I mixed Synchromesh & MTL : How long before transmission explodes?
 

Finally changed the transmission fluid, I'd put in Redline MTL 6-7 years and 40k miles ago. Drain plug had some metal shavings powder on it, but didn't even cover the magnet at the center. It used to crunch going into 2nd, and going into 3rd required some quick shifting action, but was mostly OK. In fact I think the clutch and shifter linkage were probably what caused the crunching. Anyway, I put in 2 qts of Pennzoil Synchromesh with a funnel and tube, and the stuff was so thin, that I used some leftover MTL I had to make up the remaining 0.6 qt (man, that stuff was thinner still). I had the driver's side jacked up, so I didn't get any overflow; was strictly going by the book spec.

I can't say the shifting improved greatly, but I haven't crunched yet. Fifth was somewhat dodgy to get in... but I'm going to wait a couple hundred miles before I do anything more. Unless somebody says their transmission bought it right after they put Synchromesh in? Haven't seen any long term reports of Synchromesh on this site.. just some saying it is "the bomb." Hope the bomb doesn't blow up my transmission!

just dont try redline's shockproof oil. I put that in and it is great for slamming gears but normal shifting grinds like crazy with it. i think it was a waste of $30

RP synchromax :-)

royal purple

Transmission wont explode so dont worry you can sleep tonight. I would however flush the witch's brew oil as soon as you can simply because you dont know what the mixture is going to do to the seals over the long term and heat, for all we know it will mix into something wierd that causes the seals to shrink and leak. Would get it out and maybe pour in some solvent to flush everything clean and go with the good stuff. Mixing oils is bad yea but not a catastrophe overnight. Remember wet gears are happy gears so long as oil is getting around to keep them cool.

988

MTL is too thin for Mazda recommended weight ranges.
Mazda recommends 75W90 transmission fluid, which Redline has a comparable "MT90".

People have experienced increased noise and crunching when shifting with MTL.


-Ted