4+3 Manual Transmission Removal write-up
03-05-2010, 04:22 AM
#1
Drifting
Thread Starter
4+3 Manual Transmission Removal write-up
This is my first write-up but after getting so much help from the forum on all my builds I figure it's only fair to give back a bit. Unfortunately I'm a terrible photographer so I bringing a camera to my builds usually passes my mind. I'll take pictures during reassembly and add them to the writeup 
Tools Required:
-Jack stands OR a set of ramps OR a lift, the higher the car is the easier it will be.
- 1-2 Jacks
-Transmission jack (optional)
-standard socket set
-breaker bar
-stubby SAE wrench set (regular wrenches will work but make things a bit harder)
-bucket
-paint marker
-tape/sharpie
-Duct Tape.
-PB Blaster (or equivalent penetrating oil)
The first step is to open the hood of the Vette and remove the distributor cap. Mark the wires as you take them off with masking tape and on the cap make sure you at least mark where the 1st cylinder plug wire is connected (the rest can be found using the firing order when reassembling). If you don’t remove the cap then when you’re removing the transmission the engine will swing back and crack the cap. Once that’s done get into the car, put the transmission in neutral and put the parking brake on.
The second step is to raise the car as high as you can, if you have ramps to get the whole car off the ground that’s great, or if you have the room to safely jack the 4 corners up then that works too. When I tackled this project so that I could rebuild my transmission I felt more comfortable to leave the rear wheels on the ground and lift the front of the car high, this was a safety decision as the vette was in a tight space and I did not feel like balancing the car. Be sure to block the rear wheels if you leave the rear on the ground.
Once the car is raised and supported safely you can get under the car to start working. The first thing to do once under the car is to remove the exhaust system. Remove any sensor wires first and plumbing if applicable (I have a custom exhaust but I believe in stock form there is AIR plumbing going into the exhaust in the main cat region). Then unbolt the system; there should be bolts at the collectors by the engine, a mount at the transmission itself, and mounts at the muffler. Some of these bolts will probably be difficult to remove so be patient and use penetrating oil like PB Blaster.
Move the exhaust system to a safe place and start removing anything attached to the transmission. There are two oil lines running to the automatic portion and I believe there were 3 wire connections in total to disconnect.
Now place your jack under the transmission using a piece of wood. Raise the jack enough to support the transmission and get out your stubby wrenches (sizes __ and __ in my case) and at the minimum a ¾ drive ratchet with sockets (__ and __ in my case). There is a beam under the car that connects the transmission to the rear end differential and covers the driveshaft. There are 2 long bolts on the transmission end going up with nuts securing it at the top of the beam, as well as 2 long bolts at the differential end secured the same way. This next part requires patience and a bit of hand contortion. You need to reach around the C-beam in the tunnel with one hand and the stubby wrench until you get to the top and find the 2 nuts holding the long bolts. Then, while holding the nut with the wrench take your ¾ drive ratchet and start backing the bolt out. (Note: another option to try would be to use either an electric or air impact gun to remove the bolts without having to hold the nuts, I had neither so I made do). Repeat this process for the rear two bolts which are a different size. If any bolt has troubles coming out once the nut has been removed then adjust the jack on the transmission which will change the geometry and assist in bolt removal. When all 4 bolts have been removed you’ll have to force the C-beam towards the driver’s side, this takes a decent amount of effort and be careful of the transmission which may jolt itself off the jack and tilt down when you shift the C-beam.
The next step will be removing the driveshaft now that the C-Beam is out of the way. You’ll need to use a wrench for this step. There are of the driveshaft has a U-joint which connects the driveshaft to the differential. This U-joint is held in by 2 straps on the differential’s yoke each with 2 bolts. If you’re lucky these bolts will be easy to access and you can remove the straps easily. If they are not all easily accessible, do the ones that are then you’ll need to get one rear wheel off the ground, I jacked up the rear knuckle of my driver’s rear wheel just enough so I could rotate it. You’ll need to rotate it a bit then look under the car to determine if the driveshaft has rotated into a more suitable position. Once you get the position you need lower the wheel back down and re-engage the parking brake. Remove the straps and get your paint marker. Take the paint marker and mark the transmission’s relation to the front driveshaft yoke so that during reassembly the splines will return to their worn in pattern. Before you remove the driveshaft get a bucket and put it under the rear of the transmission to catch any fluid that comes out. Now grab the driveshaft and push it into the transmission as far as it will go, then once the rear u-joint has cleared the differential yoke drop the driveshaft down and pull towards the back of the car (while keeping the marks you made lined up) until the driveshaft comes out of the transmission. Now you’ll want to tape the rear u-joint up so that the caps don’t come off and make you chase roller bearings.
Now you can remove the shifter linkage nuts from the driver’s side of the transmission, there will be 3 of them. At this point do a quick check to make sure everything is disconnected from the transmission before moving forward. If it looks all clear then there are 4 bolts holding the transmission to the bell housing which can be removed without the transmission dropping. I didn’t have a specific transmission jack so what I did at this point was put a second jack under the engine with a block of wood to support it then lowered the first jack slowly from under the transmission. Once the jack was away from the transmission I got under it and pulled it to the rear of the car rotating it slightly clockwise then counterclockwise until it came out. The whole assembly weighs about 80lbs with the fluid in it so it isn’t the lightest in the world but it won’t kill you. At this point you should have you’re 4+3 out from under you C4 Corvette.
I haven’t tackled the clutch yet and hope I don’t have to but at this point to get access to the clutch all you have to do is remove the bell housing to engine bolts and remove the clutch slave cylinder (not the bolt with the hydraulics, the support bolt!). Then you’ll have access to the clutch assembly.
