4l80E differences???????

[625fireman]

Do any of you know what if any differences there are between a 94 and 97 4l80E???
I am scrapping a 97 that has a recent rebuilt 4l80 in it, and I am in need of one for my 94. The only thing I see is the shift rod into the trans is longer to incoporate the nuetral safety switch. I am hoping to just swap out the shift rod from mine into the 97 and bolt in and go. Hahahaha

 

[THEFERMANATOR]

The 97 will go into the 94, but a 94 will not go into a 97. You will have to swap shift shafts, and either make new cooler lines, or run adapter fittings(91-96 had both cooler lines up front and used 5/16" lines, 97+ had one in the front and one in the rear and used 3/8" lines). There are companys out there that make adapter lines and sell the fittings to reuse your old lines on the new trans.

 

[tanman_2006]

I too would like to know the differences. I know at some point wiring harnesses changed. I think 92-93 were an old style, I would guess 94-95 are also different than 96 and newer (but I don't know that for sure). Late 99 started stronger input shafts.

 

[THEFERMANATOR]

91-93 used old style wiring harness, and a different valve body due to a different lockup frequency and eliminiated teh PWM cleaning cycle for 94. 94 is a one year only trans in that it still used the shift shaft for old style mechanical shift linkage, had no bosses for a NSBU, but the new style wiring harness and lockup setup in the valve body. It should also be noted that 91-93 with factory PROMS can not use the newer 94+ lockup solenoid, but uses it's own style(455MHZ VS the 805 of the newer style. Don't quote me on the exact frequencys off the top of my head). 95-96 is just like 94 except they have bosses for the NSBU and the newer style shift shaft for a shift cable instead of mechanical shift linkage. 97 started the rear oiler as it is called where they enlarged the fittings for the cooler lines and made it so one was in the front and one was in the rear. Starting late 99 GM upgraded them again with a solid input shaft, a 1/4" wider band, and a few other internal changes to improve oiling. There were also other running changes through the years to correct problems and failure prone areas, and I'm sure many other things I'm forgetting right now.

Also a 94 trans will fit into any 94 without issue, but cannot be used in a newer truck without finding some way to modify it to accept a NSBU. A 95-96 trans can be used in a 94-96 plug and play so long as you use the correct shift shaft. A 97+ can go into a 96- with afapter lines and fittings and using the correct shift shaft. If you put a 94+ into a 91-93, you either have to use the 91-93 valve body, or get a custom PROM for your controller for the new style lockup solenoid.

 

[tanman_2006]

Now that there is good info!

 

[625fireman]

Now that there is good info!

Yes it is!!!!!!! A lot more than I expected to get..

Thanks Ferm your awesome!

 

[billyg38120]

91-93 used old style wiring harness, and a different valve body due to a different lockup frequency and eliminiated teh PWM cleaning cycle for 94. 94 is a one year only trans in that it still used the shift shaft for old style mechanical shift linkage, had no bosses for a NSBU, but the new style wiring harness and lockup setup in the valve body. It should also be noted that 91-93 with factory PROMS can not use the newer 94+ lockup solenoid, but uses it's own style(455MHZ VS the 805 of the newer style. Don't quote me on the exact frequencys off the top of my head). 95-96 is just like 94 except they have bosses for the NSBU and the newer style shift shaft for a shift cable instead of mechanical shift linkage. 97 started the rear oiler as it is called where they enlarged the fittings for the cooler lines and made it so one was in the front and one was in the rear. Starting late 99 GM upgraded them again with a solid input shaft, a 1/4" wider band, and a few other internal changes to improve oiling. There were also other running changes through the years to correct problems and failure prone areas, and I'm sure many other things I'm forgetting right now.

Also a 94 trans will fit into any 94 without issue, but cannot be used in a newer truck without finding some way to modify it to accept a NSBU. A 95-96 trans can be used in a 94-96 plug and play so long as you use the correct shift shaft. A 97+ can go into a 96- with afapter lines and fittings and using the correct shift shaft. If you put a 94+ into a 91-93, you either have to use the 91-93 valve body, or get a custom PROM for your controller for the new style lockup solenoid.

