transmission question

[Copterdoc]

Has anyone adjusted the bands on their trannys? If so, what is the easiest way to do it? thanks copterdoc

 

[hdm48]

Copterdoc, do you know anything about auto's? If you do, I can explain it easily. If you don't, it will take a little more time.

And when I say auto's, I mean the 727 torque-flite.



-dave-

 

[Copterdoc]

autos

Yea I know which end is which. I have changed converters, done shift kits, etc, but I have never spread one out on the bench and overhauled one. thanks copterdoc

 

[BushWakr - RIP]

Copterdoc,



Here it is right out of my 93 manual...



FRONT BAND: Loosen band adjusting screw locknut and back off 4-5 turns.

Tighten band adjusting screw to 72 in. lbs.

(If adapter extension C-3705 must be used to reach adjuster screw, tighten screw to only 47-50 in. lbs)

Back off adjusting screw 2 1/2 turns on all transmission models.

Hold adjuster screw in position and tighten locknut to 30 ft. lbs.



REAR BAND: Remove trans. oil pan.

Loosen band adjusting screw locknut 5-6 turns.

Tighten adjusting screw to 72 in. lbs.

Back off adjusting screw 2 full turns.

Hold adjusting screw in place and tighten locknut to 25 ft. lbs.

Install pan gasket/pan/etc.



Hope that helps.



Bob.

 

[hdm48]

OK, here we go. The rear band, adjust as per manual. I set mine at 4 turns. This band only works when your in reverse or have the shift lever in first.

The front band, use a spacer between the K/D servo push rod and the rocker arm. The spacer will be 5. 16" (. 3125"), adjust the band in untill the adjuster stops. Don't crush it in, just till it stops. Lock the adjuster, REMOVE THE SPACER!

Bands are done.

Now, if you know where the line pressure adjuster is, set it at 1. 250". You will need to modify an allen wrench for this.

If you REALLY want to help it, go to a transmission shop and pick up a aluminum accumulater piston and pull your valve body and replace the plastic one with it. And when you put it back together, leave the spring that was under the piston out. This will help the 2-3 shift.

Any more than this will require a complete tear down and modifying the guts.

Setting the line pressure and removing the accumulator spring is doing the same thing as what a shift kit will do. And cost a lot less.

The reason for adjusting the front band this way is because the rocker ratios vary from year to year and you need to get the timing right.

Unless you have over heated the unit, the rear band should never need adjusting again.

If you don't get this the way I typed it, just PM me and I will make it clearer. Or we can swap phone numbers and we can talk person to person.



--dave--

 

[BushWakr - RIP]

I have heard the thing about using an allen key (3/16") in my case for this adjustment. Is the 5/16" specific to the 92 trans hdm48?

One more thing as well... I understand that the transmission comes set at around 52 psi line press. and that it can be increased to about 60 psi max. After that you can damage the drum seal and other stuff. Is this different on the 92 as well. I ask because "1. 250" is seems at first look to be an arbitrary setting... by that I mean, what does it translate to in psi and on a used transmission?? No flame here, just asking Dave.





Thanks, bob.



Good post BTW. .

 

[hdm48]

Bushwakr, the 5/16" is the standard for the 727. And as you know, a 518 is just a 727 with an overdrive.

If you were to check the line pressure setting at stock you will find it to be 1. 3750". Which is about as low as you can go a still have it work.

1. 250" will set your full throttle pressure at 105psi +/- 5psi. Your max pressure is what you need to be concerned about. Go any highed than that and you will hurt the lip seals and it will refuse to shift down when you come to a stop.

On some of the drag racing transmission's I've done in the past I have set the max pressure to 130psi. Worked great but didn't live very long and made no ET gains. If you want it to shift like a drag racer you need to make some changes inside. Plus add some lubeing improvements. Poor lubeing is one of the most common causes of transmission failures. This is also why I run 2 to 3 quarts of 30wt engine oil in my transmission. Really helps.

The torque-flite does not know horse power. What that means is, as long as it has been set up right and it has the proper amount of pressure, it will transfer all the power and live forever. There is no reason for a torque-flite to fail. Poor maintenance, lack of cooling, and abuse is what kills them.



-dave-

 

[BushWakr - RIP]

Dave, thanks bud..... that will go into the ole brain repository for future reference.



Thanks again. .



Bob.

 

[rdodd]

hdm48---------The shop that serviced my trans. puts 2 qts. 10w-30 synthetic mobile one engine oil into trans. along with the regular fluid. Would this work equally as well for lubrication as 30 wt. oil. Also, what type of transmission oil works the best for 518?

