How to LS Swap a FJ60 or FJ62. Quick and dirty guide for regular folks wanting to do an engine swap in their driveway.

[cruisermatt]

You don't know anything about him or his experience. But, on the other hand...

Seriously?

I’ve rebuilt 4l60’s and 4l80’s.

Parts from one are not going into the other.

 

[cruisermatt]

Need to do some

are you using a stock torque converter? How is it offroad on 4Lo both up and down steeper inclines. I am doing some interwebs reading and its not very clear. Most discussions are on drag street stuff looking at peak rpm and peak Hp and tapping the sweet spot. Higher stalls rpm creates more heat. Not where i want to be. Also lots of information on torque converter diameters. Appears stock 5.3L LM7 on a 4x4 Denali is about 1700 rpm. Still trying to find stock Dia and stock pilot bearing information as well. Several #s floating out there that I cant validate as stock. Going for the FJ60 4 speed behavior out of my 4L60E. Great engine breaking at about 2500 rpm so mechanical cooling fan does its job at slow speeds on the trails. I read that larger diameter is better for offroad applications. Want to benefit from the higher rpm power on the highway. I know you run a mechanical fan on your rig and your observations/info will be valuable to many.

@thatcabledude, anything you can add to this discussion?

Any of the stock converters will be what you want. They are all so close that you won’t be able to tell a difference with a stock engine.

A looser converter will make the truck feel faster on the street but the sloppiness will be annoying off-road without a lot of camshaft

 

[Megadoomer]

Is your wiring set up so the ecm knows your in low range ?

No. I have an NP205 and it is very unsophisticated. I have not had an issue with shifting or the vss.

 

[thatcabledude]

@thatcabledude, anything you can add to this discussion?

I would just freshen up the trans with a regular rebuild kit, throw in a corvette servo, stock converter, and change the tune to “tow/haul” all the time.

Keep nice clean fluid in it and run a nice cooler and it I’ll last just fine. Mine is to almost 200k. My truck is heavy, I drive like a maniac, and I tow decent loads on occasion. Mostly this boat.

 

[thatcabledude]

Which I should add that I did not rebuild it. It had 116k when I put it in with a new filter and fresh fluids.

You can drive it when I get your house in a couple weeks CD.

 

[cruisermatt]

Is your wiring set up so the ecm knows your in low range ?

I haven’t done this before on any of the ones I’ve done, haven’t had issues, however FJ62’s have a low-range switch if one really wanted to

 

[tmxmotorsports]

I haven’t done this before on any of the ones I’ve done, haven’t had issues, however FJ62’s have a low-range switch if one really wanted to

It's something that really isn't discussed and most aftermarket harnesses do not provide any thing for 4x4 applications to provide a signal wire to tell the ecm hey I'm in fwd low and change the shift points. Something to look into .

 

[cruisermatt]

It's something that really isn't discussed and most aftermarket harnesses do not provide any thing for 4x4 applications to provide a signal wire to tell the ecm hey I'm in fwd low and change the shift points. Something to look into .

I have been ordering my harnesses for our in-house installs without loom and without fuse/relay panels and been adding pins/circuits in as well as extending DBW, In-cab wiring etc... Lot to ask for the typical DIYer though.

 

[tmxmotorsports]

I have been ordering my harnesses for our in-house installs without loom and without fuse/relay panels and been adding pins/circuits in as well as extending DBW, In-cab wiring etc... Lot to ask for the typical DIYer though.

I absolutely hate the psi wiring harness it'd so bare bones. I think wiring specialties could do a harness that has every option. 4 low tow haul cruise control... as a aftermarket harness. I'm not completely satisfied with my engine guys modified oem harness it's missing some stuff and don't like the fuse panel .

 

[BurntToast]

I have been ordering my harnesses for our in-house installs without loom and without fuse/relay panels and been adding pins/circuits in as well as extending DBW, In-cab wiring etc... Lot to ask for the typical DIYer though.

How is that 6l80 swap going? Hope to have something soon to start working on here soon

 

[dbbowen]

It's something that really isn't discussed and most aftermarket harnesses do not provide any thing for 4x4 applications to provide a signal wire to tell the ecm hey I'm in fwd low and change the shift points. Something to look into .

I have been ordering my harnesses for our in-house installs without loom and without fuse/relay panels and been adding pins/circuits in as well as extending DBW, In-cab wiring etc... Lot to ask for the typical DIYer though.

Totally agree on this, i ordered the painless harness since it was unloomed and had to add the high pressure transducer, repin the pcm to run AC correctly etc.


I didnt know about the 4 low thing, defintiely going to look into that and try and add it to my pcm. Didnt even think about that! @tmxmotorsports im guessing thats a grey/black wire in pin 16 in the green connector?

 

[thatcabledude]

I can’t speak for trans other than 60s and 80s, but I don’t see the need for the ECM to know what range your t-case is in.

 

[ceylonfj40nut]

Been reading up on LS transmissions because i wanted to know 4L65E stock stall (1650 -1700 rpm), torque converter diameter (11.81” or 300 mm).

Came across this great resource that has some great information on the 4L60 series and other GM transmissions. Parking it here for others to refer to as part of their builds. Without this reference, i found it hard to pick one.

4L60E Transmission Specs, Gear Ratios, & History

GM 4L60E automatic transmission specifications, gear ratios, model year changes, application information, and additional details on the long-lived transmission platform. Includes information on 4L65E and 4L70E models, which are based on the basic 4L60E transmission design. The 4L60E was...

www.dieselhub.com

Also found a GM stock torque converter that seems geared toward 4x4 and tow/hauling, seems suitable for my needs and @thatcabledude’s suggestion to tune for tow/haul all the time.