This information is only PARTICALLY CORRECT. There is no such "different valve body due to a different LOCK UP FREQUENCY". What is this LOCK UP FREQUENCY? Elimination of the PWM cleaning cycle? Do you mean the TCC PWM cleaning cycle that is NOT REAL? What is the 91-93 PROM can't be used in a 94+ BECAUSE OF THE lock up solenoid?

WHERE DID YOU LEARN THIS??

 

[tanman_2006]

I wish my phone had a popcorn smiley...

Source Unknown

 

[Chevypoor]

Here you go! opcorn: opcorn: One for me one for you!

On the subject when they did they start using the 4L85E? My understanding is that it is a 4L80E with stronger internals and would bolt up with I am assuming the differences noted already.

 

[tanman_2006]

I am not sure but would think a 99-00 4l80 would be a 4l85

 

[Chevypoor]

That was kinda what I was thinking. I also think it depended on what motor it was behind. For example our 02 8.1L Burb had a 4l85e but I am pretty sure the 6.0l gas motors had a 4l80e. The gcvw might have something to do with it as well.

 

[THEFERMANATOR]

This information is only PARTICALLY CORRECT. There is no such "different valve body due to a different LOCK UP FREQUENCY". What is this LOCK UP FREQUENCY? Elimination of the PWM cleaning cycle? Do you mean the TCC PWM cleaning cycle that is NOT REAL? What is the 91-93 PROM can't be used in a 94+ BECAUSE OF THE lock up solenoid?

WHERE DID YOU LEARN THIS??

OK, it's been a long time since I messed with 4L80E's so I went and dug out my manual. I was incorrect that it isn't the TCC but the PCS that changed from 93 to 94(it was the ALLISON that changed TCC from 05 to 06, MY BAD). Since I have my manual of changes over the years, let me list them off straight from the service manual(Guess my memory has slipped some doing ALLISON's and only doing them). The case conenctor plug that was prone to leaking changed from 92-93. The force motor AKA PCS that controls the line pressure changed from 93 to 94. It went from a 292.5HZ(cycles per second) to a 614HZ(cycles per second) and eliminated the cleaning cycle every 10 seconds that was used on the previous 91-93 force motor. Also a new spacer plate was used for 94 and the torque signal compensator valve in the accumualtor housing was eliminated. In order to use the older style force motor and accumualtor housing you have to swap valave bodies I have been told(have not tried this myself to verify it, but many have done this swap and had issues until they either changed PROM's or valve bodies). One can use the new style trans and force motor with a PROM update to eliminate the cleaning cycle and change the force motor cycles per second. If one uses a new style trans with an old PROM the force motor will likely live a short life at the different HZ, and you will have a pressure spike every 10 seconds when it commands a cleaning cycle. And if it happens to shift during said cleaning cycle you could get one funky shift with the pressure fluctuation. ON EDIT(in case somebody in the future references this thread) The valve body difference comes into play if you put a 94+ trans into a 93- truck you either have to use the 91-93 valve body, OR open up the 94+ valve body and drill out the seperator plate as well as swap force motors to make it work. So yes there is a difference, but it is in the seperator plate and passages drilled or not drilled. Otherwise you have to use the new style PROM that eliminates the cleaning pulse every 10 seconds.

Beggining in production for 99(trans built in 99) the planetary pinions were made 10% thicker and a .041 shim was added due to the thicker parts. In 97 the sun gear shaft was changed for a shorter bearing journal, and then in 99 it was changed again to accomadate the .041 shim. And in 97 the sun gear got deeper oiling grooves as well as a reduced diamter oiling hole. Starting in 97 the rear ring gear shaft changed from the hollow version to the solid version, and oiling passages were added in the splines of the rear ring gear and bearing race. Also at the start of production for 99 the manual 2nd band was changed from .995 to 1.250. Begining in march of 01 the overrun roller clutch was also redesigned as well as the ramp angle on the inner cam that the clutch enagages against. These change also included a new design roller clutch return spring, a new design overdrive planetary carrier, and a new design turbine shaft that was cross drilled.

