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#1 Does anyone know if the 4 speed transmission in a 68 can be removed without pulling the engine? The trans frame mount is welded in. #2 The clutch is making an ugly sound when putting the clutch in. I'm pretty sure the throw out bearing is shot. The trans is 50 years old so I'm thinking about a rebuilt M-22 rock crusher with a 2.56 gear ratio to go with my 3.08 rear while I check the clutch. I'll rebuild the original to use in my 49 Chevy truck.
Thanks Dave
#1 Does anyone know if the 4 speed transmission in a 68 can be removed without pulling the engine? The trans frame mount is welded in. #2 The clutch is making an ugly sound when putting the clutch in. I'm pretty sure the throw out bearing is shot. The trans is 50 years old so I'm thinking about a rebuilt M-22 rock crusher with a 2.56 gear ratio to go with my 3.08 rear while I check the clutch. I'll rebuild the original to use in my 49 Chevy truck.
Thanks Dave
your trans chassis mount should not be welded in.. the cross member is welded in. your trans mounts should unbolt along with the shifter and you should have enough room too slide the trans back and out, and down towards the front. pulling the motor sometimes is easier inmost cases...good luck..troy
I think you should bite the bullet and pull the engine to get to the trans. It will be easier in the long run, The M22 is not a good choice in my opinion. Noisy (will sound like a truck) and is a close ratio trans, 1st gear too tall, good for drag racing only. Why not just have your 4 speed rebuilt.
your trans chassis mount should not be welded in.. the cross member is welded in. your trans mounts should unbolt along with the shifter and you should have enough room too slide the trans back and out, and down towards the front. pulling the motor sometimes is easier inmost cases...good luck..troy
I have the close ratio 2.20 first gear now but I'm thinking the wide ratio will help with the 3.08 rear. I had the 3.73 ratio before. If I get another trans I'll rebuild the old one to use in a 49 chevy truck street rod. Works out perfect for me!
Absolutely can pull the trans leaving the engine in place. Not hard at all. Look at one of the Autogear Muncie’s with the 2.98 first gear. Would be perfect with your 3.08’s. Jody Haag of Jody’s Transmissions is in Reading, PA could build you one. He is a terrific guy, have dealt with him myself, and these new Muncie’s are great transmissions.
Last edited by 69ttop502; Nov 26, 2018 at 07:24 AM.
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Are you looking at the m22s at thegearbox.org. I've been eyeballing their kits. I have an old 63 m21 that I'm thinking of rebuilding into a newer auto gear 1" box and having a backup. Sounds like a good plan. I have an m21 in front of a 3.55 rear and it's a dog off the line. I'm changing the first gear ratio in it to a m20 2.52. 5hat be better off the line
for me.
As for pulling the tranny, I always pull the motor, then the tranny. it's less of a hassle that way, but I put them back in as 1 unit.
Yes. Well, for my M-21 it can. It can be removed with the welded-in crossmember in place. It's a royal pain in the @zz.... After you remove all the support and shifter equipment, and disconnect the driveshaft, then you can also remove one (or 2) of the rear tranny bolts to give you another quarter inch as you slightly rotate the tranny, and lower both the engine and tranny to slide down the front of the bellhousing (just enough to get tranny below bellhousing lower end. I did that a couple of times and then made my crossmember removable.
Originally Posted by 68vetteman
#1 Does anyone know if the 4 speed transmission in a 68 can be removed without pulling the engine? The trans frame mount is welded in. #2 The clutch is making an ugly sound when putting the clutch in. I'm pretty sure the throw out bearing is shot. The trans is 50 years old so I'm thinking about a rebuilt M-22 rock crusher with a 2.56 gear ratio to go with my 3.08 rear while I check the clutch. I'll rebuild the original to use in my 49 Chevy truck.
Thanks Dave
#1 Does anyone know if the 4 speed transmission in a 68 can be removed without pulling the engine? The trans frame mount is welded in. #2 The clutch is making an ugly sound when putting the clutch in. I'm pretty sure the throw out bearing is shot. The trans is 50 years old so I'm thinking about a rebuilt M-22 rock crusher with a 2.56 gear ratio to go with my 3.08 rear while I check the clutch. I'll rebuild the original to use in my 49 Chevy truck.
Thanks Dave
Dave I've done it both ways....engine tranny and just tranny..... Frankly, I thought it was easier with the engine attached. This also allows you to R&R the engine at the same time.
Preferentially...I'd rather be standing up, than flat on my back!
I would recommend an M-21 with the helical cut gears. The M-22 is basically unpleasant to drive. It's really a drag-racing tranny.
remove your pipes too, will give you lots of extra room.
since its out, always do whatever seals you can do on the trans if you are not gonna rebuild. plus the clutch, pilot bearing and throwout bearing.. probably the driveshaft ujoints too since its all out.
its tuff, if not near impossible to remove engine/tranny combo with radiator support in place.. removing the radiator support rapidly complicates the effort.. bolts will break and you have to remember and reshim so your fan blade clears the shroud.. and many other issues..
don't pull the engine unless you really want to do a major cleanup and fixup because you will find several other things to spend your money on when you pull that engine.
The last time I did it....it came right out. But you will have to slide it back toward the rear and turn it a bit to clear....then drop the front down and out.
I want to add that this job is MUCH easier when equipped with a Hurst shifter.........the original shifter bracket was designed to be in the way of EVERYTHING.
The Hurst bolts to the side of the trans and can be removed before you begin.
2020 Corvette of the Year Finalist (performance mods)
2019 C3 of Year Winner (performance mods)
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Also about your 3.08, with the 2.56 or 2.52 first gear of the wide ratio m21 or the m20, you're going to have a launch ratio of 7.8 or so. It's okay for for mild starts but you will find you're riding the clutch out of stop lights unless you find a nice grabby clutch. What motor are you running?
you may consider 3.55 rear if you dont want to go back to a 3.70 rear. That will give you about 9:1 for decent acceleration with a 2.52 wide ratio, it's about the same as the 3.70 for launch but slightly less revs for the highway. You'll have both needles vertical on the highway, about 3500 rpm at 80 mph
This winter I'm cutting and welding brackets to make my crossmember removable. I got mine from a member here but I've seen them online
I want to thank everybody for your input. I have a 383 stroker with the 2.20 first gear and a 3.08 rear. This combo gives me a 6.77 launch ratio. I have no problem starting out so the 2.56 first gear ratio should be better than what I have now. The rock crusher might be over kill but with the headers and side pipes, what's a little more noise? Call me an old motor or gear head but at an early age for me, a neighbor of mine had an Impala with a 327 and rock crusher trans and I fell in love with the sound. I'm going to try to pull just the trans but I'll be ready to loosen the motor mounts for extra room if needed.
Thanks Dave
2020 Corvette of the Year Finalist (performance mods)
2019 C3 of Year Winner (performance mods)
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You're right, you should have plenty of torque to get you going. When I was a kid that was the hot combo to have. Everyone claimed to have a rock crusher, but few did around here. Good luck, keep us updated
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4 Speed Trans Question
