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I need a little advice on dropping the rear drivetrain; torque tube, trans, diff, and rear cradle. I will be doing a clutch swap this weekend and will most likely be doing the majority of the work by myself using jack stands. I have read several how-to's, looked at tons of pictures so I am confident I can do it.
I purchased 2 scissor trans jacks from Harbor Freight for this just like in the clutch swap write-up by Dope (hope I am crediting the correct person).
I was thinking of supporting the TT, trans, and diff assembly with one jack then dropping the rear cradle on the other and removing it. Then drop the TT/trans/diff separately using the second jack. I figured it may be easier to manipulate the separate assemblies by myself this way.
Is this a good way to do this? Anything I need to keep in mind or watch out for? Any and all suggestions are welcome.
Thanks.
Last edited by Spaceme1117; 06-28-2017 at 05:28 PM.
2020 Corvette of the Year Finalist (performance mods)
C5 of Year Winner (performance mods) 2019
atv jacks work great, if you have one of those lower the whole rear suspension cradle and all with an atv jack and take the trans to torque tube bolts out and remove that as once piece while leaving the torque tube in the car... once that is out of the way you can get under the car and remove the torque tube, it is not very heavy and easy to maneuver without the trans, diff, and suspension connected to it... after replacing the clutch install the torque tube first, it will be really easy to get the splines of the input shaft aligned with hardly any weight on the rear of the torque tube... once that is in place you can raise the cradle/suspension/diff/trans back up with the atv jack and stab the trans into the torque tube... I have done mine twice on my own and it isn't all that bad doing it that way in my opinion
atv jacks work great, if you have one of those lower the whole rear suspension cradle and all with an atv jack and take the trans to torque tube bolts out and remove that as once piece while leaving the torque tube in the car... once that is out of the way you can get under the car and remove the torque tube, it is not very heavy and easy to maneuver without the trans, diff, and suspension connected to it... after replacing the clutch install the torque tube first, it will be really easy to get the splines of the input shaft aligned with hardly any weight on the rear of the torque tube... once that is in place you can raise the cradle/suspension/diff/trans back up with the atv jack and stab the trans into the torque tube... I have done mine twice on my own and it isn't all that bad doing it that way in my opinion
I do appreciate the advice but I don't have an ATV jack. I think I will try to separate the rear cradle onto one jack and put the rest on another jack. I have seen this done in a couple of write ups and it looked like I may be able to manage without much help.
I know this job won't be a lot of fun, that's for sure.
I am sure its far safer and smarter to use a helper, but I have done this job a few times now and I have managed it alone each time with only one scissor jack from HF, and using my two low profile floor jacks as needed.
Once you are ready to drop it, put the scissor jack underneath the rear cradle the long ways (wheel to wheel), position it in the middle as best you can, but don't be alarmed later when you're lowering it and the cradles moves in the jack a bit. The diff mount flexes and the cradle will flop forward or backwards a bit, once I get it on the ground I always set up some blocks to take the pressure off the mount.
Undo the 4 large subframe bolts and lower slowly watching for the brake lines and other wire connections. Careful not to lower the cradle too far before separating the TT from the engine as you can stress the dash.
Once the TT is separated I usually support it on a floor jack and then return to the back of the car and finishing lowering the cradle.
Here is a pic after it was out of my car on my most recent C5 clutch job.
Oh, I almost forgot. The HF jack is not strong enough to get the cradle up, but it does work well going down. Put your floor jacks under the spring/ball joint and lift little by little, follow with the scissor jack, goes in nice and easy. I also like a recommendation I received from here to separate the TT from the trans for reassembly, I have found it to be far easier to wrestle those two pieces back in when they are apart. Having a helper may make it more feasible to leave them together... Leave them together for the removal though!
I am sure its far safer and smarter to use a helper, but I have done this job a few times now and I have managed it alone each time with only one scissor jack from HF, and using my two low profile floor jacks as needed.
Once you are ready to drop it, put the scissor jack underneath the rear cradle the long ways (wheel to wheel), position it in the middle as best you can, but don't be alarmed later when you're lowering it and the cradles moves in the jack a bit. The diff mount flexes and the cradle will flop forward or backwards a bit, once I get it on the ground I always set up some blocks to take the pressure off the mount.
Undo the 4 large subframe bolts and lower slowly watching for the brake lines and other wire connections. Careful not to lower the cradle too far before separating the TT from the engine as you can stress the dash.
