Transmission oil (alternate options)?
#1
Full Member
Thread Starter
Join Date: Nov 2002
Location: Grand Junction Colorado
Posts: 190
Likes: 0
Received 0 Likes
on
0 Posts
Transmission oil (alternate options)?
So I've been under the impression that the 90w in the transmission and diff was used on cars till about the mid '80s then manufactures found that they could spec. a lighter weight oil and benefit from easier shifting, better gas mileage and less parasitic hp loss.
I'm changing my trans oil ('85 GSL, 5spd, road/race pressure plate road/race clutch). I am switching to Amsoil and want the best product for my car. Also changing the oil in the diff.
I wanted to know what others were using, why they were using it and the results they got.
Thanks
I'm changing my trans oil ('85 GSL, 5spd, road/race pressure plate road/race clutch). I am switching to Amsoil and want the best product for my car. Also changing the oil in the diff.
I wanted to know what others were using, why they were using it and the results they got.
Thanks
#2
Moderator
iTrader: (3)
Join Date: Mar 2001
Location: https://www2.mazda.com/en/100th/
Posts: 30,827
Received 2,595 Likes
on
1,843 Posts
ive been using atf in the trans for quite a while, shifting is improved like synthetic, but its cheap
keep the 75-90 in the diff
keep the 75-90 in the diff
#5
Lives on the Forum
I'm glad to see that the 50/50 mix is working well for so many people. The ATF lubes fine, and is loaded with detergents that really gets the crud out of the synchros. Definitely allows faster and smoother shifting. Also, you end up with a thinner mixture, so a reduction in parasitic loss just like you were hoping for.
The old Datsun race teams used this mixture for years and swore by it. I've been using it for about 20 years, on probably over a dozen vehicles, and always see great improvement...
The old Datsun race teams used this mixture for years and swore by it. I've been using it for about 20 years, on probably over a dozen vehicles, and always see great improvement...
Trending Topics
#8
Smoke moar
Does it help the shifter not be jerky into gear? 1,2,3, & R have a stiffness it changes but theres no common reason (temp, etc)
The shifters just jerky like when I shift into R theres a metal sound like DING if the clutch was slightly not all the way down, but sometimes you'll move the shifter and it wont go further and you have to re do it. It's odd, like somethings not lubed the tranny fluid was fresh when changed few days ago
now it got harder to shift, if I push the clutch fully down and use some ***** it's okay I guess but just relaxing it's difficult everything appears to be redone with the tranny and well taken care of...
The shifters just jerky like when I shift into R theres a metal sound like DING if the clutch was slightly not all the way down, but sometimes you'll move the shifter and it wont go further and you have to re do it. It's odd, like somethings not lubed the tranny fluid was fresh when changed few days ago
now it got harder to shift, if I push the clutch fully down and use some ***** it's okay I guess but just relaxing it's difficult everything appears to be redone with the tranny and well taken care of...
#9
FB=OS Giken LSD
iTrader: (20)
Join Date: Apr 2001
Location: Wilmington, DE
Posts: 2,279
Likes: 0
Received 0 Likes
on
0 Posts
I just changed out with Royal Purple which is already mixed in the bottle 50/50. Works great, shifts a little smoother and all of the gears are easier to find, especially reverse.
#10
Full Member
Thread Starter
Join Date: Nov 2002
Location: Grand Junction Colorado
Posts: 190
Likes: 0
Received 0 Likes
on
0 Posts
So when you mix ATF with gear oil can you use a synthetic gear oil? Say mix Amsoil Super Shift Racing Transmission Fluid (ART) and Amsoil 75W-90 Long Life Synthetic Gear Lube.
Thinking of using Amsoil Severe Gear 75W-90 in the diff.
Thinking of using Amsoil Severe Gear 75W-90 in the diff.
#11
1st-Class Engine Janitor
iTrader: (15)
I switched my diff to Royal Purple about 300 miles ago, and was sufficiently impressed that I switched the trans over as well. I've only driven the trans about 40 miles thus far, but it does seem a little lighter on the shift. I haven't noticed any real change in trans noise, one way or the other.
Another nice feature of Royal Purple is that it doesn't reek like traditional hypoid lube does... It still has an odor, but it is faint. If your shift lever boots are aging, you might find that a nice side benefit.
When I swap my steering gear out, I plan on using it there as well.
Another nice feature of Royal Purple is that it doesn't reek like traditional hypoid lube does... It still has an odor, but it is faint. If your shift lever boots are aging, you might find that a nice side benefit.
When I swap my steering gear out, I plan on using it there as well.
#12
Lives on the Forum
#13
Lives on the Forum
Cmans, clunking or grinding when going into reverse is normal (if you are not doing it right, that is). Try this:
Clutch in
Move lever into 1st gear
Move lever into reverse
Release clutch
This is due to the lack of synchros for reverse. Shifting into 1st gear sets everything up for a smooth shift into reverse. Do not release the clutch between 1st/reverse.