Like I said earlier, I tried going off of memory and doing the best I could. It has been over 5 years since I had a 4L80E, and haven't worked on much but the ALLISON since. Hopefully this info STRAIGHT FROM THE MANUAL OF DESIGN CHANGES is close enough for you.

 

[THEFERMANATOR]

That was kinda what I was thinking. I also think it depended on what motor it was behind. For example our 02 8.1L Burb had a 4l85e but I am pretty sure the 6.0l gas motors had a 4l80e. The gcvw might have something to do with it as well.

The 85 has 5 instead of 4 gear planetarys is what I could find for the differences between the two. It only increased the rated torque input 10 foot pounds between the two.

 

[billyg38120]

responses are in Italics.
YOU SAY:
The force motor AKA PCS that controls the line pressure changed from 93 to 94. It went from a 292.5HZ(cycles per second) to a 614HZ(cycles per second) and eliminated the cleaning cycle every 10 seconds that was used on the previous 91-93 force motor.

91-93 was a BOSCH manufactured FM. 94-03 was a Holley manufactured FM 04-end production @ GM was Borg-Warner manufactured.


YOU SAY:
Also a new spacer plate was used for 94 and the torque signal compensator valve in the accumualtor housing was eliminated.

The spacer plate change @ the FM was due to the 3 circuits being changed from the Bosch (1991-1993) FM to the Holley (1994-2003) FM. They were not to be interchanged within one another. You shouldn't have a 91-93 valvebody/spacer plate and install a Holley FM. The set MUST remain together: FM, Valve body, Spacer Plate, and Controls (TCM). In some swap cases with a given VB changing to another FM you can end up with very high/uncontrolled line pressure.


YOU SAY:
In order to use the older style force motor and accumualtor housing you have to swap valave bodies I have been told(have not tried this myself to verify it, but many have done this swap and had issues until they either changed PROM's or valve bodies). One can use the new style trans and force motor with a PROM update to eliminate the cleaning cycle and change the force motor cycles per second.

A PROM UPDATE???? How can a PROM change a routine embedded within the TCM? This is where the FM cycling software is contained. What is a NEW Style TRANS? You mean a 94 forward I take it. A PROM CHANGE WILL NOT ELIMINATE ANY Cleaning cycle of the FM.


YOU SAY:
If one uses a new style trans with an old PROM the force motor will likely live a short life at the different HZ, and you will have a pressure spike every 10 seconds when it commands a cleaning cycle.

The FM running at the different HZ will NOT have ANY reduced life in either HZ. The cycling of the FM runs it to each end of the duty cycle. The Accum compensates for the pressure loss/gain for a few milliseconds this occurs.

YOU SAY:
And if it happens to shift during said cleaning cycle you could get one funky shift with the pressure fluctuation.

How do you know this will occur? The software will not allow the routine during an upshift nor a downshift event. Shift Pressure (up or down) has a higher placement than the cleaning routine within the pressure routine operation. And if it happens during a shift????? What is "ONE FUNKY SHIFT"?

YOU SAY:
ON EDIT(in case somebody in the future references this thread) The valve body difference comes into play if you put a 94+ trans into a 93- truck you either have to use the 91-93 valve body, OR open up the 94+ valve body and drill out the seperator plate as well as swap force motors to make it work. So yes there is a difference, but it is in the seperator plate and passages drilled or not drilled. Otherwise you have to use the new style PROM that eliminates the cleaning pulse every 10 seconds.

