[Rising Sun]

What is the best fluid to use, I thought I may just get some from Mazda? My MX-6 2.5 has done 115000 miles and runs fine but the gears are a little notchy, especially when cold and even more especially in second!

 

[Mike 94PGT]

The factory fluid is a GL-4 or GL-5 75W90 or 80W90 (hot climate) gear oil.

Most people will recommend using Redline MTL or MT-90, a good synthetic replacement.

Next would be Royal Purple and I've heard good things about GM Synchromesh too.

 

[Stage36]

i think that mazda trannies in general arent the best. my blown tranny started with a grinding 2nd gear

 

[lemongopher]

How long did your tranny last with the grinding in 2nd gear.

 

[Stage36]

about 8 months. actually when it blew, i was goin into 2nd but it didnt even grind. maybe the gear was already off the hook

 

[lemongopher]

dang.....i love my 6....it grinds in the morning or whenever it is cold then it goes away. is this the start of my tranny going.........the tranny fells strong.....i will replace the oil in the tranny and see if that helps

 

[Stage36]

if it only grinds when its cold then thats no biggie... thats just the synchros taking their time. mine only grinded when i was speed shifting. To everyone with an MX-6 who races:IF YOU THINK YOUR TRANNY IS GONNA BLOW, START SAVING FOR A PERFORMANCE CLUTCH AND FLYWHEEL, THE BEST TIME TO DO IT IS AT REBUILD TIME. you should already have an account for emergency repairs anyways.

 

[Greg S]

Best bet is to run Redline MT90 or Royal Purple 75W90 gear oil. Make sure the oil is GL-4 rated and not GL-5. Most GL-5 gear oils have sulfer in them which will eat the brass in teh synchro up and really destroy your tranny. If used both of the above and love them. They get rid of the notchiness and make shifting easier.