over drvie problems ????HELP please

[johnandjen]

ive got a 97 mercury mountaineer 5.0 awd automatic 3 speed with overdrive
i think its a 4w70 or something like that transmission

it started felling like a un balanced tire in the front of the truck

today around 40 mph to about 45 it fells like a shutter
when its in overdrive i can flip it out of overdrive and i dont fell anything
it fells fine . But when in overdrive i fell the shake or shutter in the front of the truck

any ideals would be great thanks
u guys

 

[SmoothJimmy]

when was the last time you checked or changed your transmission fluid?

 

[johnandjen]

ive check it 2 time today
i havent changed to fluid
i replaced the rad. about 1 year ago
and i think i put 2 quarts in then
the fluid looks new still a little high but in good shape
this truck has 150,000 odd miles on it

 

[SmoothJimmy]

I'm a little confused by your statements.
So you changed the radiator and the fluid level in the reservoir looks good and the coolant is still bright green? Hopefully that's the case and since the radiator cools the transmission, they are intertwined.

However, that's not where the level in the transmission is checked. There's a yellow handled dipstick behind the engine that measures the level in the transmission. It has a cold and hot level. If the rig is on a level surface and is cold, the fluid level should be somewhere between the hot/cold indicators. If it's dry, you may have low fluid and this could contribute. Also check the color of the fluid by wiping on a white paper towel or the like. If it's anything other than a bright red, it's possibly old and burnt.

Regardless, unless you know when the fluid was last changed, the time is NOW!

 

[SmoothJimmy]

and also, as these rigs get older, they don't like running in overdrive at those speeds (under 45). It places greater loads on the engine and the transmission. For pottling around town, I recommend keeping OD off. Once you get on the freeway, press the button and enable it. It's just one more thing to remember though. You still wanna check that tranny fluid level and probably change the fluid and filter if it's been awhile. There are multi writups on the site for the procedure if you feel up to it.

 

[johnandjen]

the rad. fluid is fine when i changed the rad. i replaced about
2 quarts of transmisson fl. but thats all thats been over a year ago
the fluid is nice and red. It just started this i guess u could call it a slip
of a shake i thought it was a out of balance wheel but u can make it stop by
kicking it out of o.d but ill go and have the transmission fluid changed and filter.
Im the 2nd owner of the truck and i bet it has never been changed
ive had it since 80 000 miles and its just ive 150000
so ive put about 70000 miles on it .....

thanks for the info
all ideals are welcome