5.3 compatible with older 4L60?

[L&M]

I have a 94 2wd with the early 4l60E, and i plan on doing a 5.3 swap and sticking with EFI.Id like to run either a stock truck harness or a Nelson harness.Is it possible to wire up the truck to maintain the older 4l60 or should i start looking for the later model trans?

[classic79]

look under the threads dealing with 700r4's should be the same or close for you.

[TimeLimitHit]

i swapped a 6.0 into my 93 yukon, the first year of the 4l60e. all you need to do is get a 1995+ wiring harness for inside the trans that comes with the round 20 pin plug and a tcc pwm solenoid. There is an extra pin in there for the torque converter clutch pulse width modulated solenoid. If you are standing under your truck facing the rear, the solenoid goes into the hole closest to you and on the left. The new harness has an additional plug right there for the solenoid. You can also have it programmed out i believe but i thought it was easier to just get a $14.99 4l60e harness from ebay and a free used solenoid by chatting up a tech at a local chevy dealer. Been a few months and no issues or codes so I would say it works, at least as far as the pcm is concerned. I think the pump is different also for the pwm, but like i said, mine works just fine.

[L&M]

thanks guys for the help.Im not much of a wiring guy, but ill give it a shot.Worse comes to worse, ill snag a newer 4l60 that had a 5.3 bolted to it already.

[TimeLimitHit]

the wiring is easy, no cutting or splicing. Just replace the internal harness. But if you are going with a newer one get something at least 2002 or newer. There were a lot of internal updates through the years. or find a 4l65e out of an 04 or newer and put a tail housing on it.

[Z-Rod]

I have a 94 2wd with the early 4l60E, and i plan on doing a 5.3 swap and sticking with EFI.Id like to run either a stock truck harness or a Nelson harness.Is it possible to wire up the truck to maintain the older 4l60 or should i start looking for the later model trans?

Hi L&M,

Be very careful with the advice you receive about your '94 4L60E transmission and ECM controls. All late model computers expect to see a PWM TC. The difference between a PWM TC and non-PWM TC is about $2,000 in an unneccessay tranny repair. Running the wrong TC will ruin the TC "clutch plates" in a few months. There are too many examples of failed tranny because of this.

Here is what I did on my 1994 Z-71 with the stock non-PWM tranny. Nelson tuned my 2005 computer so it did not pulse the TC clutch. He also had to re-pin the tranny plug to match my tranny. Code P2761 was deleted among other things needed to make the computer control the non- PWM TC. The proper operation of my TCC was confirmed with a GM Tech II scanner. My TCC locked and unlocked as it should with 0% slippage. You need to hook up the wire from the brake pedal that lets the ECM know when the brake is applied. I would, however, make sure your tranny is modified to handle the extra HP... the factory 350 was rated at 200hp.

there was a period of ECMs that could not be modified like the 2005 ECMs... so you will find some people say that you can't use these trannys. If you are using a ECM like mine... you are in luck providing it is programmed correctly.

This is a blatant plug for Nelson Performance... The guys there know their stuff. They are experienced with these swaps and understand the inside of those little magic little boxes.

Z-Rod

[TimeLimitHit]

the torque converter in a 4l60e is the same as one in a 700r4, the 700 being NON pwm. That being said, there is no difference between the tc's, just stall speed and size. All the pwm solenoid does is smooth the locking of the torque converter clutch. What I did to my trans is basically analogous to rear o2 simulators. The pcm sees the circuit and the circuit functions properly. Now weather or not the hydraulic aspect of the pwm solenoid functions is irrelevant. You still have the regular tcc lockup solenoid, the tc clutch will still lock. You have an old trans designed to run without pwm, it would be different if you had a pwm trans that you wanted to make non pwm. Sure, nelson can tune out that part in your pcm, remove dtc's and whatnot, but for those of us on a budget the route i took seems a lot cheaper and works just fine. It's been a few months and my ORIGINAL tc with 225k is still going strong. Cost me about $30 and an hour of my time. I have no trans codes, and i didnt have to delete any from my pcm.

Get a level one rebuild kit, upgraded sunshell, hardened input shaft, 5 pinion planetary, and you'll be set to 450hp. get a 1999+ case so you can use the bottom two bellhousing bolts that go into your oil pan, that and the internal design of the case is stronger.

By the way, some 1994's were pwm. Its stamped on the front of the pump if it is...

[L&M]

after reading the info you guys posted, im thinking it might be smarter to get a matched trans when i pick out my 5.3 or 6.0.Another question that popped into my head, when reffering to the engine harness....is there any differences in the engine harness between 2wd and 4wd? In my area, the 4wd harness seems to be easy to find, but i dont want to run into headaches when trying to run the harness in a 2wd application.I wasnt sure if the extra 4wd equiptment wiring was part of the engine harness or part of the chassis harness.Since I'm not going to rush into the swap, i plan to pick up a harness first and rewire/rewrap it to fit my truck.Im aware of the premade harness's but id have more pride if I tackled the harness myself.Is there a disirable stock harness that works better than the others that i should start searching for? I really appreciate the help so far, im a recent GM convert and so far im loving how easy these trucks are to get along with.