88 YJ Build

[oh_boxer]

Figure I'd start a build thread for my 88 YJ I picked up. I've been out of Jeeps for 20 years now and just getting back into them. Previously lived up northeast and now am out in Ohio.

What's really motivated me to grab one and build it up is that I went through 2 pretty severe health issues about 2-3 years ago back to back and didn't think I'd get through them. Given that, there's no time like now and I don't ever want to look back and say "I wish I did that". My goals of the project is first to do something with my young son so he learns some valuable skills for working on vehicles/fabricating, leave something for him and my wife if anything were to happen, and lastly to have something I can enjoy.

Build goals: medium duty YJ on 35s that is still pretty streetable and capable off-road. I know that there's plenty of folks who say that there vehicle on 38's and 1 Ton's is very streetable and I'm not here to dispute that. Part of this "medium" size build is looking across factors like ease of my family members getting in and out, the YJ being pretty straight to start with, and finding parts (axles are getting hard to find) amongst others. I do have 2 tow rigs so maybe one day I'll go ton's and 40's and cut this jeep up.

Story behind the Jeep is that the lady I bought it from here in Ohio had purchased it when she moved to California from the original owner. When she moved back to Ohio she had it in garage or outside of her home for 5-6 years. Of course this is what I was told and I never bother to do a full records check because it look really straight and clean for an Ohio jeep so it was all believable.

As best as I can tell the YJ I got is 100 percent original and never had the nutter bypass done. It came stock with the BA10 and after a quick once over I found some things that need addressed; leaking transmission slave, rear glass lift springs worn out (original AMC logo parts), bad fuel pump, clogged up parts, and some other minor odds and ends you'd expect on a 36 year old jeep. (I can't believe YJ's are this old now)

Build plan:
4.2 with EFI
Jeep T-18
Dana 20
Waggy 44s
35s
Flat skid, high steer, on board air, and some other fun stuff.

First challenge is going to be procuring parts. I'm shocked how rare every has got for drivetrain components over the last 20 years or so.

I'll be sure to do lots of pictures as I go along, I'll try and nerd out on some details and compile a lot of technical info as I go along. I'm sure most of what I post may be found on the "other" forum or this one but sometimes having stuff in a build thread all in one spot can help others along the way.

 

[Tryloff]

Welcome to the forum and welcome to Ohio!

What part of the state are you in?

 

[oh_boxer]

Transmission:

BLUF:

• BA-10 needed a slave cylinder and if I was going to pull it I was just going to replace it
• AX-15 was a leading candidate but I was not finding many close to where I live for a reasonable cost
• I did find a CJ 4.2, T18, and Dana 20 combo locally for sale that I was able to grab for cheap from a 78 CJ-7
• With that I was going to roll with a T18 and Dana 20 for the build

More Info:

• When I went to pickup this T18 I wanted to ensure it was the wide ratio Jeep T18 that is sought after
• Novak's site has tremendous amount of information and I would encourage everyone to check it out (more on this later)
• Visually the numbers I found on the top cover of the T18 was (13-01-097-807) and the drivers side of the case was (13-01-065-906)
  • After disconnecting the Transmission from the CJ4.2 and getting the Dana 20 into 2wd high and counting input/out shaft turns I confirmed it was the sought after wide ratio T18 with the ~6.3 first gear and the original bellhousing that came with it.

Opening it Up:

• I found that the Low & Second speed gear (T-18-12 OEM Part Number) had more wear on the teeth than I was comfortable with
• Additionally the Reverse Idler Gear (T-18-10 OEM Part Number) also had some wear
• Both needed replacement and I was apt to rebuild the whole transmission as well so I got ahold of Novak
• Huge shoutout to Easton at the rest of the gang at Novak for the following info:
  • There are two style Low & Second speed gears (1st gears for this convo)
  • There are early style and later style
  • Sometimes vendors can source used gears for later style T18's, but Novak has either new or used for the earlier versions
  • When it comes to replacing the 1st Gear there is not a visual difference to the 1st gears that you can typically see without removing the hub
  • Looking at the hub that the 1st gear slides on, if the vertical face of the hub is solid, than you need the earlier style that uses springs & balls under the synchro keys
  • If the vertical face has holes machined in it, then you need the later style gear that uses radial springs & keys only
  • Novak recommended that if you are replacing the 1st gear that they recommend doing so as an entire assembly due to the tolerances in the machining. They regularly have to try different gears on hubs to ensure a perfect fit (going the extra mile here for their customers)
• *I'm going to up load some photos from my phone later to show all of this and some of the differences

Extra Parts:

• I picked up another T18 Dana 20 combo as who doesn't like having spares and maybe I'll have enough leftover parts to build another jeep for my boy one day when he's a little bit older
• This 2nd T18 has the following numbers top cover (13-01-097-907) and drives side of case (13-01-065-906)
• I confirmed this transmission was also the sought after ~6.3 first gear ratio as well and has the same earlier style hub as the previous one I bought
• Of note - the shifters for the transmissions each had a different bend associated with them despite both coming out of CJ's
• One has a largely straight shifter with 1 bend and the other has 2 bends to make it more "S" like.
  • *placeholder for pictures

Next up: discussing bellhousings and how to adapt a T5 bellhousing for a T18. Given that I have 1 of each I will post some pictures and measurements of both as I remember folks discussing whether this can be done about 20'ish years ago.

 

[oh_boxer]

Welcome to the forum and welcome to Ohio!

What part of the state are you in?

Southwest near Dayton. I've made it down to Southern Ohio a whole bunch when I was racing enduro bikes for a couple years though so I've got a few thousand miles of riding down there.

 

[Tryloff]

I'm about an hour north of you, but Beavercreek born and raised.

 

[NovakAdapt]

More Info:

• When I went to pickup this T18 I wanted to ensure it was the wide ratio Jeep T18 that is sought after
• Novak's site has tremendous amount of information and I would encourage everyone to check it out (more on this later)
• Visually the numbers I found on the top cover of the T18 was (13-01-097-807) and the drivers side of the case was (13-01-065-906)
  • After disconnecting the Transmission from the CJ4.2 and getting the Dana 20 into 2wd high and counting input/out shaft turns I confirmed it was the sought after wide ratio T18 with the ~6.3 first gear and the original bellhousing that came with it.

Thanks for the shoutout!