Slow engage '04 Buick LeSabre 4T65E

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I recently bought a '04 Buick LeSabre with 82K. I am having a problem where when the car is cold, it doesn't want to engage in any gear, forward or reverse. Let it warm up and it seems OK. There are no CEL codes indicated I have seen this problem mentioned in other GM's with this transmission. I doubt the transmission fluid/filter was ever changed, so that is my first step. Since this seems to be a common problem, I am wondering if there is anything else I should do or look for while the car us up and the pan is down? Thanks in advance!!
 
Originally Posted By: Russ300
I doubt the transmission fluid/filter was ever changed, so that is my first step.


That's not a wicked amount of miles on a factory fill.

If that doesn't fix it...
Bad pressure control solenoid, or sticky spool valve
 
PCS probably failing or plugged up. It would be hard finding a transmission shop that wouldn't want to sell the entire rebuild.
 
Not sure if this is the possible issue, but I used to own a 1979 Mercury Cougar auto trans shifter on the column. I bought it used in about 94 and kept it till 99. It seemed to run and shift fine but the last couple of years when the temps would drop below about 0 It would not shift out of park. It was locked in park. After the floor heater ran for about 10 minutes it would suddenly be able to shift. As it turns out it was the shift cable. The shift cable was a cable enclosed in hard plastic tube that had grease inside. Apparently the grease got old and would freeze and make shifting the shift lever very difficult... until the engine heat or air temp warmed up the grease and then it would be fine No way to replace grease so my mechanic had to find a used one from a junkyard and then replace it... then it worked fine.
 
Originally Posted By: beast3300
PCS probably failing or plugged up. It would be hard finding a transmission shop that wouldn't want to sell the entire rebuild.


Yep buy the kit that includes all the solenoids on ebay. Replace them all and change fluid to Dexron V1.
 
Thanks for the info!! I agree from a mile perspective on the trans fluid, but it has been in there almost 14 years. Pulling the stick, it shows a dark red.
 
On your'04 Buick LeSabre + 4T65E:

1) I'd consider a fluid and filter change AND get more magnets to go on the oil pan where
the diff is (towards right side) there's not a lot of room on the pan anywhere else, since it is zero
clearance and the filter sits on the pan.

2) 2 yrs ago I put neodymium bar magnets on the filter it's self on the metal next to the oil pick-up,
I used a compass to make sure the N pole faced the same way, making the metal plate the S pole,that helps pick
up lots of wear metals before they contaminate the shift solenoids and Pressure control solenoid.
This spring I'll drop the pan and see how it went while I'm in there. I'll take pics.

3) For slow / delayed shifts I've been using Seafoam Trans Tune, my 4T65E is so bad over time, that
40% of the ATF is Trans Tune! It looks like it thins out the ATF so valves & solenoids will cycle.

4) If you can get it to improve, watch out for other problems to showing up, like delayed / harsh shifts, often
shift accumulators with new stiffer Trans-Go 4T65E shift kits work well, does in mine.

5) See these PDFs on 4T65E:

GM 4T65-E COMMON TRANSMISSION PROBLEMS
https://app.box.com/s/n3eaao2pzopusd3bx8qrd7xmgaibj3n1


GM 4T65-E TRANSMISSION UPGRADE PARTS
https://app.box.com/s/drsf61akkxu6bw2a2qcnl1ajuhgkh9hx
 
*First thing to do with ANY transmission issue is to check the fluid level!
*Second thing to do is SERVICE the unit with a GOOD (OEM preferably) Filter & check for TSB's that pertain to your vehicle.

This sounds like Converter Charge Drain-Back issue.....Which will be pretty chronic on a 4T65E if the converter drain-back valve isn't holding as the cooler discharge fitting is way below the torque converter!!
The Discharge Fitting is the one that points straight down.

*Test....
Raise & support vehicle.
Run the engine to operating temperature (This will ensure the converter is fully charged with ATF.
Disconnect the Discharge cooler line at the transmission (DO NOT remove the fitting)
Swing the line away from the fitting.
A LITTLE ATF will come out of the fitting.
IF the check Valve is holding.....ATF will NOT continue to drip/leak out of the fitting!
IF it continues to drip....Pull the fitting.
IF the check valve assembly is part of the fitting....Replace the fitting.
IF the check valve assembly is NOT part of the fitting....Removal & Partial disassembly of the transmission is required to repair/replace the Channel Plate.
***The Channel Plate CAN be replaced with the trans in the car, But I don't really like doing it that way***

If there is a leak where the fitting meets the case.....The converter charge will be lost as well, You didn't mention leaks?
 
