quick tranny question

[heavy85]

Just put a new (at least to me) early datsun 5 speed in my 240Z and it grinds when downshifting from 3 to 2 unless I double clutch it, but the 1-2 shift is fine. I thought second gear had only one synchro and therefore if it was bad it would grind shifting into second from either direction? Does this mean the syncro is bad or could there be a clutch adjustment or other problem causing this? It's got Mobil 1 synthetic 75W90 if that makes a difference. The old tranny I took out grinded when shifting into second or third but it did that no matter if it was an upshift or downshift and I found the sychros had a few teeth missing. From what I could tell the new tranny's synchros look good and it's suppose to be low mileage.

 

Thanks

Cameron

[datsunlover]

Umm... from what I'v heard, weren't the early 5-speeds a somewhat week tranny? Mind you.. my 81 280zx did the same thing you describe... I took it to a trany shop, and after a short ride, the guys told me either the 2nd+3rd syncros were chewed/worn, or there was a thrust(?) bearing gone...

[Guest ON3GO]

my friends rx7 did that and it was his blocker ring for that gear.

is it a stiff gear or is it mushy

 

Mike

[heavy85]

What do you mean stiff or mushy? It feals like any other gear on the upshift.

 

One other thing is that it had been sitting for somewhere between 12 and 20 years before I got it. I flushed it several times with auto tranny fluid before finally filling it with gear lube. I also only drove it about a mile or two so could it be that it just needs a little break-in period so to speak before it works good or is it just plain broken .

 

Thanks

Cameron