Can you change the oil in your transmission/diff too early? I have done the reasearch and have 4 quarts of RP 75w90 being shipped to me. My question has to do with when to do it. I have ~1800 miles at this point. People have talked about lots of metal shavings in the oil when it was changed but there doesn't seem to be any concensis about when to do it. So what do you think, have the gears worn-in sufficently to change to synthetic?

 

Nothing is too early, you can change your oil after every trip, but thats going to cost you alot of money and time.

My first Engine oil change was @ 1000 miles. Gear & Rear Diff @ 5K miles.

20K miles (Today) still running strong.

Doesnt matter if its Synthetic or not. but Synthetic oil protects better (Against heat, etc) and last longer.

but down the line is your choice.

 

Bought an '06 a few months back. Changed my Trans and Diff at 1000 miles. Changed both with BG Products - BG SyncroShift II for the trans and BG Ultraguard 75W-90 for the Diff.

This almost totally eliminated the "whine" the rx-8 driveline tends to have (mostly from the trans syncros)

 

I notice certain lube products are popular with certain groups. It seems like BG products are popular with the Mitsubishi people, while Redline is used a lot by the Impreza people. A lot of rotary people tend to like Royal Purple. These are just my observations.

 

i did first oil change ~1k miles. First trans/diff at ~2k miles.

You can do it even earlier, i think things set by about the 5th time the fluids are brought up to normal operating temp.

 

I didn't change my trans or diff fluid until I had about 14K miles, when I changed I went to Amsoil synthetics. There was a little bit of grey material on the drain plug, nothing as big as metal shavings.

Synthetic is great once the gears are broken in. A little bit of wear is okay when new as the gears polish each other. A side effect of the wear is increased heat in the gear oil and perhaps some dark grey material on the drain plug. IMHO, if you go to a synthetic too early, the new oil will protect the gears better and it will take longer to finish mating the gear surfaces. The side effect is that the synth oil will take the brunt of the abuse between the gear teeth (as designed) and will run warmer than normal. Not a problem on the street, could be an issue if you get into HPDEs. A potential problem under intense use for gears not totally broken in is thermal runaway, where the oil gets hotter and hotter and just cannot expel heat as fast as it is being absorbed from the gear surfaces. Eventually the oil starts to break down and your protective barrier is gone. But that would only happen under extreme use that most of us will never see.

Not a bad idea to change case oil early, but I would go with dino, like Castrol, and wait until 6-10k miles before switching to synthetic.

Everyone has an opinion...

 

same

 

Thanks for the replies. I lean toward the earlier change, thinking the wear will have taken place within the first 500 miles, but it is always a good idea to see what everyone else has to say.

I plan on doing my first engine oil change at the same time.

 

I don't know about the gears, but on mine the shift mechanism didn't really wear in until about 2000 miles. By then 1-2-3-4 became buttery smooth. I'm a little over 3000 miles now, and 5-6 (which get shifted into less often) are coming around.

Once I get the nerve to crawl under a car supported by four jack stands I'll replace the gearbox and rear end oil with synth. And I'm mulling over the AFE short shifter. Before the stock shifter broke in, I thought it would be necessary.

Ken

 

See Sig.

 

I realize most people either use RP or redline, but what kind of oil do people use specifically. Our manual trans takes gl4 or gl5 and our diff takes gl5, both with 75W-90.

Do people use the gl5 or the gl4 in the transmission?

do we need hypoid friction modifiers?

Would these be the best for RP and Redline?

RP:
diff: max gear 75W-90
trans: Synchromax 75W-90
or is it max gear for both the trans and dif?

Redline
diff: 75w-90 gear oil or 75-90 NS?
trans: MT-90 or 75W90 NS?
Edit/Delete Message

 

this one.

RP:
diff: max gear 75W-90

beers

 

Tip: When installing Gear Box Oil just put it in through the shifter with a funnel if you dont have a pump to pump it into the Trans itself.

 

so funny,

i just had my shifter out on tue.. i was wondering if you could do that... the other option was just tubing it into the bolt in the tranny by way of the shifter hole, not the shifter itself.

have you done this?

beers

 

I am running RP Maxlife 75-90 and good stuff so far. Will keep ya posted on any changes.
As a side note does anyone notice the colors of the RP bottle? Do you know the deeper meaning of this?
Hint: We won 2003 National Championship.

 

The first time i did mine i pumped it in...PIA!!!! i was working on my friends supra and he put it in through shifter. now that i have the rebuilt trany is almost time for me to put back redline fluid and i will definitely be putting it through the shifter. just dont spill any in the cabin...gear oil smell will last forever!