08 GMC Sierra 1500 Trany Issuses

cleaner · February 23, 2015

My 08 has 161K miles on it and the transmission went. I was towing a light enclosed trailer about 70 mph down the interstate and all of the sudden the motor revs and the tranny act like its in neutral. I coast to a stop and kill the engine. Try to start the truck again and the starter sounds like it is spinning but does not turn the motor over.

Transmission mechanic tells me the tranny neds to be rebuilt and while pulling the transmission, he tells me the fly wheel fell apart. He rebuilt the tranny, replaced torque converter and fly wheel. Picked up the truck from the shop and took the truck and a trailer on a 300 mile trip. 220 miles into the trip, the tranny does the exact same thing as a week earlier. Act like its in neutral and starter will not turn the motor over.

Any ideas what could be going on with my truck?

Thank you in advance for your time and feedback.

gmtech4 · February 23, 2015

My 08 has 161K miles on it and the transmission went. I was towing a light enclosed trailer about 70 mph down the interstate and all of the sudden the motor revs and the tranny act like its in neutral. I coast to a stop and kill the engine. Try to start the truck again and the starter sounds like it is spinning but does not turn the motor over.

Transmission mechanic tells me the tranny neds to be rebuilt and while pulling the transmission, he tells me the fly wheel fell apart. He rebuilt the tranny, replaced torque converter and fly wheel. Picked up the truck from the shop and took the truck and a trailer on a 300 mile trip. 220 miles into the trip, the tranny does the exact same thing as a week earlier. Act like its in neutral and starter will not turn the motor over.

Any ideas what could be going on with my truck?

Thank you in advance for your time and feedback.

Yes I do , you got ripped off and you need to take the truck back to that shop on the hook and have him try again ,

You have warranty . Every garage has a 1 yr warranty on repairs

cleaner · February 24, 2015

Yes I do , you got ripped off and you need to take the truck back to that shop on the hook and have him try again ,

You have warranty . Every garage has a 1 yr warranty on repairs

If the flywheel keeps faulting, what do you think is causing that?

gmtech4 · February 24, 2015

If the flywheel keeps faulting, what do you think is causing that?

Did he even change it ?

A crappy starter gear already damaged will do it if not aligned although they don't need shims now a days , not sure on your 08 though ,

I doubt it has a shim

cleaner · February 24, 2015

Did he even change it ?

A crappy starter gear already damaged will do it if not aligned although they don't need shims now a days , not sure on your 08 though ,

I doubt it has a shim

Before the tranny went out it was making a loud clanking noise when starting. I and my motor mechanic were thinking it was a catalytic converter going bad. My motor mechanic was moving his shop so he could not tear into it. My engine mechanic did go to the transmission shop and look at the damaged fly wheel. When the tranny was rebuilt and fly wheel replaced it didn't make the noise any more. The engine was rebuilt 12k miles earlier.

Have you ever herd of or seen engines have successive fly wheel issues? What would cause a fly wheel to fracture at the crank bolts?

Thanks again for your feedback!

gmtech4 · February 24, 2015

Before the tranny went out it was making a loud clanking noise when starting. I and my motor mechanic were thinking it was a catalytic converter going bad. My motor mechanic was moving his shop so he could not tear into it. My engine mechanic did go to the transmission shop and look at the damaged fly wheel. When the tranny was rebuilt and fly wheel replaced it didn't make the noise any more. The engine was rebuilt 12k miles earlier.

Have you ever herd of or seen engines have successive fly wheel issues? What would cause a fly wheel to fracture at the crank bolts?

Thanks again for your feedback!

I can't answer the cracked flywheel question , I'm not an engineer , it maybe as simple as an under engineered flywheel