Gear Oil Shopping

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Rick Wall
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Gear Oil Shopping

#1 Post by Rick Wall »

I am replacing the gear oil in my 1964 C transmission. The car has been dormant for decades, and I want to refill the transmission with the appropriate oil. The local auto parts store recommended 90 wt. mineral gear oil, API GL-1. "mineral oil"?
Not knowing the leak potential of the transmission, I am thinking Valvoline 80/90, but is there a recommended "GL" level I should be using?

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C J Murray
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Re: Gear Oil Shopping

#2 Post by C J Murray »

I just use common gear oil. I have used synthetic but only in the race car. I read recently that some gear oils attack bronze and are not good for some older motorcycle transmissions. Porsche has less bronze than most transmissions, I think just the shift forks. The garden variety stuff should be fine.

Oil is always a fun opinionated subject. :P
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Brad Ripley
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Re: Gear Oil Shopping

#3 Post by Brad Ripley »

For years among Porsche guys it was Swepco 201 see Zim's : http://www.allzim.com/store/swepco-201- ... ory_id=944

Stoddard NLA sells Motul see: https://www.stoddard.com/mot100118.html

Vic, what do you recommend?

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Vic Skirmants
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Re: Gear Oil Shopping

#4 Post by Vic Skirmants »

I've been telling people for years; any good brand 80/90. I have recommended Valvoline more than once.

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Paul Lima
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Re: Gear Oil Shopping

#5 Post by Paul Lima »

I'm sure Vic is correct, though I do like Swepco 201. It does seem to find its way out of the transaxle more places and more often than other oils, but I also think the shifting is smoother that with other oils

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Sean M Rooks
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Re: Gear Oil Shopping

#6 Post by Sean M Rooks »

I don't like the swepco. Too leaky. I have had regular old 80/90 in mine for 4 years and it seems A-OK.

Strangely I still find the blue stuff leaking out after replacing it 6-7000 miles ago.

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Vic Skirmants
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Re: Gear Oil Shopping

#7 Post by Vic Skirmants »

The problem with the "blue stuff" is that it wicks through the paper gaskets. So I suppose it would keep doing it long after you changed the oil.

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Doug McDonnell
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Re: Gear Oil Shopping

#8 Post by Doug McDonnell »

I am not sure what Vic does but mine doesn't leak Swepco after his rebuild.
1965 356C 2000 BMW 740i Sport 1967 Honda CL77 There is never enough time to do it right, but always enough time to do it over.

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John Clarke
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Re: Gear Oil Shopping

#9 Post by John Clarke »

Hi All
Further to Rick's gear oil question
We always had leaks using Swepco oil, strangely ours was red! because of the leaks from the diff side plates, we had PR Services (356 Specialists) replace the gaskets. I was happy with the way the box changed gears using Swepco. No leaks now but not using Swepco. I would like to refill with Swepco at the next oil change,, but can't risk the leaks starting again after having those gaskets replaced !
Regards Jay
 

Rick Wall
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Re: Gear Oil Shopping

#10 Post by Rick Wall »

Thanks everyone for your replies. Since I don't know the condition of the transmission and it hasn't been active since 1972, I will probably avoid Swepco, and leaks hopefully. The 80/90 Valvoline sounds like my best choice, but is there a recommended GL rating for a 356?

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George Hussey
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Re: Gear Oil Shopping

#11 Post by George Hussey »

Vic Skirmants wrote:I've been telling people for years; any good brand 80/90. I have recommended Valvoline more than once.
I agree, any good 80/90. Quaker state used to make a special 80/90 for vwporsche transaxles that we used for years, do not know if it is still around
George Hussey

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Al Zim
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Re: Gear Oil Shopping

#12 Post by Al Zim »

%Thank you Brad for the referral to Zim's previous post about Swepco. The fact that it leaks from everywhere indicates that the oil is getting everywhere. Which is a plus. In my 250K Volvo I have differential noise which was "repaired" bu the use of Swepco 201. We almost never change transmission oil any more! It does not break down and most cars are not driven hundreds of thousands of miles any more. A one gallon bottle will fill the transmission and take care of the leaks for a long period of time. Full synthetic oils do not adhere well to steel. If you are in a damp climate synthetics for the engine and transmission may not be the best choice,
I would be glad to tell you a story about the changes in transmission oil ingredients over the years but you will think I concocted the story! A lot has changed in the 55+ years I have associated with these cars. Zim, 2018/12/15
Last edited by Al Zim on Sat Dec 15, 2018 3:53 pm, edited 1 time in total.
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Walter Reich
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Re: Gear Oil Shopping

#13 Post by Walter Reich »

Look at synthetic AMS.oil on the internet. Contact them talk to the technical department tell them what car you have
And get which gear club you need. I have a 1964 356c coupe check them out.

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Paul Lima
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Re: Gear Oil Shopping

#14 Post by Paul Lima »

Regarding Swepco: after replacing a seal, and tightening side plates, there is no leakage.

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