's crapstain (mustang for the short bus and dorf guys) that had, iirc a wet clutch lining on the syncros. Or a Dodge Daytona of about that same era. Same thing. The GL6 oil is "slick" enough that the syncro can't grab the gear and slow it down. Now you have grinding. Don't ask me how I know this.

It's 2016 and I can't imagine anyone NOT running a synthetic oil anywhere you can. I have done the testing and a QUALITY synthetic oil always makes more HP and lasts longer and runs with cooler than any dino oil. Just a plain fact.


BTW, do we really care what they were doing in 1970? Do we run that era camshaft? Piston? Tires? Heads? No most of us wouldn't. I know there are some guys who still live in the past but that is just stubbornness or fear.we should be ruled by neither.
 
yellow rose said:
Just saw. This thread. I only use GL6 oil in my trans and diffs. 75/140 for the diff and 75/90 for the gear box. While the test is obsolete the oil is not. The real issue is that the GL6 test was a mother bear to pass so when the need dropped off, most oil companies just went to the GL5 rating.

A quality GL6 oil only has one issue and it's not brass. Because brass has a sticky feel to it, and because the factories wanted to cut back on how many lubricants they had to buy and store, they started using linings on and different materials for the syncros. An example would be an early 90's crapstain (mustang for the short bus and dorf guys) that had, iirc a wet clutch lining on the syncros. Or a Dodge Daytona of about that same era. Same thing. The GL6 oil is "slick" enough that the syncro can't grab the gear and slow it down. Now you have grinding. Don't ask me how I know this.

It's 2016 and I can't imagine anyone NOT running a synthetic oil anywhere you can. I have done the testing and a QUALITY synthetic oil always makes more HP and lasts longer and runs with cooler than any dino oil. Just a plain fact.


BTW, do we really care what they were doing in 1970? Do we run that era camshaft? Piston? Tires? Heads? No most of us wouldn't. I know there are some guys who still live in the past but that is just stubbornness or fear.we should be ruled by neither.
Click to expand...

I am a strong supporter in using synthetic oil and lubricants.
However, i will not use it in my stock A-833 gear box because it is too slippery and the transmission wasn't designed for it.
I have tried it, and the gears clash when you are trying to shift at any speed.......
It would take a lot of modifications that i would not know how to do properly, so i use the recommended oil in this case.
That being said, i use synthetics exclusively everywhere else on the car.
With the statement you are making, we all should run a modern drive train with EFI etc.
Points ignitions, carburetors, bias ply tires, and dino oil is what a lot of these cars were run with back in the day.
Are they totally lousy? No.

Let's keep it in perspective here........
 
Dartnut said:
I am a strong supporter in using synthetic oil and lubricants.
However, i will not use it in my stock A-833 gear box because it is too slippery and the transmission wasn't designed for it.
I have tried it, and the gears clash when you are trying to shift at any speed.......
It would take a lot of modifications that i would not know how to do properly, so i use the recommended oil in this case.
That being said, i use synthetics exclusively everywhere else on the car.
With the statement you are making, we all should run a modern drive train with EFI etc.
Points ignitions, carburetors, bias ply tires, and dino oil is what a lot of these cars were run with back in the day.
Are they totally lousy? No.

Let's keep it in perspective here........
Click to expand...

I have no idea why your stuff grinds on synthetic oil. I do it all the time.

As for perspective, I think you have lost yours. Where did I say to run a "modern" drivetrain with efi? You are correct in that I don't run points ignitions, nor have I since 1980. Still run carbs. What I'm saying is there is no reason not to update. If your into points then go ahead, but I don't leave performance on the table.
 
The first choice from the FSM is ATF.
 
yellow rose said:
I would ignore FSM on that. I doubt you could actually ever find a tribologist who would agree with brass syncros and ATF. Were synthetic oils around when the FSM was printed?

Geebus.
Click to expand...

Regardless, that's what the book says.
 
I just looked online and there is at least ONE GL-6 gear oil on the market. It comes either in synthetic or Dino and in 2 grades of each.

That is what I use and have since 1990. Before that I used other brands of synthetic gear oils without issue.

YMMV.
 
Used a quart of NAPA. It had a shrink wrap label. Don't know why, but before I threw the bottle away I peeled off the NAPA label, and the bottle was printed with all Lucas info. I believe it is possible to have ten brands of a product ( or more) all made with the same specs by the same manufacturer. I was told years ago that if I would buy a certain number of auto batteries that the manufacturer would put my name on them.
Yote
 
Once again. Early FSM specified SAE 90 gear oil, ATF in colder climates. Later ATF. I believe Dartnut when he says he had problems with synthetic. I've rebuilt enough 4 speeds to tell you, I can see more wear in an ATF gearbox. I see no advantage to synthetic lube and have heard of problems. Racers count every .01 of a second and do not have long term maintenance issues. SAE 90 will keep everything lubed and shifting as intended for 2 to 3 hundred thousand miles.
 
yellow rose said:
BTW, do we really care what they were doing in 1970? Do we run that era camshaft? Piston? Tires? Heads? No most of us wouldn't. I know there are some guys who still live in the past but that is just stubbornness or fear.we should be ruled by neither.
Click to expand...

This was the reason for my response in post#13.
So, you're modern(ish) i see.
Sorry i made you mad.
 
Dartnut said:
I am a strong supporter in using synthetic oil and lubricants.
However, i will not use it in my stock A-833 gear box because it is too slippery and the transmission wasn't designed for it.
I have tried it, and the gears clash when you are trying to shift at any speed.......
It would take a lot of modifications that i would not know how to do properly, so i use the recommended oil in this case.
That being said, i use synthetics exclusively everywhere else on the car.
With the statement you are making, we all should run a modern drive train with EFI etc.
Points ignitions, carburetors, bias ply tires, and dino oil is what a lot of these cars were run with back in the day.
Are they totally lousy? No.

Let's keep it in perspective here........
Click to expand...
I totally agree, I just changed to Red Line MT90 synthetic in my 833 and it only took about 20 miles for the transmission to start grinding between the gears both up and down shifting. Before I changed the oil, the transmission always shifted very smooth and solid. The book calls for ATF or an all purpose sae 140 gear oil. I am looking for the 140 gear oil but have not had any luck so I will be going back to the ATF. So, my 2 cents from experience, is do not put synthetic oil in your 833. I just started a thread asking where I can find sae 140 gear oil before I ran across this thread, I also don't want to hi-jack this thread
 
I wouldn't worry about hijacking a five-year-old thread that was 99% opinion.
gunmetal72 said:
I totally agree, I just changed to Red Line MT90 synthetic in my 833 and it only took about 20 miles for the transmission to start grinding between the gears both up and down shifting. Before I changed the oil, the transmission always shifted very smooth and solid. The book calls for ATF or an all purpose sae 140 gear oil. I am looking for the 140 gear oil but have not had any luck so I will be going back to the ATF. So, my 2 cents from experience, is do not put synthetic oil in your 833. I just started a thread asking where I can find sae 140 gear oil before I ran across this thread, I also don't want to hi-jack this thread
Click to expand...
 
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