300d 4 speed trans making noise

[mamali]

unfortunately bought a 84 300d turbo diesel with a 4 speed manual conversion. First and second gear are fine 3rd and 4th makes a grinding noise. Without giving gas. Any way to adjust? Thanks

[pimpernell]

Originally Posted by mamali

Hi unfortunately bought a 84 300d turbo diesel with a 4 speed manual conversion. First and second gear are fine 3rd and 4th makes a scraper if sound. Without giving gas. Any way to adjust? Thanjs

Could be a number of issues.........the synchronizer rings could be worn and not doing their job. Check for the clutch adjustment to make sure that when the clutch peddle is depressed the clutch is actually free to stop spinning. Last but no least, make sure that the tranny is properly aligned with the clutch housing. Good luck!!

[Frank Reiner]

mamali:

1) Is the trans an iron case version, or an aluminum case version?

2) What does "a scraper if" sound mean?

[mamali]

How do I check clutch adjustment?

[leathermang]

One of our forum Moderators at one time listed the ' correct ' trans fluid to use..
from REDLINE
to keep from eating up the synchros.
Mr Smith I believe.

In addition to any internal wear which may be causing noise... there is a discussion back when RLEO put a manual trans into his Turbo Diesel Station wagon
The factory did not mate the turbo with the manual trans.
and when mated to other diesels there is some kind of antivibration buffer I think
necessary to keep it smooth. You could check with RLEO to see if he remembers what it was...

[imgolden]

Have you checked the driveshaft bushing and flex discs?
I once had a 4-speed 240D that would make a scraping noise when off the throttle, as you describe, and it was the center support bearing in the driveshaft.
Here's a video I recorded when I was diagnosing it: https://www.youtube.com/shorts/S0jTuFyUV14