Ok I have an 89 D250 with the 360 and an Auto trans. which has been slipping for while now. I put some of that Lucas trans fixer stuff in it and it seemed to help a little, but then I checked the fluid level today and there's nothing showing on the stick, whereas before it was actually overfilled a little due to me adding the lucas stuff. There are no signs of leakage. Where did the fluid go? So anyways I added enough to bring the level up but I'm thinking I'm gonna go ahead and drop the pan next weekend and see what's up with it. What can I expect to see? Other than the filter and valve body? Anything I should be aware of before I do this? Thanks in advance for any input!

 

mine was leaking out of a tranny cooler line, at a part that was a bit higher than the rest of the system. It was really "weeping" trought a heavily corroded area more than dripping. Only when there was pressure and the fluid was thinned (from heat) did it get forced out. Point is, i only lost fluid while driving - so when id check under the car for drips in the driveway i never saw anything substantial. you might also check the oil seal at the back of the tranny if you havent already.

if not dripping, the only other way to lose fluid that i can think of would be burning. youd smell it for sure - the best i can describe it is that it smells like burning oil but maybe a bit "sweeter"

check the lines though


good luck

 

Whoa man, mine is jet black and very stinky. Way past time for service I suppose. It is acting much better now that I added a little fresh fluid. A full service should make it back to normal, I hope.

 

If the tranny is slipping you need to adjust the bands when you change the filter and fluid. Slippage will cause low fluid level as it burns the fluid. When you change fluid you only change the part of the fluid in the tranny and you leave the fluid in the torque converter. When slippage has caused burning of the fluid as in your case you may have to change the fluid again after you drive the truck for a couple of hours.

 

really black and stinky probably means youve been burning it

 

OK cool. Now, I know I sound all newbie when I ask this, but how does one "adjust the bands"? I have serviced the trans on my 91 Dodge Stealth, so it's not exactly greek to me, but there were no "bands" to adjust on that. Whole different animal I suppose. Ok I'm ready for my whipping now. Also, how much fluid will I need for the job. Thanks again.

 

First, you must identify what tranny you have. The 727 is the most common but there are 6 3 speeds, 4 4 speeds, and even 5 speed trannys that are used in our trucks. On the drivers side just above the oil pan there is a flat flange where you will find the numbers stamped that will ID the tranny. There are 3 sets of numbers. First is the part number, second is the build date, third is the serial number.
Best advice you will ever get if you are going to work on your vehicle is this. Invest in a good manual. I had to buy 3 to cover all the systems in my truck but the money was well spent as I have saved thousands by using them.

 

This is a basic understanding of how to adjust the bands. It is not hard but you should know this first.

Beware of band adjustements! On old torqueflites, the reverse band is also used in "D" gear so you could disturb the good functioning of your transmission. If you loosen the band you'll have slippage or no engagement of reverse and Drive. If adjustement is too tight, you'll ruin the band.

To adjust the bands you must follow the method in the manual: loosen the locknut, back off the adjustment screw, tighten to specific torque and back off a specific number of turns (see manual for specs). You must hold the adjuster as you tighten the locknut.

Here is an explanation of the clunk many of us feel when we shift into reverse. It is involved and technical but I found it interesting.

There is a definite reason for the famous "Clunk" when the rear wheel drive vehicles are put into Reverse. It is designed in. When put into Reverse, an entire different hydraulic circuitry is used and the line pressure will flow to a different part of the Regulator Valve which causes the line pressure to rise. This line pressure is directed to the Low / Reverse Servo and the Front Clutch. The need for higher pressures is due to the design features of each clutch assembly. Both clutches are applied by hydraulic force and the Rear clutch utilizes a Bellville Spring, which multiplies this force. This multiplied, higher force pushes against eight mechanical levers to assure a firm application of the band without slippage. Rear Clutch pressure here can rise to 270 psi - they deem necessary to prevent slippage. The other, forward circuit design does not have this pressure range to control those shift points. The front cluch, in this circuit does not require this higher pressure because it is used only in the upshift to Drive, and since the car is already under way, there is no likelihood that there will be any slippage here. Chrysler tried to reduce this shock somewhat, but they didn't want to revise the whole thing. If you look at a cross section of the Low / Reverse Servo, you'll see the spring cushoning the piston travel as it applies the band; This lever has the Low / Reverse Band adjustment on its' end. If you loosen the adjustment to reduce the shock, the shock will become more harsh, this adjustment is not recommended. There is one aid a Chrysler dealer recommended to me, he said that they modified the circuit flow rate by adding a small Cotter Pin into the hole for this circuit in the valve body. What this did was to delay the pressure build-up , not eliminate it, but build it up slowly, and they had many happy owners with no more complaints.