318/360 swap into a 99

This guy did a series of YT videos on doing the swap and covers the wiring pretty good.


Honestly don't let it intimidate you too much. We've all been there and got it figured out.

@Paparock1 & @Dan_Goodwin both just did their Magnum swaps in the last 2 years and I just got done building a new harness for mine 2 years ago so there is help here.

Start a build thread in the https://wranglertjforum.com/forums/tj-build-threads-members-rides.127/ area and you'll get lots of help as needed along the way.

Wildman said:

This guy did a series of YT videos on doing the swap and covers the wiring pretty good.

Honestly don't let it intimidate you too much. We've all been there and got it figured out.

@Paparock1 & @Dan_Goodwin both just did their Magnum swaps in the last 2 years and I just got done building a new harness for mine 2 years ago so there is help here.

Start a build thread in the https://wranglertjforum.com/forums/tj-build-threads-members-rides.127/ area and you'll get lots of help as needed along the

Click to expand...

Wildman said:

This guy did a series of YT videos on doing the swap and covers the wiring pretty good.

Honestly don't let it intimidate you too much. We've all been there and got it figured out.

@Paparock1 & @Dan_Goodwin both just did their Magnum swaps in the last 2 years and I just got done building a new harness for mine 2 years ago so there is help here.

Start a build thread in the https://wranglertjforum.com/forums/tj-build-threads-members-rides.127/ area and you'll get lots of help as needed along the way.

Click to expand...

Wildman said:

This guy did a series of YT videos on doing the swap and covers the wiring pretty good.

Honestly don't let it intimidate you too much. We've all been there and got it figured out.

@Paparock1 & @Dan_Goodwin both just did their Magnum swaps in the last 2 years and I just got done building a new harness for mine 2 years ago so there is help here.

Start a build thread in the https://wranglertjforum.com/forums/tj-build-threads-members-rides.127/ area and you'll get lots of help as needed along the way.

Click to expand...

I appreciate it buddy!

Yep, I'm happy to answer any questions you have. I went from a 2.5 5 speed to a 5.9/46RE and have really enjoyed the final product and have put close to 5k miles on it so far. I'd never done any wiring close to this complex and while it did take me a minute to get through, a good spreadsheet to go with the FSMs will get you there. I have notes typed out to write a lengthy lessons learned from my swap, but a few things I'll touch on:

• Documentation and good notes are key. Take pictures of your TJ and donor before you ever put a wrench on them. Label wiring, hardware, etc.
• Mock up the engine location with radiator in place and choice of fan before committing. Had I moved my engine back 1" from the recommended location it would have saved me some trouble.
• Go ahead and do a tummy tuck and separate transmission crossmember. Being able to remove the skid plate without having to support the transmission with a floor jack has been great.
• Check your donor out really well before pulling it apart. Even better if its running and driving. Compression test it, check for cooling system leaks, etc.
• Buy a spare TJ wiring harness to use as the base and keep your stock one in tact.
• Plan to upgrade your rear axle in the not too distant future.

Dan_Goodwin said:

Yep, I'm happy to answer any questions you have. I went from a 2.5 5 speed to a 5.9/46RE and have really enjoyed the final product and have put close to 5k miles on it so far. I'd never done any wiring close to this complex and while it did take me a minute to get through, a good spreadsheet to go with the FSMs will get you there. I have notes typed out to write a lengthy lessons learned from my swap, but a few things I'll touch on:

• Documentation and good notes are key. Take pictures of your TJ and donor before you ever put a wrench on them. Label wiring, hardware, etc.
• Mock up the engine location with radiator in place and choice of fan before committing. Had I moved my engine back 1" from the recommended location it would have saved me some trouble.
• Go ahead and do a tummy tuck and separate transmission crossmember. Being able to remove the skid plate without having to support the transmission with a floor jack has been great.
• Check your donor out really well before pulling it apart. Even better if its running and driving. Compression test it, check for cooling system leaks, etc.
• Buy a spare TJ wiring harness to use as the base and keep your stock one in tact.
• Plan to upgrade your rear axle in the not too distant future.

Click to expand...

Like Dan I've been meaning to work on a wiring harness writeup but just never seem to get it done. And I've been busy dealing with other problems also so it keeps getting put on the back burner.

There are about 18 wires total I think you have to blend.