Well sir you do not understand what has to be placed within a package to make it function. Each package is like this:
For the Force Motor package you should keep these items as a package and together: The FM, Valve body, spacer plate, Controls or TCM/PROM. The Bosch FM is a 91-93 and is SILVER in color. The Holley FM is 94-2003 and is Black in color. The Borg-Warner is 2004 until the end 08 for GM and is black. The Borg FM has a different connector.
The 91-93 vs the 94-2003 FM Circuits can be viewed in the service manual hydraulic layouts. If you lay each of the 3 FM hydraulic circuits out you can see how replacing OR SWAPPING one with another WILL NOT WORK and will give you uncontrolled/high line pressure in ONE CASE. No PROM change can eliminate any of the embedded routines or add any as the cleaning cycle of the FM.
YES you CAN have a 2006 model trans with a 1994 TCM or PCM and it will run correctly. OR said like this: You can use a Holley TCM or PCM control to operate a Borg-Warner FM. I personally would suggest to increase the pressures somewhat or exactly 10 to 15 PTS (Pressure Torque Signal) to compensate for the ODD operation of the Borg-Warner FM. The Borg-Warner FM will give you a given pressure when NEW and it will DECREASE over aprox 5 to10k miles by the said 10 PTS amount. If the PCM has Adapts or SHIFT ADAPTS it will compensate for the loss. It is the nature of the beast. So I would add this "commanded" PTS to the calibration. Now PTS is a number from 0 to 90. It has a direct bearing on line pressure. To find what ending line pressure will be in a NON REVERSE gear take the PTS multiply this by 1.4 and add 40. This number will give you a pretty good indication of actual line pressure (but not in Reverse)
Why does the loss occur in the B-W FM? Sediment in the fluid. If you cleaned the FM and retested it, you would be exactly on the mark for pressures. But since sediment lives within the fluid just bump it a bit. No you can't filter this out within reason and it does not need to be replaced.

 

[THEFERMANATOR]

EDIT: Since I just received a pm about this today, please make sure to expand and read the quoted message as the responses are in the quote.

In green

responses are in Italics.
YOU SAY:
The force motor AKA PCS that controls the line pressure changed from 93 to 94. It went from a 292.5HZ(cycles per second) to a 614HZ(cycles per second) and eliminated the cleaning cycle every 10 seconds that was used on the previous 91-93 force motor.

91-93 was a BOSCH manufactured FM. 94-03 was a Holley manufactured FM 04-end production @ GM was Borg-Warner manufactured.

Who cares who made it, the FACT is IT CHANGED FREQUENCYS and eliminated a required cleaning cycle every 10 seconds that it required. The 94+ did not use said cleaning cycle due to the different cycles per second the 94+ used(also GM made the change to the same FM that the 4L60E/4T80E used).


YOU SAY:
Also a new spacer plate was used for 94 and the torque signal compensator valve in the accumualtor housing was eliminated.

The spacer plate change @ the FM was due to the 3 circuits being changed from the Bosch (1991-1993) FM to the Holley (1994-2003) FM. They were not to be interchanged within one another. You shouldn't have a 91-93 valvebody/spacer plate and install a Holley FM. The set MUST remain together: FM, Valve body, Spacer Plate, and Controls (TCM). In some swap cases with a given VB changing to another FM you can end up with very high/uncontrolled line pressure.

So which is it, are all the valve bodies the same or are they different from 91-93 to 94+ as far as controls go. I wil ladmit I was mistaken and it was the FM that changed, not the TCC. But in your first post you say there is no different valve body. So which is it?

YOU SAY:
In order to use the older style force motor and accumualtor housing you have to swap valave bodies I have been told(have not tried this myself to verify it, but many have done this swap and had issues until they either changed PROM's or valve bodies). One can use the new style trans and force motor with a PROM update to eliminate the cleaning cycle and change the force motor cycles per second.

A PROM UPDATE???? How can a PROM change a routine embedded within the TCM? This is where the FM cycling software is contained. What is a NEW Style TRANS? You mean a 94 forward I take it. A PROM CHANGE WILL NOT ELIMINATE ANY Cleaning cycle of the FM.

You obviously have NO idea what a PROM is. PROM stands for programmeable read only memory(or EEPROM starting in 95 and fully implemented in 96 is electronically eraseable programmeable read only memory). The PROM or EEPROM is what tells any controlelr what to do. ALL controllers wether it is a ECM/TCM/PCM/BCM WHATEVER type of controller from any era use a PROM or EEPROM to tell it what to do and for the algorythims it follows for it's controls. So yes the PROM can tell it to flash out morse code with how it controls the FM, or whatever it is programmed to do. And the "NEW STYLE TRANS" simply refers to a 94+(I guess I thought wrong in ASSUming one could figure this out). So YES a PROM change CAN and HAS eliminated the cleaning cycle of the FM.

