best tranny fluid combo

[eric91gst]

Hey I just wanted to see what you guys were running. I am currently running all penzoil syncromesh but it seems too thin. Shifting has improved a little since the weather has gotten hotter. I just wanted to see what mix I should run with the syncromesh, instead of running it just straight. Thanks

 

[JackM]

That fluid is terrible! We recommend the factory Mits oil. BG and Penzoil will wear down gears, cause fretting of the intermediate shaft tapered roller bearings, cause serious 3/4 fork wear on 2Gs and burn through the gear-to-hub thrust surfaces for 1st and 2nd. They shift well with those fluids, because they cause so much friction in the trans. You want a fluid that will be able to not only work as a lubricant, but allow the synchro blockers to opperate properly. The original Mits gear oil has the perfect blend of modifiers to not only get long life against wear, but the synchro blockers will also work their best. Shoot, it is from the company the designed your trans, so you would think they know best. We (www.jackstransmissions.com) recommend using the 3rd gen Eclipse 6-speed manual Mits brand oil from the dealer. It seem to be the best on the market and we NEVER had a gear or bearing failure using it. Also, we have tried just about every oil on the market and the synchros seem to be happiest with that oil too. We have also tried blends with some success, but the Mits oil still works better. The next best oils IMO are Mobil 1 full synth, and Redline MTL gear oils. If your trans is grinding or notchy with the oils we recommend above, then you need a rebuild. Putting an oil in there that will create so much friction will just cost you more money in the long run.

Jack
www.jackstransmissions.com

 

[Raph]

I use (as well as other people i know ) Castrol SMX-S 75w-90 .. misubishi says its ok to use ..soo (at least here they do) make sure to get a gl-3/gl-4 (has to meet gl3 and 4) oil..

Gl-5 oils (newer oils) have different ingredients used (these actually give more "bite" to the synchros and gears) esp. for LSD trannys.. these cause too much friction in our older trannys.. and will inevitabley cause increased wear.

Cliff notes : NEVER EVER USE GL-5 GEAR OILS ..our old cars wont handle it! ie..read the bottle before hand.. if you dont understand whats on the bottle..ask someone..or ask the manufacturer.

 

[Dagda]

syncromesh works great for me, but then again i have a shep tranny. u say it feels too thin?

 

[RamenPride]

The next best oils IMO are Mobil 1 full synth, and Redline MTL gear oils.

If I recall correctly, Mobil 1 full synth is GL-5 rated. I'm not sure why you would say it's the next best when it shouldn't even be used in the first place.

I used Redline MTL one time and when I changed it out it smelled like rotten cheese and felt like it was full of sand.... I've had no problems with BG Syncroshift or Pennzoil/GM Syncromesh

 

[jking29]

I have a mixture of one quart Redline shockproof light and topped off with BG synchroshift. I have been running it for over a year. The trans shifts like butter and I have had 0 problems. It is the combo that AMS recommended.

 

[THE REAL DEAL]

i was using straight synchromesh in mine because i thought it might get rid of my grind in third gear. just made it worse. so now i'm running some 80w-90 valvoline synth and it's a lot better. it's GL-5 but the owners manual says "GL-4 or higher" and my chiltons says GL-5. if it makes it worse, so be it. i think my 3rd gear synchro is going out anyhow. synchromesh is too thin but there's been people on here who have had no problems with it.

 

[Defiant]

Another transmission fluid thread?

No.