Stiff shifting

[Gigharborvair]

My 4 speed is very hard to shift and especially going into 3rd gear. Any ideas?

[Gigharborvair]

Extremely hard to shift like moving through molasses and hard to find 3rd gear3…any ideas or thoughts would be,appreciated. Low on transmission fluid? Something else causing these problems…itA’s like moving through sludge

[Dennis66]

Stiff shifting: check shift tube, shifter base, and alignment where shifter shaft comes out of tunnel and to transmission. Most require removing tunnel cover under car. Shifter tubes can get rusty. Sagging transmission mounts can cause alignment problems. Also check for slop at trans - shifter tube coupler.

[jimbrandberg]

Do you think the oil is too thick?
Sometimes someone will use a straight 90 weight or a something/140.
I used to use Sta-Lube GL-4 85/90 because it was available locally.
Now I get Brad Penn GL-4 80/90 12 quarts at a time on Ebay.
If I want synthetic I use Amsoil GL-4 as it seems to suit both our differential and transmission requirements. It's 75/something.

Just about anything will feel thin enough after a few miles so it may not be your problem.

[66vairguy]

You list a 62 and a 65. I suspect you are taking about the 65, but let us know.

Jim is correct about the 80/90 lube, but it usually on is a problem for shifting in temperatures below 50. I use Brad Penn and it make a difference for cold temperature shifting.

I'll bet it is the 65 shifter and tube assembly, but just guessing until you tell us what car has the problem.

[Allan Lacki]

Hi Gigharborvair,

When you wrote that it's hard to get the transmission into third gear, did you mean that you need to put a lot of force on the shift lever but you can find all four gears, <<<< OR >>>> did you mean that it's hard to find the gears, especially the third gear gate, with the shifter?

If the latter, it could be due to a variety of worn parts.

If your Corvair is a '60-64, it could be due to a worn transmission coupler, broken plastic bushing in the tunnel pan, or worn rocker pins inside the shifter housing.

If your Corvair is a '65-69, it could be due to a worn transmission coupler, broken plastic bushings at both the front and rear of the outer shift tube, worn rocker pins inside the shifter housing, or a smushed carboard liner.

The shift linkage on a '65-69 consists of a three concentric tubes: A steel outer tube, a steel inner tube and a cardboard tube sandwiched between the outer and inner steel tubes. It's that steel inner tube that does the actual shifting, but that cardboard tube can jam-up the shifter action, making it necessary to use a lot of force on the gear shift lever to get the transmission in gear.

If you need to put a lot of force on the shift lever but you can find all four gears, I would remove that cardboard liner. It runs inside the whole length of the outer shifter tube and is meant to serve as an anti-rattle device, to keep the inner shifter tube from rattling against the inside of the outer shift tube. Often it gets deformed with moisture and grease making it difficult to shift the transmission.

It isn't necessary and you can remove it entirely. Sometimes, it's very hard to extract.

If all this sounds confusing, let me know.

[Gigharborvair]

It is on the 65 Corsa. If it is the shifter tube or mounts. Does Clark’s have the parts?

[66vairguy]

It is on the 65 Corsa. If it is the shifter tube or mounts. Does Clark’s have the parts?

Clark's sells the tube bushings, original plastic, replacement bronze - but take some work to make fit. They also make the rear coupler to transmission. There is a lot of other issues like the shifter pins (you have to make them) to make it all work well. If you don't have mechanical skills, then find someone who can rebuild it.
See article from Corsa West newsletter on what is involved.

[Frank DuVal]

Be glad it is a 65, as the 66 -69 transmission is even harder to move through the gears, so issues with the shift tube are more problematic with those. As long as the shift tube comes out straight (people bend them trying to remove just the engine without disconnecting the shift coupler) putting in the bronze bushings is not tooo hard. You can do the screw install method or the solder in method. Makes shifting so much easier!

[66vairguy]

Be glad it is a 65, as the 66 -69 transmission is even harder to move through the gears, so issues with the shift tube are more problematic with those. As long as the shift tube comes out straight (people bend them trying to remove just the engine without disconnecting the shift coupler) putting in the bronze bushings is not tooo hard. You can do the screw install method or the solder in method. Makes shifting so much easier!

