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Discussion Starter #1 (Edited)
Comments, corrections and suggestions are welcomed. No questions please.

Last updated 1/30/2019

A what-body? - refers to the GM vehicle "platform": (relevant years are included)
B-body: Chevy Caprice, Buick Roadmaster, Olds Custom Cruiser (1991-1996)
D-body: Cadillac Fleetwood (1993-1996)
F-Body: Camaro & Firebird (1993-2002)
Y-Body: Corvette (1992-1996)

4L60E similarities:
All 4L60E/4L60/700R4 have the same gear ratios from the factory.
1 - 3.06:1
2 - 1.63:1
3 - 1.00:1
4 - 0.70:1
There is a Sonnax 77284-K aftermarket gearset available which reduces 1st and 2nd to 2:84:1 and 1.55:1; it is ~$700.

Are LT1 sedans and wagons the same?
Yes. All '94-96 wagons came with LT1s standard.

What about '94-96 Impala SSs vs. 9C1s vs. civilian cars?
If they had the LT1 engine, they're all the same.

GM B and D-body 4L60E differences by year:
’94: First year of electronic controls in the valvebody (versus the ’93 4L60, which did not have this). The PCM controls line pressure (holding power and shift feel), 1-2, 2-3 and 3-4 shift points (rpm), and TCC lockup (timing and in the ’95-up models, apply feel). Everything else is done mechanically/hydraulically.

’95: Added a Pulse-Width Modulation Torque Converter Clutch (TCC) apply solenoid to control the feel of the TC clutch lockup (blamed for many 4L60E problems; TransGo HD2-C bypasses this, or you can stake the TCC apply valve in place). Also changed 3-2 downshift solenoid mid-year (see '96, below).

’96: PWM TCC plus a different tailhousing design with new-style Vehicle Speed Sensor (VSS). Also changed the 3-2 downshift solenoid in mid-1995 from TBD to TBD. There was a new manual valve added along with a relief port over the manual valve on the valve body casting with this change. This solved the low/reverse clutch release problem and makes the TransGo manual valve mod unnecessary (see ATRA bulleting 2002-46).


How to visually tell B and D-body transmissions apart by year:
'94: VSS on driver's side of tailshaft housing, and when you remove the torque converter, there is no "PWM" on the front surface of the pump. In the pan, only one solenoid on the front face (relative to the transmission in the car) of the valvebody. Inside of the wiring connector is purple.

'95: VSS on driver's side of tailshaft housing, and when you remove the torque converter, there is "PWM" in raised letters on the front surface of the pump. In the pan, there are two solenoids on the front face (relative to the transmission in the car) of the valvebody. Inside of the wiring connector is green.

'96: VSS on passenger side of tailshaft housing, and when you remove the torque converter, there is "PWM" in raised letters on the front surface of the pump, and around the outside of the pump there are raised ridges. In the pan, there are two solenoids on the front face (relative to the transmission in the car) of the valvebody. There will be two brackets on the top rear of the case for the rear O2 sensor wiring. Inside of the wiring connector is green.

9C1 Trans differences:
9C1 4L60Es come with a “1st gear lockout” function that is a tab secured next to the shift linkage by the oil pan bolts. This can be removed by removing the two bolts and then reinstalling and torqueing them to 9ftlbs.

LT1 vs. L99 Trans differences:
4L60Es in L99 4.3L V8 cars come with a smaller servo than the LT1 5.7L V8 cars, which come with the cor-“vette” servo for more holding power on the 1-2 and 3-4 shifts. If an L99 4L60E is going behind an LT1 engine, the servo assembly should be swapped over before installed (easily accessible on the passenger-side of the case). TransGo also sells a vette servo that can be installed as part of their 4L60E HD-2C reprogramming kit, or you can get one out of a junkyard 4L60E that was behind a 5.3L or larger V8. Also, the boost valve is smaller (again, Transgo fixes), and it is possible that some holes in the separator plate are smaller. While we're talking servos, Sonnax and others make larger ratio servo pistons for both 2nd and 4th gear. There may be some minor differences inside the valvebody in the springs.

Cadillac Fleetwood V4P differences:
Cadillac spec'd the Fleetwood towing package (V4P) to tow up to 7000lbs. The transmission was factory setup to shift a bit firmer. If you swap one of these transmissions into your car, be careful how much line pressure you add in via the PCM. Each vehicle and package generally had some small tweaks (L99 vs. LT1, truck vs. car), so be aware that the shift feel will probably not feel the same after a swap.

