Royal Purple Syncromax in Getrag 420g 6 speed

[daveyto]

Can anyone please tell me what fluid I should use in my 6 speed transmission for my 540i 2003?

IS it ATF? Or Gear oil?

Can I use Syncromax?

And what can I use in my dif to replace BMW LT2?

Regards

[BMVV]

I think there is a sticker on the trans. oil pan for each car.

[daveyto]

I can't the find the sticker on the dif but the tranny was LT1. I substituted synchromax from Royal Purple and so far no difference in shifting.....we'll wait and see.


Dave

[MLue1]

Originally Posted by daveyto

I can't the find the sticker on the dif but the tranny was LT1. I substituted synchromax from Royal Purple and so far no difference in shifting.....we'll wait and see.


Dave

I just recall seeing a post that you posted in another thread, indicating that you have a LSD... you can cause damage with the use of fluid that is designed for open diffs. Redline makes diff fluid for both LSD and open diffs.

[daveyto]

Hi Mark,

I read the post from Dave Zechhausen and a rep from Royal purple on Bimmerfest, extensively. according to them Syncromax is a direct replacement for LT1 or LT2. Which accordin to Royal purple are transmission based lubricants. The diff is gear oil in mine i belive. This is what Dave puts in his BMW race cars.

After a chemical lab analysis of The BMW fluid there was was nothing special in it or any of BMW fluids which apparently are similar to Castrol Syntec products. I chose Royal Purple because I thought it best. I just wanted to not pay the $90 for supposedly "off the shelf" castrol fluids as I was told.

here's royal purple cross reference for the most common auto manufacturers.

I even had my mechanic friend's blessing to use it, sayin it was a "superior" product.

http://www.royalpurple.com/transmission-chart.html

regards

David

BTW...IF you or anyone is interested in the chemical analysis of the BMW fluids...I can dig it up once again

[MLue1]

Originally Posted by daveyto

...After a chemical lab analysis of The BMW fluid there was was nothing special in it or any of BMW fluids which apparently are similar to Castrol Syntec products. I chose Royal Purple because I thought it best. I just wanted to not pay the $90 for supposedly "off the shelf" castrol fluids as I was told.

here's royal purple cross reference for the most common auto manufacturers.

BTW...IF you or anyone is interested in the chemical analysis of the BMW fluids...I can dig it up once again

Thanks David, that's great info, I for one have never though BMW fluids were special.

I use the Redline 75W90NS (NS is for non-limited slip applications)product in my open diff mostly because it's readily available. I use the Redline 75W90 in my other car which has a limited slip diff.

[daveyto]

Hi Mark,

I have heard that if you have a limited slip diff that it requires an "extra" additive.

Have you heard of this?

Also, I spoke to the dealer and they told me that my car has a limited diff after I supplied them the serial number. However, I have heard that the LSD only came on e39 M5's. IS this true?

Any Ideas?


BTW...The Royal Purple feels just as lousy as the BMW LT-1 with respect to gear changes...I guess the guys on Bimmer fest were imagining a "noticable" improvement in shifts. I for one dont feel anything better..perhaps I have to give it more time.
Perhaps the only cool thing about Royal Purple is the color.

[MLue1]

Originally Posted by daveyto

Hi Mark,

I have heard that if you have a limited slip diff that it requires an "extra" additive.

Have you heard of this?

Also, I spoke to the dealer and they told me that my car has a limited diff after I supplied them the serial number. However, I have heard that the LSD only came on e39 M5's. IS this true?

Any Ideas?


BTW...The Royal Purple feels just as lousy as the BMW LT-1 with respect to gear changes...I guess the guys on Bimmer fest were imagining a "noticable" improvement in shifts. I for one dont feel anything better..perhaps I have to give it more time.
Perhaps the only cool thing about Royal Purple is the color.

I take it your car has low milage, if so if the tranny oil was still good I doubt you'd see much of a difference.

With respect to weather you have LSD or not,... there is only one way to say for sure... jack up the rear so both wheels are off the ground, then turn one of the wheels... if the wheel on the other side turns in the opposite direction it is an open diff if the wheel on the other side turns in the same direction you have an LSD.

[daveyto]

Ok, Ill check it out....BTW I have 110k on my car. I don't think its that much but certainly a lot for the BMW "lifetime" fluid.lol

I'll let you know.

Thanks for the info,

Regards