Re: Replacing freeze plugs on 240Z
Posted: Sun Feb 28, 2021 9:20 am
Dale,
The "tell" on the transmission is this: Engine running and in Neutral listen for transmission noise, depress the clutch and listen. If you hear noise from the transmission that goes away when you depress the clutch, you have bearing slop (damage or wear) which will only get worse. (another check: while driving in 2nd and 3rd put your hand lightly on the shift lever - now do the same in 4th. (normally while driving you should NEVER rest your hand on the shift lever. Grab it to change a gear and then immediately remove your hand.) Do you feel any shift lever vibration in 2nd or 3rd that lessens or goes away once you're in 4th?) Ya, it needs new bearings. If the "noise" doesn't change try GM Syncromesh transmission fluid and see what you think.. Syncromesh seems to be the fluid of choice these days.
I tried several fluids in mine (but not syncromesh YET) and ended up with good old Sta-Lube GL4 which is moderately difficult to find (NAPA, maybe Amazon). I did not have a good experience with Royal Purple or Redline MT90 that seem to get good reviews from others. And remember that GL5 is NOT the "new and improved version" of GL4. They are two completely different spec lubricants for completely different uses. GL4 in Datsun transmissions and GL5 for Datsun differentials.
(I write a lot of things here that Dale already knows but include little things for others reading this post that may not already know...)
The "tell" on the transmission is this: Engine running and in Neutral listen for transmission noise, depress the clutch and listen. If you hear noise from the transmission that goes away when you depress the clutch, you have bearing slop (damage or wear) which will only get worse. (another check: while driving in 2nd and 3rd put your hand lightly on the shift lever - now do the same in 4th. (normally while driving you should NEVER rest your hand on the shift lever. Grab it to change a gear and then immediately remove your hand.) Do you feel any shift lever vibration in 2nd or 3rd that lessens or goes away once you're in 4th?) Ya, it needs new bearings. If the "noise" doesn't change try GM Syncromesh transmission fluid and see what you think.. Syncromesh seems to be the fluid of choice these days.
I tried several fluids in mine (but not syncromesh YET) and ended up with good old Sta-Lube GL4 which is moderately difficult to find (NAPA, maybe Amazon). I did not have a good experience with Royal Purple or Redline MT90 that seem to get good reviews from others. And remember that GL5 is NOT the "new and improved version" of GL4. They are two completely different spec lubricants for completely different uses. GL4 in Datsun transmissions and GL5 for Datsun differentials.
(I write a lot of things here that Dale already knows but include little things for others reading this post that may not already know...)