BMW M5 Forum and M6 Forums banner

201 - 220 of 222 Posts

·
Registered
Joined
·
1,285 Posts
Its more than that. Its too thick to let the synchomesh do its job. Imagine sandpaper covered with thick oil. Sandpaper doesn't work. Same concept. When trans oil gets older people notice it take much much longer to thin out.

Agreed, I should have elaborated. I don't believe in lifetime fluid, especially when I plan to drive my car to high miles (above 200,000), or until it no longer makes sense to do so. So I figured I would change my trains fluid every 60k miles. Since I don't like the RP in the cold anymore, I'm probably going to change it again soon to something different.
 

·
Registered
Joined
·
395 Posts
I should elaborate on something as well.

MT90 damaged my Getrag V160. I don't know what the tolerances are like on this car's, but MT90 is intended to be GEAR oil. As in diff fluid. It's not intended to be used in any way EVER with synchros. If MT90 works for more than oneof you guys with absolutely no issues then I take it back. MT90 damaged my other Getrag and I'll never let that go!
 

·
Registered
Joined
·
6,014 Posts
MT90 is designed to be manual transmission fluid, it is just not the right specs for the M5's transmission.
 

·
Registered
Joined
·
111 Posts
In my opinion its not wise to switch to some "random" transmission or differential oil without real knowledge of the possible negative effects. I understand the need for constantly finding "better" oil and parts, but it would be wise to get information from a credible source first. Of course if the manufacturer tells that its applicable for the use, then it should be. Just wouldn't want to trash a perfectly good transmission for instance. :confused2
 

·
Registered
Joined
·
395 Posts
MT90 is designed to be manual transmission fluid, it is just not the right specs for the M5's transmission.
No, its not. Call a transmission rebuilder. If its made to be transmission fluid it would say it is compatible with synchos in some way. If its made for your diff they call it GEAR oil because its for gears only - and not synchros. Come on Rob! You know better. Or is that why yout T-56 shifts like a rubber mallet attached to a shift folk??
 

·
Registered
Joined
·
6,014 Posts
No, its not. Call a transmission rebuilder. If its made to be transmission fluid it would say it is compatible with synchos in some way. If its made for your diff they call it GEAR oil because its for gears only - and not synchros. Come on Rob! You know better. Or is that why yout T-56 shifts like a rubber mallet attached to a shift folk??
I wonder what the "MT" stands for? oh yea, Manual Transmission :rofl:

I'll call RedLine instead Red Line Synthetic Oil - Gear Oil for Manual Transmissions - MT-90 75W90 GL-4 Gear Oil

which goes out of its way to tell you just how great it is for syncros.

My transmission shifts very well thank you, probably because it has the proper Dexron III ATF that is specified for it ;)
 

·
Registered
Joined
·
395 Posts
-_- you're right. It is for manual transmissions. Ones that don't have really tight clearances like almost any Getrag. I retract my statement about it not being for manual trans synchros however I haven't seen a transmission ywt that has like 90w oil in it vs T-IV ATF type weight oils. Matter of fact Toyota T-IV is what a large portion of folks run on the V160 when they want to clean out the old getrag synchro oil.
 

·
Registered
Joined
·
529 Posts
In my opinion its not wise to switch to some "random" transmission or differential oil without real knowledge of the possible negative effects. I understand the need for constantly finding "better" oil and parts, but it would be wise to get information from a credible source first. Of course if the manufacturer tells that its applicable for the use, then it should be. Just wouldn't want to trash a perfectly good transmission for instance. :confused2
It's not a "random" selection method. There are a lot of threads on here with varying opinions/testing. Consumable parts wear out. What tires are you running on your M5? Pilot Super Sports, Conti extremecontact DW, PS2? Either way, why would you not run the factory rubber that came on the car? Because they make better tires in 2014 than they did in 2000. A similar mindset is applied to fluids. If you only want to put what BMW tells you to put in, that's perfectly respectable. But, straying into other fluids doesn't inevitably lead to exploding transmissions.
 

·
Registered
Joined
·
395 Posts
It's not a "random" selection method. There are a lot of threads on here with varying opinions/testing. Consumable parts wear out. What tires are you running on your M5? Pilot Super Sports, Conti extremecontact DW, PS2? Either way, why would you not run the factory rubber that came on the car? Because they make better tires in 2014 than they did in 2000. A similar mindset is applied to fluids. If you only want to put what BMW tells you to put in, that's perfectly respectable. But, straying into other fluids doesn't inevitably lead to exploding transmissions.

https://www.youtube.com/watch?v=WHads6dI26Y&feature=youtube_gdata_player
 

·
Registered
Joined
·
12,866 Posts
MT90 is designed to be manual transmission fluid, it is just not the right specs for the M5's transmission.
Let me dig out my records, it might have been MTL, but I thought it was MT90. I don't want to be giving out wrong info.

