need enlightenment on auto transmission

[superdave]

stock 99 auto 3. 54 rear. . when at speed and in OD, push button to take out of OD. . engine revs twice. . once i assume out of lokup, once down shift... am i right??? then will drop about 300 rpm... going back to lok up... right?... had a BD pressure lok put on ... now when push button out of OD revs up about 400 rpm... seems only to drop of of lok up... then NEVER will shift back into lok up... at least no drop in rpm..... question... . is the BD pressure lok KEEPING the torque converter locked up at ALL times when into top gear????? help me out here fellows... the transmission is definitely different with the pressure lok... also causes the transmission temp to run about 150 degrees empty... whereas the transmission temp before the BD pressure lok ran below 140 when empty... . transmission never gets over 170 when loaded except in mountains and then only around 180 max... am i good to go???? thanks.....

 

[BK]

Sorry, but I can't add info about the pressure lock.



I had a chance to run my truck with my buddy's SnapOn computer hooked up and we spent a few hours playing to see what real time data we could get and what the computer would tell use.



We could see when the computer was telling the transmission to do what and a half a second later it would happen. I'm guessing that once the computer had all the correct inputs it would give the command, and then maybe the pressures had to be right for the final exacution.



Based on watching the commands... ...

I can tell you that a stock auto transmission will always unlock 1st before it does anything, and after hitting 3rd (if OD is off) will lockup, or if OD is on-lock after in OD.

The transmission , stock, will not down shift while in lockup.

So the last thing a stock transmission will do is lockup, the 1st thing it does if it's in lockup, is unlock.



So that part that your seeing is correct.



Whats up with the pressure lock... sorry don't know.

But if it's allowing shifts WHILE the TC is locked... . I don't think thats a good thing on the stock transmission..... ???

 

[Strick-9]

BK,



Good info!



FYI, the delay you speak of before shifting 3-4 or 4-3 is the time required for the 3-4 accumulator to fill/vent.



I've got mine completely blocked off to speed up the 3-4 shift a bunch. The shifting occurs almost immediately after the command is sent.



-Chris

 

[CumminsPuller]

Strick-9 (Chris)?????

Could you give me/us more information about what you have blocked off. I have never heard of this... ... . Sounds like something i might be interested in.



Thanks



Jason

 

[Chipstien]

Me too. Oo.

 

[pwr2tow]

Superdave,

The best thing to do is call Steve at BD 1-800-887-5030. He will answer any questions you have about the pressure lock.



Ron

 

[superdave]

thank you ronsram... . will try to call him... .

 

[Dak - BD Power]

The PressureLoc works ONLY when the transmission controller sends the signal to lock up the torque convertor. When all conditions are set in the transmission for TC lock up, a signal is sent to the lockup solenoid, the TC locks up, and that signal is what is used to control the PressureLoc on and off.



When the PressureLoc is engaged the Valve Body throttle shaft is rotated slightly to increase pressure @ 30 psi.



If the TC lockup signal is off, the PressureLoc is off, and vise versa. Unless the PressureLoc is hooked up to the wrong wire it will only function when TC lockup is engaged.



Hope this help a bit.

 

[chucksram]

Strick-9,

When the converter locks-up, does it feel like a solid gear shift? Does this affect converter lock-up and O/D engagement or just tc lock-up? Please let us know what you did to block off the accumulator.



Thanks



Chuck

 

[Snow man]

Strick-9,is the 3-4 shift harsh with the accumulator plugged/blocked?. I'd like to try that trick on mine too,if it doesnt firm it to much.

 

[SlyBones]

Originally posted by Strick-9

FYI, the delay you speak of before shifting 3-4 or 4-3 is the time required for the 3-4 accumulator to fill/vent.

Well I guess I'll be the one to ask the stupid quesions. by "to fill/vent" I assume this means with transmission fluid. By blocking this off, is the transmission shifting with/without fluid in a place where it should/should not be? What are the side effects of this? IE clucth packs wear out much faster, bla bla bla. ( And I dont know that is true, just a sample answer. Nothing implied. )

 

[fox]

You guys who want to eliminate the the annoying lag into OD can do this.

Next time you remove the pan, as you lay under the trans ,with fluid dripping in your face, look for the plate just forward of the shift lever. There is 5 screws holding it on the Valve Body. Remove these 5 and you will get more fluid and a big spring. The piston may or may not fall out. Go find a 5/16 to 1/2 inch rod or bolt and cut it to 2. 35 inches. Less is ok more is not. If it is too long the plate will not seal and will leak.

Re-assemble it putting the spring in also. This will quicken up the lag to od. I don't think it will firm up the shift.

Lets see anything else?? Oh ya, no warrantee!!! But you will like it!!



fox

 

[chucksram]

Fox,

That sounds like what we used to do to the Turbo 350 trans with the short head bolt in the accumulator.



Chuck

 

[TxDieselKid]

I'm just guessing that Chris isn't going to tell us ALL the secrets of his ride. We already know that he is spiting out 1050cc of No. 2 only!



Andrew

 

[fox]

Chucksram, yes I'm familiar with those. The gm turbo trannys use the accumulator for the upshifts and the mopar only uses it for 1-2 shift and n-drive I beleive.

The accumulator I described is used only for od on our mopars.



fox