Pennzoil Synchro-Mesh and...?

[unDummy]

Just use a gearoil that meets the required spec.
What is the required weight/type that your vehicle needs?

I find that a full synthetic boutique fluid, in the required spec, can give a smooth grind-free shift. I also find that defective or broken transmissions with problems won't be fixed with a fluid change. Also, shifter linkages cables and bushings, clutch linkages cables or hydraulics, and drivetrain mounts cause many shift problems.

Why everyone thinks that they need Synchromesh is foolish. Its is a light oil for those transmissions that require it. It shouldn't be used to replace a 85 or 90wt gear oil.
But, it is a thicker than ATF and possibly an upgrade for manual transmissions that require ATF.

 

[toocrazy2yoo]

Well, mine is a 2005 AccentGT 5 speed. Spec is 75W85. GL4. I see 80W90, and a house brand that Advanced Auto sells that's 75W90 in GL5. I've read that the GL5 isn't for the "yellow" metal synchros this car has. I think they're copper or brass if I recall the threads I've read.

The 50/50 blend of 80W90 conventional with the Pennzoil Synchromesh supposedly puts the mix right at 75W85.

 

[TooSlick]

Redline MT-90
Amsoil 75w-90, GL-4
Castrol Syntorq

A top tier, synthetic transmission fluids will last for 100k miles under normal use. So it makes sense to get the good stuff. I ran the same Amsoil 80w-90 gear lube for 11 years and 120k miles in my 1985 Jetta and it hardly discolored. I'm sure RL would hold up extremely well also....

TS

 

[unDummy]

If it requires a 75w85, use OEM, Castrol Syntrans, or Specialtyformulations MTL-P products.

Good luck finding the Pennzoil 'GL4' products. They are rare in the local stores here(but available online).
And, since you want better shifts, stick with the Pennzoil synthetic GL4 if you want to blend your own 75w85 fluid, or lean out the 80w90 Gearplus to only 25-33%.

I would try a mix of Redline/Amsoil 75% MTL/MTF and 25% MT90/MTG.

Notice that I don't jump on the 50:50 bandwagon. 85wt gear oil needs to be 11-13.5 CST. Use your calculator!
Going a little higher % on the thinner fluid for easier shifting and better cold performance. Go higher % on the thicker fluid if you want better protection(for hot weather or if engine is modded for power).

You could probably get away with the straight MTL, Synchroglide, or MTF. These fluids are just a tad thinner than an 85wt. But, they are using the better basestocks and additives, and should protect just as well as an OEM 85wt.

 

[toocrazy2yoo]

A few folks in my search mentioned Quaker State GL-4 conventional 50/50 with the Synchromesh for the manual transmission. All I'm finding is GL 5 in various and sundry brands.. I can't really find anything that indicates the difference in real terms between GL4 and GL5. Hyundai thinks it means something, they spec and emphasize GL4.

Anyone find a combination that gives a smooth shift, no grinding and good sync when downshifting?

 

[W115nut]

Hi there,

I would not worry about 80W90 or 75W85 etc. Just make sure you use GL4 oil. After all, the 75W85 has different viscosity at different ambient temperature.

My recommendation for you is to use dino and change every 30K if you can find dino. Otherwise, MT90 should be good. I would not mix two different oils. This is not antifreeze.

Virginia is not that cold. You can only take advantage of the synthetic a few days at most. There is a Redline dealer gas station in Nova, Alexandria or so. I used buy MT90 from him.

W115nut