YOU SAY:
If one uses a new style trans with an old PROM the force motor will likely live a short life at the different HZ, and you will have a pressure spike every 10 seconds when it commands a cleaning cycle.

The FM running at the different HZ will NOT have ANY reduced life in either HZ. The cycling of the FM runs it to each end of the duty cycle. The Accum compensates for the pressure loss/gain for a few milliseconds this occurs.

I didn't say it would, but most likely shorten it's life. Others HAVE tried this in the tuning by running the solenoid at a higher duty cycle and it normally resulted in a burned out coil in the solenoid(ask somebody with a 6 speed ALLISON what happens if you set the TCC duty cycle up to 96% instead of the stock max of 60%). So the duty cycle/cycles per second, HZ, or frequency CAN have a bearing on solenoid life. If a solenoid is meant to be run at 250 cycles per second for a max duty cycle, running at double the cycles per second could in fact burn the coil out. And if you use a 94+ accumualtor WITHOUT the torque compensating circuit(you know the exra circuit you admitted was in 91-93 valve bodies for the 91-93 FM) in a 91-93 truck with stock programming, you will get pressure jumps when it commands the cleaning cycle every 10 seconds as the required extra circuit isn't there to dampen it.

YOU SAY:
And if it happens to shift during said cleaning cycle you could get one funky shift with the pressure fluctuation.

How do you know this will occur? The software will not allow the routine during an upshift nor a downshift event. Shift Pressure (up or down) has a higher placement than the cleaning routine within the pressure routine operation. And if it happens during a shift????? What is "ONE FUNKY SHIFT"?

For the unimagainative a "funky shift" would be one that happens when the pressure spikes because you are running a trans without the required extra circuits that you yourself admits are there in 91-93 valve bodies that are not present in 94+ trannies. In a perfect world the controller wouldn't do a cleanign cycle during a shift, but say it begins a cleaning cycle and a split second later the conditions are met for a shift. Do you think the controller is going to not shift, or is it going to shift? And if it shifts duirng a pressure spike(because of that pesky missing fluid circuit) don't you think a pressure of 300 when it wants 125 could be a cause for a harsh or violent shift. Or say it does in fact delay the shift most would call that abnormal or "funky".

YOU SAY:
ON EDIT(in case somebody in the future references this thread) The valve body difference comes into play if you put a 94+ trans into a 93- truck you either have to use the 91-93 valve body, OR open up the 94+ valve body and drill out the seperator plate as well as swap force motors to make it work. So yes there is a difference, but it is in the seperator plate and passages drilled or not drilled. Otherwise you have to use the new style PROM that eliminates the cleaning pulse every 10 seconds.

Well sir you do not understand what has to be placed within a package to make it function. Each package is like this:
For the Force Motor package you should keep these items as a package and together: The FM, Valve body, spacer plate, Controls or TCM/PROM. The Bosch FM is a 91-93 and is SILVER in color. The Holley FM is 94-2003 and is Black in color. The Borg-Warner is 2004 until the end 08 for GM and is black. The Borg FM has a different connector.

And some of us have had to "make it work", and found that though it may not be "factory approved", it CAN work.


The 91-93 vs the 94-2003 FM Circuits can be viewed in the service manual hydraulic layouts. If you lay each of the 3 FM hydraulic circuits out you can see how replacing OR SWAPPING one with another WILL NOT WORK and will give you uncontrolled/high line pressure in ONE CASE. No PROM change can eliminate any of the embedded routines or add any as the cleaning cycle of the FM.

Ok now you back saying the PROM doesn't control it, but the TCM does control the cleaning cycle. You know as I put above, the PROM TELLS the TCM what to do, so the PROM controls said cleaning cycle and those embedded routines. And others HAVE interchanged and drilled the neccesary holes to make it work. I don't have the instructions anymore because I don't mess with 4L80E anymore, but peopel HAVE interchanged the FM's.