 

[BushWakr - RIP]

As I understand it different oils will result in different shift characteristics...

For example the higher the content of friction modifier the smoother the shifts.

In my case I firmed up my shifts by using Dexron fluid. It's descibed as "more aggressive".

The "book" calls for mopar 7176 ATF. aka: Type 3.

Type 4 has more modifiers in it.



Dave?



Bob.

 

[hdm48]

First off, I just read my post on the band adjustments. I goofed on the rear band adjustment. It is 2 turns out just like the manual says. I was counting how many 1/2 turns I make when doing it. Sorry.



OK, now the oil. I have found dexron3 to work the best. Too much friction additives will cause slipping which you might mistake for smooth shifting. As for the motor oil, use a fixed weight oil only. DO NOT use multi weight. I use Quaker state or Castrol GTX.

Be careful with any fancy fluids that are out there. Like Trick shift. It works ok in a hot rod, but it will cause the pressures to go out of control. And I read somewhere on this site where some guy recomended useing ford fluid in the torque-flite. This is a major no-no. Acts the same as trick shift.

Just make sure you have the biggest cooler you can put in the truck. Don't worry about it running cold. It likes cold. And always remember to let it idle in neutral for 10 to 20 seconds the first thing in the morning.

I have an additive that I hope to be able to sell soon. It comes out of south africa and is the best thing since oil was invented. And no, it is not slick 50 or any of that other stuff. I know it works. To give you guys an idea how well it works, I did not need to adjust my bands, or in the motor I have not needed to adjust the valves for 50,000 miles. I have already talked to Lenny at DDP in Monroe and we are going to use his truck as a test bed so we can have Dyno numbers to show what it does. More on this later.



That's it



--dave--

 

[DPKetchum]

Why use motor oil in a auto trans?It won't cause seals to balloon/distort/swell. Want some tech. type reason to use it!And yes you learn something new everday but I've ran repair shops 20 odd years and this is a new one on me!:--)

 

[rdodd]

What is the difference between dextron ll and dextron lll? It says on dipstick that dextron || may be used instead of 7176. Will dextron lll work even better in 518 trans?

 

[DPKetchum]

Ok not to start any trans wars here but I had to know about motor oil in a automatic. Called tech assistance with TRANSGO products and they said YES motor oil is ok for a auto trans. Said NOT TO USE NOTHING BUT SYNTHETIC OIL!!Prefered a 0w30 or a 5w30,10w30 was ok but not the prefferd. Said the reason really wasnt shift quality but that it increased boiling point of fliud and added a gear to gear crush cushion mainly in the overdrive unit were most autos/trucks are driven for substaned speeds. Said as much as 6 qts could be used if unit was flushed etc. but 2 to 4 were average on a drop the pan trans service. LEARN SOMETHING NEW EVERYDAY!!!:--)P. s differant trans fliuds have differant amounts of heavy metals and other additives to work ok with the metals and matierals inside of a trans etc. Certain oil classes were used for certain type of bearings,cams,valve guide matierial etc. Trans fliud is the same way.

 

[hdm48]

DPk, yes, transmission fluid does not lube very well at all. Plus it turns to gunk at 275 degrees. Motor oil lubes very well and will not burn until you hit 550 degrees. I still stick to a 30wt fixed rate oil. Why? Because a multi-grade oil falls back to it's base stock when under pressure. And that would be lower than the 7 1/2 that even transmission fluid is. And if you want, you could run straight motor oil. It would shift like a mule, but it wouldn't be a good idea unles you lived somewhere it stayed above 80 degrees all the time.

The motor oil is NOT a shift aid, it is insurance. If you need thicker oil to help the shifting or pressure, you have a mechanical problem that needs to be fixed.

Synthetic oils are nice but not needed. Unless you live in north dakota. And if you get right down to it, synthetics are nothing more than petroleum cracked twice. A friend of mine is an engineer for chevron and he and I have gotten into lots of arguments.

That's my 2c. I guess after doing this stuff for over 35 years I've picked up a few tricks.



-dave-

 

[rdodd]

Does dexron lll have more modifiers than dexron ll?

 

[DPKetchum]

Times and technology change.

 

[BushWakr - RIP]

rdodd,



I don't know for sure what the change was when they went to Dex. III but Dex II is harder to find now. I am running Dex III in my transmission and it works just fine.



Bob.