Once the TT is separated I usually support it on a floor jack and then return to the back of the car and finishing lowering the cradle.
Here is a pic after it was out of my car on my most recent C5 clutch job.
Oh, I almost forgot. The HF jack is not strong enough to get the cradle up, but it does work well going down. Put your floor jacks under the spring/ball joint and lift little by little, follow with the scissor jack, goes in nice and easy. I also like a recommendation I received from here to separate the TT from the trans for reassembly, I have found it to be far easier to wrestle those two pieces back in when they are apart. Having a helper may make it more feasible to leave them together... Leave them together for the removal though!
Thank you. That's very helpful. Once the assembly is lowered, is it relatively easy to manouver around on the trans jack?
Also, about how high do you lift the rear of the car to get enough clearance?
Just out of curiosity, what clutch are you running? Thanks again.
Last edited by Spaceme1117; 06-28-2017 at 10:34 PM.
Its not bad on a smooth garage floor. I was able to slide it in and out from underneath the vette as needed to pull in the wife's car at night. The higher the better, the very last thing you ever want is to have that thing halfway out of the car, and not be able to get it out because the car isn't high enough. And now you won't have much left to jack from either...
I usually use some 4x4 blocks in addition to my full jack heigh, probably 2 1/2-3ft. Get it as high as you can safely go. There is no such thing as too high when doing this.
I did mine alone with two HF transmission jacks. I took the cradle out first and supported the drive train. Then took out the drive train. I was concerned with reinstallation alone so I used a laser level to record angle prior to removal once the engine was supported in its final removal position/angle. Here is a thread on that: Laser Level Use for Drive Train Installation
Drive train supported, cradle removed. Block of wood on forward cradle is cupped to support torque tube.
I did mine alone with two HF transmission jacks. I took the cradle out first and supported the drive train. Then took out the drive train. I was concerned with reinstallation alone so I used a laser level to record angle prior to removal once the engine was supported in its final removal position/angle. Here is a thread on that: Laser Level Use for Drive Train Installation
Drive train supported, cradle removed. Block of wood on forward cradle is cupped to support torque tube.
I don't have a laser level but I will be taking several measurements before I unbolt and drop the TT.
How heavy is the cradle assembly? Can it be taken off the jack once it is lowered out of the car by 1 person?
I would highly suggest buying a HF hydraulic transmission jack for the rear cradle. I did it by myself with that. It's best to disconnect the trans from the torque tube and remove the whole rear end assembly from there. Then remove the torque tube separately. Upon reassembly install the torque tube separately also. You will not be able to lift the rear end assembly alone hence the trans jack.
Here's a thread I did for a whole drivetrain rebuild with plenty of pics:
Well, I started disassembly this afternoon. I am almost to the point to start dropping the rear cradle. So far it's not too bad, just a bit time consuming. The half shafts popped right out no problem. I unbolted the brake calipers and brackets and also removed the rotors. It's easy to remove weight that I won't have to handle with the cradle. But so far so good.
I did mine with one HF scissor jack. Placed another floor jack up near the bellhousing, but it turned out the balance of the transaxle and torque tube was pretty good as it was, and the extra floor jack wasn't necessary.
Made quite a lot of progress today. I dropped the rear subframe then dropped the TT/trans/diff. Half shafts came out pretty easy. Taking the brake rotors off make handling the subframe a lot easier. Old clutch looked not too bad. Slave didn't seem too bad either. The old pilot bearing came out in about 10 wacks with a blind hole bearing puller and some heat from a precision torch. New bearing went in nicely also. New LS7 clutch and flywheel didn't want to go in at first but a quick search and I drove in the locating dowels on the flywheel until bottoming out and that gave just enough room to get the clutch in. I installed the new slave and Tick remote bleeder plus a .113 slave shim. The put it back together. Torque tube when together relatively well. Took a few tries getting things exactly lined up but then it came together. I put the rear subframe back in and bolted it back up. Decided to stop for the day because I am super tired. going to finish up tomorrow morning. I did everything myself without any help. Nothing was too difficult; its really just a lot of work.
Rear cradle assembly removed. Rotors and caliper brackets removed helped a lot.
TT/Trans/diff dropped
Old clutch removed.
Stock LS6 clutch. Still held good but lots of hot spots.
New LS7 Pressure Plate.
