Slipping transmission.. what can I do?

Oct 27, 2005 Last reply: 20 years ago 6 Replies
F

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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J

Is the trans fluid up to the full mark?

Has the trans ever been flushed? You could try that. It might buy you some time, and then again it might kill the trans all together. I think the trans is living on borrowed time. I would get it looked at before you end up being stranded somewhere.

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L

If your C6 3 speed is correctly filed with fluid and it still slips, there is pretty much nothing you can do. It does however have an adjustable intermediate band if the slippage is in second gear. It is externall adjustable. If you do not know what you are doing, have it checked. Other than that here is not much to be done less than an overhaul. The longer you drive it slipping if this is the problem, the less chance you have that the problem can be helped.

Lugnut

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A

You describe a failing transmission. That's why nobody has commented on a bandaid for it. Use the remaining miles to find a replacement. Keep the slipping to a minimum as that means extreme wear.

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H

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.

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O

how steep a hill?fluid level right when warm on level ground and engine running?are the shift points too low?ajust kickdown cable.low shift points mean lower oil pressure.or add extra fluid in the form of an oil stabilizer.(pint)(more oil pressure).or drain some fluid and add 30wt hydraulic oil.(increase pressure).oil pumps usually are worn on high mileage cars.maybe your trans has external pressure adjust!?do you know what gear your in when this happens.1-2-3.does it happen because of a downshift due to climb?good luck.

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O

is the fluid level right.check on level ground warm with engine running.are your shift points right?under moderate accel 1-2 15-25mph

2-3 25-35mph.higher shift points also command more oil pressure which is what tightens the clutch mechanisms in trans.adjust kickdown cable to change shift points.what gear are you in when it slips?high mileage means worn pump.hot means thinner oil.drain some fluid and add an oil stabilizer or 30wt hyfraulic oil to boost pressure.good luck
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