3 speed automatic Tranny problems

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Jun 17, 2001 | 09:03 PM

canadianfordman

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From: Campbell River, BC Canada

3 speed automatic Tranny problems

It was a beautiful sunday morning as I was driving to work and my automatic transmission would not automatically switch into 2nd. The engine was revved very high and I pulled over right away. I got going again and the same thing happened so I manually switched it to second and then put it back into drive and there were no problems. Then as I was driving home from work the same thing happened. What is going on, could it be just a vacuum or is the tranny shot? It is in a 1984 F150 and the engine is a 351W. I have a 4 speed AOD from an 86 that I would get rebuilt and put in if it isn't too much work. Has anyone swapped the speed auto for a 4 speed AOD? How much work is involved?

Thanks
CanadianFordman

Jun 18, 2001 | 08:00 AM

larry derouin

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From: Glen Burnie Maryland

3 speed automatic Tranny problems

Check the vacuum modulator for a fractured diaphram.

Pull the hose off of the modulator and check for atf. If wet, the modulator is bad.

Upshift problems are what I have noticed first when modulator goes T*T's UP.

Larry

Jun 20, 2001 | 12:39 AM

canadianfordman

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3 speed automatic Tranny problems

Thanks I will have to check that out.

Jun 21, 2001 | 02:45 AM

canadianfordman

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3 speed automatic Tranny problems

Modulator is changed and the problem still exists. I think it is time for a rebuild, it has almost 300,000km on it so I can't complain. What does a proper rebuild go for these days?

Thanks

Jun 21, 2001 | 09:49 AM

larry derouin

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From: Glen Burnie Maryland

3 speed automatic Tranny problems

Have you ever changed the fluid and filter????

Rebuilds for C-6 (R & R tranny & Rebuild) run the gamut from 400 to 1000 depending on where you go or what you have put into it.

That C-6 is probably the toughest slushbox ford ever built. If I had a choice of the C-6 or overdrive unit, I'd put the C-6 back in.

Jun 21, 2001 | 04:22 PM

canadianfordman

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3 speed automatic Tranny problems

[font size="1" color="#FF0000"]LAST EDITED ON 21-Jun-01 AT 05:25 PM (EST)[/font][p][font size="1" color="#FF0000"]LAST EDITED ON 21-Jun-01 AT 05:24 PM (EST)[/font]

Thanks Larry, I am going to put the c6 back in. The fluids and filter has all gotten changed before. I am looking at a shift kit. The stage 2 seems good but how much stress does it put on the rest of the truck? Has anyone tried one of these?

Thanks,
C'Fordman

Jun 21, 2001 | 09:24 PM

larry derouin

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From: Glen Burnie Maryland

3 speed automatic Tranny problems

[font size="1" color="#FF0000"]LAST EDITED ON 21-Jun-01 AT 10:26 PM (EST)[/font][p]Stage 2 will stiffen up your shifts, quicker engagement than stock which is good as the FORD's have a tendency to smooth shifting, which eats clutch packs. You will definately feel the difference. Also it will improve on shift points (Higher rpm). If you plan on any kind of towing this is good to have. Also get an aftermarket cooler and put it downline from your radiator based cooler.

As for the rest of the drive train....while you've got the tranny out go ahead and put NEW U-JOINTS in. The rear end will be able to handle the extra boost. Change the rear end fluid while your at it.