Rear Diff

I’m about to start on 67 CJ5. I’ve been looking at chassis on other build threads. Most seem to have tc output on pass side, lined up with offset rear diff. Here my D18(I think, correct me if I’m wrong) & center stump Dana 44(again, I think). Should my drive shaft be running so crooked? Rear has 11” drums if that’s useful information.

 

Looks like someone put a 72-75 centered rear axle under your Jeep. Not optimal at any speed. Easily remedied by swapping in a 20 transfer case. Best to pull the diff covers and double check what gear ratio is in them and make sure they match.

 

What Daryl said. It would also appear you have an open knuckle front axle, which, if from the same donor Jeep, is probably a D30. That makes it likely the gear ratios are the same. Realize, if you swap in a D20, your low range goes from 2.46:1 to 2.0:1 but it is possible to swap in lower gears.

 

Let's look at the front axle. Also tell us the gear ratios of the front and rear axle.

 

If you were closer, I would give you an offset tapered axle for it. I have several around here with varying ratio's.

 

Had the exact situation from the previous owner. Switched to an offset d44 and everything is good.

 

So my options are switching to D20 or offset D44. Show of hands, which would y’all do?

 

Offset rear diff.
The 18 tcase has disadvantages, most notably being noisy and prone to leaks, but offers a lower low range, better driveline angle, and most importantly, the ability to add an overdrive.

 

Depends on which front axle you have. Also on whether the ratios match. Need more data.

 

Swapping to an offset D44 would likely be easier and cheaped. You just need to match gears to what's up in the front diff.
-Donny

 

you can get a fancy driveshaft..

 

If you dont have vibrations leave it alone it seems to be a good combo.

 

What is your final goal for the jeep?

I'd leave it alone if it's just for weekend ice cream runs if you don't notice any bad vibrations. Keep an eye on your u-joints because they'll probably wear out a little quicker than usual.

Option 2 - Swap to an offset rear if you can find one with matching ratios. The ratios are more than likely 3.73s which won't really benefit from an overdrive anyway, so...

Option 3 is swap in a Dana 20 t-case. You'll lose a bit of crawl ratio, but it will still be fine for 99% of what you'll encounter on stock tires.

Again, make sure your front and rear ratios match before you decide on anything. Gear swaps can get expensive.

 

lots of good information here on that drive shaft alignment
it's possible that the front and back came from same jeep
something you would have to check . ratios

something to consider is do you want to hook up the rear brake shoes for the parking brake
then swapping to a D20 would be my choice

 

If the axles match it would be best to go with a 20. The gear ratio difference between an 18 and a 20 is so tiny that it is completely unnoticeable other then on paper by people that love to figure out crawl ratios.

 

Tons of good info. Thanks. I’ll definitely check the ratio to make sure they match. ITLKSEZ probably nailed it with the weekend ice cream run. I’ll probably run it like it is if ratios match, and keep my eyes open for D20 in the future.

 

Would a D-300 TC be in the running as an option?

 

The only bolt-in option for a D300 is one from an '80 Scout (if the bull gear is even compatible?), and they're as rare as hen's teeth.

 

The D300 is a good choice, but not an inexpensive choice. There were very few made that have the right pattern ("texas" pattern) to mate to the OP's existing transmission, and they are not available inexpensively. Most D300s have the circular New Process pattern, which either requires an expensive adapter or a transmission swap. A '67 should be either a T-90 (with the F134) or a T-86 (with the 225). Both of those will bolt up to the D20 using a 6-spline D20 input gear. Pick the right gear from this chart: The Novak Guide to Dana 18 & 20 Gears Interchange 1941-1979