Tranny quit working right, need advice

YenahsYenzow · #1 (**permalink**) 07-05-2008, 02:43 PM

Hello guys, i'm not a tranny expert myself...but do need an advice!

I own a 78 F-250 Supercab 2wd with a 351m/400 v-8
One day i was driving down the road and decelerated the truck towards the red lights and was trying to shift over to Neutral and accidentally put it in reverse and the motor died. I restarted the motor and it ran fine then shifted it into Forward and the tranny seemed to shift into gear, however it didn't move but just barely moved along with engine revving high. I suspected I broke something inside the tranny and have done a check up on rear end axle gears and rods they seem to be intact and not broken. driveshaft seems good and tried rolling the shaft to see if tranny and shaft is hooked up (i took off the filter part under the t ranny to do a check) and seems to be intact (only managed to see the half part of the tranny before the torque converter and seems to be intact) I suspect it would be the torque converter...what do you think?
Because I would like to know whats wrong in general first so I might have to get the motor/tranny pulled out. (fluid level was full before I removed the filter part)

Thanks

Shane

Dr. Dirt · #2 (**permalink**) 07-05-2008, 02:53 PM

now on the new cars they have the feature where they automatically shift into neutral when stopped at a light to save gas. that's a good thing but if you're gonna do that do it when your truck is completely stopped. if you are still rolling and you take the truck out of gear you can burn up the gears. I used to do that and my dad told me what could happen so I stopped. sorry I can't help you with the real problem......good luck.

mudslingin'78 · #3 (**permalink**) 07-05-2008, 08:55 PM

It sounds like you've messed up your clutch bands. Does the transmission eventually shift or does it stay in first revving.

jlk5269 · #4 (**permalink**) 07-05-2008, 09:20 PM

You may have damaged the stator in the torque Convertor, clutches or bands. It sounds like you must have a C-6 Auto.

YenahsYenzow · #5 (**permalink**) 07-05-2008, 10:06 PM

its an auto from what i know, not sure precisely what model as i havent looked into it yet. it stays revving in first i believe...i couldn't tell since my muffler just blew and gotten pretty much noisy enough and couldn't hear the problem from the tranny. I strongly believe the gears arent busted because I could feel it shift into gear either reverse and forward...and seems to slip either way no matter how high I rev. I certainly believe it has something to do with the Torque Converter though.

Am thinking about just getting a used tranny from somebody for $100 bucks and have it swapped instead of $1,500 at a damn shop.

P.S. my computer internet is down as of the moment...will be using wireless somewhere close to home to get back to you guys so it will take awhile.

Tedybear · #6 (**permalink**) 07-05-2008, 10:50 PM

Put the truck into MANUAL LOW. There is a chance the one way roller clutch ate itself. If the truck all the sudden moves forward under normal power? The roller clutch is shot. (manual first bypasses the one-way setup and applies full power to the clutches/bands used).

From the sounds of it? While normally I'm the last person to suggest torque converter failing? There is also a one-way clutch built into the torque converter to direct the fluid coupling action for max torque/power at the right points. At this point--looks like the transmission and torque converter should be replaced or rebuilt.

Taking a moving forward car/truck and slapping it into reverse at anything but a crawl can do. I understand it was an error to do so (I've seen people do it intentionally to show off). However the extreme pressures inside the transmission moving forward--and then suddenly into reverse? It would not surprise me to find internal damage to either a clutch pack or it's actuator...heck that much force would be enough to snap a band as well.

Check Car-Part.com and enter in the information. There might be one at a salvage yard in your area for a quick replacement. Rebuilding is an option also to be considered, however it would REQUIRE a new/rebuilt torque converter (it's foolish to attempt to reuse the old one, as any trash got dumped in there). You really won't know the full story until it's torn down if you rebuild it.

At this point, might be best to locate a good used one.

S-