Engine/Transmission (1994 - 1998) To change or not to change, transmission fluid?

[Fordiesel69]

It is the 47RH and the fluid is unknown. The PO only owned the truck for 24k miles and did not know exactly when it was last changed. He said when he bought it, the fluid was very red and smelled clean. I got it now it is it still red, but looks dull and has that common stale smell. It is burn't at all and does not show any metal fillings on the stick. Do I dare change it? All the minivans went bad after I changed them, however they all had 120k or more on the original fluid.



I heard that changing it, restores the detergents and washes all the debris out and plugges the valve bodys. Is this true?



Also how do you drain the TC?

 

[TBartlett1]

Absolutely change it! I change the filter and fluid in all my new vehicles and also adjust the bands if possible. Oil does wear out (shear) and needs changing to restore the additive package.

I purchased a small diaphragm pump on e-bay and use it to suck the fluid out of the transmission thru the filler tube, that way I can change it without removing the oil pan, also if I need to change the filter I can do so without creating a mess.

Some manufactures say that the color and smell of the fluid are no longer indicators of the fluid needing to be changed!! WELL what other indicator do we have?

If my fluid is dark or no longer smells pleasant I change it.

Lubricants are cheaper than the parts they protect!!



My 2 cents

Tim

 

[Fordiesel69]

Absolutely change it! I change the filter and fluid in all my new vehicles and also adjust the bands if possible. Oil does wear out (shear) and needs changing to restore the additive package.

I purchased a small diaphragm pump on e-bay and use it to suck the fluid out of the transmission thru the filler tube, that way I can change it without removing the oil pan, also if I need to change the filter I can do so without creating a mess.

Some manufactures say that the color and smell of the fluid are no longer indicators of the fluid needing to be changed!! WELL what other indicator do we have?

If my fluid is dark or no longer smells pleasant I change it.

Lubricants are cheaper than the parts they protect!!



My 2 cents

Tim

That is my mind thought as well, but some think changing "unknown" fluid is more harmful. Changing it at 30-40k intervals is fine, but some say 60k~100k will ruin a transmission if changed. That fact the I truly don;t know how many miles are on mine, I was just curios if anyone had any problems.

 

[Skydiver]

I use a small 12-vdc fuel pump with a 1/8" semi-ridged tube to vacuum all the fluid from the pan then refill. I do this every 10 k miles. At 176k no problems except at 100k the transmission would shift late when cold. I had the power flush done that included adding a pre-something to loosen the sludge. I drove it with the pre additive for 100 miles. It corrected the cold late shifting problem.



This truck tows a 13800 lb 5er about 500 to 700 miles a year.

Less than a teaspoon full of metal filings every 30k is normal in the pan. I change my filter every 50k.



My friend who is a full time mechanic says if you completely clogg up your filter it's time for a rebuild (replies welcome). He never changes his personal auto transmission filters and he has never had a failer.

Never lug your auto transmission.

 

[fox]

Drop the pan, change the filter too.

Rotate the converter to see if it has a drain plug. The factory does NOT install them but some aftermarket ones are equipped. Drain it too if possible.

 

[Dieseldemon]

If you unhook the line that goes to the trans cooler in the front of the truck (The one closes to the engine) clamp a 1/2" piece of hose on the metal line put it into a bucket and start the engine in netural (so the pump in the transmission comes on) and run it until it quits pumping stop the engine then drop the pan and change the filter adjust the rear band put the pan back on pour 6 qts transmission fluid(I use ATF+4) back into the trans then start the engine again to pump the fluid you just put into the trans into the convertor and the old fluid out of the convertor and you have changed all the fluid from the trans and the convertor. You can adjust the front band anytime as the adjustment is outside of the pan.