Effect of gear oil viscosity on transmission efficiency (Metro owners take note)

[TOOSTUBBORN2FAIL]

Originally Posted by Christ

Yep, many manual transmissions call for ATF. I think most Ford transmissions actually call for it, but you can use engine oil as well.

many chrysler mtx's call for atf, but, and this is a big but, it is used to save money. The synchros will wear faster with it, and it will not shift as easy as the correct mopar fluid ($16 a quart) or mobil one 10w30 high mileage. Its very important to use mobil one 10w30 high mileage if you choose to use engine oil, especially in a neon, as the synchros are made of a material called fiberide, and according to oil analysis, only those 2 oils (the mopar stuff and mobil one stuff) have enough zdp to prevent premature wear to the synchros. Mobil one is 99% the same as the mopar stuff.

ive used both royal purple and penzoil synchromesh oils, and neither shifted as smooth as the correct mopar fluid or the mobil one oil

[Christ]

Cool. I'm not personally concerned about synchros, cuz I don't use the clutch anyway, but yeah.

[TOOSTUBBORN2FAIL]

ya, i dont use them much either, 90% of my driving is freeway, but just wanted to make sure i posted in case anyone switches to atf then has problems. Its not really a immediate thing, more like a if you plan on putting 300,000 miles on the transmission thing

regular 75-90 gear oil on the other hand can destroy neon synchros in 5000 miles tho, thanks valvoline oil changers

[bzipitidoo]

Been using ATF in a 1967 4 speed manual Ford for years now. Originally had some heavy oil, might have been as much as 140W. It was getting very hard to shift into 2nd gear. Used to be fine, but then the shift to 2nd became stiff when the car was cold. Got worse, so that 2nd was hard to shift into when warmed up, and almost impossible when cold. Was taking serious force on the gear shift to get it in 2nd.

We switched to ATF, and 2nd gear has been fine ever since. Not sure how many miles we have put on it since switching, but at least 20k.

One thing about differential oil: has to be specially formulated for hypoid gears. Lot of pressure on those. ATF won't cut it.

[stovie]

Does any1 know what the viscosity of lucas oil additive is because it says if u put all lucas in ur differential it will iliminate wear and if it's about a 65w when ur supposed to use 90w i'd say it's definently worth it????

[trooper Tdiesel]

this incorrect oil problem ive dealt with in Isuzu's too.


many fast lube places for some strange reason
have it in there computer that they take 80W-90 gear oil in the trans, when its really needs to be 5W-30 engine oil

in one to five years the bearings are shot

[Moriene]

The high viscosity ensures transfer of lubricant throughout the gear train. This is necessary since the devices needing this heavy oil do not have pumps for transferring the oil with only a portion of the lowermost gears bathed in an oil sump.