LS7 Flywheel
LS7 clutch and flywheel installed. You can see one of the broken exhaust flange bolts on in the lower left corner.
Drive train and rear cradle back in.
Last edited by Spaceme1117; 07-02-2017 at 09:49 AM.
Car is back together and running good. Old slave was actually in good condition. I don't think the old clutch was slipping but I am glad I changed it. Pedal still feels the same. I guess it is just normal. I am guessing that maybe I need to change my motor mounts. This may be allowing more engine vibration to come through the pedals? LS7 clutch actually feel lighter than the stock LS6 clutch.
A few things that I have learned while doing this:
1. Harbor Freight scissor jacks are kind of crappy. They work okay to support the cradle and TT/trans/diff and to move them around but are terrible for lifting. If I ever need to do this again, I will get a hydraulic trans jack.
2. Before you unbolt the TT from the bell housing, measure the angle of the torque tube and measure the front and rear of the drivetrain and record these for re-assembly. Makes re-assembly way quicker/easier.
3. Get a blind hole bearing puller for the pilot bearing and use heat on the crank where the bearing goes. It will make it much easier to get the old bearing out.
4. Make sure the wiring harness on top of the bellhousing doesn't get pinched between the TT and bellhousing during assembly. At first I couldn't figure out why they wouldn't go together but it was the wiring harness getting caught. It is easy to overlook as the harness is black and easy to miss it.
5. If installing an LS7 clutch and flywheel, hammer the Pressure Plate locating dowels until they bottom out in the flywheel. Otherwise, there isn't enough room to get the disc and PP installed.
5. It's not too difficult of a job, just time consuming. I did it by myself on jack stands in the parking lot of my apartment. Total time was about 15 solids hours of work. 13 hours if I don't include the time it took to remove 2 broken exhaust flange bolts.
6. You should measure if you need to shim the slave. I used a stock LS7 flywheel and clutch and a GM slave and it needed a 0.113 shim to be in spec. Don't just assume yours is okay.
Another thing. I had a lot of curious people stop by while I was working and either ask me questions about what I was doing or to ask advice about things they need to fix with their cars (which I don't mind at all). It was surprising but also kind of cool.
Last edited by Spaceme1117; 07-02-2017 at 09:50 AM.
Old post with great info and pictures. I'm just curious, are your rear jack stands just sitting directly against the frame in the area where pucks would normally be? Was it very sturdy that way?
Originally Posted by Spaceme1117
Car is back together and running good. Old slave was actually in good condition. I don't think the old clutch was slipping but I am glad I changed it. Pedal still feels the same. I guess it is just normal. I am guessing that maybe I need to change my motor mounts. This may be allowing more engine vibration to come through the pedals? LS7 clutch actually feel lighter than the stock LS6 clutch.
A few things that I have learned while doing this:
1. Harbor Freight scissor jacks are kind of crappy. They work okay to support the cradle and TT/trans/diff and to move them around but are terrible for lifting. If I ever need to do this again, I will get a hydraulic trans jack.
2. Before you unbolt the TT from the bell housing, measure the angle of the torque tube and measure the front and rear of the drivetrain and record these for re-assembly. Makes re-assembly way quicker/easier.
3. Get a blind hole bearing puller for the pilot bearing and use heat on the crank where the bearing goes. It will make it much easier to get the old bearing out.
4. Make sure the wiring harness on top of the bellhousing doesn't get pinched between the TT and bellhousing during assembly. At first I couldn't figure out why they wouldn't go together but it was the wiring harness getting caught. It is easy to overlook as the harness is black and easy to miss it.
5. If installing an LS7 clutch and flywheel, hammer the Pressure Plate locating dowels until they bottom out in the flywheel. Otherwise, there isn't enough room to get the disc and PP installed.
5. It's not too difficult of a job, just time consuming. I did it by myself on jack stands in the parking lot of my apartment. Total time was about 15 solids hours of work. 13 hours if I don't include the time it took to remove 2 broken exhaust flange bolts.
6. You should measure if you need to shim the slave. I used a stock LS7 flywheel and clutch and a GM slave and it needed a 0.113 shim to be in spec. Don't just assume yours is okay.
Another thing. I had a lot of curious people stop by while I was working and either ask me questions about what I was doing or to ask advice about things they need to fix with their cars (which I don't mind at all). It was surprising but also kind of cool.
06-28-2017, 05:26 PM
Best Way to Drop Drivetrain?
