The 90 4door Montero that I recently bought to replace my V6 Raider is driving better in every way except for the transmission. 2nd gear is really irritating me. Recent posts indicate that I am far from alone. Anyway, I have seen Red Line MTL recommended to smooth it out. It certainly makes my Miata happier (2nd synchro worn out there too; both vehicles over 100,000 miles), but I have also seen posts that indicate GL4 to be very bad for Montero synchros. Those posts said GL5 is needed. Checking the Red Line web page, I see that MTL is a GL4 lubricant.<P>Comments? Recommendations?<P>Thanks,<BR>-Rod
Nope you got it wrong. GL4 are preferred anytime a syncros are present. At least on Japanese manual tranny. <P>GL5 are preferred for Hypoid gear use such as differential gear. <P>You would be fine with MTL or MT-90. Use MTL if you live in colder climate, Use MT-90 if you live in warm climate.
GL5 will eat up your synchronizers,as they are bronze. I couldn't find any in my area,and use 20w50 motor oil with great results. I'm sure that I will get some feedback on this,but the shifting improved a lot,and after 350,000 miles,that's good.
Sta Lube (?) At NAPA is the only GL-4 lube I have found on the shelf. Stay away from any that say GL-4 & GL-5 compatable, they are Gl-5 oil, admittedly a better high pressure gear lube, but hard on synchros. There has been lively debate here about this, but Mitsu directly specifies GL-4 for the x-fer case with GL-5 for the diffs, must be for a reason.
1995 SR, dark blue, cloth seats, flare and cladding delete, 10 Guage custom skid plates, ham radio
I keep reading the same thing about GL-5 and brass synchros. I'm glad I did some research because both My user manual and factory service manual specify "GL-4 or higher" for all fluids. Guess I'll order a few quarts of MTL or MT-85, or go cheap with a jug of the StaLube 85-90, seems a little thick but reviews are good. The old stuff in there now takes a few mins to warm up when it's freezing anyway (prolly used the same stuff last time, but that was a loong time ago when i first got the truck).
Last edited by Maciek; 01/25/1710:24 PM.
'88 Raider - 250+K | 2.6L G54B; no balance shafts, non jet-valve head, ARP head studs| Weber 32/36 DFEV | Pacesetter 4>1 | 2 1/4" magnaflow | 32" BFG A/T | 2" bar crank & add-a-leaf | +2 SkyJackers | bumpstop del | Optima Yellow-Top | Curt GenII receiver
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