transmission popping out of gear ?

[tumtum]

for some reason in 3rd gear around 1300 rpms ill be going at a steady rate of 35 mph. now it seems to shift into neutral or to second gear and when i press on the accelerator, it revs up but doesnt increase my speed until about 1700-1800 rpms. someone said there could be something wrong with the vacuum modulator. any thoughts?

 

[jrm81bu]

I had a th350 that did something like that. Wasn't too long before 3rd was completely gone. Then driving in second it would drop to neutral/1st. Then all i had was first, til it would no longer move. Hope this isn't the case for you.

 

[tumtum]

mine is a th350. so what should i do?

 

[jrm81bu]

If its the same problem as mine i'm pretty sure i was just burning it up the more I drove it. Pull your dipstick and see what color the fluid is if its starting to turn brown or smells burnt then start looking for a new transmission. Or plan on a rebuild soon. And stop driving it.

Of course there could be a seperate problem causing it in the first place. That will eventually cause it to burn up. I'm not sure. I kept driving mine because I didn't care. I already had a replacement.

 

[shotgun]

Do a trans service.

I crutched a trans that was doing the same thing for about 10k miles.

Drained the fluid,replaced the filter,added 2 bottles of Lucas and filled the rest of the way with Type "F" fluid.

I fill the pan with Lucas and then lift it into place since it is so thick and sucks squeezing it down the fill tube.

Straight type F is getting harder to find, you can use "FH".

 

[tumtum]

the fluid is not turning brown yet but it does kind of smell burnt. what causes this? is there anything i can do besides a rebuild or transmission swap?