What is it with LM BENT inner shift tubes? EVERY ONE I have rebuilt was BENT. They can be fixed, but it takes time and I have to wonder why some many characters abuse the shift tube getting the drivetrain out.

The 66-69 transaxle is longer and trying to install or remove the drivetrain requires the transmission support to be ON the transmission (unbolt transmission support from the body "house collar" or you will damage things).

Yes the 64-65 is probably the best shifting of the early transmissions. Contrary to common belief ALL Corvair transmissions were made at the Saginaw division. The 66-69 is called a "Saginaw" because GM got into little feud with Borg Warner (long story) and told there Saginaw division to make a new light duty 3 and 4 speed for six cylinder and small V8 cars. It was decided to use these parts in the Corvair transmission for commonality (cheaper to build), but in fact many of the "Saginaw" parts used in the Corvair transmission are redesigned. So much for "commonality". So yes the 66-69 is robust so shifts can take a bit more "push" on the shifter, but the higher torque rating made it popular with Crown V8 conversions.

Comparing shifting of the 66-69 to the 64-65 is like comparing the HD Muncie to the big car Saginaw. Definitely a little more shift force, but not excessive. You do feel the synchro parts doing their thing.

[Allan Lacki]

Regarding the rocker pins inside the shifter housing. They are just little things - each is basically a piece of round stock about a half-inch long. They are press fit into the shifter housing (the casting) such that the ends protrude about a quarter inch inside the housing cavity. The shift lever rocks back and forth on them, and over time, the sides of the pins get worn flat.

That's one of the several potential causes of sloppy shifter action. In and of itself, it would not make it hard to move the shift lever. Instead, it would make it hard to get the lever to engage the gear you are looking to shift into.

An easy solution is to tap the pins out of the shifter housing with a punch, reverse them, and push them back with a C-clamp so that the shift lever no longer rocks on the worn end. And although the worn end is now inside the casting, there's plenty of metal to assure a good friction fit that will last for many years.

If those rocker pins are really beyond hope, it's easy to make new ones. Go to your local hardware store and get a steel rod 5/16" in diameter. Cut off a piece that's 1/2" length. Push it in to the housing with a C-clamp. That's a perfect substitute.

This is not to say worn rocker pins are the only cause of sloppy shifter action. It's just one of several.

P.S. Bent shift rods - I've seen that, too!

[66vairguy]

Regarding the rocker pins inside the shifter housing. They are just little things - each is basically a piece of round stock about a half-inch long. They are press fit into the shifter housing (the casting) such that the ends protrude about a quarter inch inside the housing cavity. The shift lever rocks back and forth on them, and over time, the sides of the pins get worn flat.

That's one of the several potential causes of sloppy shifter action. In and of itself, it would not make it hard to move the shift lever. Instead, it would make it hard to get the lever to engage the gear you are looking to shift into.

An easy solution is to tap the pins out of the shifter housing with a punch, reverse them, and push them back with a C-clamp so that the shift lever no longer rocks on the worn end. And although the worn end is now inside the casting, there's plenty of metal to assure a good friction fit that will last for many years.

If those rocker pins are really beyond hope, it's easy to make new ones. Go to your local hardware store and get a steel rod 5/16" in diameter. Cut off a piece that's 1/2" length. Push it in to the housing with a C-clamp. That's a perfect substitute.

This is not to say worn rocker pins are the only cause of sloppy shifter action. It's just one of several.

P.S. Bent shift rods - I've seen that, too!

Good advice, but when new those darn pivot pins were are JUST under 5/16" as stated in the article. Do not ask me why, but I've verified it myself on different shifters. Easy to knock off metal by just rolling the soft metal rod under an orbital sander, yes crude but your only need to reduce diameter a few thousands of an inch. If you try to press in 5/16" rod, it could be too large for the hole you might crack the shifter housing! Keep in mind each time the pins are replaced (or reversed) the hole in the shifter gets a little bigger (soft metal), so this is trial and error. Just me ---- but I use soft hardware store 5/16" rod, sure it will wear out again, BUT it preserves the shifter lever half ball slots as the article mentions. Very difficult to fix worn shifter ball slots (must be welded/brazed), and you will end up rechroming the whole lever.
Just my for what it is worth.