For those running the older 4L60 trans on their LS swap

Hey guys I wanted to get some feedback on those of you that have an older 4L60 trans on you LS swap. I am going to use my 1994 4L60 without PWM on my 5.3. I already have the LS dished flexplate bolted up to the engine with the spacer at the end of it with the elongated flexplate bolts and have opened up the flexplate bolt holes to line up with the 4L60 torque converter. I just wanted to know how you guys personally had the LS PCM work with the older 4L60 ? Any simply mods done to make the trans withstand the power, like a shift kit, different torque converter ? I was simply going to change the internal trans harness to that of a 13 pin and add the PWM solenoid to the valve body. I read about this on a previous thread and was thinking it would be easiest way to go on my application. Also I would like feedback from you guys on how that 4L60 has been holding up, I do NOT plan to race or abuse it, just the occasionally "push" when I need it. If I were to run a 4L80 in the future, I would not have to have the PCM reflashed again, is this correct? That is another reason I was going to change the internal trans harness. Thanks and this site has been awesome so far for the swap !!!

im not sure but i dont think the new pcm can control it since its not pwm... so i cant really help you there. but i do know that if u want to run the 80, the pcm will have to be programed for it. since its a 5.3, im pretty sure it didnt come in an HD truck which comes with the 80's so im almost positve your pcm is setup for a 60e or 65e which will not controll the 80e. also you will need to repin a few wires on the round connector for the 80. i just bought an 80e about an hour ago.. lol so im about to dive into that swap. ill know more about it after i go through with it so i cant help too much more. hope i helped a little though.

So far, my 4L60E from a 99 Escalade has been holding up well behind my '99 6 Liter. I don't abuse it either. Occasional 3500-4000 lb. loads of scrap to the scrap yard and still holding fine. I have 6500+ miles since the swap and don't really know how many miles on the trans since the Escalade donor had the dash ripped out of it.

As for the PCM flash, I would have to think your 5.3 PCM should be able to run the older 4L60E provided you change your internal harness. Not sure but it sounds reasonable. My PCM was reflashed to remove VATS and to program it to run the 4L60E since the 6 liter originally had the 4L80E behind it. Was also programmed for tire size, gear ratio, tachometer, etc.. To date, no issues. Knock on wood.....LOL.

Hey guys. Got her running finally and drove it around the block. But the trans does not shift out of 1st gear. I can manually put it on "2" and its on 2nd gear. I checked the trans fluid and its at a normal level even with the larger trans oil pan. I changed the internal harness to the one with the extra pin on it. And also installed the pwm solenoid to the opening on the valve body where it should go and installed a new oem filter. The pcm was reflashed but I did not tell him to touch anything that has to do with the trans. I connected the old vss by soldering it and heat shrinking. And hooked up the tcc switch. Am I missing something?

What was behind the 5.3 before? was it a 60e? if not and you didnt get the trans portions flashed into the pcm... then maybe you need to? make sure you didnt reverse wires for vss.... im not sure. need more info

Your guess is as good as mine on what was behind the 5.3 ! This is a Frankenstein swap ! I have pieced everything together from Craigslist and ebay. I thought I did all the research and could use my pre `95 4L60 on the 5.3. I would just have to change the internal harness to that of a `96 and later. All the trans controls are from factory on the pcm I would assume. I just told Brendan from lt1swap.com to remove vats and give me some better fuel mileage. Will check the wires on the vss but I soldered them to each corresponding wire and from the harness by color.

Don't know if its the problem, but i have not connected the speedo wire yet to my cluster.

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Originally Posted by droopyzda1

Don't know if its the problem, but i have not connected the speedo wire yet to my cluster.

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You don't need to wire the speedo only the VSS signal to PCM and a tune for 4l60e.

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Originally Posted by bobbylog

You don't need to wire the speedo only the VSS signal to PCM and a tune for 4l60e.

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yeah. like he said. thats all i had to do to get my trans running first time around. just make those two things are good and you should be on your way... BUT... not trying to scare you but this happened to me when i did the 80e swap.... i too bought mine off craigslist and the guy told me that it worked just fine... well when i finally got everything hooked up, it too wouldnt shift out of first. in fact it was in first not matter what...even in reverse it would go forward!! took it to the trans shop to fix and the planets/clutches were shot and was "welded" in first gear cuz it got to hot or something... needed a full rebuild. hope that you didnt get royaly screwed from craig like i did, but just wanted to point out that might be a possibilty.... good luck man

I got the motor, wire harness, pcm and flex plate off Craigslist. The only reason I had to rebuild the heads was cause my old man tries to help me remove a broken exhaust manifold bolt and ended up drillingall aroundit and o down to the water jacket. Had to get another set of heads (off Craigslist) sent them to be rebuilt. The trans is originally off the truck. I wanted to keep it cause of budget and the previous owner told me it was rebuilt a couple yes back. When I removed the old transfer fluid, it was red and clean. When I removed the pan to change the internal harness they was just some tiny black particles on the magnet which I heard is normal.So aside from the VSS and speedo,any other wires that must be connected from the LS stand alone harness to the older 4L60 ?

