360 gear oil question - LSD or not?

Okay, I was just getting ready to order some Redline 75W90 gear oil for the gearbox on my 360 and I noticed it comes in a LSD version and a non-LSD version. The LSD version of Redline's 75W90 gear oil includes "limited-slip friction modifiers". So my question is which does the 360 gear box use? I have a manual gear box and I would assume the differential on the 360 is limited slip, but I cannot find anything in the workshop manual which backs this up, nor can I find any note that the gear oil must contain LSD friction modifiers. Anyone know?

Also, molykote is recommended for the o-ring on the gear oil filter. However, there are about 20 or 30 different varieties of "molykote". Does anyone have any idea which # molykote is suggested?

Ray

 

Interesting; thanks very much for the info. I'm actually going to call Redline tomorrow and ask them how many ounces of friction modifiers are included in the 75W90 with the modifiers - just out of curiosity. Is there some logic to how you arrive at the 8 oz figure? My only concern would be that 8 oz could be too much of the friction modifier and that this could lead to too much slipping within the LSD.

Is there any advantage to adding the modifier separately as opposed to buying it pre-mixed?

Ray

 

Okay, thank you for the info; that's great to know.

Also, when I mentioned calling Redline (which I'm still going to do), I wasn't suggesting that they would have any information regarding what should be used on the 360. I am just interested to know how much FM is in the 75W90 that already has FM in it. I think it would be interesting to know just as a reference point with regard to the 8 oz figure is all

My car has always shifted beautifully - even when ice cold - so I'll be interested to see how it feels after changing the gear oil. I'm also going to change the oil in my SUV, which is 4x4 and has LSD. I was planning on using 75W90 there as well. Not sure if I will use the redline with the friction modifiers already in there, or add it myself. Again, it will be interesting to get an idea from Redline as far as how much is in the combo version

I'll report back when I find something out. No matter what the answer is, I like the idea of controlling exactly how much is present by adding it myself. Again, great info, thanks!

Ray

 

Well, I'm going to list it again in a while. I want to change the engine oil/filter and also do the gear oil. I'm also going to change the plugs and do a compression and leak down test on the car. Prices are so soft right now that I may just end up keeping the car - although I do need the room in the garage.

Ray

 

The F1 is basically the same gear box. The only difference is whether you shift or whether the computer shifts.

Ray

 

you couldn't give me an F1 car for the street! The only time I would ever consider one is on the race track. Even then, I'm more happy shifting the gearbox myself.

Ray

 

I was reading through the information at Redline's website tonight regarding gear oils, etc. It appears the 75W90NS is the way to go all right. They suggest that you start with this and then add the friction modifiers until the chattering from the LSD stops. Perhaps the 8 oz figure stems from someone starting with just the 75W90NS and then adding the friction modifier until the chattering from the LSD quiets down.

I'm going to attach a white paper from redline that covers the oil pretty well. I still am going to give them a call and see what they have to say. I'm also interested in perhaps using redline oil in the motor. However, I'm not sure if it would be better to use their street oil or try their racing oil? I was going to use Mobil 1 5W-30 synthetic, but since I'm going to use redline in the gearbox, I might also check into the engine oils they offer.

Anyway, as far as the gear oil issue, I think what I'm going to do is start with straight redline 75W90 NS gear oil and see how that goes. The specs call for approximately 3.70 quarts of gear oil, which works out to about 118.4 oz. So by my calculations, adding 8 oz of friction modifier would result in about a 6.75% mix of modifier by volume.

Like I say, I think I'm going to just start out with straight 75W90 NS and see how it performs. I'm not super worried about a little chatter from the LSD/tires. I mean, I used to drive a turbo charged datsun that had the spider gears in the diff welded :-D so having a little less slip in the diff on the 360 wouldn't be the end of the world. And if it is, then I can always remove a little gear oil and toss in a few ounces of friction modifier if needed.

I'll still call redline in the morning and see what the % is for the non-NS version just out of curiosity. I just ordered the gear oil (and some friction modifier) off ebay now, so once my second floor jack shows up, then I should be about ready to roll

Ray
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Okay, thanks for the run down - good to know. So on the royal purple (for the gear box), are you using their 75W-90 "gear max" product?

I can always toss the redline oil into the differentials on my truck, although I don't push my 360 very hard, so the redline might be okay there as well.

When I contacted Redline to inquire about the friction modifiers, they said exactly what you just mentioned - that the additive could potentially inhibit the syncro action. That was eye opening

Ray

 

okay, as a follow up I did call Redline to inquire about their gear oils. I spoke with a tech person that seemed very knowledgeable about their products. I believe his name was Dave. In any event, he told me that when it came to the 75W90 gear oil - which already has friction modifiers in it from redline - the percent by volume is about 5%.

I mentioned to him that it had been suggested that I use 75W90NS and then add 8 oz of friction modifier. I explained that based on the roughly 120 oz that the transaxle takes, this would result in roughly 6% ratio of friction modifiers by volume. His response was that this was probably excessive. I asked him what the result would be if you had too much friction modifier and his response was that it might make the gear oil so slippery that it could hamper the functioning of the syncros. I asked him to explain that in practical terms and he did. The upshot is that the syncros require some level of friction - this is because as you shift, the friction of the syncros is used to sort of spin up the gear you are shifting into. The friction in the syncros is needed to help spin the next gear at the proper speed, so that shifting occurs smoothly. If there is too much friction modifier in the mix, it could make things so slippery that the syncros can't gain enough friction. This in turn could make shifting notchy (similar to not putting in your clutch for example).

Anyway, when I asked what ratio of friction modifiers sounded more reasonable, he stated "around 1.5% or maybe 2% max". So with regard to the 360, which takes 3.70 quarts or 118.4 oz of gear oil, 1.5% would translate into about 1.75 ounces of friction modifier in the gear box. He also stated that you could just add friction modifier until any chattering/grabby feeling from the LSD went away (when going around turns).

So that's the run down from Redline insofar as the % of friction modifiers in the non-NS version of their 75W90 gear oil, as well as their recommendation for how much friction modifier should be called for when/if it's needed in the 75W90NS gear oil.

Since the 75W90 version has about 5%, I think adding 8 oz of friction modifier to the NS version falls into the excessive category - given that you end up with a nearly 7% mix (6.75% to be exact) when everything is said and done. Not only do you end up with more than if you just used the normal 75W90 version, but based on what Redline had to say, you could end up with a mixture that is so slippery that it could hamper the function of the syncros in the transmission.

I really don't know either way, because I don't have any first hand experience with redline or using it in the gear box. So don't kill the messenger I'm just passing along what I found out by calling Redline. I think it is good to know what you are dealing with before adding stuff to gear oil.

Anyway, hope this info is helpful.

Ray

 

That's quite a battery of tests they put the oils through. It was interesting to note that in some areas Royal Purple failed miserably, while in others Redline did. Based on the overall results of the test, it appears Redline stacks up fairly well.

The Amsoil looks like it performed great, of course the test was commissioned by Amsoil also, so that has to make you pause for a moment

Ray

 

Brian definitely knows his stuff when it comes to these cars. I suspect that no matter what oil you use, the key here is to change it frequently. The gear box lives in a very hot environment to begin with - we all know how much heat is generated back there from driving the car even just on a normal daily trip. I think frequent oil changes with any of the higher quality gear oils, as well as frequent cleaning of the filter in the gear box (even if it means popping the rear bumper off - which isn't really that horrible a job frankly) is probably the key to extending the life of the transaxle on the 360's.

Ray