my trans is slipping bc i overfilled it and didnt drain the excess in time so now my trans is slipping pretty badly. im thinking im going to need a new trans but i was wondering would it be a waste of money or maybe to save 1300 bucks to drain the fluid and put new fluid in?

 

At the cost of fluid and a filter, it can't hurt anything to change the fluid and get the level correct. If I'm not familiar with a certain vehicle, when I refill the trans I put about 3/4 of the recommended capacity in at first. Then, start it and shift through each gear selection, pausing for a couple seconds to let the fluid passages fill up. Be sure to check the level on a flat level surface, and slowly sneak up on the full level, adding a quart at a time, then half a quart as you get closer. When cold, fluid reading at the bottom of the cross hatched range is ok. And don't worry, just shifting the gears without moving won't hurt a thing as you proceed with the fill process. Also, be sure that you check the level with the vehicle idling in park. Some folks overfill the trans that way. Finally, be sure to use the correct fluid - probably Dexron III for the trucks in this forum!

 

Just what he said. well worth a try

 

drain convertor also.

add lucas trans treatment.

 

I can't see overfilling the transmission causing it to slip... doesn't make any sense... but I'm not a tranny expert. Is this an '88 with an AOD? If so, have you checked your T.V. cable for correct adjustment? It's the cable that runs from the throttle control plate to the transmission. It's adjustable and controls the line pressure exerted on the bands and clutches in the transmission. If the adjustment mechanism is broken or has become dislodged from the throttle plate, the transmission will slip constantly.

 

how do i drain the convertor. i have an AOD trans if that helps

 

how do i adjust the TV cable?

 

look for rubber access plug below convertor, remove, than you need to tap starter to align drain bolt, helps to have assistant.

try not to start engine. watch hands and fingers if using a helper.

buy a manual.

 

im pretty sure the TV cable is the original so should i just replace it?

 

I'm guessing you found it then? You have to take off the black plastic cap over the top of the throttle body. There you'll find the linkage that operates the throttle, and the TV cable is just behind it. It should move in sync with the throttle. You can easily verify this with the engine off. If it still connected properly and working there is nothing to be gained by changing it. Try adjusting it first.

Also note that the combined fluid capacity of the torque converter and transmission is 12-13 liters!!

 

To adjust the TV cable on the AOD, you need a bungee cord and a flat bladed screwdriver. Under the truck, you'll notice the shift lever in the side of the transmission is actually two levers - one connected to the shift linkage, and the smaller one on the end of the shaft is the TV lever. It's hooked to a cable that threads up to the throttle body. If you move it, it moves one direction - forward, and it springs back. Use the bungee cord to apply about 10 lbs of rearward pressure to the TV lever - hook the other end on whatever's convenient. What you're doing is holding it firmly "shut," toward the rear of the truck. Now go under the hood, and remove the plastic shield on the throttle body. The other end of the TV cable is here, and it gets pulled on by the throttle linkage - note, the accelerator cable and the cruise cable are at 3:00, and the TV cable comes in at 12:00, as you look down on the throttle body. Look at the bulbous part of the TV cable , there is a plastic clip that can be pried up to unlock the adjuster. It is captive, and it will come up about an inch. When you unlock the cable, the spring will automatically adjust the cable for you - just unlock it, then push down to lock it. Remove the bungee, and you're done. It probably won't move much at all, but a little adjustment goes a long way.

There is another way to adjust the TV, but it requires a special high pressure gauge.

 

If you overfill an automatic tranny, the fluid level reaches above the mid-line of the planetary gears. When this happens it is beaten into a foan, thus not properly allowing for the bands and clutches to apply enough pressure to hold without slipping. Do this enough and you glaze/burn the friction material resulting in a rebuild to fix the problem. As said drain it all, refill to proper amount and double check that all your linkages are adjusted. Also, if you can get some pressure readings to see if you have the right pressure in each gear.

 

From my experience with the AOD very small adjusments of the TV cable really can change the way it shifts.As stated by Conanski no point in changing the cable unless it is broken.

 

do you thijnk adjusting the cable can maybe steer me clear of having to my a trans or is that asking too much?

 

Based on my personal experience.If it is slipping real bad I dont think the tv is the problem. If the shifts are harsh ,real late or early or doesnt shift at all I would check the tv adjustment. I have had success with transmission additives when my tranny was slipping and the seals were starting to get hard.I used a product made by WYNN'S. If it is slipping one problem is that the seals are hard and the clutch packs cannot build up enough pressure to apply properly.Or, the clutch pack friction material is worn down to the steel plates and is plain worn out. If the pan was removed fluid would be dark and in some cases black and there would be a fair amount of junk in the bottom of the pan.