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Torque Tube assembly and installation procedures needed for A8
I'm going to be installing a new torque converter and carbon drive shaft this winter and am looking for assembly and installation procedures. Mostly I just need the torque for the drive shaft coupler hardware and the procedure for setting crank shaft end play when installing the torque tube. I tried looking at the torque chart on here for the drive shaft hardware but didn't see it. Any information anyone can offer would be much appreciated.
I was able to find what I was looking for and much much more from https://www.repairprocedures.com. Totally worth the 15.00 for 24hrs of access. As for the procedure its straight forward and a fairly simple process.
I have a 2015 Z51 A8. I've had some driveline vibrations for more than 2 years. I had the transmission fluid changes as described in the various TSB's that didn't help. I had a Chevrolet dealership do a PICO test about 6 months ago but they couldn't determine the source of the vibration. So now the drive shaft in the torque tube has slide back into the tube. So I'll be replacing the torque tube and torque converter. Trying to decide if it can be done as a DIY through the winter in my garage using a quick jack.
I have a 2015 Z51 A8. I've had some driveline vibrations for more than 2 years. I had the transmission fluid changes as described in the various TSB's that didn't help. I had a Chevrolet dealership do a PICO test about 6 months ago but they couldn't determine the source of the vibration. So now the drive shaft in the torque tube has slide back into the tube. So I'll be replacing the torque tube and torque converter. Trying to decide if it can be done as a DIY through the winter in my garage using a quick jack.
I also have a 2015 Z51 A8 and I’m looking at doing my own converter swap. I have the shop manuals and I wouldn’t want to begin the job without some sort of repair manual. There are just little things here and there that I wouldn’t think of that are critical. An example of that is checking crankshaft end play after you join the torque shaft. Between the shop manuals, this forum, and YouTube you can pull it off if you’re mechanically talented.
FYI, I replaced the torque tube and converter without any issues. So far I have around 400 miles on the Corvette since replacing. The Corvette is driving great.
I did it in my garage with a quick jack and two harbour freight transmissions racks. I used the information from another thread that provided great details without having to remove the complete driveline. In short, remove exhaust, disconnect hard brake line, drop cradle about 6 inches using a transmission jack, remove bolts from torque tube and bell housing, remove bolts from torque tube and torque converter. Slide the transmission and e-diff back and down just enough to remove torque tube to the other transmission jack. Remove the torque converter. Then it's easier to install the new converter and tube when they are not attached to the transmission. No forcing or damaging the engine flex plate or main bearing. Put back together and double check everything.
FYI, I replaced the torque tube and converter without any issues. So far I have around 400 miles on the Corvette since replacing. The Corvette is driving great.
I did it in my garage with a quick jack and two harbour freight transmissions racks. I used the information from another thread that provided great details without having to remove the complete driveline. In short, remove exhaust, disconnect hard brake line, drop cradle about 6 inches using a transmission jack, remove bolts from torque tube and bell housing, remove bolts from torque tube and torque converter. Slide the transmission and e-diff back and down just enough to remove torque tube to the other transmission jack. Remove the torque converter. Then it's easier to install the new converter and tube when they are not attached to the transmission. No forcing or damaging the engine flex plate or main bearing. Put back together and double check everything.
I hope you followed the procedure for torquing down the clamp bolt and checking the movement on the crankshaft.
1. install your own supplied bolts into the two threaded holes to hold the front bearing in place before trying to insert the torque tube into the flex plate. This prevents the bearing from pushing back when you insert the torque tube into the flex plate. Failure to do this can result in torque tube failing prematurely.
2. If your flex plate has rivets and not bolts, upgrade to the bolt/nut flex plate (the rivets can rattle over time and then you are doing this all over again).
3. Remove the front bearing positioning bolts after torque tube is bolted up.
4. with the front spline bolt finger tight, run the car 10mins and then let it cool to room temp. push the front of the crank towards the back of the car and then torque the spline bolt to spec.
5. Run the car 10 or more miles. Let it completely cool. Untorque the spline bolt an then re-torque it to spec.
6. When removing or installing the torque tube, you can't let it drop down more than flush with the bottom of the undercarriage. The engine mounts prevented that much movement on mine (even with the engine mounts loosened to allow more tilt).
7. The torque converter has a machined dot on it and the torque tube rear flex plate has an X on it. Make sure that the dot on the torque converter aligns with the X on the flex plate.
These are just from memory, but I think that is pretty much it for special procedures. While in there it is a good time to replace the rear main engine seal, and any seal weeping in the rear end (axles/rear cover, etc).
I found it was easier to install the torque tube to the engine bell housing and then mount and bolt up the transmission/rear cradle to the torque tube. This gives you much more control on angle when installing the torque tube and makes it easier to ensure you don't exceed the 100lbs insertion force. The factory procedure is to bolt the torque tube to the transmission and then insert the splines into the flywheel and bolt the torque tube to the engine.
All in all it wasn't that bad of a job. The biggest thing you want to make sure of is that the crank is centered when you tighten the splines, so you don't wear the crank thrust bearings.
1. install your own supplied bolts into the two threaded holes to hold the front bearing in place before trying to insert the torque tube into the flex plate. This prevents the bearing from pushing back when you insert the torque tube into the flex plate. Failure to do this can result in torque tube failing prematurely.
2. If your flex plate has rivets and not bolts, upgrade to the bolt/nut flex plate (the rivets can rattle over time and then you are doing this all over again).
3. Remove the front bearing positioning bolts after torque tube is bolted up.
4. with the front spline bolt finger tight, run the car 10mins and then let it cool to room temp. push the front of the crank towards the back of the car and then torque the spline bolt to spec.
5. Run the car 10 or more miles. Let it completely cool. Untorque the spline bolt an then re-torque it to spec.
6. When removing or installing the torque tube, you can't let it drop down more than flush with the bottom of the undercarriage. The engine mounts prevented that much movement on mine (even with the engine mounts loosened to allow more tilt).
7. The torque converter has a machined dot on it and the torque tube rear flex plate has an X on it. Make sure that the dot on the torque converter aligns with the X on the flex plate.
These are just from memory, but I think that is pretty much it for special procedures. While in there it is a good time to replace the rear main engine seal, and any seal weeping in the rear end (axles/rear cover, etc).
I found it was easier to install the torque tube to the engine bell housing and then mount and bolt up the transmission/rear cradle to the torque tube. This gives you much more control on angle when installing the torque tube and makes it easier to ensure you don't exceed the 100lbs insertion force. The factory procedure is to bolt the torque tube to the transmission and then insert the splines into the flywheel and bolt the torque tube to the engine.
All in all it wasn't that bad of a job. The biggest thing you want to make sure of is that the crank is centered when you tighten the splines, so you don't wear the crank thrust bearings.
I need to replace my TT and TC. I am having trouble understanding direction #1
The new torque tube has two plastic plugs in the front of it. Remove the plugs and you will see threaded holes. You insert bolts into those holes and tighten them down. They tighten down onto the front bearing and hold it in place. You do this before install or removal. If you dont do this, inserting the torque tube during install or pulling out the torque tube during removal can cause the bearing to move which can cause torque tube failure over time. Once the torque tube is installed or removed, you remove the bolts.
When you replace your torque converter, I see people talk about zeroing the slip tables. Can someone explain this to me please? Can GM service do this?
10-09-2019, 02:46 PM
Torque Tube assembly and installation procedures needed for A8
