matt5462

Maybe a stupid question maybe I missed the answer when I searched...................Any thoughts on using shockproof gear oil in the rear end????

Icemark

I have used superlight shock proof in RX-7 rear ends with good results, but have not tried it on a Torsen type rear end like found on the RX-8.

fahrfegneugen

no, I put Mobil 1 in it, seems to work.

kersh4w

iTrader: (3)

not mobil1 engine oil, right? it was a good 75w-90 or something similar.

i have redline mt-90 in my rear diff.

nycgps

iTrader: (1)

shockproof is either too light or too heavy.

for rear diff

use mobil1 75w-90 GL5 oil, Redline 75w-90, Royal Purple maxgear 75w-90.

you can even use 75w-140.

fahrfegneugen

haha, no, I used Mobil 1 75w90 GL-5 LS Gear Oil. It recommends like straight 90, which doesn't exist it seems.

I guess you can use engine oil w/ gears, isn't 75w90 the equivalent to like 10w30?

Icemark

Redline superlight shock proof is the equivalent to a GL5 75W90 gear oil while Redline light weight shock proof is the equivalent to GL5 75W140 gear oil.

Neither are saddled with LSD friction modifiers.

Redline MT-90 is actually only a GL4

http://www.redlineoil.com/products_g...6&categoryID=6

StealthTL

iTrader: (1)

Doesn't the back of the SuperLight Shockproof bottle say not to use in a daily driver/race use only?

"Equivalent to...." = virtually = it's NOT.

Yes, "......not for use in syncro type transmissions."

Recommended for "stock car qualifying laps."

S

nycgps

iTrader: (1)

Of course I know what MT-90 is. I have it in my tranny.

Redline does have 75w-90 for rear diff. GL-5 stuff.

http://www.redlineoil.com/products_g...5&categoryID=6

got 3 bottles of those like 1/2 yr ago. gonna replace it tomorrow or friday.

I8U

iTrader: (1)

We run Redline 75w-90 in diffs on our cars.

Icemark

I guess you missed that he was asking for experience in a rear end use

Unless I am totally uniformed, there is no such thing as a syncro type rear end.

Rear end gear lube should not be confused with a tranny gear lube.


Kinda like 75W90 is the same thickness as 30WT, yet you wouldn't use 30Wt in your rear end.

Redline shock proof is for rear ends/differentials. I have used both light weight and superlight weight in numerous RX-7 and Toyota Rear ends with great results on street driven vehicles. And it doesn't start breaking down at 250F like Mobil1 and Valvoline synthetic gear lubes do.

AND just as a FYI, shock proof shouldn't be used in trannys due to it being too slippery and the syncros don't slow down enough for proper shifting... that is why it is used JUST IN DIFFERENTIALS on street driven vehicles.

I just love people that have never even used a product having any sort of opinion.

StealthTL

iTrader: (1)

Yes, I missed it was for just the rear.

That was why you pointed out the GL-4.

I use MT90 and MTL in my own gearbox.

S

I8U

iTrader: (1)

^Found something new for the gearbox that seems to make them last longer in a race setting...50/50 blend of Redline 75w-90 and Redline ATF. I know it sounds weird but it is working very well for us.

kersh4w

iTrader: (3)

interesting.

nycgps

iTrader: (1)

Hmm ... really ? ... hmm ....

dillsrotary

I've used RP Max in the rear diff for nearly 25,000 and love it. I also have shockproof heavy in the trans for the same mileage, its been flawless since.

TeamRX8

iTrader: (25)

For road racing maybe, but my experience is that thinner oil = trans breakage under extreme duress for hard launches and the 1-2 shift i.e. drag strip and ProSolo autox events

I don't really recommend the Heavy Shockproof oil except for racing use only as it seems to break down and needs to be changed regularly, my sole choice now is the Redline 75W140NS oil.

blew out 2nd gear twice on the 1-2 upshift (note brownish color is from choosing wrong camera light setting, parts are bright, clean machined metal in person):











.

Icemark

I generally do not recommend RP gear lubes at all:

http://www.amsoil.com/lit/g2457.pdf

nycgps

iTrader: (1)

I had RP Max gear in tranny for over 35 K miles AND it had some weird noises + harder and harder shifts.

Switched to Redline MT-90. no problems. almost 10 K miles.

might have something to do with Max gear's GL5 LSD additive damaging the soft metal in our gear box ?

Icemark

Read how corrosive and what the viscosity break down that happens under shear loads on the Royal Purple on the PDF link I posted.

I8U

iTrader: (1)

Team is there any other kind of racing!?! But yeah, those pics were not good at all!

fahrfegneugen

The question was about grade equivalents, I know gear oil and motor oil are not the same, eh, nvm