waddisme

Didn't realize it had been almost 4 yrs since I changed trans and diff fluid. I used RP for both last time but cannot remember how much is needed. Probably go with Mobil this time and change more often. How much do I need for each?

travisnd

Buy 4 quarts for the trans - Takes 3.2

Buy 2 quarts for the diff - Takes 1.6

waddisme

Not to start a pissing war here, but is the RP really worth 2x as much as the Mobil 1 ATF? Car is a dd doing 10-12 track days a year driven at about 8/10s.

travisnd

Never used any Royal Purple products. Only M1 and Amsoil. I use all Amsoil now because of the preferred customer discount.

geerookie

Not to start a war but I wouldn't put RP in my enemies car.

For the money I have found Amsoil to be the best bang for the buck.
I ran all season last year on their 10w-40 oil and oil filter without ever changing oil or filter. Also I don't have an oil cooler.
I tore down my motor this winter after 115k and it showed no scoring at all.

Same for Trans and rear end but I do change those mid season.

travisnd

I change my oil every 3 track weekends and change the trans/diff annually. However when I changed them at the start of this season I found that the trans fluid looked brand new but the diff fluid was pretty nasty. From now on I'll change the diff mid-season. FWIW I run the Severe Duty 75w110.

longdaddy

if you have coolers, the procedure is a lot more annoying and you need more fluid.

one thing that's important is to make sure the car is as level as possible when you fill, otherwise it is very hard to get the right amount it (esp. the diff) and these cars do not like extra fluid!

C66 Racing

I use and recommend:
AMSOIL Torque-Drive Synthetic Transmission Fluid (Product Code ATD1G)
AMSOIL Severe Gear Extreme Pressure Synthetic 75w90 (Product Code SVGQT)

froggy47

I have never used it, but often there are very negative remarks re: RP.

I have used a lot of M1, Redline, a little Amsoil, Castrol, Valvoline.

No complaints.

What is the problem with RP, as they market it as a premium / high performance product?

Let's try for specific facts (oil analysis, manuf. spec. ) or at least personal experience, not he said/she said, or I know a guy stuff.

Bills Z06

Use Amsoil!

C66 Racing

In this 2007 AMSOIL sponsored study of gear lubes, RP finished 12th of 14. Even if you discount the AMSOIL, the RP did not perform well against the others in the test:
AMSOIL Gear Lube “White Paper” (2 MB pdf file)

Not directly related, but draw your own conclusions, RP performed similarly in a 2005 AMSOIL sponsored study of motorcycle oils ranking 7 of 11 in 40 grade and 8 of 15 in 50 grade:
AMSOIL Motorcycle Oil “White Paper” (1 MB pdf file)

Though both of these tests are clearly somewhat dated and formulations for most of the fluids have probably changed since these tests, what would concern me most about RP is that it sheared low out of grade in all three tests (gear lube and both 40 and 50 grade motorcycle oils).

froggy47

Thanks Brad, right on point.

Hat_Trick_Hokie

I purchased my Amsoil transmission and diff fluid through this gentelman, and have been very happy with the smooth transaction and the results

Make sure you have a pump before draining your system!!

Scooter70

Are those your recommendations for a race car or street/HPDE car?

C66 Racing

Yes.

That is what AMSOIL recommends for the Vette and what I run in my track day car. Also happens to be the exact same fluids I ran in my 06 CTS-V (LS2 engine with same Tremec tranny and GM diff) which was my daily driver from 06-09 before it became a casualty of my move to DC. Only difference in fluids between my Vette and the V was the engine oil. I ran a street oil in the V and I run a racing oil in the Vette.

Bills Z06

That's what I use in my track and street cars.

Toilets

Stupid question but is this ok for a manual? Also, if you have all three coolers would you still recommend these?

Also, does anyone know what the annoyIng part is if you have coolers?

froggy47

Yes for manual, don't understand the rest?

Sub gave you the tranny & diff fluids.

Toilets

Thank you! What I was trying to get at was Appearently it's harder to change the fluid if you have a diff cooler and trans cooler?

C66 Racing

Yes - it is a pain. I don't have diff cooler, but have aftermarket tranny cooler on my tranny that was installed by Phoenix Performance.

I've tried several methods to change my tranny fluid... and I like none of them. The one I use most often is sort of a feed and bleed type approach. I change it often, but don't get all the fluid out.

The easiest approach I've found on mine is to not disconnect the line from the drain plug port to my pump (which then goes up to the nose where the cooler is and then back to the fill port), rather disconnect the cooler return line where it attaches to the fill plug on the tranny. Once the line is disconnected, I direct the cooler return line to a pan and have a helper turn on the pump. I stop the pump after a few quarts to keep the lines from getting air bound. I then pump in new fluid until the tranny is full again and then repeat one more time, call it good and reconnect the line. In this was I also get peace of mind that the pump actually works.

I normally order my Torque Drive by the 4 gal case so I always have plenty around.

I suspect a diff with cooler lines would be equally painful.