Boss Hog 49450 Boss Hog LS Night Stalker Torque Converters | Summit Racing

Free Shipping - Boss Hog LS Night Stalker Torque Converters with qualifying orders of $109. Shop Torque Converters at Summit Racing.

www.summitracing.com

 

[White Stripe]

Been reading up on LS transmissions because i wanted to know 4L65E stock stall (1650 -1700 rpm), torque converter diameter (11.81” or 300 mm).

Came across this great resource that has some great information on the 4L60 series and other GM transmissions. Parking it here for others to refer to as part of their builds. Without this reference, i found it hard to pick one.

4L60E Transmission Specs, Gear Ratios, & History

GM 4L60E automatic transmission specifications, gear ratios, model year changes, application information, and additional details on the long-lived transmission platform. Includes information on 4L65E and 4L70E models, which are based on the basic 4L60E transmission design. The 4L60E was...

www.dieselhub.com

Also found a GM stock torque converter that seems geared toward 4x4 and tow/hauling, seems suitable for my needs and @thatcabledude’s suggestion to tune for tow/haul all the time.

Boss Hog 49450 Boss Hog LS Night Stalker Torque Converters | Summit Racing

Free Shipping - Boss Hog LS Night Stalker Torque Converters with qualifying orders of $109. Shop Torque Converters at Summit Racing.

www.summitracing.com

I got a Hughes xtm converter. I think it's around 1800 stall. I kind of wish I got something around 2300 rpm. Hughes had good reviews. You can upgrade the internals of a 4l60e to make it a 4l75e. The 4l75e is supposedly the strongest version of the 4l60e.

 

[cruisermatt]

Been reading up on LS transmissions because i wanted to know 4L65E stock stall (1650 -1700 rpm), torque converter diameter (11.81” or 300 mm).

Came across this great resource that has some great information on the 4L60 series and other GM transmissions. Parking it here for others to refer to as part of their builds. Without this reference, i found it hard to pick one.

4L60E Transmission Specs, Gear Ratios, & History

GM 4L60E automatic transmission specifications, gear ratios, model year changes, application information, and additional details on the long-lived transmission platform. Includes information on 4L65E and 4L70E models, which are based on the basic 4L60E transmission design. The 4L60E was...

www.dieselhub.com

Also found a GM stock torque converter that seems geared toward 4x4 and tow/hauling, seems suitable for my needs and @thatcabledude’s suggestion to tune for tow/haul all the time.

Boss Hog 49450 Boss Hog LS Night Stalker Torque Converters | Summit Racing

Free Shipping - Boss Hog LS Night Stalker Torque Converters with qualifying orders of $109. Shop Torque Converters at Summit Racing.

www.summitracing.com

I would stick with the stock GM converter over that.

 

[KodiakFJ62]

If you are using a 4l60/4l65/4l80 etc, you HAVE TO USE A 2WD TRANSMISSION!!

Howdy all! So I’m new here. Stupid new!

But first, much kudos to dbbowen for his work here! This thread is huge and I’m replying in part to bump it up. Thank you. I’ll be using it. A whole lot.

Anyway I‘ve just purchased a ‘90 fj62 for a frame off restomod and an identical ‘89 for parts. I’m going to purchase a new LS3 and tranny crate from Jegs. I need it soon so I can get it on a fishing boat to Alaska next month - if possible. The 4L70 trans is the only one available in the paired Connect & Cruise crate. They have them in a 4WD model with an extended shaft but the statement above contradicts this. Can someone please clarify? Also, the next paragraph lists all the tranny options but never mentions the 4L70. Is there a reason for the exclusion?

Thanks for your help in advance. Any additional advice is always welcome.

 

[dbbowen]

Howdy all! So I’m new here. Stupid new!

But first, much kudos to dbbowen for his work here! This thread is huge and I’m replying in part to bump it up. Thank you. I’ll be using it. A whole lot.

Anyway I‘ve just purchased a ‘90 fj62 for a frame off restomod and an identical ‘89 for parts. I’m going to purchase a new LS3 and tranny crate from Jegs. I need it soon so I can get it on a fishing boat to Alaska next month - if possible. The 4L70 trans is the only one available in the paired Connect & Cruise crate. They have them in a 4WD model with an extended shaft but the statement above contradicts this. Can someone please clarify? Also, the next paragraph lists all the tranny options but never mentions the 4L70. Is there a reason for the exclusion?

Thanks for your help in advance. Any additional advice is always welcome.

Thanks man! So the 4l70 is a beefed up 4l60 I believe. The main reason you are looking for the 2wd trans is the longer output shaft coming out of the back of the trans. Do they not offer it in a 2wd configuration?

 

[gregkline55]

Thanks man! So the 4l70 is a beefed up 4l60 I believe. The main reason you are looking for the 2wd trans is the longer output shaft coming out of the back of the trans. Do they not offer it in a 2wd configuration?

He mentions that they offer the 4WD version with an extended shaft, do they state how much longer than stock it is?

 

[KodiakFJ62]

Thanks for the replies guys.
First, yes the 4l70 is offered in the 2wd version. In fact it’s readily available. There’s a wait for the 4wd.
Second, they didn’t say how much longer the shaft is on the 4wd but I’ll do some research and get back.

 

[gregkline55]

Thanks for the replies guys.
First, yes the 4l70 is offered in the 2wd version. In fact it’s readily available. There’s a wait for the 4wd.
Second, they didn’t say how much longer the shaft is on the 4wd but I’ll do some research and get back.

No need, if 2WD is available thats what you want