The NP435 is pretty good on the road. That is, it's not really noisy. The split between 3rd and 4th isn't that tight, so downshifting can't really be done at freeway speeds. With 3.55s you'll have a top speed of probably 50mph in Third gear. There really aren't any performance shifters for that tranny. It sort of is what it is. Check the early Bronco guys like Jeff's Bronco Graveyard, Wild Horses, or James Duff for the flywheel or any replacement components for that tranny you may need.
Regarding the driveshafts, I just don't know. I bet you'll need to move something because nothing is ever that easy, but there's a decent chance your existing driveshafts will have enough travel left in the splines to work with the new tranny. Since you've got the components right there, I'd say you've got a better idea than I do.
Liberty Or Bust?
My son is currently serving in the military down in Georgia after being overseas. I would like to take his '94 YJ to him that we brought back to life after rescuing it from the salvage yard. It is pretty much stock except for a hard top, 32-inch tires, and a body lift. Oh, and the CJ front end. My question is, do you think it would be okay to tow it 1,100 miles with my Jeep Liberty CRD with a 5,000 lb tow capacity? I am concerned about the transmission. I heard that it is a weak link. Any guidance you can give me would be greatly appreciated.
Bob Cilino, Bath, New York
PS. The white Jeep on the left is the one that I will be towing.
I'd plumb an aftermarket transmission cooler into the tranny return line and keep the tranny in the tow/haul mode the entire time you're towing. That'll help keep the tranny temps down and will go a long way towards ensuring longevity.
As for the weight, if your tow rating is 5,000lbs you'll be pretty much at the vehicle's limit. I'd estimate your YJ weighs about 3,500 lbs and the average twin-axle car hauler weighs about 1,200 lbs. Make sure you run a trailer brake controller so that the trailer can aid in stopping. With hauling that much weight with that vehicle, braking will actually be your biggest concern.
Stability is going to be your second biggest concern. Watch your trailer tongue weight. You'll want enough to keep trailer sway at bay. It'll be better to squat the rear of the Liberty a little more than normal if it aids in stability. You'll probably reposition the YJ on the trailer a few times in the first couple dozen miles until you find the sweet spot.
Power-wise, that CRD diesel has plenty. Hope some of this helps. Good luck delivering the Jeep to your son. Give him a big thanks from all of us at Jp for his service.
Haulin', Not Crawlin'
I'm doing a quick rebuild of a '80 CJ-5 with a '79 258, T-18 tranny, and a Dana 20 T-case. All the drivetrain components are rebuilt. I'll be looking at running 31- or 32-inch tires. The CJ-5 is still running the original 2.73:1 gear ratio in the axles. This vehicle will be used mostly for road-running, with maybe some easy off-road work in the snowbelt of the Midwest. What I'm looking for would be the best overall ring and pinion ratio.
Leo Riley, Via E-mail
I'd think 3.73s would be a good ratio considering your focus on street use and the lack of an Overdrive gear in the tranny. That'll give you an engine speed of about 2,950rpm at 70mph with the 31s, which should be okay for the 258. The 32s would drop the rpms by about 100rpm.