Can I use a 4L60E from a...?
Note: This info assumes you can swap or remove cooler line fittings, electronics modules, tailshaft housings, and shifter brackets yourself.
Note: 4x4 vehicles have a shorter and different output shaft which cannot be swapped without partially disassembling the transmission. It's a relatively quick procedure for someone (like a local shop) who knows how to do it and only snapring pliers are required, but it's not for the novice.
1. CK Truck or Fullsize Van: Any case with a "K" casting in the upper passenger side out of a '94-97 GM full-size 2WD pickup will work. 4WD transmissions have shorter tailshafts which cannot be swapped without disassembly. 4L60Es behind the 305 V8 and 4.3 V6 came with the smaller '..553' servo which should be replaced with an '..093' "corvette" servo. Other V6 versus V8 internal differences are unknown. Using 4L60Es from LS-engined trucks will probably encounter the same issues as ones from LS1 camaros (see below).
2. S10/Blazer (2WD V6 only): Probably. 4L60E was used '93 up to '96???. You will need to swap the servo assembly out of your b-body 4L60E (make sure to put a new blue o-ring on the servo cover). You will have to swap the longer shift shaft assembly with electronics for the shorter B-body one without electronics. Other mounting, electrical and internal differences are unknown at this time.
3. F-body (Camaro-Firebird) LT1 4L60Es from '94-97 will fit. They also have the "corvette" servo.
3b. LS 4L60Es from '98 up will NOT work without swapping the input shaft to the earlier style, which requires partially disassembling the transmission. The LS 4L60E converter sticks out 10mm farther forward than the LT1 ones do.
3c. V6 (3.4L and 3.8L) transmissions have incompatible bellhousings and will not work.
4. Corvette 4L60Es from '94-96 are identical internally (and obviously have the "corvette" servo). The case will need to be modified to bolt the exhaust hanger bracket to the vette case.
5. 2001-up GM 4L60E/4L65E powertrains added an input shaft speed sensor on the backside of the pump that allows the PCM to monitor and control converter slippage. You can use control one of these newer units with an LT1 PCM as it doesn't care about that sensor. I don't think it's true the other way around.

Can I use a 4L60 or 700R4? from a '91-93 Caprice or other vehicle?
Don't bother. You could, but it's not worth the effort. The internal rotating parts are basically identical but everything else is different. Sell it and get a 4L60E.

Caprice Transmissions from '8x-96:
198?-1990 - 700R4 (also 200-4R on some models)
1991-1993: 4L60
1994 - on : 4L60E
 

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Discussion Starter #2 (Edited)
Year to Year B/D-body Swap Guide:
To put a ’94 4L60E into a ’95 car: Direct bolt-in. The PCM must be reprogrammed with ’94 transmission base code to avoid setting a silent code (Check Engine Light (CEL) does not illuminate, but code stored in memory). Trans will operate normally without reprogramming, but the silent code (code 83) will inhibit TCC lockup. Three potential fixes (any one will work); 1. reprogram PCM so it doesn't look for the PWM solenoid, 2. Add the wire into the harness or swap the '95-96 harness into the car ALONG WITH the internal transmission harness with the PWM solenoid connected but leave the solenoid in the pan, not installed in the valvebody as a '95-96 setup would have, or 3. wire up a manual TCC lock switch by which you can lock and unlock the converter yourself.

To put a ’94 4L60E into a ’96 car: The ’96 tailshaft housing and VSS must be installed on the ’94 4L60E before the trans can be bolted into the car. The PCM must be reprogrammed with ’94 transmission base code to avoid setting a silent code (Check Engine Light (CEL) does not illuminate, but code stored in memory). Trans will operate normally without reprogramming, but the silent code (OBD2 equivalent of code 83) will inhibit TCC lockup. Three potential fixes (any one will work); 1. reprogram PCM so it doesn't look for the PWM solenoid, 2. swap the '95-96 harness into the car ALONG WITH the PWM solenoid connected but leave the solenoid in the pan, 3. wire up a manual TCC lock switch by which you can lock the converter.

To put a ’95 4L60E into a ’96 car: The ’96 tailshaft housing and VSS must be installed on the ’95 4L60E before the trans can be bolted into the car. Technically, the 3-2 downshift solenoid should be swapped also, but experience shows that it is not required.

To put a ’95 4L60E into a ’94 car: No mechanical mods required. The TCC valve mod must be performed to remove the PWM function. The trans will operate normally without the mod but TCC lockup will not work, so highway and cruising gas mileage will suffer and more heat will be produced in the transmission.

To put a ’96 4L60E into a ’95 car: The ’95 tailshaft housing and VSS must be installed on the ’96 4L60E before the trans can be bolted into the car. Technically, the 3-2 downshift solenoid should be swapped also, but experience shows that it is not required. No other modifications are necessary.

To put a ’96 4L60E into a ’94 car: The ’94 tailshaft housing and VSS must be installed on the ’96 4L60E before the trans can be bolted into the car. The TCC mod must be performed. The trans will operate normally without the TCC mod but TCC lockup will not work, so highway and cruising gas mileage will suffer and more heat will be produced in the transmission.

TCC Mod (method 1):
An additional wire must be run from the PCM connector D pin 6 to pin "U" on the trans harness for the TCC to work. Also, the PCM must be reprogrammed with ’95 transmission base code. In my opinion this is more work than its worth due to the amount of labor involved in properly routing an additional wire into the powertrain wiring harness.

TCC Mod (method 2):
Leave the PWM solenoid unplugged but installed. On the valve directly to the right of the PWM solenoid – push that valve all the way towards the outside of the valvebody, and stake it into place. That’ll lock keep the valve acted on by the PWM in the full-open position and it’ll function like a '94 style lockup. No PCM reprogramming required. How to.


Notes for '91-93 B-body owners: You should be able to use a 2WD truck transmission as a swap donor, but I would recommend the motors match (5.0 donor =5.0 car only, 5.7 donor could be used in a 5.0 car). Also, check to make sure your electrical connectors match. GM changed the connector plug at least once between 1987 and 1993. Tailshaft housings house the VSS assembly which can be removed and swapped but make sure you get the gears and everything swapped over correctly.

I am no expert on this - anyone with more knowledge, please PM me and I will gladly update this information.
 
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