Wavetrac specifically says not to use Limited Slip (LS) oils. It doesn't use clutch plates like a standard (Quaife) LS diff:
-------------------------------------------------
In conclusion, when using a Wavetrac®:

• Use factory spec oils for your car
• Use Motul Synthetic high performance oils if you wish to upgrade the oil. Please consult Autotech Driveline for recommendations.
• Avoid gear oils with limited slip additives.
• Do NOT use RedLine, Shockproof® or similar gear oils.

Performance Gear Oils we recommend:
Requirement Oil75W90Motul Gear 300 (100118 1l)75W140Motul Gear Competition (101161 1l)Motul Gear Oil is available from Wavetrac dealers
Please note that you will void the Wavetrac® Limited Lifetime Warranty if incorrect gear oil is used.

 

Is this http://www.needswings.com/ProductIma...0gear75w90.jpg just an image mistake on NW's website?

 

.....yes the same document from where I got the quote I provided below....
"fill your....with only premium synthetic 75W90, 75W140 or 80W140 GL-5 hypoid gear lubricant."

 

My first fill with the Wavetrac was with Eneos 75W90. 2nd fill was Motul 75W140 which btw is used in the GTR. With 75W90 I could feel the Wavetrac pulsing as it transferred or locked the power from one wheel to both. Why change? Hoping to quiet the noise and handle the heat from racing. At first I was worried about the 75W140. I didn't feel the pulsing any more. Did I err? was my first reaction. A year later I feel the heavier oil was a good choice for my usage. It works like it should and I never feel the pulsing as the tires loose traction.

Les

 

there are many oils you can use. heres the key to long life that many dont use. if you race the car hard and often CHANGE THE OIL OFTEN! its sop for the porsche road guys to change the diff oil at least 2 times a yr for heavy track use. its cheap and easy compared to swapping a burnt diff

 

Hi all! I am new to this forum, but I bought my 05 Crossfire SRT-6 about a year ago. I am located near the VA-TN border and I have a question. If I floor it I leave two tire marks on the pavement and the only time the traction control light comes on is if I am gunning it in gravels or something like that. It has about 52k mi on it and I don't hear any whine sounds coming from the rear end at all. Is there a way to tell if the previous owner changed the rear end?

 

the only real way to know is to pull an axle and look inside. if you know the previous owner you could ask them or post the vin on the forum database and see if it was a forum member and contact them that way

 

if it is a wavetrac done by Unitraxit will have a tag on it saying the wavetrac is installed, you can also check by jack the rear on one side and if it is a posi it will drive Backward or forward off the jack, you could just , With the motor off, hold one tire,from turning with the car in neutral then the other side should not turn also. if you have both rear tires in the air, car in park if you turned the left tire forward the right tire should turn backwards if there is no Posi jim

 

yes - looks like I might be swinging over to the 80W140...
first sniff....
MOTUL MOTYLGEAR 80W140 2L TRANSMISSION OIL HEAVY DUTY GEARBOX W/O LSD API GL4 | eBay

although this is only a GL4....

b22b

 

why buck what the manufacturer wants you to use? do you use mobil 1 as your engine oil? if mercedes said it was fine to run either mobil 1 or the local parts store generic brand petrol oil which would you run?

use what autotech wants in the diff. its less than 50$ to fill it. change it twice a yr and enjoy it. no need to reinvent the wheel. if the want gl5 oil run gl5 oil

 

wo horsey.....
I wasnt "bucking the manufacturers recomm."...which says...I was just heading towards the 80W140 instead of the 75W90 300 LS that I originally purchased....
if the ebay link added doesnt comply with this - then point taken.
But I did point that out in the first post....

b22b

 

Did you cross chek with Unitrax before changing to the 80W140, what brand did you go for?


from here.....
http://www.kewengineering.co.uk/Auto..._explained.htm

API GL-4, oils for various conditions - light to heavy. GL-4 contain up to 4.0% effective anti-scuffing additives. Designed for bevel and hypoid gears which have small displacement of their axes, truck gearboxes, and axle units. GL-4 are recommended for non-synchro gearboxes of US trucks, tractors and buses and for main and other gears of all vehicles. GL-4 oils are basic for synchronized gearboxes, especially in Europe.

API GL-5, oils for severe conditions. They contain up to 6.5% effective anti-scuffing additives. The general application of GL-5 in this class are for hypoid gears having significant displacement of axes. GL-5 are recommended as universal oils to all other units of mechanical transmission (except gearboxes). GL-5 oils, which have special approval of vehicle manufacturers, can be used in synchro manual gearboxes only. API GL-5 oils can be used in limited slip differentials if they correspond to the requirements of specification MIL-L-2105D or ZF TE-ML-05. In this case the designation of class will be another, for example API GL-5+ or API GL-5 LS

 

The shop that did the instal called Unitrax. I'll have to find out exactly which Motul they used but I was under the impression it was 75W140. The time I talked to them on the phone they told me if the lube was too slippery (friction modifiers/lsd lube) it hurt the performance of the unit but it wouldn't damage anything. I went with the heavier oil mainly because my Wavetrac was making noise which by the way, has subsided quite a bit.

Les

 

I have at least 2000 miles on my roadster. I used the motul 75/90. Just my .02.

 

this is were you posted using gl4 . but hey its only a 1500 $ diff no worries

 

Well, I bothered to look up the documentation that came with my Wavetrac. Motul Gear Competition 75w140 is a recommended lubricant. You guys were making me feel bad about my choice.

Les

 

here's an interesting comparison on viscosities
http://www.oilman.com.au/gear-oils/s...-80w90-80w140/

75W140 seems to be a more common grade compared to 80W140.

Motul do a 75W140 GL5 but the cheapest I can find is $97 for 2x1L delivered.
Motul Gear Competition 75W140 Diff Transmission Gear Oil - 1 Litre Autosphere
There are a couple of others out there....

Amsoil I can get in my town (pickup) for $60 (for 2)
Amsoil Severe Gear 75w140 Gearbox Oil | eBay

Spectro
Spectro Platinum Synthetic Differential GL-5 SAE 75w140 | eBay

Redline
Redline 75W140 GL-5 Gear Oil 1-Quart | eBay

Royal Purple
Royal Purple Max Gear 75w140 Cheapest in Australia !!! Ample stock RP 75w140 | eBay

any thoughts on "best of breed"......

 

It's always fun to try and find a better lube .... or cheaper one. Let me try and remember how I got to the 75w140. My shop installed the Wavetrac and were all out of Motul. They called Unitrax and got the OK to use Eneos 75w90 which they had in the shop. Put it in. Wavetrac made noise. Worried owner sweating bullets on the way to the drag rental. Got to the rental and touched the differential to check the temperature and it was too hot to keep a hand on. Nothing broke. Ordered a selection of clips to adjust the end play and purchased new side bearings. The shop installed the side bearings, said the end play was fine but adjusted it a little because of the noise. Filled with Motul 75w140. I requested it be used over the 75w90 because of the Puerto Rican heat and the track usage .... and owner mania. I don't know if I needed 140 weight. If and when I have reason to change the rear end oil I'll go back to 75w90 just to compare the "feel" of the engagement of the Wavetrac. As I mentioned already, I could feel it pulsing (disconcerting) as it was doing what it does. With the 140 I don't feel the pulsing. Anyone out there feel their Wavetrac pulsing going down the 1/4 mile? Just wondering.

Les

 

I am sure we went with what was recommended...now you have me worrying....stop it....But it is not 95 here all the time either....

 

Beats me which one I used. I did what I always do - I asked Rob.