Delayed engagement (4T65E)

[Joelfke]

Coming off a stop the motor revs a bit and the car doesnt move much and then it bangs into gear with a jolt and then im in first. If I were to rip out the trans and pull it apart what can i fix to prevent this? (this trans has other issues so pulling it apart for this is only the beginning

oh yea. the car is an 04 chevy monte carlo 3.4L OHV with the 4T65E

[RedZMonte]

im by no means a trans expert... but it doesn't sound very good... slipping clutches? next thought would be TQ converter or it could be simple like a bad valve or spring or something like that...

Are you getting a Check engine light?

S

[bszopi]

Could be as simple as the tranny being low on fluid...

[Joelfke]

well like i said there are other problems...delayed engagement being one. Currently the trans set the P1811 code max adapt shift or something of that nature, and most techs i work with say the EPC needs to be replaced. When the code is set it jumps the line pressure to max. so im getting harsh shifts and long shift times. it shifts from 1-2 and i feel it take awhile to shift before i get acceleration. same for 2-3 except 2-3 takes longer and 3-4 actually feels somewhat smooth compared to the others. Hence why im going to pull the trans apart. the high pressure is destroying the clutch packs and the shifts are getting harsher by the day. On top of this, when i slow down to make a turn all seems well and good but then when i lightly press the gas pedal after making the turn it bangs into gear. Not sure if that is because of the high pressure or if the pressure switch in the trans is bad and it doesnt know which gear to be in. (if that makes any sense at all)

any help would be greatly appreciated as i am a GM tech but have only been wrenching for a couple years. This would be my first trans teardown other than the minuscule schooling ive gotten

[Joelfke]

Could be as simple as the tranny being low on fluid...

its leaking out of the p/s axle seal but ive kept a close eye on the level.

also the fluid smells burnt but it is still cherry red. ive replaced the fluid at 60000 miles for a lab in school to replace the filter and i put lucas no slip stuff in there and that made things better temporarily but its steadily gotten worse. There is now 71000 miles on the clock

[86FieroSEv6]

When you replaced the filter, did ya'll replace the lip seal for the filter pickup tube where it enters the valve body? Have you performed a fluid exchange (flush) using the correct fluid? If there are sensor issues, those must be cleared up before blaming the tranny. The fact that it "bangs" into gear suggests that "slipping" is not your issue.

[turboD]

P1811 is the DTC for maximum adapt /long shift. If you have access to a Tech 2, look at the shift adapts - they'll be at 29.95lbs on most of the cells. The problem is the pressure control solenoid. the solenoid is stuck, causing low pressure thruout the trans. If you pull the lower pan, you'll find very little clutch dust. To change the PC Solenoid, you don't need to pull the valve body, the clip is accessable. I would also suggest replacement of the TCC solenoid at the same time. D

[Joelfke]

When you replaced the filter, did ya'll replace the lip seal for the filter pickup tube where it enters the valve body? Have you performed a fluid exchange (flush) using the correct fluid? If there are sensor issues, those must be cleared up before blaming the tranny. The fact that it "bangs" into gear suggests that "slipping" is not your issue.

yes the lip seal was replaced as well. i have not flushed the fluid but put in the correct fluid when i drained it to do the filter change. im aware that the TC still would have old fluid on a filter change, but like i said its not like the fluid was brown and dirty.

[robertisaar]

Lucas no-slip is FTL and will almost always contribute to the demise of a tranny... it's nothing more than a way to cover up an issue before selling a vehicle.

[Joelfke]

P1811 is the DTC for maximum adapt /long shift. If you have access to a Tech 2, look at the shift adapts - they'll be at 29.95lbs on most of the cells. The problem is the pressure control solenoid. the solenoid is stuck, causing low pressure thruout the trans. If you pull the lower pan, you'll find very little clutch dust. To change the PC Solenoid, you don't need to pull the valve body, the clip is accessable. I would also suggest replacement of the TCC solenoid at the same time. D

exactly. I hear the EPC goes bad on these quite often. when i replaced the filter i did notice minimal/normal amounts of clutch material on the magnet. Changing the pressure solenoid wont fix the delayed engagement though would it? It would definitely fix the harsh shifts and shift times i believe

[86FieroSEv6]

Consider this. If the EPC is slow to react, then line pressure will be likewise. Therefore a pressure spike occurs and you get the "bang". I have used Trans-X just prior to doing a flush to clean up varnish in the sealing ring bores and actuators. Modern fluids have a rather odd smell compared to the old stuff which can be mistaken for a burned odor, but when you smell truly overheated fluid there is no mistaking it.

[Joelfke]

ive smelt badly burnt trans fluid. its a one of a kind smell. my trans has a HINT of that smell. it is in no way overwhelmingly bad

[86FieroSEv6]

Probably from the contamination of an incomplete fluid change due to only doing the filter drop.

[turboD]

The problem is that with the low pressure, the servo won't apply the low band properly, thus the delayed engagement. A quick test for the low roller clutch slip is to put the trans in manual low/2nd. The delayed engagement/slip will go away.
Just a word of caution, anything that can cause low line pressure can cause the delayed engagement/trans slip. The PC sol is the most likely cause of the condition - I've replaced about a dozen since the first of the year. D

[Joelfke]

thats actually a major relief. I was afraid it was ripping apart splines and gears when really its only hurting the clutch packs...which i plan on replacing anyway. Or am i completely wrong in saying that...