I also dont know if it matters, but there is a plug that was cut off from my original harness that I left all the wires there just in case. I was able to trace tha lt harness to the red and blue connectors. Some of the wires were for one of the O2 sensors in which I soldered a new pigtail to it. The other wires I labeled and tucked them away. Those were for the digital gear shift indicator. But in my case, its mechanical. Could it be that I missed some of those wires? As far as my trans wiring from yhe ls stand alone goes, I only connected the round plug and the vss.

Not sure if the PCM uses the shift switch on the side of the trans to allow the trans to shift out of first gear automatically. It could be a possibility though. I retained my selector switch not kinowing if it would work without it.

Another possibility, although remote, is that the VSS is defective or the harness to the VSS could be at fault.

I had a similar problem with my swap when I first started to drive it, no upshift from 1st to 2nd. Turned out I wired the VSS to the PCM and the DRAC box to allow the speedo to work. After removing the wires to the DRAC box and leaving the PCM wires on the VSS, the trans shifted perfectly.

Thanks Mickey. I will double check the harness going to the VSS and will check to make sure it is working. As for as a DRAC box is concerned, isn't that for cruise control? If it is, I don't have it on mine cause its a plain jane trim, work truck.

im pretty sure it is used for both. it reads the pulses that the vss from the transmission sends out. it then deciphers it and sends a new signal to the speedo and also to the crusie control module. on the newer trucks there is no drac box because the pcm now does the deciphering. so you have two options to control the speedo on our older trucks (which i didnt find out until later) either by the new pcm or the old drac box like original.

but im not sure why mickey had that problem because im doing the same thing he did originally. i kept the wires from my vss going to my drac so it could control the speedo and cruise like its supposed to. but the pcm needs signal also so it can control the transmission. so i just spliced into the vss wires and ran them to the new pcm also.... and both my 60e (worked) and my 80e i have now work just fine hooked up that way.... so i dont see how that could have messed up his shifting....

im willing to bet its the 4 gear shift wires that you dont have hooked up. they also go directly to the pcm.

I meant I have a plain Jane work truck. It does not have cruise control so I think I do not have a DRAC box. Where would it be located? By the way, this pass weekend I ran all the wires from the engine bay to the cluster. My speedo works, oil pressure, voltage, and coolant temp. I ran a 3 wire camaro temp sensor but it reads 40 degrees below what it should be

glad you got it all working. but i want to say that you have to have a drac box because that is what controlled your speedo before. ACTUALLY to be correct you have a VSSB (Vehicle Speed Sensor Buffer). the DRAC (Digital Ration Adapter Controller) came on 90-91 trucks and the VSSB came on 92-95 tucks. They both do the same thing and control 3 things. the speedometer, cruise control and antilock brakes. it is located behind the glovebox next to the old pcm. i dont remember off the top of my head if its sitting on top or hanging below it... i want to say underneath....

I never new about the DRAC box. I learned something new about the obs. Thanks.

I still have to go over the VSS and trans wiring though. I did not have a chance to look over the trans issue this pass weekend. But I do have to clarify the problem I am having again. Whether on low 1 or 2 its on 2nd gear. If on overdrive or drive, its on first gear and never shifts to 2nd. I can drive it on OD or D then have to manually shift on low 2 to get to 2nd gear but I can never get 3rd or 4th gear.

Interesting. Not sure why my initial parallel wiring of the VSSB and PCM didn't work. After doing some research, I found out exactly what 'Jay had said. The new PCM does all the deciphering so I wired the speedo directly from the new PCM. My cruise control still functions although I feel the my rear ABS has have been compromised by eliiminating the DRAC/VSSB box.

Don't want to hack the thread but does some of you know how to wire my rear ABS? According to LT1SWAP the my 2005 PCM output 129K mille on the PIN 49 and

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Digital Ration Adapter Controller (DRAC) and Vehicle Speed Sensor Buffer (VSSB) are both electronic devices that simply convert the input AC signal (from the VSS) to a calibrated digital DC signal. The DRAC sends 2,000 digital pulses per mile to the ECM (Electronic Control Module), 4,000 digital pulses per mile to the cruise control module, and 128,000 digital pulses per mile to the ABS (Anti-Lock Brake) computer. The DRAC and VSSB units are pre-calibrated from the factory according to the vehicle's stock gear ratio, and tire size. But, it can be re-calibrated by simply moving jumpers around. 1990-1991 vehicles should have the DRAC, and 1992-1995 vehicles should have the VSSB unit. The main difference between the DRAC unit and the VSSB unit (from what I can tell) is that the VSSB unit has an extra "bank" of 7 jumpers in addition to the same bank of 7 jumpers that the DRAC unit has. I would assume this extra bank of jumpers is for the electronically controlled transmission that GM started using in 1992.

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(from TBICHIP.com)
http://img823.imageshack.us/img823/3050/5c8z.png


Do you think if I wire the pin 49 green connector to the white wire (D)going to the ABS module on the diagram if it will work?
Thanks