C6 Auto Trans oil
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C6 Auto Trans oil
Picked up a real nice 1975 F150 Ranger Super Cab, that has a 390 Hp w/C6 auto trans w/large oil cooler. There is about (odometer reading) 140,000 miles. The trans oil has got a brownish tint to it, and slite hint of somthing like real old gas. The oil was changed 25,000 miles ago. ( conv as well as trans )
I know this truck and its previous owner well, could it be that the service to the trans was not done by the (auto trans service shop), or is there a problem on its way ? ? :
confused:
I know this truck and its previous owner well, could it be that the service to the trans was not done by the (auto trans service shop), or is there a problem on its way ? ? :
confused:
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Joined: Dec 2001
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From: Louisville,Ky.
If it isn't causing any problems, then just change it. It is about due anyway. I do not know if the torque converter has a drain plug or not. If not , you are only changing about 1/3 of the fluid.
You may want to take it to a shop that can actually power flush it. This will get most of it out.
Jimmy
You may want to take it to a shop that can actually power flush it. This will get most of it out.
Jimmy
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Joined: Mar 2003
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Sometimes a power flush can knock varnish and debris loose inside the valve body, and it can wind up clogging some of the valves and cylinder passages. I would do this as a last resort.
If it's working OK, change the fluid and screen (you can clean it, but I just get another one with a new gasket). The torque converter should have a drain plug just next to one of the attachment studs - rotate the engine until you see it. Be aware that it may tough to get off - I had to use vise-grips on mine and then just got a new plug.
Also change the vacuum modulator and be sure that the vacuum source is full manifold, not ported. Full manifold is found below the carb throttle blades or on the intake and is present at idle (18"to 22"). Ported vacuum is found above the throttle blades on the carb and is low or none at idle and increases as engine speed increases. The smell of gas may be indicating that there may be a small leak in the diaphragm of the modulator. There's several types (different colored stripes) that are based upon the amount of vacuum needed to by the modulator to work. If in doubt, the green stripe is in the middle of the pack and works fine.
If it's working OK, change the fluid and screen (you can clean it, but I just get another one with a new gasket). The torque converter should have a drain plug just next to one of the attachment studs - rotate the engine until you see it. Be aware that it may tough to get off - I had to use vise-grips on mine and then just got a new plug.
Also change the vacuum modulator and be sure that the vacuum source is full manifold, not ported. Full manifold is found below the carb throttle blades or on the intake and is present at idle (18"to 22"). Ported vacuum is found above the throttle blades on the carb and is low or none at idle and increases as engine speed increases. The smell of gas may be indicating that there may be a small leak in the diaphragm of the modulator. There's several types (different colored stripes) that are based upon the amount of vacuum needed to by the modulator to work. If in doubt, the green stripe is in the middle of the pack and works fine.
