Tranny overdrive Question???
09-25-2003, 01:08 PM
#11
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I know this is nerve wrecking by now, but I have the problem at 30 mph, 25mph, 40 mph without OD even being thought of yet. Now, is this a tranny issue? Or its still normal :?:
09-25-2003, 03:07 PM
#12
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It is totally normal for the rpms to fall dramatically when your foot is lifted below ~45mph. Above torque convertor lockup speed(40+ -- dependent on load, throttle position, engine temp, etc.) once the torque convertor has locked up the rpms should hold UNLESS you touch the brake. In fact, that is the best way to test if the lockup is working.
If you're not coasting uphill with vehicle speed rapidly dropping, you shouldn't see significant tach movement above 55 mph when you re-apply the throttle.
If you're not coasting uphill with vehicle speed rapidly dropping, you shouldn't see significant tach movement above 55 mph when you re-apply the throttle.
09-25-2003, 04:11 PM
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Originally Posted by jr's3800
yeah all of this is normal for the 4T60, 4T60-E, 4T65-E... When you tap the brake pedal, remove your foot from the accellerator, or depress the accelerator to a certain degree the Torque Converter Clutch will dissengage... When you put your foot back on the accelerator, the PCM will see the load factors, and command the TCC to fall into lock up mode... you are still in OverDrive, but the TCC is engaging and disengaging due to various driving conditions... All a normal part of these transmissions... 
09-26-2003, 02:33 AM
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No problem... A lot of people see this as a problem... But it a normal operating factor of these transmissions.... some of the newer 4T65-E'* have a PWM I think, or Pulse Width Modulator valve, and the PCM will control apply at various percentages, making the application of the converter smoother... In the 4T60-E'* the bonnevilles didn't use the PWM for 92-95.... Not sure about 96-97... I have driven a few cars with the 4T45-E'* and the 4T65-E'*, I like the 4T60-E better as far as how it performs... But the 4T65-E'* apply the converter at varying degrees, allow for lower reves from the engine, and a little better fuel effiency... But for all of the abuse I have given my 4T60-E, all I can say is that its a winner... [/quote]
THanks Don. I see know why the car does it. The simple breakdown of the different trannies these cars have. Now I understand.
[/quote]THanks Don. I see know why the car does it. The simple breakdown of the different trannies these cars have. Now I understand.
09-26-2003, 03:37 AM
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Originally Posted by jr's3800
Originally Posted by aviator327
Outstanding. I like it.
Off topic..... Aviator, I should get a set of those " Bonneville SE " emblems that you have on your doors... That would throw a lot of people off about my car.... I'll have the 92 badges and the 94-95 front grille....
No one will know its a " Series II 3800 " 
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