Transfer case started making a real loud grinding/clunking noise

2000 CHEVROLET BLAZER
190,000 MILES • 4.3L • V6 • 4WD • AUTOMATIC
Avatar
MADDEN420
  • MEMBER
  • 1 POST
From my inspection It's the transfer case making the noises. what could possibly be wrong with it?
Oct 22, 2020 at 11:00 PM
Advertisement
Avatar
ASEMASTER6371
  • CERTIFIED EXPERT
  • 52,796 POSTS
Good morning,

There are bearings and gears inside the case that could be worn causing the noise.

When was the last time you changed the fluid? It needs to be changed every 50,000 miles. By not doing that, the bearings will wear out quickly. There is also a chain and a synchronizer that can make the noise as well.

It will be cheaper to replace it rather than fix it due to the cost of parts and the time to rebuild it.

I attached a YouTube video of removing the transfer case for you.

https://www.youtube.com/watch?v=dM149JtOcqI

I attached a breakdown of the case for you to view.

Roy

Removal Procedure
1. Raise and support the vehicle. Refer to Vehicle Lifting.
2. Remove the transfer case shield. Refer to Shield Replacement.


imageOpen In New TabZoom/Print


3. Remove the front and rear propeller shafts. Refer to Propeller Shaft Replacement (4WD and AWD Models).
4. Remove the vent hose from the transfer case vent.
5. Disconnect the electrical connectors from the three speed sensors.
6. Disconnect the electrical connector from the encoder/motor.
7. Remove the wiring harness from the transfer case.
8. Support the transfer case with a jack.
9. Remove the bolts securing the transfer case to the transmission.
10. Remove the transfer case from the transmission.


imageOpen In New TabZoom/Print


11. Remove and discard the gasket.
Apr 25, 2021 at 11:26 AM