Slipping transmission.. what can I do?

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- Ford Warrior
  
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posted
18 years ago

Thu, Oct 27, 2005 8:19 PM

I have a 1995 Ford E250 3/4 ton cargo van with 176k miles. 3-speed C6 auto transmission, 4.9L L6 engine. The transmission has been slipping every once in awhile when driving uphill between 20-25 mph. By slipping I mean there is a loss in velocity & acceleration and the engine seems to 'race'.. i then let off the gas pedal and just barely accelerate until I make it over that 25 mph mark and it seems fine afterwards. I just changed the fluid, filter, and cleaned the pan out and am still having the problem. The problem seems to get worse once I've been driving for awhile and heat builds up. Are there any sub-components of the drivetrain/transmission assembly I can check out to hopefully 'bandaid' or even possibly fix the problem before it gets worse? Does this problem always lead to complete transmission failure? The driveshaft was just balanced/straightened out and all the splines on the yoke/output shaft are solid. Would appreciate any help here!.. I have haynes & chilton's manuals but please keep in mind im a novice mechanic.

thanks Jay

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- oldkid
  
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posted
18 years ago

Sat, Oct 29, 2005 5:15 AM

check trans fluid level on flat ground with engine running warmed up.high mileage usually euals worn oil pump.lower trans pressures.adjusting kickdown for hiher shift points will increase pressure.but if you already in high when this happens and it aint due to an attemped downshift from hill grade then part drasin and refillup with 30wt hyd oil may be a fix.this will boost pressure.if it aint doin it cold then then as oil warms and thins out it is leaking internally more you could also try an oil stabilizer which improves viscosity characteristics.

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- <HLS
  
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posted
18 years ago

Sat, Oct 29, 2005 1:28 PM

Did you do a band adjustment when you changed the fluid and filter? (The old C6's, at least up to 1994, had an intermediate band adjustment, and just assumed the newer ones are of the same general design.)

Your transmission has enough mileage on it that, I suspect, the clutches are worn down. If so, an overhaul is probably in its future. No amount of additive, etc, will help if your clutch packs are worn out.