4 speed gearbox oil change

[Foxbrk]

on a '66 Corsa 4 speed...the best way a remove the old oil...
Does not seem to have a drain on the bottom of the gearbox or transaxle ...

[fred bagnall]

You are correct that there is no drain plug for the 66 transmission or differential. Short of making your own , which some people do at rebuild time. you are stuck with going into the fill plug and inserting a flexible hose and sucking it out with a small pump. You can purchase a cordless operated drill pump at most home improvement stores. You can also find a hand operated pump at a Harbor Freight stores to do the same thing. I have also seen people use the pump that comes with some gear oil containers and use those in a pinch. I hope this helps.

[fred bagnall]

You are correct that there is no drain plug for the 66 transmission or differential. Short of making your own , which some people do at rebuild time. you are stuck with going into the fill plug and inserting a flexible hose and sucking it out with a small pump. You can purchase a cordless operated drill pump at most home improvement stores. You can also find a hand operated pump at a Harbor Freight store to do the same thing. It all depends how you want to go about it. You are pretty much relegated to having to suck it out to replace the oil.

[terribleted]

Removing the transaxle and inverting it works well:)

[VairsRule]

Please note that the '66 and later manual transmissions have a number of moving parts mounted to the inside of the side cover (everything was inside the case on the 60-65 gearboxes). If you remove side cover, some of these parts can fall out, because there is nothing holding them in place. Putting it all back together can be a real challenge!

[ranger372]

In addition to sucking the gear oil from the transmission. The oil must also be sucked from the fill plug on the trans axle. These units share gear oil between the two. My guess is the bean counters back in the day thought they could save a nickle per car, by not providing drain plugs. Be sure to use GL4 gear oil.

Steve D.
63 Monza Convert.
65 Monza Coupe (project)
65 Corsa Convert (project)

[Foxbrk]

Well, I got the old oil out of the gearbox/ transaxle using a 60CC veterinary syringe.
question? can you tell from the outside of the transaxle if it's a limited slip?
I got 4 3/4 quarts of old oil out of the transaxle & transmission... is that about the right? just start sucking air after a while.
I plan on filling it for tomorrow w/ GL4...
the Corsa is new to me... nobody seems to know too much about it... i.e. Optional equipment etc. (trim tag?)
the bad news... i think it could use a second gear synchro...(62k)

[terribleted]

Did you mean 4+ pints? Capacity is listed as 4.5 pints in your 65 GM Chassis Shop Manual...see the first page of Specifications under rear axle. Sounds like you got most of it. I do not think 4+ quarts could hide in there. In any case refill at the plug by the left rear axle and fill until the gear oil just runs out:)

[bbodie52]

Welcome to the Corvair Forum! If you don't have a set of Corvair manuals and other technical references to guide you, I strongly suggest you purchase and/or download these manuals and make full use of them. These books, Internet resources like the Corvair Forum, and perhaps a local Corvair club (CORSA club chapter — if one is available near you) will go a long way toward a successful effort in mastering your 1966 Corsa and getting the most enjoyment from it.

The link below will provide you with a list of useful websites that are Corvair-related. Some of the links will lead you to an extensive technical library that will allow you to download shop manuals and other technical references in Adobe Reader format at no cost. There is also a link that will help you to locate nearby CORSA (Corvair Society of America) club chapters. While the Corvair Forum can be very helpful as you work on your Corvair, having local friends and contacts in your region who are knowledgeable about the Corvair can also be very helpful. These family-friendly CORSA chapters often offer picnics, group scenic drives, technical training and assistance, car shows, and competition events that can greatly enhance your enjoyment of Corvair ownership. You will also find a list of essential Corvair parts suppliers.

Common and Useful Corvair Websites

viewtopic.php?f=225&t=6007

I would like to encourage you to expand on your earlier post and tell us more about yourself, as well as about your Corvair. Your personal assessment of your mechanical skills and abilities helps a lot. Members of the Corvair Forum love to be helpful in assisting other Corvair owners with technical support and advice, but it helps a lot if we have some understanding of your technical background and mechanical abilities, your Corvair-related knowledge, etc. Helping us to know more about you will help us to write comments to you that are tailored to your needs and experience. Some detailed photographs of your Corvair would be great! I also recommend that you post your location, as knowing your location can often suggest possibilities.

If you will post close-up photographs of the VIN Tag and Body Tag (both riveted to the engine compartment perimeter frame) I will decode them for you.

The table below was taken from the 1966-Chevrolet-Corvair - GM Heritage Center Specs (attached). It provides some information about rear axle identification.

The specifications pages in the 1966-Chevrolet-Corvair - GM Heritage Center Specs indicate that the differential lubricant capacity is 4.0 pints (page 23), and the 4-speed transmission has a capacity of 3.6 pints. The 3-speed manual transmission holds 3.1 pints (page 41).

The specifications pages in the 1965-Chevrolet-Corvair - GM Heritage Center Specs indicate that the differential lubricant capacity is 4.0 pints (page 30), and the 4-speed transmission has a capacity of 3.6 pints. The 3-speed manual transmission holds 3.1 pints (page 50).

The specifications pages in the 1965 Corvair Chassis Shop Manual states that the 4-speed manual transmission has a lubricant capacity of 3.6 pints, and the 3-speed has a capacity of only 2.2 pints. It also indicates that the differential holds 4.5 pints. The 1962-1963 Shop Manual Supplement indicates a differential capacity of 4.5 pints in 1963, but only 3.1 pints in 1962. It also stated a 4-speed capacity of 3.75 pints, and a 3-speed capacity of 3 pints.

1965-1966 Corvair Transmission Specs

http://corvaircenter.com/phorum/read.php?1,27400,180286

Left-click on image to enlarge for better viewing...

...can you tell from the outside of the transaxle if it's a limited slip?

The differential allows you to turn one yoke or the other independently, even if the transmission locks the input drive gear (as long as one wheel i off of the ground). The differential spider gears allow one wheel to rotate independently. If one wheel loses traction (on mud, ice, etc.) it will allow one wheel to spin, while the other wheel receives no power and will not be driven at all. A Limited Slip (Positraction) differential helps compensate for this fault. (With the wheels both off of the ground, manually turning one wheel in one direction will cause the opposite wheel to turn in the opposite direction. If you have a limited slip differential, both wheels will turn in the same direction). The videos below will explain the principles behind the function of a differential...

[joelsplace]

Easy to tell - with it in neutral and both back wheels off the ground turn one wheel forward. If the other goes backwards it is an open differential. If the other goes the same direction it is a posi.

[Foxbrk]

Thanks to all...!
My Corsa: '66 turbo 4speed convert.
Member of CORSA.
Clarks MEGA late model info pack.

Recommendations for top notch transmission rebuild shop..?

Mechanical experience: Aircraft restoration, Land Rover sIII, Porsche (air cooled), Audi, first gen Mini, Alfa, MG, Diesel, etc, etc .
farm in VA.

[joelsplace]

caroseiii on the other forum seems to know his stuff on transmissions. At least on EMs. You can ask him about LMs.