Replacing Manual Transmission Fluid...

darkstar_one

Registered User
Okay... well when i converted to a stickshift a while back i didnt put ATF like everyone recommends. Me and my dad put GEAR OIL like a 70w90 something around that area.... well the thing i dont like about it... it takes a real long time to warm up.... When i turn my car on i wait for a while for it to warm up because if it doesnt then i have an annoying grind going into 2nd gear. All other gears okay in the cold except second.... I am getting tired of waiting the car to warm up so i wont get the annoying 2nd gear grind... it only does it for maybe like 5 -6 minutes into a drive then it just totaly goes away.... but its still annoying.... if i replace the gear oil with MOBIL 1 SYNTHETIC ATF fluid will it cure up my annoying cold grind into 2nd gear? Thanks. I know alot of people recommned GM SYNCROMESH fluid and i am thinking of that also. THanks..
 
Redline

Darkstar,

After my Transmission got rebuilt, Im not sure what the shop put in it, but it was doing the same exact thing yours is doing, I think it was in 3rd gear though. It would grind for the first 5-10 minutes of driving then go away.

What I did was flushed the fluid they put in out, and filled it with Redline D4.
I did not add any friction modifier, and now it shifts GREAT!. Never any grinding, cold or warm.

I do not have any other experience with different kinds of tranny fluid, but I do know that the D4 does work.

Mike
 
I was under the impression that the thicker the oil the more it slowed down the snychro and the better the shifter, however I think thats for the brass synchros and not fiber lined ones.
There are two plugs on the side of the transmission, fill and drain. Some people have filled trans through shifter housing, not familiar with this though.
Phil
 
sure it wouldnt kill you to do it while the tranny is out.... in fact its better... wont risk dropping any fluid on the insides of ur vehicle if ur filling it through the top.... thanks for the 411 dudes..
 
If the car is on jacks and you have one of those pump things to speed up the process of putting oil in the trans do it while its in the car. Its much lighter to put back in and you don't have to worry about oil out the tailshaft of the trans. I used a tube threaded up through the engine bay and a cut milk jug, it was some heavy weight oil, I guess you could say i was standing there for awhile.
Phil
 
GM synchro, Redline D4 (synthetic ATF) or even Mobil 1 ATF is definitely the way to go. Regular 75w90 gear oil isn't used these days (except in the diff) and will get very stiff in cold weather. That is why most manufacturers now use ATF in manual trans. Ford used to spec regular Mercon ATF, but today the synthetics are better, especially in the SC which is hard to shift in the first place. You can even add Redline's synthetic friction modifier if you want. Draining is easy because the trans has a plug on the bottom. As mentioned above for filling, you have a fill plug on the side of the trans & you'll need one of those cheap plastic pump kits or a long plastic hose attached to your oil bottle (and then fed down from the engine area); because there isn't enough height under to car to gravity fill the trans. You need just over 3 quarts to fill it.
 
Gear oil will not lubricate where it needs to because it is soo thick, plus it will make shifting very very hard especially in cold weather. I prefer the syncromesh. There is a drain plug and a fill plug. You want to refill it the final bit with the transmission in the car and level to make sure you have it filled correctly. When fluid runs out the top hole it is full.
Alan
 
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