your opinions, pls. do i need to put LSD additive in to Royal P 75w140...

[ryan roopnarine]

i asked jeff B (aka regal) about it, and he asked if i got any replies before he discusses it with me, (i had only posted at bitog.com, they said no). I bought two litres of royal purple synthetic 75w140 gear oil for my rear end. Seeing as this is a rather thick oil, was wondering if i would still need to add any additive stuff to it...the bottle says "made for LSDs". it cost me about 11 dollars a bottle, so i'd rather not waste it (in either case) if not necessary. thanks.

[632 Regal]

OK, this is my personal oppinion, nothing written in stone for whatever reason k?. That being said.

75w 140 wt is WAY ****in overkill! Just get some synthetic anything 75w 90 thats suited for LSD and forget the additive. as long as its synthetic I wouldnt worry about a thing. If you cant get anything suited for LSD then get an additive, I would try to not utilize any additives to ANY fluids myself.

Is this the grinding rear end car you were bragging about? If so then I can see your effort on the 140 weight in an effort for it to last a bit longer. If not then I think the 140 would put a lot of useless strain on your fuel consumption and not really protect any better.

just my 2¢

[ryan roopnarine]

if you look at my thread from yesterday, i emailed castrol UK and asked them if they could provide me with any assistance as to what BMW SAF-XLS differential fluid is. XLS (the bmw recommended fluid for limited slip) is 75w140 weight. the bmw recommended fill for NON limited slip is a 75w90. I put 75w90 mobil 1 in there a little while ago, and it only helped a tiny bit. again, people over at bobistheoilguy.com said that mobil1 75 is formulated VERY thinly, and may explain why it is still complaining a little. if i'm going to use a 90wt, i'll mail order some redline, which apparently is unmatched in its ability to stop bmw differential chatter. i can't put any in now because no one in orlando carries redline gear oil :(


OK, this is my personal oppinion, nothing written in stone for whatever reason k?. That being said.

75w 140 wt is WAY ****in overkill! Just get some synthetic anything 75w 90 thats suited for LSD and forget the additive. as long as its synthetic I wouldnt worry about a thing. If you cant get anything suited for LSD then get an additive, I would try to not utilize any additives to ANY fluids myself.

Is this the grinding rear end car you were bragging about? If so then I can see your effort on the 140 weight in an effort for it to last a bit longer. If not then I think the 140 would put a lot of useless strain on your fuel consumption and not really protect any better.

just my 2¢

[rph]

...I got my Redline (in NC). Actually it was MTL but they "carry" all the Redline oils. They had to special order it, but they have it in their computer. Of course I had to wait about 4 days for it to ship in, but that's about how long it would take to come from CA, which is where I got mine from previously.


if you look at my thread from yesterday, i emailed castrol UK and asked them if they could provide me with any assistance as to what BMW SAF-XLS differential fluid is. XLS (the bmw recommended fluid for limited slip) is 75w140 weight. the bmw recommended fill for NON limited slip is a 75w90. I put 75w90 mobil 1 in there a little while ago, and it only helped a tiny bit. again, people over at bobistheoilguy.com said that mobil1 75 is formulated VERY thinly, and may explain why it is still complaining a little. if i'm going to use a 90wt, i'll mail order some redline, which apparently is unmatched in its ability to stop bmw differential chatter. i can't put any in now because no one in orlando carries redline gear oil :(

[ryan roopnarine]

i was just in advance in gainesville, fl today, and asked them if they could order mobil 1 75w140, and the gentleman told me "the only oil we can obtain is the selection that's currently on the shelves." guess i'll have to go to another once i'm in orlando. it might just be "comforting" for me, but if this new stuff comes out of the diff looking dirty, i might just "flush" it out with walmart cheapie stuff before i put the molasses in.

[ryan roopnarine]

and progress marches on......(1989 oil vs. 2004 oil)
went to look at the stats on the factory fill/vs the royal purple 75w140

castrol/factory http://amtulld001.bp.com/bpglis/lubtds.nsf/e1cd48f22cd02c6280256dff00509ca4/097303f7f75683b080256cbf00353e21?OpenDocument

Viscosity @ 40ºC ISO 3104 / ASTM D445 mm2/s 177
Viscosity @ 100ºC ISO 3104 / ASTM D445 mm2/s 25

royal purple aka molasses
http://www.royalpurple.com/prodsa/mgeara.html

Viscosity

cSt @ 40 245.0
cSt @ 100°C 33.6

thick stuff, but most other 75w90s don't come close to matching the range. i'll just say, that, if i have to get a new diff for this car, the RP 75w140 or redline 75w140 is going into it.

[rph]

.... I could get it in my zipcode area in NC, Advance Auto came up all over the place. Further, the folks in the AA store I got mine had a Redline promotional flyer done in grubby paw-resistant plastic, with all their products on it. In fact they only had a few lines in stock, like engine oil, and water wetter, and something else I forget. The only difficulty I had was I couldn't get the manual tranny oil on overnight order, as I said, it had to be special ordered, and those orders only come in on Thursdays (here).


i was just in advance in gainesville, fl today, and asked them if they could order mobil 1 75w140, and the gentleman told me "the only oil we can obtain is the selection that's currently on the shelves." guess i'll have to go to another once i'm in orlando. it might just be "comforting" for me, but if this new stuff comes out of the diff looking dirty, i might just "flush" it out with walmart cheapie stuff before i put the molasses in.

[DanDombrowski]

are you buying a box of it, or just enough to do your 2 quarts?

[DanDombrowski]

oh, and did you determine if it has an LSD in it or not?

[ryan roopnarine]

i went down to the carquest on the corner, and bought two bottles of the RP stuff for about 11/each after tax. RP seems easier to get to than redline....i was gonna buy some redline from jegs or summitracing, but they sell it for about 7.95 per, plus an 8 dollar handling fee, so it works out to be about the same as if i bought it locally.

and if you read this thread

http://www.bimmer.info/forum/showthread.php?t=5451

you will see i've found the tag for my diff, and it said S4.10 (the S means lim. slip). hence my deluded insistance on trying the 75w140.

[DanDombrowski]

Interesting. I'll have to get under the car and check to see if I have limited slip before I do my gear oil then, wouldn't want to get stuff thats too thin. IIRC though, I'm pretty sure I only feel my right wheel spinning in wet weather, so I don't think I have one. Only one way to be sure.

It will be awhile before I'm able to check, I'm coming up to gville tonight to move my stuff, but Im leaving straight from work and I have the girlfriend's Camry right now, so I won't get to see my REAL sweetheart until next week.