Jeep LS swap for the LJ

DaveB

Long Jeep Fan
Location
Holladay, Utah
It looks like we both used the same coolant reservoir. My transfer case crossmember is bent out of 1.5 DOM and luckily I managed to put in enough drop on the transfer case to clear the body.
 

glockman

I hate Jeep trucks
Location
Pleasant Grove
Current issues
-Tach doesn't work - haven't looked at this yet.
-Oil pressure doesn't read -caused by the tach.
-Fuel gauge shows E with a full tank. - Need to figure this out. I have skimmed the wiring but all the gauges go into the can buss. I'll have to see if I have correct reading at the line from the tank. I had to cut and re-solder those wires, maybe I missed something.
-Dash is showing a SKIM key warning and CEL. - I need to pull the dash apart, pull the lights out for these two and install the LED for my GM CEL in the slot on the dash.
-Volt meter in the dash is reading nothing. -The alternator is putting out 14vdc and it's making it to the battery. I'll have to dig into schematics.

-The JB conversions 1350 flange uses 7/16 fine thread bolts for the ford flange on my rear drive line. Need to pick 4 of those up today.

-Air filter placement. I have ran it to both sides, each with their own issues. Drivers side is really close to the Alternator pulley. Passenger side is tight on the upper radiator hose. Both sides point the end of the filter (where it sucks on this particular filter) at the vent in my inner fender which should be great for drawing in cold air. Once the transmission is solidly mounted on it's permanent mount, I'll determine which side is better and make it permanent.
 
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DaveB

Long Jeep Fan
Location
Holladay, Utah
The Jeep check engine light that came from my old ECM provided 12 volts to turn the light on. The GM check engine light wire pulls the signal low which is opposite to the Jeep. On my son's Jeep the Renix fuel sending unit reads backwards from the obd1 gauge. When we swapped his Renix for obd1 we had to go back to the Renix fuel gauge. On the newer Jeeps I'm not sure which way they read. Are you using the Jeep sending unit or the GM one ?
 

glockman

I hate Jeep trucks
Location
Pleasant Grove
The Jeep check engine light that came from my old ECM provided 12 volts to turn the light on. The GM check engine light wire pulls the signal low which is opposite to the Jeep. On my son's Jeep the Renix fuel sending unit reads backwards from the obd1 gauge. When we swapped his Renix for obd1 we had to go back to the Renix fuel gauge. On the newer Jeeps I'm not sure which way they read. Are you using the Jeep sending unit or the GM one ?
I have an independent LED wired to 12V that will be triggered by a ground signal from pin 46 on C2 connector of the GM PCM. I just need to stuff the light in that hole in the gauge cluster to illuminate the CEL.

As for the fuel gauge, I am using the Jeep factory fuel pump and sender. Nothing was changed so I am assuming I removed power or ground to that circuit.
 

glockman

I hate Jeep trucks
Location
Pleasant Grove
I did the self test on the instrument cluster and all needles sweep so there is power and ground. Looks like a PCI bus issue. I'll troubleshoot that more later.

Got the transmission secured and the belly pan on. Man it fit nicely. Also got both drive lines connected.
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IMG_20200402_215354_986.jpg
Fired it up to take it's first spin around the block and...... it doesn't move in any direction in any gear. :(

The engine does change pitch when shifting, but zero movement.

Here are my theories.
I replaced the pan filter before mating the trans to the engine. I don't remember pulling the filter seal out. I don't know it if was still in the valve body and the new filter isn't sealing, causing a loss in pressure.

Second theory is I didn't get the torque converter fully seated against the pump and thus, no pressure. I also have some slight grinding when going from a gear into park but not the other direction.

So tonight, I am going to drop the pan and check for the filter seal. If it's there, I'll assume that is the issue. If not, I'll pull the trans and check the torque converter.
 

Greg

I run a tight ship... wreck
Admin
When you install a convertor, as you spin it, it will engage twice, dropping in deeper each time. If it didn't catch and drop twice, your pump may be effed.

Hope its something simple and cheap!
 
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glockman

I hate Jeep trucks
Location
Pleasant Grove
Transfer case is in gear, right?
LOL. It was in N when I hopped in. I wasn't that lucky. Pulled it back into 2H and still no go.

When you install a convertor, as you spin it, it will engage twice, dropping in deeper each time. If it didn't catch and drop twice, your pump may be effed.

Hope its something simple and cheap!

When I bolted the trans to the engine, i was lining them up and didn't have it seated. The bolts didn't even reach and I knew something was wrong, my son said, "did you hear the three clicks? I hadn't seated the TQ converter at all, had just slid it on and got side tracked. We turned/pushed it and it did the 3 clicks and he said I guess not. So I think it was seated but I'm reading that there is a spec on flywheel to converter bolt pad and some need to be shimmed so you don't pull the converter off the pump. I'll have to measure that when I get home.

According to the thread I read today the spec is

GM 700 R4, 4L60E, 200-4R = 1.125" from bellhousing to converter pads.


