Stocker

Hyundai recommends

All the cool kids here know we should be using Redline MT90 GL4 for ultimate smoooooooth shifting ACTION! I was getting set to order some and I read this on the product webpage:



(and by the way, the Redline application guide calls out MT-85 for our transaxles)



So before they open for business tomorrow and I call them up, has anyone else contacted Redline and asked specifically about our cars? Yes, the gearbox would be fine with MT-85 or MT-90, BUT the oil is also sloshing around in the (hypoid) differential gear set.



The alternative by the way is to go with Royal Purple's recommendation for "API GL-4 or GL-5: 75W90, 80W90" applications:

Royal Purple is about the same price and specifically recommended for the application. You know, I think I just convinced myself. RP shifts fine for me and it is recommended for the application. Maybe I'll still call Redline and ask anyway.



Note: this thread is not intended to be a "I used xxxxxx oil and it works great so far" topic. IF you have asked Redline if their oil will work in our differential, contribute please. Otherwise, feel free to refrain from all mention of ATF, regular engine oil, or synchromesh.

187sks

I have not heard of anyone calling. I have never seen MT-85 on a shelf. For what it's worth my synchros are almost shot to the point that I'll replace the trans, but it shifts far better cold than warm with MT-90. That would seem to indicate that thinner is better with all else being equal. It would be interesting to see how MT-85 fares. The other properties of the lubricant seem to be more important than the viscosity ratings.

Stocker

Dave at Redline says:



Hyundai specified a GL4 which (being a GL4) is already suitable for zero and low-offset hypoid gears. Because it is transverse mounted there is a very low likelihood of having a hypoid gearset anyway. Sometimes "hypoid" is in the eye of the beholder and the differences can be slight. I seem to recall that there IS a hypoid gearset, but if someone has a photo of the insides of a differential still assembled that would be a good thing to add to this discussion. With low-offset hypoid gears the stress is MUCH lower than with extreme interface angles so their plain GL4 (MT-90/MT-85) would be suitable.



MY take-away message: "we don't really know, but you'll probably be fine." I think I'll go with Royal Purple who specifies their oil for use with a hypoid gear set.

BetaRD2

well i ve had MT90 in my RD2 for over a year now and it has worked great, it shift nice cold and better when it warms up



it also solved 3 issues i was having when i had mobil1 synthetic, MT90 eliminated grinding when upshifting at high rpms from first to second gear and fourth to fifth gear and it also eliminated grinding when downshifting from fourth to third gear also revers engages better now



bottom line it has worked wonders for my trans so i endorse it

WytchDctr

I have a beta trans sitting outside that sings in third gear (a little in 2nd) after using royal purple and it shifted like crap in are , ummm harsh?, winters on the gulf of mexico. I would go with whatever the dealership runs before I dump RP Maxgear GL4/5 in my trans again.

larryinkc

The Tib manual tranny doesn't have hypoid gears and GL5 gear oil is not good for the synchro rings in a manual transmission.



You should only use a GL4 lube in manual transmissions that have synchronizers.



I have bbeen using Redline in mine for 60,000 miles and it still shifts greatn no grinding at all.



Here's a Hyundai maunal trans teardown video and some pics of the inside





http://video.google.com/videoplay?do...8004811197423#





http://www.newtiburon.com/forums/sho...d.php?t=173016

Stocker

+ and thanks larryinkc for that. It looks like just a bigger gear of the same type, definitely not a hypoid set, so that's good to know.



After seeing that and knowing what I know now, I would be confident buying Redline MT-85 or MT-90 a couple of years from now . . . as I just bought my 3 quarts of silly-expensive Royal Purple yesterday.

pas1216

I run Redline MT-90 in my car...... now I'm a little worried and a touch confused

Loneshark

when i did the auto the manual swap i filled her up with MT-90 and drove around for 30k miles. the trans was a dream to shift... until my stock motor mounts cracked at the 8th mile drag strip, which caused severe transaxle shake during the launch, which led to snapping BOTH halfshafts at the differential immediately after take off.... dumping all of the MT-90 on the track. The clean up crew said is was like cleaning molasses off the track, they actually came up to me and asked me what fluid i was running because it was such a b*tch to clean up ! LOL, they were real cool tho, and gave me a free tow back home.





but MT-90 ran great !

Stocker

pas1216 feel free to skip the "worried and confused" stage and skip right on ahead to "confident use with no worries." GL4 MT-90 is appropriate for use in this transaxle and has many, many reports from happy member/MT-90 users.