Clutch in
Move lever into 1st gear
Move lever into reverse
Release clutch
This is due to the lack of synchros for reverse. Shifting into 1st gear sets everything up for a smooth shift into reverse. Do not release the clutch between 1st/reverse.
#14
I need a new user title
Join Date: Oct 2005
Location: Yaizu, Japan
Posts: 2,646
Likes: 0
Received 0 Likes
on
0 Posts
I started with 50/50, had to drain some later and replaced it with straight gear oil, so it's probably more like 30/70 now. Anyway, second gear was nearly unusable before. Didn't matter what you tried, it would always grind really badly. Now it still grinds a bit if you try to shift too fast, but it's perfectly drivable. It's sufficiently better that I have no plans to swap trannies until I get a TII unit.
#15
Water Boy
Join Date: Aug 2007
Location: MontCo, MD (Speed Cameras FTL)
Posts: 363
Likes: 0
Received 0 Likes
on
0 Posts
Cmans, clunking or grinding when going into reverse is normal (if you are not doing it right, that is). Try this:
Clutch in
Move lever into 1st gear
Move lever into reverse
Release clutch
This is due to the lack of synchros for reverse. Shifting into 1st gear sets everything up for a smooth shift into reverse. Do not release the clutch between 1st/reverse.
Clutch in
Move lever into 1st gear
Move lever into reverse
Release clutch
This is due to the lack of synchros for reverse. Shifting into 1st gear sets everything up for a smooth shift into reverse. Do not release the clutch between 1st/reverse.
#16
Rotary Freak
iTrader: (3)
I race my car and I have found that 75-140W Amsoil or Royal Purple in the transmission provides the best performance during a race. The viscosity range allows for good shifting when the car is cold (I have raced in 40 degree weather) and later when the car is red hot. I have also used Mobil One 80-90w in the past but by the end of a race I had shifting issues.
It is true that thinner lubes don't consume as much HP as the thicker ones do. But I really need my gear box to last so I am going to stay away from an ATF mix.
By the way, while ATF is used in allot of manual transmissions it isn't necessarily because of fuel mileage concerns. For example, the T-5 used in Mustangs and GM F Bodies used ATF because the syncros have clutch material bonded to them. Standard gear lube disolves the glue that holds the clutch material in place and ruins the syncro's.
It is true that thinner lubes don't consume as much HP as the thicker ones do. But I really need my gear box to last so I am going to stay away from an ATF mix.
By the way, while ATF is used in allot of manual transmissions it isn't necessarily because of fuel mileage concerns. For example, the T-5 used in Mustangs and GM F Bodies used ATF because the syncros have clutch material bonded to them. Standard gear lube disolves the glue that holds the clutch material in place and ruins the syncro's.
#18
i'm a poser
iTrader: (1)
Join Date: Apr 2006
Location: san leandro, Ca
Posts: 1,919
Likes: 0
Received 0 Likes
on
0 Posts
Cmans, clunking or grinding when going into reverse is normal (if you are not doing it right, that is). Try this:
Clutch in
Move lever into 1st gear
Move lever into reverse
Release clutch
This is due to the lack of synchros for reverse. Shifting into 1st gear sets everything up for a smooth shift into reverse. Do not release the clutch between 1st/reverse.
Clutch in
Move lever into 1st gear
Move lever into reverse
Release clutch
This is due to the lack of synchros for reverse. Shifting into 1st gear sets everything up for a smooth shift into reverse. Do not release the clutch between 1st/reverse.
#20
I have a rotary addiction
iTrader: (18)
If I can't get it into reverse the first try I usually stick it in 5th and edge up a few inches then shift to reverse. Only thing I'm sick of is that when I want to downshift to 2nd at 40MPH it won't let me... Same with 3rd at 60MPH. The FC would let me do it all day long, but the SA won't! I may have to try this 50/50 deal.
#23
Smoke moar
Cmans, clunking or grinding when going into reverse is normal (if you are not doing it right, that is). Try this:
Clutch in
Move lever into 1st gear
Move lever into reverse
Release clutch
This is due to the lack of synchros for reverse. Shifting into 1st gear sets everything up for a smooth shift into reverse. Do not release the clutch between 1st/reverse.
Clutch in
Move lever into 1st gear
Move lever into reverse
Release clutch
This is due to the lack of synchros for reverse. Shifting into 1st gear sets everything up for a smooth shift into reverse. Do not release the clutch between 1st/reverse.
Ohh thanks man, that'd make sense
btw I found that the shifter is very very smooth till driven hard it seems or driven alot, then it just stiffens a bit randomly (Im guessing the syncros)
no grinding or anything though
#24
Moderator
iTrader: (3)
Join Date: Mar 2001
Location: https://www2.mazda.com/en/100th/
Posts: 30,827
Received 2,595 Likes
on
1,843 Posts