10.After the transmission bellhousing bolts are tightened, check to see if the torque converter will turn by hand. Push the torque converter back into the transmission as far as it will go. Using feeler gauges or calipers measure the gap between the flexplate converter mounting pad and the torque converter mounting pad. If gap distance is between .060" and .187" it is OK to bolt up the torque converter. If the gap is greater than .187" install a .060" flat washer between the torque converter and flexplate.
 

UNSTUCK

But stuck more often.
I’ve had issues in the past with using LED lights for the MIL. They have key on power and ground through the ecu, as you said, but that LED can somehow find enough of a ground to partially light up all the time. I have since started using regular lights and have had no problems. I think using LEDs on the dash are too bright anyways.
 

glockman

I hate Jeep trucks
Location
Pleasant Grove
I’ve had issues in the past with using LED lights for the MIL. They have key on power and ground through the ecu, as you said, but that LED can somehow find enough of a ground to partially light up all the time. I have since started using regular lights and have had no problems. I think using LEDs on the dash are too bright anyways.
Good info.

Well, I pulled the starter and checked the clearance on the torque converter yesterday. It is 0.156" which is in spec and means the converter was fully seated on the pump.

After some more research, I found the a 4L60E will go into limp mode if no power, gnd or other signal is received from the 20 pin plug on the passenger side. That means that it is very unlikely that I have wired something incorrectly to cause this issue as I'd still be in limp mode which would give me 2nd and Reverse.

I drained the fluid, which was pretty dark after only a few minutes of circulation in the trans. Checked the filter, it was fully seated. I also verified that the trans was fully seating into each gear on the trans when the shifter was cycled.
Looks like its a full rebuild. I paid $200 for this trans which is what a core charge is. The guy said it worked fine but I had my doubts. I was worth the gamble, I lost but am still out the same as if I'd picked up a rebuilt unit and paid the core charge. I'm going to just call it my mock up trans :D
I'll pull it today and see about getting a rebuilt unit.
 

Greg

I run a tight ship... wreck
Admin
After looking at transmission options and costs, I opted for a Summit Racing 4L60E. They run $1599, come with a warranty and have some nice upgrades.


Wish I could tell you how it worked, but I'm not there yet!

I'd also say to get a new convertor with the rebuilt trans, you don't want material/debris in the converter running thru the new trans. Same with the transmission cooler and lines... flush them well!
 

UNSTUCK

But stuck more often.
After looking at transmission options and costs, I opted for a Summit Racing 4L60E. They run $1599, come with a warranty and have some nice upgrades.


Wish I could tell you how it worked, but I'm not there yet!

I'd also say to get a new convertor with the rebuilt trans, you don't want material/debris in the converter running thru the new trans. Same with the transmission cooler and lines... flush them well!


Sounds like you need to let Chad test it out for you. :D
 

glockman

I hate Jeep trucks
Location
Pleasant Grove
The guy I bought the motor from is a senior tech at the gmc dealership in American Fork. He gave me the number of a guy who he knows the rebuilds them. He is doing Kevlar clutches, an upgraded sunshell, upgraded solenoids and springs. With a new converter it's just over $1,000. He had one done that I can pick up hopefully tomorrow.
Took 1 hour 30 minutes to get to here today. Not bad for a shade tree with no trans jack.
20200406_104542.jpg
 

zmotorsports

Hardcore Gearhead
Vendor
Location
West Haven, UT
Sorry I'm a bit late but just saw that you were replacing your 4L60E. I've built quite a few of these over the years and they can be made to be a pretty good trans with some good shifting characteristics with a few tricks.

The items you mentioned are a good start. If you can have them add a 5-pinion planetary and a Corvette 2-4 servo piston or a billet piston.

The 5-pinion GM planetary carrier from the Corvette is made from sintered metal and much more resilient to shock loads and the billet or Corvette 2-4 servo piston really firms up the 2nd and 4th gear shifts. Don't use the aftermarket 5-pinion planetary's as I have not heard good things about them although I have not personally used any aftermarket ones, I've only used the GM planetary's.

Mike
 

glockman

I hate Jeep trucks
Location
Pleasant Grove
Well, I put the new trans in and.....Same thing. NO movement in any gear. I made sure to seat the converter fully and measured the spec on it prior to bolting it to the flywheel so I know for sure it isn't a damaged pump.
With the knowledge that even a completely unplugged trans will have 2nd and rev, I started thinking about what else would affect all gears. The transfer case. I put the trans in park and rocked the jeep, it moves. Made sure the T case was in 4, 2 or 4L, still rocks. I pulled the case to inspect the internals. Just for S&G's I counted the input splines. 32! The input is wrong. Luckily, the trans output is so much smaller that it didn't engage any of the splines on the T case, so no damage. I don't know how I did this. I counted them at the junk yard, I even documented it in a post. I can imagine I could confuse 27 with 29 but not 32. I don't think the input is changed with the SYE but I am not 100% sure.
At least I know what it is. Now I either get a new input or another T-case from the junkyard and have spare parts. The price isn't much different.
 
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