When you get ready to start working on the wiring like I said start a build thread which makes it easier for us to help you. And then it keeps everything in one place too.

Yes making sure you have your engine placement figured out is very important. I've got very limited room between my engine & radiator but when my swap was originally done the engine was moved 1" forward.

And I'll agree 100% on getting a spare harness to use as it makes things a lot easier. And when laying out your harness onto the engine give yourself some extra slack.

Jeeperporn said:

I have the FSM pinouts and schematics for both vehicles but don’t feel comfortable cutting the harness until I’m 100% sure on what to splice. Any help would be appreciated and will pay someone for their time if they’re close to York Pennsylvania if they come lend a hand. Thanks!

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They always say the first cut is the hardest or deepest not sure lol. I read a lot of Aircraft wire schematics and it took me a while to blend the two harnesses. Everyone has done their way as to what they figured would be the best for them. I used the 5.9 wire harness and blended into my TJ and others have used the TJ wire harness. So it can be done both ways but it is up to you to figure out what is best. I have notes but I guaranty they are not readable to most LOL. My 97 TJ was also a manual, my PDP did not have any provisions for an automatic transmission so I had to figure that out also and create something that is hokey but it works. You just have to put time into it. My main issue was that I would work on it for a day or so and then not get back to it for a few days and then have to go back over everything again for memory sake. I do suggest that you set aside a block of time to dive in and do it from start to finish. It would have saved me a lot of time in the long run.

I also went with the 46re. It crapped out quickly after a few days so I rebuilt it in my garage with all the best parts I could find. That was actually fun and honestly if you watch a lot of youtube vides its pretty easy. I will 100% agree that you will be changing out your dana 35 quick. I had mine on the road for about a month and the carrier itself broke in half because the spider gears let loose. I am sure the power braking burnouts didn't help much but I also only did that a few times lol.

Ask away and good luck and do your research and then dive in.

Paparock1 said:

They always say the first cut is the hardest or deepest not sure lol.

Click to expand...

Either or works... Even though I had a harness to use for reference it was still hard doing that first cut.

Paparock1 said:

I also went with the 46re. It crapped out quickly after a few days so I rebuilt it in my garage with all the best parts I could find. That was actually fun and honestly if you watch a lot of youtube vides its pretty easy. I will 100% agree that you will be changing out your dana 35 quick. I had mine on the road for about a month and the carrier itself broke in half because the spider gears let loose. I am sure the power braking burnouts didn't help much but I also only did that a few times lol.

Ask away and good luck and do your research and then dive in.

Click to expand...

The 46RE was only offered behind the 5.9 GC in 1998. All other GC's got the 5.2 & 44RE instead. The 44RE is a good transmission for behind the 5.2 & according to the shop that built my 46RE the 44RE could be built to handle 400-500 HP.

I'd read about guys that made their Dana 35 last for a few months but yes they all ended up having to replace them with something stronger.

One other thing to think about as mentioned above. Engine placement; I mounted my engine 2 and 3/8 inches back from where Advanced adapter suggested as I kept reading how others were having a hard time finding or fitting in an electric fan. I wanted to run a mechanical fan. The down side to this is that I had to trim the pinch seam on the firewall down around the exhaust manifolds. I run the stock manifolds that came on the Jeep Grand Cherokee. Plus I could not tuck my transfer case up as far as others have, even with the 1" body lift without doing a lot of hammering/clearancing on the tub floor in that area. My transfer case is about 2" inches into or under the front seat pocket mount location. on the bottom of the Jeep, that area of the tub comes down about 3 inches. I am sure it is for structural integrity of the tub but it also forms a pocket area for the front seats and center console.

But I have an eleven blade ford fan with a heavy duty fan clutch to ensure the 5.9 and my 46re stay cool. I live 7 miles from the Florida line and had concerns about overheating the 5.9 in traffic as I use mine as a daily driver. I heard over and over that the 5.9 had cooling issues and could crack the heads easier and I wanted to prevent that the best way I could.

again make it fit and do what you plan as it can be set up many different ways so there is no wrong answer when your passing people with the air conditioning on and music blasting LOL

This is another really good build thread over on Jeepforum. I haven't seen him active in a while on the forum.

https://www.jeepforum.com/threads/m...ps-my-stroker-wiped-its-cam-bearings.1516649/