Tools Required:
-Jack stands OR a set of ramps OR a lift, the higher the car is the easier it will be.
- 1-2 Jacks
-Transmission jack (optional)
-standard socket set
-breaker bar
-stubby SAE wrench set (regular wrenches will work but make things a bit harder)
-bucket
-paint marker
-tape/sharpie
-Duct Tape.
-PB Blaster (or equivalent penetrating oil)
The first step is to open the hood of the Vette and remove the distributor cap. Mark the wires as you take them off with masking tape and on the cap make sure you at least mark where the 1st cylinder plug wire is connected (the rest can be found using the firing order when reassembling). If you don’t remove the cap then when you’re removing the transmission the engine will swing back and crack the cap. Once that’s done get into the car, put the transmission in neutral and put the parking brake on.
The second step is to raise the car as high as you can, if you have ramps to get the whole car off the ground that’s great, or if you have the room to safely jack the 4 corners up then that works too. When I tackled this project so that I could rebuild my transmission I felt more comfortable to leave the rear wheels on the ground and lift the front of the car high, this was a safety decision as the vette was in a tight space and I did not feel like balancing the car. Be sure to block the rear wheels if you leave the rear on the ground.
Once the car is raised and supported safely you can get under the car to start working. The first thing to do once under the car is to remove the exhaust system. Remove any sensor wires first and plumbing if applicable (I have a custom exhaust but I believe in stock form there is AIR plumbing going into the exhaust in the main cat region). Then unbolt the system; there should be bolts at the collectors by the engine, a mount at the transmission itself, and mounts at the muffler. Some of these bolts will probably be difficult to remove so be patient and use penetrating oil like PB Blaster.
Move the exhaust system to a safe place and start removing anything attached to the transmission. There are two oil lines running to the automatic portion and I believe there were 3 wire connections in total to disconnect.
Now place your jack under the transmission using a piece of wood. Raise the jack enough to support the transmission and get out your stubby wrenches (sizes __ and __ in my case) and at the minimum a ¾ drive ratchet with sockets (__ and __ in my case). There is a beam under the car that connects the transmission to the rear end differential and covers the driveshaft. There are 2 long bolts on the transmission end going up with nuts securing it at the top of the beam, as well as 2 long bolts at the differential end secured the same way. This next part requires patience and a bit of hand contortion. You need to reach around the C-beam in the tunnel with one hand and the stubby wrench until you get to the top and find the 2 nuts holding the long bolts. Then, while holding the nut with the wrench take your ¾ drive ratchet and start backing the bolt out. (Note: another option to try would be to use either an electric or air impact gun to remove the bolts without having to hold the nuts, I had neither so I made do). Repeat this process for the rear two bolts which are a different size. If any bolt has troubles coming out once the nut has been removed then adjust the jack on the transmission which will change the geometry and assist in bolt removal. When all 4 bolts have been removed you’ll have to force the C-beam towards the driver’s side, this takes a decent amount of effort and be careful of the transmission which may jolt itself off the jack and tilt down when you shift the C-beam.
The next step will be removing the driveshaft now that the C-Beam is out of the way. You’ll need to use a wrench for this step. There are of the driveshaft has a U-joint which connects the driveshaft to the differential. This U-joint is held in by 2 straps on the differential’s yoke each with 2 bolts. If you’re lucky these bolts will be easy to access and you can remove the straps easily. If they are not all easily accessible, do the ones that are then you’ll need to get one rear wheel off the ground, I jacked up the rear knuckle of my driver’s rear wheel just enough so I could rotate it. You’ll need to rotate it a bit then look under the car to determine if the driveshaft has rotated into a more suitable position. Once you get the position you need lower the wheel back down and re-engage the parking brake. Remove the straps and get your paint marker. Take the paint marker and mark the transmission’s relation to the front driveshaft yoke so that during reassembly the splines will return to their worn in pattern. Before you remove the driveshaft get a bucket and put it under the rear of the transmission to catch any fluid that comes out. Now grab the driveshaft and push it into the transmission as far as it will go, then once the rear u-joint has cleared the differential yoke drop the driveshaft down and pull towards the back of the car (while keeping the marks you made lined up) until the driveshaft comes out of the transmission. Now you’ll want to tape the rear u-joint up so that the caps don’t come off and make you chase roller bearings.
Now you can remove the shifter linkage nuts from the driver’s side of the transmission, there will be 3 of them. At this point do a quick check to make sure everything is disconnected from the transmission before moving forward. If it looks all clear then there are 4 bolts holding the transmission to the bell housing which can be removed without the transmission dropping. I didn’t have a specific transmission jack so what I did at this point was put a second jack under the engine with a block of wood to support it then lowered the first jack slowly from under the transmission. Once the jack was away from the transmission I got under it and pulled it to the rear of the car rotating it slightly clockwise then counterclockwise until it came out. The whole assembly weighs about 80lbs with the fluid in it so it isn’t the lightest in the world but it won’t kill you. At this point you should have you’re 4+3 out from under you C4 Corvette
.I haven’t tackled the clutch yet and hope I don’t have to but at this point to get access to the clutch all you have to do is remove the bell housing to engine bolts and remove the clutch slave cylinder (not the bolt with the hydraulics, the support bolt!). Then you’ll have access to the clutch assembly.
03-05-2010, 09:28 AM
#2
Burning Brakes
Good Timing!
Thanks for the write up. I will be putting a new T/O bearing in my 84 next month and this & the shop manual will help! My Vette has 85k miles and the last owner said that the clutch was replaced at about
68k miles -wish they would have done the T/O bearing too!
Thanks again, Glen
68k miles -wish they would have done the T/O bearing too!
Thanks again, Glen
