[TR] TR4A Gear Lube Recommendations

[Ben Zwissler]

Hello,

I'm looking for some advice on the lube to use in my TR4A transmission 
w/the electric overdrive.  I rebuilt it with new synchros and it has 
about 1500 miles on it.  I started with "normal" GL-5 MT-1 80W90 gear 
oil.  It worked well overall, and shifts smoothly in all gears, up and 
down, when its cold or warm.  However, if I drive for 30 minutes or more 
getting the transmission fully warmed up and make "spirited" shifts, 
upshifts from 2nd to 3rd result in some grinding.  All other upshifts 
and downshifts are smooth.  I switched to some synthetic blend 75W90 
GL-5 MT-1 and it works no better. Maybe a little less balky when cold, 
but no better and maybe worse on the hot 2-3 upshifts.

I have a TR8 and use the GM/Pennzoil synchromesh fluid there, but wasn't 
sure if the TR4A box w/overdrive would like that.  I'm looking for 
advice on if anyone has had the same problem and how they resolved it.  
I'm wondering if I shouldn't be going to straight 90 weight oil since it 
seems to work worse when the oil is hot and presumably thinner.  People 
seem to switch the the GM fluid to resolve cold shift issues so I'm 
afraid that may take me the wrong direction here.  My other choice is to 
get better at matching engine speed to tranny speed and making slower 
shifts.

Thanks, Ben....

-- 
Ben Zwissler
bjzwissler at gmail.com
Columbus, IN
1966 Triumph TR4A
1973 MG Midget
1980 Triumph TR8
2007 Mazda RX8
2002 Yamaha FZ1
2003 Honda ST1300