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Tranny Lube?

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fireinc

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Howdy Guys,

I'm trudging along in my "road"storation (just getting it running/driving ;-)) and have just replaced the rear axle seals (a bear!!), bearings, and obviously the gaskets and O-rings. Oil saturated brakes are next on the list but I hope to get them done in the next day or so. Getting closer to the "Drive" phase (fingers crossed)...

My Question: As a matter of preventitive mantienance what is ya'lls opinion as to what my best choices are regarding Transmission lube? Haynes manual that I've got advocates just using 20-50 engine oil, but what are my best choices re: synthetic or not? TIA

'68 sprite w/1275 and original/ribbed 4spd.(sat undriven since '84. Last P.O. started on it and got the motor running and a few other ancillaries).

Edward G.
 
I've always read straight dino 20W-50 for the tranny. You really want to avoid putting any detergent type of oils in there (I'm assuming because they will foam up too much). This basically rejects all forms of synthetics as they all contain detergents.

Ben
 
Another point to remember is that the syncro rings don't like real slippery oils. They need the viscosity of good old oil to function properly.
 
Don't use synthetic oil in the gearbox. It will burn up the syncros. Don't worry about modern detergent oil. it will not foam up in the gearbox. In 1960 yes the detergent did foam a bit. Oil engineers have solved many concerns since then. I like 20w50 in warm climates, 10w40 in cooler areas.
 
When I rebuilt my gearbox I bought a kit of all the bits that wear out and the company that supplied it recommended synthetic SAE 80.
The original book sdo say use 20/50 - I've always thought that sounded a bit thinfor a gearbox!
 
fireinc:

As you can see, there are a lot of opinions on what to use.

I have had good results with 10W-30 motor oil in a ribcage Spridget trans here in the northeast US.
In your warmer area, the 20W-50 is probably a good choice.

But I do want to comment on the notion of using sythetic gear oils. Newer 1500 Spridget transmissions (not the ribcage) are supposed to use 80W gear oil (not motor oil). I have been using Redline sythetic gear oil in my 1500 trans for three years with excellent results. The shifting is noticably better. There have been many comments that synthetic gear oils are not good for brass syncronizers. Redline has issued a white paper on their website that specifically points out that their gear oil works fine with brass syncros. And as I said, it works fine for me.

I cannot speak about sythetic motor oils when used in a ribcage...I have no experience with that.

But I did want to point out that there is technical info supporting the use of sythetic gear oils for manual transmissions where gear oil is recommended.

https://www.redlineoil.com/tech.asp
 
Thanks for all the info and food for thought guys! As I've just bought a full case of Castrol GTX twenty-fiddy, I'll likely start w/that and know I've got fresh lube in there. I don't even know the conditon/driveablitily of the transmission yet as it stands.

With natural mulit-viz oils, what change intervals do ya'll recommend due to the flow inhibitors degrading, and does anyone ever run a straight (fairly heavy?) weight in High-temp regions like S.Texas for a summer only ride?

Edward
 
I use the same castrol 20- w50 as in the engine. No problems here in Florida. I change them both at the same time. Just easier to keep track of them. Every 2 to 3000 miles.
 
My trans supplier (Quantumechanics)told me to use 30wt. non detergent eng. has worked great so far just my 2cents Mark /ubbthreads/images/graemlins/driving.gif
 
I run Castrol 20W-50 in mine - same as the engine. Never had any problems.
 
You guys really don't have to change the oil in the gearbox that often. It doesn't hurt....but it might be a bit of overkill.
In regard to a straight weight oil, a 30 weight oil has the viscosity as a 5W30 oil when hot. The only difference is when the 5W30 is cold it is not thick and goes to all the places it needs to be(bearings) a bit easier. Makes it a bit easier to shift in the colder climates too. Don't be afraid of the modern oils...they do work quite well...even in an old transmission.
In regard to the synthetic engine oil in the gearbox..it is not a good idea on a ribcase...ask me how I know. Don't do it...unless you like changing syncros a lot. That stuff is really slippery.
 
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