Changing Transmission fluid

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Oct 19, 2000 | 12:08 PM

robert_boyd

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Changing Transmission fluid

My 1986 F-150 4x4 has 92,000 miles on it. It's in super condition. I bought it with 42K on it. It has never had the transmission fluid changed. Several techs have told me not to change it. They say only to add as needed? I think it needs changing has anyone else heard this? Should I change the filter too? Is there anything else I shold do while I'm changing it?

Thanks,

Oct 19, 2000 | 12:21 PM

bgodkin

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From: Stanton, Suffolk England

Changing Transmission fluid

I recently bought a 1986 F350 with a 6.9 liter diesel and a C6. It has 79000 original miles on it. The trans had been rebuilt 10000 miles ago I went ahead and changed the fluid and filter in it when it started to shift funky and it cured the problem. The filter was full of crap from the rebuild. I also adjusted the intermediate band and changed the modulater (put the right one on) at the time. I have no clue as to why a tech would tell you not to change the fluid and filter. when you change it don't forget to drain the torque converter too. it should take around 13 quarts if I remember right. hope this is of some help

Brad

Oct 19, 2000 | 12:49 PM

slikness

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From: Durham

Changing Transmission fluid

Like all other fluids, the tranny should be changed periodically. Some folks change their fluid annually. A popular way to change the fluid today is to pump new fluid through a machine and supposedly the reverse pump flow will clear the filter and remove all of the old fluid. I think that dropping the pan to change the filter is probably the best method and, as mentioned, before, drain the torque converter. You could also disconnect your cooler lines from the tranny and force air down one of the tubes to drain the fluid in your trans cooler.

'82 F150 2WD w/351W (orig 300 I6)
Slik

Oct 19, 2000 | 01:22 PM

tim_1911

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Changing Transmission fluid

I was told the same thing once. The reason for not changing the fluid was that the detergents in the fresh fluid would loosen the crud that had built up over the years and cause problems. In severe cases, he said the car couldn't get out of the parking lot after the fluid change. I'm not saying this is true, just what the mechanic told me.

Oct 19, 2000 | 02:56 PM

bgodkin

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From: Stanton, Suffolk England

Changing Transmission fluid

I agree with Slik. I hadn't thought about undoing a coolerline and using air to force the old fluid out though. Now I feel dumb. I would only use low pressure air though. Don't go blasting it with 100 psi shop air

Definatly change it though. if it has enough crud built up to hurt it by changing the oil it is better to find out in your driveway or garage then out on the road.

Brad

Oct 19, 2000 | 09:37 PM

mrlaserboy

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From: St. Paul, MN

Changing Transmission fluid

What I did to flush my fluid was this- I bought a see-through 5 gal water jug, marked off every quart using a measuring cup and water. I then disconnected the rubber tranny cooler lines and attached longer rubber hose so that both ends (tranny side and cooler side) would go into the jug. I started the engine and ran it until two quarts went into the jug then shut it off. Then I put two new quarts of tranny fluid in through the dipstick. I repeated the whole process until I went through the complete capacity of my AOD, 12 quarts. I already replaced the tranny filter just prior to doing this so I knew that was good. Shifting was so much better afterwards- driving in the mountains of CO didn't treat my tranny fluid well, especially with 38" tires.

Dustin Siebert
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