Originally Posted By: i_hate_autofraud

On your'04 Buick LeSabre + 4T65E:

1) I'd consider a fluid and filter change AND get more magnets to go on the oil pan where
the diff is (towards right side) there's not a lot of room on the pan anywhere else, since it is zero
clearance and the filter sits on the pan.

2) 2 yrs ago I put neodymium bar magnets on the filter it's self on the metal next to the oil pick-up,
I used a compass to make sure the N pole faced the same way, making the metal plate the S pole,that helps pick
up lots of wear metals before they contaminate the shift solenoids and Pressure control solenoid.
This spring I'll drop the pan and see how it went while I'm in there. I'll take pics.

3) For slow / delayed shifts I've been using Seafoam Trans Tune, my 4T65E is so bad over time, that
40% of the ATF is Trans Tune! It looks like it thins out the ATF so valves & solenoids will cycle.

4) If you can get it to improve, watch out for other problems to showing up, like delayed / harsh shifts, often
shift accumulators with new stiffer Trans-Go 4T65E shift kits work well, does in mine.

5) See these PDFs on 4T65E:

GM 4T65-E COMMON TRANSMISSION PROBLEMS
https://app.box.com/s/n3eaao2pzopusd3bx8qrd7xmgaibj3n1


GM 4T65-E TRANSMISSION UPGRADE PARTS
https://app.box.com/s/drsf61akkxu6bw2a2qcnl1ajuhgkh9hx




Are those articles written by you? ......You could remove all the negative slander & just present what seems to be decent information. I could post some pretty slanderous things about Sonnax & Trans Go!
 
Originally Posted By: Linctex
Originally Posted By: Russ300
I doubt the transmission fluid/filter was ever changed, so that is my first step.


That's not a wicked amount of miles on a factory fill.

If that doesn't fix it...
Bad pressure control solenoid, or sticky spool valve

It is a lot of miles especially with a poorly designed transmission like the 4T65E. Likely the filter is impaired, the lonely magnet has long since been saturated and debris has been attracted to the solenoids.
 
clinebarger,

If you had negative experiences with Sonnax or Trans-Go and the part numbers that have problems,
please post it so we can avoid those parts!


Thanks!
 
Originally Posted By: i_hate_autofraud


clinebarger,

If you had negative experiences with Sonnax or Trans-Go and the part numbers that have problems,
please post it so we can avoid those parts!



Thanks!


My issues with Sonnax & Trans-Go aren't with their 4T65E products (Besides Trans-Go never updating their application guides)
There are enough REAL issues with 4T65E's for them to make healthy profits.

For other units Sonnax invents parts for issues that DO NOT exist.
4L60E parts that do nothing to help the end user.....
77805E-K TCC Apply Valve, This valve & bore do not wear.
77754-35K Forward & Reverse Abuse valves. These valve hardly ever move much less wear.
77754-42K 3-4 shift valve kit, Not a wear item (requires expensive tooling)
77964-04K 3-4 sequence valve kit, Not a wear item (requires expensive tooling)
77998-03K Pinless accumulator piston, Limits accumulator ranges, Breaks parts when used in the 2nd accumulator.
77701-076 Servo release check valve, Does Not work as advertised.....Burns frictions.
77733-11S & 77733-12S Billet Input Shafts, They are splined into a Aluminum Drum for [censored]'s sake, Stock Shafts DO NOT break.

Most Trans-Go product problems revolve around their accumulator springs breaking, Pressure Blow-off assemblies being miscalibrated, And mismachined boost valves..... The TG 4T65E accumulator kits limit accumulator range...So spring breakage is rare for this particular kit.
DO NOT use the Blow Off kits on GM 4L80E & Ford AODE/4R70W units.
4L60E & 4L80E Boost Valves are mismachined/have excessive clearance issues.
 
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I seem to remember an issue when the inner surface of the input clutch piston wears, the piston seal (a poorly designed item) will leak internally, causing similiar symptoms you describe.. There are revised aftermarket kits available with better sealing lips on the seal itself. Unfortunately, it is a big deal to replace this. A possible area to look into.
 
Last edited:
Originally Posted By: Lubener
I seem to remember an issue when the inner surface of the input clutch piston wears, the piston seal (a poorly designed item) will leak internally, causing similiar symptoms you describe.. There are revised aftermarket kits available with better sealing lips on the seal itself. Unfortunately, it is a big deal to replace this. A possible area to look into.


Input Clutch piston wear doesn't generally affect Reverse engagement times, Yes.....It IS applied in reverse as the "driving member" but Reverse Boost takes care of any leakage that is present.

The use of earlier "Long Lip design seals" from 440-T4/4T60 will fix Input Clutch issues, Most aftermarket 4T65E paper/rubber kits come with the long lip seals now.
 
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