Finally Started The Sm420 To Dana 18 Swap

Did some research and it looks like I would just have to swap yokes at the transfercase and at the axle. before I continue with that I'll see what the shop can do.

 

New D27 yoke for 1310 joint:
Northern Drivetrain, LLC: Northern Drivetrain 2-4-2291

Dana 18:
OMIX 16580.04 Yoke for 41-79 Jeep Vehicles with Dana Spicer Model 18 or Model 20 Transfer Case

 

These are the parts you need.
When I installed my D30 axle and D20 transfer case I scored a cj7 drive shaft cheap....$20... I shortened it and installed new U joints.
Steve is running an SM420, D18 with 1310 joint, but the little V6 joint on the D27.... He just ordered the D27, 1310 yoke from Northern Drivetrain so he can upgrade his drive shaft.

 

I'll look into that. Is there any clearance issues with Steves front drive shaft? Apparently the trouble area is with the bigger 1310 u-joint clearing the 420 case.

 

No issues so far. He has not been off-road yet, but looks like it will be fine.

 

He has always had a 1310 on the transfer case end. He is just upgrading the d27 end after promptly breaking it on the rubicon last year.

 

Well Ive slowly been getting it all back together. I had to fight with the clutch fork, but finally got the motor, trans, and t-case all together and back in the jeep.
I had to modify the cross member, it obviously had to be slid back a few inches and I ended up notching it so there was more clearance for the front output. Here are just a couple pictures I snapped while in the process
. Here is the motor that is going in it. It is a 231 OF out of a 77 buick.

Here is the trans and bellhousing and Novak adapter all cleaned up and ready to go in.

I hooked the trans and adapter too the motor, and stabbed the whole thing as a unit minus the t-case.

 

Also took a quick picture after cutting the cross member. It is all welded up and back in place now. Im still waiting to hear about my driveshafts, I'm going to run by the shop today to see if any progress has been made.

 

Looks good. I have a much shorter adapter between my D18 and SM420 so I can't comment on drive shaft length. I am really happy with my AA chain setup, it's very simple and works fantastic.

 

I thought novak was the only game intown when it came to sm420 to d18. How long is your adapter?

 

Well finally got the 231 started last night. Its been a lot of small tedious things, slowing my progress. But everything eventually has to be done. It is a little discouraging when you work for 8-9 hours and everything still looks the same. And another minor set back is I misplaced my cooling fan blade. So if anyone has one they would be willing to sell or if anyone has a list of vehicles I could possible grab one off in a junk yard, that would be greatly appreciated.

 

Well the 231 is running and idling. I still need to fine tune the timing and track down a few vacuum leaks. I also rowed through the gears while the engine was running (without driveshafts) and there seemed to be no issues with the clutch disengaging like I know several people have had issues with. I did file the inner clutch hub to give a little more clearance and I cleaned up the splines on the trans input shaft. Without driveshafts there was no load on any of the drivetrain so the real test will come when its fully assembled. I was able to locate a fan that worked, then of course I found the original fan and spacer.

 

Well done. Kudos on avoiding the hell of clutch problems. Don't trust the rubber plugs for unused vacuum ports. Pull the fitting and use pipe plugs with a touch of sealent. I've had problems with them dry rotting and leaking.

 

Finally got my exhaust rerouted and in a satisfactory position. Fairly tucked up and away, and it is only short term. I plan to go power steering in the next year or so sand at that point I'll actually take the jeep down to a muffler shop to have a proper exhaust built. Sorry for a lack of pictures I've been on a time constraint while working on this project. But I decided to put some Noico sound proofing (Dynamat style) on some specific areas to try and cut down on some of the heat and road noise. I installed some on the inner hood and on the underside of the transmission tunnel. I think I may install on the underside of the tub just above the transfer case as well. I haven't been able to drive the jeep yet as I'm still waiting on drive shafts. But just to the touch the sound proofing has made a huge difference.

The hood actually sounds solid now, like closing a fancy car door.

 

Uh oh did I speak too soon? Have I embarked down the clutch misery that has a tendency to follow these swaps?....

Well I finally got my driveshafts back. I ended up with a front drive shaft at 27.5" and a rear of 16.5". So I installed everything and was finally able to drive it around the lot. So initially my clutch worked. I was able to shift it into reverse just fine. But my clutch needed to be adjusted. It was engaging right off the floor. But I just wanted to drive it around. So the clutch worked fine for R then 1-2. But I had to backup and I couldn't get it into gear at all with the clutch pushed in. It was down pouring and I was working outside so I haven't adjusted the clutch yet to see if that helps. Just curious if this is what has happened to others when the clutch sticks on the splines of the input shaft.

 

Well it just ended up being the clutch adjustment. Shifts through all the gears smoothly now. Now I'm trying to track down what I believe is a vacuum leak on the 231. It seems to idle fine but as soon as a load is put on it, its wants to spudder out and die. Mainly shifting into 3rd gear. Also the plug wires I purchased from Oreillys seem to be hit and miss. I guess I should've looked them over when I got them. But the terminal connections have been loose where they actually connect to the wires. I have an hei distributor but its needs a new cap, rotor, coil/cover, and I would need new plug wires. Also I figured out the Rochester 2gc is off a 1970 chevy v8 so that explains why the carb kit didn't work that I got for a 77 skylark. My fault for not ordering based off the stamping numbers. Hoping to be back on the road soon, as some local trails are opening up.

 

Go hei and never look back. Quality plug wires too. Congratulations on dodging the clutch hell!

 

Test drive around the driveway in 4 low. I think this will be plenty low for me.

 

Well I just picked up a warn 5687 winch for $50. Ive been looking for an upright style winch for a little while now and this one seems like the perfect edition especially since I picked it up here in town.

Ill have to pick up some dash mounted controls.