Synthetic Gear Oil Anyone?
#1
Melting Slicks
Thread Starter
Synthetic Gear Oil Anyone?
This spring I plan to swap in my 4.11 gears, and now am gathering up odds and ends so I'll have everything when the time comes. I plan to drop the trans, swap in the Neil Chance custom converter, do a little clean up while I'm at it....
Question is, has anyone tried synthetic gear oil? Any issues? Do you still need additive for the posi? I have just started looking into this.
Question is, has anyone tried synthetic gear oil? Any issues? Do you still need additive for the posi? I have just started looking into this.
#2
Had a 1976 L-82, 4-sp
Member Since: Mar 2011
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Royal Canadian Navy
Yes. I changed out the diff gear oil on my wife's '13 CTS-V. The diff had a small groan when making turns. Sound familiar? So, I replaced the gear oil with Royal Purple Max Gear synthetic gear oil. Groan disappeared. Also, the Max Gear oil doesn't require the posi additive as it is included in the formulation. I will be switching my 4.11 with Max Gear synthetic 85-140 this spring. Glad I drilled a hole in the 4.11 for a drain plug.
#4
Race Director
I tried several conventional gear oils with posi additive and had horrible groaning from my newly rebuilt diff (new posi clutches).
Finally switched to Mobil1 75W-90 (also added a bottle of the additive) and all noise went away.
Finally switched to Mobil1 75W-90 (also added a bottle of the additive) and all noise went away.
#5
Le Mans Master
The synthetics I use do not require the additive like conventional gear oil since conventional gear oil does not, on its own, have adequate lubrication qualities for the clutch discs...............
#6
Race Director
Very possible I would have been fine with just the Mobil1 and no additive. Next time I change it I'll try it without additive.
#7
Melting Slicks
Thread Starter
I bought two cases of the Royal Purple trans fluid....not cheap. Plan to use that when I do the converter swap. Guess I'll pick up some for the diff now too.
Thanks guys.
Thanks guys.
#8
Team Owner
You do understand that numerically higher rear end ratios create more heat? That is why 85w-140 is what I recommend. I've been using full synthetic from day one on my 4.11 and the Richmond gears still looked brand new after 20 years
#10
Melting Slicks
Thread Starter
Yes. I changed out the diff gear oil on my wife's '13 CTS-V. The diff had a small groan when making turns. Sound familiar? So, I replaced the gear oil with Royal Purple Max Gear synthetic gear oil. Groan disappeared. Also, the Max Gear oil doesn't require the posi additive as it is included in the formulation. I will be switching my 4.11 with Max Gear synthetic 85-140 this spring. Glad I drilled a hole in the 4.11 for a drain plug.
I just contacted the vender about synthetic gear lube, and he insists on break in with organic plus the additive, then change to synthetic after.
So I guess I too should add a drain plug. Any details would be awesome. Size drill, tap, location...maybe even pics? Mine is an 80, so it might be different, but any insight would be appreciated.
#12
I just contacted the vender about synthetic gear lube, and he insists on break in with organic plus the additive, then change to synthetic after.
So I guess I too should add a drain plug. Any details would be awesome. Size drill, tap, location...maybe even pics? Mine is an 80, so it might be different, but any insight would be appreciated.
So I guess I too should add a drain plug. Any details would be awesome. Size drill, tap, location...maybe even pics? Mine is an 80, so it might be different, but any insight would be appreciated.
#13
Advanced
Does anyone, after using LS synth oil, found their LSD less efficient ? I mean not too much at the light , but in tight corner exiting under full throttle or so, do you feel one wheel spinning more than it should ?
Me too I would like to go synthetic, but Eaton the diff man, say not recommended.
Me too I would like to go synthetic, but Eaton the diff man, say not recommended.
#14
Le Mans Master
Rather than take personal opinions like myself and others, you might want to ping Gary, GTR1999, who builds diffs for lots of folks on this forum, and get his expert opinion from him, especially since he sees older diffs for rebuilds and has experience with the different types of lubes.............
#16
Had a 1976 L-82, 4-sp
Member Since: Mar 2011
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Royal Canadian Navy
I just contacted the vender about synthetic gear lube, and he insists on break in with organic plus the additive, then change to synthetic after.
So I guess I too should add a drain plug. Any details would be awesome. Size drill, tap, location...maybe even pics? Mine is an 80, so it might be different, but any insight would be appreciated.
So I guess I too should add a drain plug. Any details would be awesome. Size drill, tap, location...maybe even pics? Mine is an 80, so it might be different, but any insight would be appreciated.
#17
Race Director
Does anyone, after using LS synth oil, found their LSD less efficient ? I mean not too much at the light , but in tight corner exiting under full throttle or so, do you feel one wheel spinning more than it should ?
Me too I would like to go synthetic, but Eaton the diff man, say not recommended.
Me too I would like to go synthetic, but Eaton the diff man, say not recommended.
#19
Race Director
Member Since: Jan 2000
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2020 C2 of the Year - Modified Winner
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Been using Royal Purple Max Lube in my Dana 60 IRS for years. Used Mobil 1 before that. Used Mobil 1 in my stock diff. Both work great with no additive...and I'm not easy on stuff!
JIM
JIM