2nd to 3rd is grinding severely while standing on the clutch pedal?

2002 GMC SIERRA
270,000 MILES • 5.3L • V8 • 4WD • MANUAL
Avatar
RB95
  • MEMBER
  • 4 POSTS
Truck initially had a 5spd 4.3 V6 2wd. I installed a 2003 5.3L V8 using the original 5 speed.

From the get go shifting acts as if the clutch was not disengaging fully. It feels like the trans input shaft is rubbing on the flywheel. So, 2nd to 3rd is grinding severely while standing on the clutch pedal. Each shift takes no less than 3 seconds

I installed a new clutch, flywheel, pilot bearing, master and slave cylinder, clutch pedal, fluid, nv4500 trans, shims on throw-out bearing. I checked part numbers to make sure they were compatible. The issue has not been alleviated at all.

At this point I'm suspecting the 2003 5.3L crankshaft bore is incompatible with a manual transmission.
Oct 28, 2023 at 2:51 PM
Advertisement
Avatar
STRAILER
  • CERTIFIED EXPERT
  • 53,855 POSTS
That could be, also the clutch disc can only be installed one way so if it is backwards, it will cause this problem as well. Either way the transmission needs to come out to see what's going on. Here are the instructions and a guide to help you get the problem fixed:

https://www.2carpros.com/articles/clutch-doesnt-work-sometimes-or-not-at-all

and

https://www.2carpros.com/articles/how-to-replace-a-clutch

Check out the images (below). Let us know what happens and please upload pictures or videos of the problem so we can see what's going on.
Oct 30, 2023 at 10:50 AM