:::Any Ideas On What This Might Be (Transmission)

[clinebarger]

Originally Posted By: NDL
Originally Posted By: clinebarger
Sounds like a leak in the Input Clutch circuit, It will cause the EXACT symptoms you describe!

There are 3 areas of concern in the Input Clutch circuit.....
1. The Input Clutch Apply Piston inner sealing area gets worn & the Inner Lip Seal can no longer effectively seal against the piston.

2. GM used a "Short Lip" inner seal, This is an extension of #1.....The short Lip allows NO compensation for the Piston wearing.

3. Leaking-Shrunk teflon sealing rings on the Input Clutch Housing.



A combination of #1 & #2 is the usual culprit, Repairing this requires removal of the trans & partial tear down, The piston can most likely be saved by polishing the sealing surface with some fine emroy cloth. Replace the short lip inner seal with a Long Lip design that was factory in TH440-T4/4T60 units. Most aftermarket 4T65E seal kits come with the early long lip design seal.

The Input Clutch & Piston are worked to death in this unit, It is "On" in 1st & 2nd gears & "off" in 3rd & 4th gears.

I don't have any input about "seal conditioners" or other additives to band-aid this well documented issue. Good Luck!


I am not being lazy by asking; I did a search, and couldn't find information that the average person would/could understand:

I am reasonably new to Charlotte; it's times like this that stink, because I don't know who's what (which shops are good, and which to avoid). Even the better shops will have a customer gripe from time to time online...

All of that said: is what you described a major job? Is it a major teardown of the transmission? Got any ideas on what a repair might cost?

Thanks in advance


Trans-Go prints tech information about this issue right on their Shift Kit directions.

In GM's eye's....A worn Input Clutch Apply Piston at 120,000 miles is normal wear, The Zombie's at the plant were cutting/rolling the long style Lip Seals, The short style was implemented only to aid in assembly.

I've been out of the general transmission service Industry for awhile now & specialize in performance transmission builds, That includes a few 4T65E-HD units from supercharged V6's & LS4 V8's.

I would charge you the book time to R&R the unit, Plus 4 hours for tear-down, Inspection, & repair of the Input Clutch Cicuit, Filter & ATF......IF you really insisted on patching the unit.

6.8hrs to R&R X $85.00 = $578.00
4.0hrs to D&R X $85.00 = $340.00
1.0hrs to install Trans-Go shift kit = $85.00

Cost + 10% on the ATF, Filter & Shift Kit.

I would install new Solenoids & converter for free if the customer supplies them.

 

[NDL]

Originally Posted By: clinebarger
Originally Posted By: NDL
Originally Posted By: clinebarger
Sounds like a leak in the Input Clutch circuit, It will cause the EXACT symptoms you describe!

There are 3 areas of concern in the Input Clutch circuit.....
1. The Input Clutch Apply Piston inner sealing area gets worn & the Inner Lip Seal can no longer effectively seal against the piston.

2. GM used a "Short Lip" inner seal, This is an extension of #1.....The short Lip allows NO compensation for the Piston wearing.

3. Leaking-Shrunk teflon sealing rings on the Input Clutch Housing.



A combination of #1 & #2 is the usual culprit, Repairing this requires removal of the trans & partial tear down, The piston can most likely be saved by polishing the sealing surface with some fine emroy cloth. Replace the short lip inner seal with a Long Lip design that was factory in TH440-T4/4T60 units. Most aftermarket 4T65E seal kits come with the early long lip design seal.

The Input Clutch & Piston are worked to death in this unit, It is "On" in 1st & 2nd gears & "off" in 3rd & 4th gears.

I don't have any input about "seal conditioners" or other additives to band-aid this well documented issue. Good Luck!


I am not being lazy by asking; I did a search, and couldn't find information that the average person would/could understand:

I am reasonably new to Charlotte; it's times like this that stink, because I don't know who's what (which shops are good, and which to avoid). Even the better shops will have a customer gripe from time to time online...

All of that said: is what you described a major job? Is it a major teardown of the transmission? Got any ideas on what a repair might cost?

Thanks in advance


Trans-Go prints tech information about this issue right on their Shift Kit directions.

In GM's eye's....A worn Input Clutch Apply Piston at 120,000 miles is normal wear, The Zombie's at the plant were cutting/rolling the long style Lip Seals, The short style was implemented only to aid in assembly.

I've been out of the general transmission service Industry for awhile now & specialize in performance transmission builds, That includes a few 4T65E-HD units from supercharged V6's & LS4 V8's.

I would charge you the book time to R&R the unit, Plus 4 hours for tear-down, Inspection, & repair of the Input Clutch Cicuit, Filter & ATF......IF you really insisted on patching the unit.

6.8hrs to R&R X $85.00 = $578.00
4.0hrs to D&R X $85.00 = $340.00
1.0hrs to install Trans-Go shift kit = $85.00

Cost + 10% on the ATF, Filter & Shift Kit.

I would install new Solenoids & converter for free if the customer supplies them.


Oh my...

I thank you for your very helpful reply. I hate going in on the blind, and what you, and others, wrote, has been extremely helpful.

Thanks to you all!