YES you CAN have a 2006 model trans with a 1994 TCM or PCM and it will run correctly. OR said like this: You can use a Holley TCM or PCM control to operate a Borg-Warner FM. I personally would suggest to increase the pressures somewhat or exactly 10 to 15 PTS (Pressure Torque Signal) to compensate for the ODD operation of the Borg-Warner FM. The Borg-Warner FM will give you a given pressure when NEW and it will DECREASE over aprox 5 to10k miles by the said 10 PTS amount. If the PCM has Adapts or SHIFT ADAPTS it will compensate for the loss. It is the nature of the beast. So I would add this "commanded" PTS to the calibration. Now PTS is a number from 0 to 90. It has a direct bearing on line pressure. To find what ending line pressure will be in a NON REVERSE gear take the PTS multiply this by 1.4 and add 40. This number will give you a pretty good indication of actual line pressure (but not in Reverse)

And all you are doing here is confirming what I said about a 95+ trans going into a 94+ truck, but you are still not addressing your arguement about using a 94+ trans in a 91-93 truck without addressing the FM problem. I was trying to address the FM problem when using a 94+ trans in a 91-93 truck as it can be done in a few different ways.

Why does the loss occur in the B-W FM? Sediment in the fluid. If you cleaned the FM and retested it, you would be exactly on the mark for pressures. But since sediment lives within the fluid just bump it a bit. No you can't filter this out within reason and it does not need to be replaced.

 

[THEFERMANATOR]

I just remembered today one other big hurdle if you have a 91-93 and swapping a newer style trans. It isn't published in many manuals, but if you have a 4X4 91-93 your truck uses both the input and output speed sensors in the trans. ONLY the 91-93 4X4 4L80E trans had a tone/reluctor wheel on the output shaft. All 2 wheel drive 4L80E's have the 2 wheels in them, but starting in 94 they did away with the output tone wheel and put a dummy plug in the rear spot. They switched over and used the speed sensor in the transfer case, and added in the ability into the PCM to multiply the driveshaft speed by the 2.72 to make up for the gear reduction while in low range.

 

[the-wes]

I wanted to add my experiences here since I just installed a 1995 4L80E into a 1994 Suburban. I got everything hooked up and working and was shocked to find that my gears are backwards! Park is 1st, 1st is Park, etc. Thankfully if I put the shifter in Neutral and wiggle it a bit, I can get it to start and move in Drive on the trans. That'll get me by until I can figure out how to work around this problem.

I believe this is because the 95 and newer suburbans use a cable shifter, rather than the mechanical linkage brackets. I will post back here if/when I find a solution.

 

[royunion]

OK, it's been a long time since I messed with 4L80E's so I went and dug out my manual. . . . . Hopefully this info STRAIGHT FROM THE MANUAL OF DESIGN CHANGES is close enough for you.

Love it . . . I have a "Mr. Goodwrench" that has the serial and manufacture stuff ground off - rebuilt early 4L80E for a Diesel I was going to rebuild - that I have not opened up yet - and it has the short shift input shaft with no selector switch - and now I have a better bolierplate to work with what to change to bring it up to 97 to 99 standards.

 

[Bud Martin]

After all this I am still confused, can someone tell me if a 1994 4l80e 4x4 tranny will bolt into a 1995 4l80e 4x4 truck and work with no mods. I have a brand new 1994 tranny I want to use in the 95.

 

[THEFERMANATOR]

After all this I am still confused, can someone tell me if a 1994 4l80e 4x4 tranny will bolt into a 1995 4l80e 4x4 truck and work with no mods. I have a brand new 1994 tranny I want to use in the 95.

Short answer, no. To make it work you'll have to drop the pan and swap shift shafts as most 94's were mechanical linkage, and 95+ is cable. Then the other problem is you'll have to make a bracket to hold the nuetral safety switch in place. A 94 case doesn't have the 2 bolt bosses needed to hold the switch onto the shift shaft. So it can be made to work, but it isn't 100% bolt in.