Tranny & Diff flush

Royksopp · 10-31-2011, 12:47 PM

Just wondering how often should you change those fluids, and best fluids to go with.

sproule905 · 11-01-2011, 07:48 AM

every season.. OEM for both. others may say this or that, but OEM is fine.

bmw tranny oil is red. diff is thick but golden in colour.

SiR · 11-01-2011, 09:00 AM

lol iirc the bmw trans oil is ridiculously expensive.

mobil 1 synthetic atf over here. relatively cheap and easily available. redline in the diff.
I have some d4 atf for the trans I got on sale for the next round. but have been quite happy with the mobil 1.

stay away from royal purple for the diff as there seems to be very strong evidence of diff failure with that fluid.

and every season is a bit excessive...depending on what you are doing with the car.

ScotcH · 11-01-2011, 10:15 AM

Quote:

Originally Posted by SiR

lol iirc the bmw trans oil is ridiculously expensive.

mobil 1 synthetic atf over here. relatively cheap and easily available. redline in the diff.
I have some d4 atf for the trans I got on sale for the next round. but have been quite happy with the mobil 1.

stay away from royal purple for the diff as there seems to be very strong evidence of diff failure with that fluid.

and every season is a bit excessive...depending on what you are doing with the car.

We've used Royal Purple in tranny and diffs for 4 years of racing now ... absolutely no issues with either. Anecdotal evidence is not a cause for alarm.

Btw, every season for a street car is WAY WAY WAY too often. BMW calls these lifetime fluids, and while I wouldn't go so far, probably 50k intervals is plenty. If you feel like getting dirty, go for it ... otherwise, leave enough alone.

kenmar · 11-01-2011, 09:16 PM

Quote:

Originally Posted by SiR

redline in the diff...stay away from royal purple for the diff as there seems to be very strong evidence of diff failure with that fluid

The opposite experience here. When I got the car, changed tranny oil to Redline MTL and the diff oil to Redline 75w90. A few years later, the bearings in the diff went south. Switched to RP 75w140 and it's been fine since.

Currently using Redline MT-90 in the tranny to prevent LTW flywheel chatter. Seems fine.

Axxe · 11-01-2011, 07:34 PM

I typically do my diff and trans right when i get the car, then about every 5 oil changes after (40k). Might be more often than needed but I like the peace of mind.

Royksopp · 11-01-2011, 07:41 PM

sweet, awesome to know guys!!

BmW1819 · 11-01-2011, 08:42 PM

yea older bmw's say 80,000 every inspection 2

doogee · 11-01-2011, 08:47 PM

I've also been running Royal Purple in my Transmission and LSD for almost 150,000km.

No issues whatsoever.

SiR · 11-01-2011, 11:28 PM

lol I knew there were some RP humpers here. You are more than welcome to use what youd like. Still doesnt take away from fact that there definitely is strong evidence pointing to it causing diff failure. No other fluid has this correlation at such levels. Doesnt mean it will happen to you but the percentage definitely is higher and with so many products...I dont see the point in using it. But as I said you are more than welcome to run it. use olive oil. I dont care.

doogee · 11-01-2011, 11:47 PM

Quote:

Originally Posted by SiR

lol I knew there were some RP humpers here. You are more than welcome to use what youd like. Still doesnt take away from fact that there definitely is strong evidence pointing to it causing diff failure. No other fluid has this correlation at such levels. Doesnt mean it will happen to you but the percentage definitely is higher and with so many products...I dont see the point in using it. But as I said you are more than welcome to run it. use olive oil. I dont care.

Where is this "evidence" you speak of? Besides some thread on the internet.

You do realize how large of a company Royal Purple is? How popular their oils are in racing? They aren't new to this.

SiR · 11-02-2011, 09:11 AM

I love your stance...somehow just because its posted on the internet means it holds no water or didnt happen....yet you constantly post up on these very forums. I guess your car has never seen a race track then...

the evidence is out there and not just from bmws.There seems to be a higher failure rate running the fluid in the diff...of course no study has been done(though that amsoil test shows it not doing very well...though funded by amsoil) and as I said you are free to use what youd like, but with the plethora of options I have no clue why you would use it in your diff....just on the off chance that the correlation actually holds true. The rate of failure seems higher running that fluid. You cant deny the rate of complaints. I wouldnt bother with it.

Ive also heard of sponsored teams filling their drums with other product while leaving the sticker on...now that definitely is a rumour.... but that kind of behaviour wouldnt surprise me.

I choose to not use it in the diff.

doogee · 11-02-2011, 10:58 AM

Quote:

Originally Posted by SiR

I love your stance...somehow just because its posted on the internet means it holds no water or didnt happen....yet you constantly post up on these very forums. I guess your car has never seen a race track then...

the evidence is out there and not just from bmws.There seems to be a higher failure rate running the fluid in the diff...of course no study has been done(though that amsoil test shows it not doing very well...though funded by amsoil) and as I said you are free to use what youd like, but with the plethora of options I have no clue why you would use it in your diff....just on the off chance that the correlation actually holds true. The rate of failure seems higher running that fluid. You cant deny the rate of complaints. I wouldnt bother with it.

Ive also heard of sponsored teams filling their drums with other product while leaving the sticker on...now that definitely is a rumour.... but that kind of behaviour wouldnt surprise me.

I choose to not use it in the diff.

When did I said I didn't believe anything that's posted on the internet?

Why do you have to get all butt hurt because I asked for evidence? For some reason you take most peoples posts as an attack when they clearly are not.

I asked for evidence because that's something I have to see in order to believe something 100%. That's just me being rational! Things that get tossed around on forums doesn't count for me because I can go anywhere and post any bullshit I want and people will believe it too.

This is the same reason people are religious. "The evidence is out there"

Okay so go find it and bring it to me and I will gladly say you're correct on the subject!

sproule905 · 11-03-2011, 08:44 AM

Quote:

Originally Posted by doogee

When did I said I didn't believe anything that's posted on the internet?

Why do you have to get all butt hurt because I asked for evidence? For some reason you take most peoples posts as an attack when they clearly are not.

I asked for evidence because that's something I have to see in order to believe something 100%. That's just me being rational! Things that get tossed around on forums doesn't count for me because I can go anywhere and post any bullshit I want and people will believe it too.

This is the same reason people are religious. "The evidence is out there"

Okay so go find it and bring it to me and I will gladly say you're correct on the subject!

+1 - SIR is always in the negative about everything.

BigD · 11-02-2011, 11:51 AM

Quote:

Originally Posted by SiR

I guess your car has never seen a race track then...

Oh snap, you just cracked this bitch wide open. Yep, doggy has never been on the track, neither has Arek.