Synthetic or conventional oil for 4WD Manual?

[Psamtik2002]

Hi Guys, I'm just about ready to do my final drain and refill on the manual tranny in my 4WD All-trac wagon, having completed an auto-rx cleaning. I remember reading something in this forum that synthetic gear oil caused chattering or something along those lines, and that plain conventional oil worked best. I was considering amsoil severe gear, but I want to hear from you guys what you're running and what your experiences have been. Thanks!

[eage8]

Originally Posted by Psamtik2002

Hi Guys, I'm just about ready to do my final drain and refill on the manual tranny in my 4WD All-trac wagon, having completed an auto-rx cleaning. I remember reading something in this forum that synthetic gear oil caused chattering or something along those lines, and that plain conventional oil worked best. I was considering amsoil severe gear, but I want to hear from you guys what you're running and what your experiences have been. Thanks!

as long as it's the right type and weight you can use whatever, I used mobile 1 during my last refill, and it was a night and day difference compared to the crap the shop that did the clutch install used.

I plan on using Redline MT-90 when I fill up my transmission when I'm done the 20V swap. I'm running that in my rx7 right now and like it.

I'd probably recommend synthetic though since you don't usually change your transmission oil very often

[DCM]

My ae95 has lasted 270K with regular gear oil, so I don't feel the need to use synthetic. It's not a race car.

[Flashmn]

Synthetics arent there for RACE purposes, synthetics help keep the oil from stiffening during winters aswell as other better properties.

[j2b4osan]

the amsoil should be fine but synthetic wont hurt either as long as its the correct weight and spec (gl-2, gl-3, gl-4) sometimes the newer gl's negatively affect the tranny on older cars. for example if there are any yellow metals in the tranny(syncro's and such) gl-5 is a no no because it corrodes softer yellow metals. use what the manual calls for.

[eage8]

Originally Posted by j2b4osan

the amsoil should be fine but synthetic wont hurt either as long as its the correct weight and spec (gl-2, gl-3, gl-4) sometimes the newer gl's negatively affect the tranny on older cars. for example if there are any yellow metals in the tranny(syncro's and such) gl-5 is a no no because it corrodes softer yellow metals. use what the manual calls for.

I think the manual states either GL-3 or GL-4 is fine.

[DCM]

Originally Posted by Flashmn

Synthetics arent there for RACE purposes, synthetics help keep the oil from stiffening during winters aswell as other better properties.

Yeah I know; my point was that it's a grocery-getter, that's all. Synthetics are produced for good reason, but I don't feel justified in spending the extra $ for this particular car.

[eage8]

Originally Posted by DCM

Yeah I know; my point was that it's a grocery-getter, that's all. Synthetics are produced for good reason, but I don't feel justified in spending the extra $ for this particular car.

how much money do you actually save though? mobile 1 is like $7 a quart? x 3 is still way less than an oil change...

[datsa]

Originally Posted by j2b4osan

the amsoil should be fine but synthetic wont hurt either as long as its the correct weight and spec (gl-2, gl-3, gl-4) sometimes the newer gl's negatively affect the tranny on older cars. for example if there are any yellow metals in the tranny(syncro's and such) gl-5 is a no no because it corrodes softer yellow metals. use what the manual calls for.

My shop manual calls for API GL5, although the transmission is supposed to have a synchromesh gearing. Do these conflict?

[Rookie_One]

if toyota say use GL5, shutup and use it

[PhatRoyale]

Just use what's stated in the manual, but get the synthetic alternative from a company like Redline or AMSoil.