 

[rshaw125]

Start asking around for the best independent transmission shop in your area. The last transmission I had rebuilt was by a shop that I found that way. They diagnosed it perfectly. Gave me the damaged part as a memento.
Get several opinions from recommended local shops.

Just called a buddy in Charlotte he swears by a place called Transart.Sorry I don't have a number for you.

 

[NDL]

Originally Posted By: rshaw125
Start asking around for the best independent transmission shop in your area. The last transmission I had rebuilt was by a shop that I found that way. They diagnosed it perfectly. Gave me the damaged part as a memento.
Get several opinions from recommended local shops.

Just called a buddy in Charlotte he swears by a place called Transart.Sorry I don't have a number for you.


That was very nice of you, and very much appreciated

!

You're a lifesaver; I actually live a stones throw from Charlotte, and Transart happens to be no more than 10 miles from my house.

Thanks again...I have been asking around and coming up short of recommended shops.

 

[NDL]

***


Okay...before taking it to a local transmission shop, I thought I would take it to a local technician who's very thorough, and seemingly qualified.

Here's his conclusion, which I think is odd:

On this 2008 Impala, a problem with the throttle body or accelerator will cause the car to have acceleration problems off the line, and cause for the car to lunge/shudder into first from a stop. Apparently, he has a background at a Ford dealership, and this was something he has seen there.

He also noted that the transmission didn't throw any problem codes, and a that a bad input clutch piston or solenoid issue should throw a code.

A code did come up with the throttle body/pedal.

What do y'all think?

 

[clinebarger]

A Input Clutch Leak will not set DTC's, The Slip Monitor/Counter is not active in 1st gear with the vehicle stopped, In fact most Slip Monitors are ONLY active when the Torque Converter Clutch is Locked/Commanded "On". But I'm not very familiar with your Impala's exact calibration.

A slipping Input Clutch is EASY to prove out by data logging the Input Speed Sensor (ISS) output vs Vehicle Speed Sensor (VSS) output.
Anytime the vehicle is stopped with the trans in Drive.....BOTH the ISS & VSS should read ZERO, If the ISS is reading ANY RPM at all in this condition.....The Input Clutch is not holding!

Data logging Info.....
It's easier for me to make some charts in paint, These are not to scale but gives you an idea of what I'm talking about....

1st chart shows what the ISS will do if the Input Clutch slips upon take-off, The Rpm's flare up before the vehicle starts moving, Once the Clutch engages....RPM's drops to zero then RPM's & MPH go up together.....They will not rise at the same rate because the 1st gear reduction.

2nd chart shows what the ISS will do when the Input Clutch Holds upon take-off.

It's very difficult to watch this in a live data stream because it happens so fast. Thus why I recommend Logging it.

 

[NDL]

Originally Posted By: clinebarger
A Input Clutch Leak will not set DTC's, The Slip Monitor/Counter is not active in 1st gear with the vehicle stopped, In fact most Slip Monitors are ONLY active when the Torque Converter Clutch is Locked/Commanded "On". But I'm not very familiar with your Impala's exact calibration.

A slipping Input Clutch is EASY to prove out by data logging the Input Speed Sensor (ISS) output vs Vehicle Speed Sensor (VSS) output.
Anytime the vehicle is stopped with the trans in Drive.....BOTH the ISS & VSS should read ZERO, If the ISS is reading ANY RPM at all in this condition.....The Input Clutch is not holding!


You have been very generous with your time and explanations. Thank you

.

At least I have a better understanding (logic) behind what's going on, and it's good to know that the input clutch won't throw codes.

Thanks again

 

[clinebarger]

I'm not sure you have Input Clutch issues, Your symptoms just sound like it........ I'm trying to help with one hand tied behind my back without access to the vehicle.....You should have the current DTC's diagnosed first!

I would like to know what DTC set? There are several for the Electronic Throttle.

 

[NDL]

Originally Posted By: clinebarger
I'm not sure you have Input Clutch issues, Your symptoms just sound like it........ I'm trying to help with one hand tied behind my back without access to the vehicle.....You should have the current DTC's diagnosed first!

I would like to know what DTC set? There are several for the Electronic Throttle.


Your assistance is appreciated. I don't know anything about/never heard of DTC (?)

The technician who worked on the car today is very thoughtful and logical about how he approaches problems. I didn't speak with him, but he claims there were codes that pointed to issues with the throttle body and accelerator pedal - both of which can be problematic on this year Impala.

He didn't see any codes for the transmission, but you're telling me the input clutch piston won't throw codes.

In the meantime, he cleaned and lubricated the throttle body, as a means to see if the problem was solved.

My Wife tried to provoke the shuddering throughout the day (after the TB cleaning), and she couldn't.

My only concern is that the transmission issue is separate from the throttle body/accelerator pedal issue, and by coincidence, the technician saw codes pointing to the TB.

Saturday I plan on taking the car to a transmission shop, though the info you have given me is very helpful. Sadly, I don't trust any shop, as mediocrity is rampant today.

I do thank you for your time, and all of the info you've given me. This issue with the 4T60E is well documented, and I have a hunch that the technician may have stumbled upon something unrelated to the shuddering issue. Time will tell.

 

[clinebarger]

DTC=Diagnostic Trouble Code, Same as "Codes"