Regards,
Jerry
 

·
Registered
Joined
·
111 Posts
It's not a "random" selection method. There are a lot of threads on here with varying opinions/testing. Consumable parts wear out. What tires are you running on your M5? Pilot Super Sports, Conti extremecontact DW, PS2? Either way, why would you not run the factory rubber that came on the car? Because they make better tires in 2014 than they did in 2000. A similar mindset is applied to fluids. If you only want to put what BMW tells you to put in, that's perfectly respectable. But, straying into other fluids doesn't inevitably lead to exploding transmissions.
Yes I see your point, but even if the "better" oil seem to work well it still might e.g. trash your synchros in long time use. So I meant to make people think before switching to stuff that was recommended by some dude on internet. Let's not take tires in to this discussion. Those won't ruin your car permanently. ;)
 

·
Registered
Joined
·
197 Posts
Very old thread this, but did 'we' ever reach a conclusion? I'm looking for which oil to use in my Getrag 420G for an E34 M5. I'm confused :)
It's still a bit a matter of opinion, but here's my reasonably unbiased take on the topic:
You can't go wrong with factory-speced BMW fluid, but with cost/availability it's also fine to use one of the different options. I don't bother with, but can say nothing against it either.
A lot of people like Royal Purple Sycromax, but I think it should only be used in cold climates, as it's viscosity is on the thin side (7.5 cSt @ 100C). Also fine in the manual transmissions that speced ATF (like my 540i called for).
I personally use Redline MTL in every one of my BMW Getrag transmissions. Works wonderfully in my '75 2002 (with brass syncros) and so I've just stuck with it for my other cars. Thicker (10.4 cSt @ 100C) so first few cold shifts are a little more sluggish, but I believe the higher viscosity provides better wear protection. I've also run a 50/50 mix of MTL/ATF in the 540i which was fine too, but think I still prefer just straight MTL.
Redline MT-90 is REALLY thick stuff (15.5 cSt @100C) and intended for a lot of Japanese transmissions, but I think it's too thick to work well in Getrag boxes. Unless it's a track car in a hot climate, in which case you might want the thicker stuff for better protection, but still, I don't think it would shift for crap and might even be too thick to flow nicely everywhere it's supposed to go, so unless a tracker can give us some additional evidence, I'd stay away from MT90 in favor of MTL.
 

·
Registered
Joined
·
191 Posts
Very old thread this, but did 'we' ever reach a conclusion? I'm looking for which oil to use in my Getrag 420G for an E34 M5. I'm confused :)
I can't comment on MTL in the 420G, I used it in my old BMW which had a Getrag 265/6 and it worked fine. My M5 had royal purple syncromax when I bought it and after about 50k on that fluid I flushed it out for Pentosin FFL-4. This is technically "DCT" fluid but it superseded the factory fill on the older M cars. I can say my shifting effort is reduced and changes are smoother.

I don't see a reason to use other fluid right now

 

·
Registered
Joined
·
406 Posts
Ravenol 75w80 is also very close spec-wise to Pentosin MTF-2 (no longer available). I've been using this in my M5 for the last 35k miles or so (just changed it at 30k miles and it was still shifting well).
 

·
Registered
Joined
·
12,866 Posts
For what it is worth, I have been using MTL for quite some time.

Years ago I did a swap of original BMW "lifetime" fluid to the newer BMW recommended MTF-2. Lousy. No better than the old MTF-1 fluid I took out.

So on the advice of some racing buddies, switched to MTL. Immediate difference, everything shifts smoother. Started using MTL in other high performance cars. Car still shifts smooth thousands of miles later.

Regards,
Jerry
 

·
Registered
Joined
·
406 Posts
Has anyone used Redline MTL in winter? (real winter, not CA/FL winter) I tried Motul Gear 300 in my RS4 once and it was far worse in cold weather than the stock fluid. Made it very difficult to get into 2nd gear until warmed up. Point is, the high performance fluid might be great in mild weather but is not necessarily better year round.
 

·
Registered
Joined
·
2,497 Posts
Good advice here. Back on page 1? I think of this thread, LCSMAN (a respected member when he was around) described the Royal Purple very well - it quick shears/loses protection properties after a few thousand miles. I can attest to that, as I ran syncromesh or whatever they call it, for a few of the many trans oil changes I've done to my M5 420g over the years. I've personally put about 180,000 miles of the 280,000 -ish miles on this transmission. The Royal Purple starts out amazing, but after a while it goes to crap and is like water when draining it. Before the Royal Purple and ever since then, I've just run 80/90 weight synthetic gear oil. Usually Mobil 1, but the latest fill was Valvoline 80/90. I change the fluid roughly every 50k miles, onvce or twice I changed it more frequently because the trans was out for a clutch or I was about to drive around the USA.

As a related side note, I ran Royal Purple gear oil in the differential for a stint. When it came time to change, it was still purple and looked pretty good. For cost/availability reasons, I've pretty much stuck with Valvoline synthetic 75/140 limited slip. No issues pounding the miles on the car with that oil either.

Final note - I live in the northeastern part of the USA. We see subzero temps in the winter sometimes and up to 100F on rare occasions in the summer.
 
  • Like
Reactions: ND4SPDLSC
201 - 220 of 222 Posts
Top