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Back in the mid-90's I daily drove a '86 CJ7 - it was a neat factory setup with the wide-track Dana axles (30 front and 44 rear) with 5.38 factory gearing (rare option) and the standard Dana 300 transfer case. Trans was the weaker SR4 Ford unit behind the venerable 258 AMC straight-6, never had a problem with the trans even though it has a somewhat bad reputation. Tons of fun and many adventures later, the body was getting pretty rusty as CJs tend to do. I made the trip over to Columbiana Ohio to pick up a new fiberglass body from 4WD Hardware's factory, and had the start on a new lease on lilfe for the '86.
Then 2 weeks later I happened on one of those deals just too good to pass up. Yeah, famous last words, I know.
A '79 CJ7 popped up within 1/4 mile..........pretty ratty, body made my '86 look like a showroom queen in comparison. But it was complete, unmolested and actually ran and drove pretty nicely.
Thinking it would be a good trial run at putting a 'glass tub on a CJ7 I grabbed it, bagged and tagged all the bits and pieces from the body, and proceeded to put them all on the new tub I had just picked up for the '86. Hey, I could just go get another new body after this '79 was sold, right?
Then marriage/kids/moving twice/etc all took place, moving both CJ7s to the back burner. Just last fall I sold the '86 to a good friend of mine - who was amazed that a splash of gas and a good battery were all it took to revive it after 7 years in the barn. One stuck rear brake drum was quickly dealt with (with the skid loader bucket) and he drove it home. Even more amazingly, he has driven it all over the place, 140 mile road trips with the occasional trip to a local mud pit and some massive snowdrift busting, and all it has needed was one rear axle bearing replaced. Great vehicle.
Kinda has me inspired to get the '79 out and finish it.
Now the '79 isn't quite as awesome underneath. It has the (upgraded option at the time) TH400 backed with the Quadra-Trac transfer case. While these were tough units they were new technology to the mechanics of the era, requiring special fluid and periodic chain stretch checking and replacement when that stretch reached a certain point, usually at 60,000 miles. The basic design was a chain drive down to a passenger-side drop with offset axles front and rear, reminiscent with the Dana 18 transfer cases that the military and civilian CJ2-CJ3-MB-JPW all used. In fact, the Dana 18 can be subsituted for the Quadra-Trac inasmuch as the driveshafts and axles are concerned. Adapting to the transmission and engine is the technical side of that swap.
The '79 also has the same front axle as the '86 (Dana 30) but instead of the Dana 44 the '79 has the AMC 20 rear, due to the offset pumpkin matching up with the Quadra-Trac rear output. These axles are the narrow-track versions, not quite as cool or good-looking as the wide-track stuff, but the AMC 20 rear is fairly tough and a 29 spline unit. Strong enough for our purposes.
Now as far as the TH400/Quadra-Trac transfer case is concerned.....we all know the TH400 is the strongest auto out there, right? This particular unit is a BOP case with the weirdo Quadra-Trac output shaft, very long course 10-spline shaft that of course can only be changed by completely tearing down the transmission as it is the first piece to go in the case. This particular transfer case seems to be in good condition, chain seems servicable and the clutch cones seem to be in good condition. You can kinda tell if they are shot, as the vehicle will not move unless the "Emergency-Lock" vacuum switch in the glovebox is engaged. What happens is the chain drives a cone-style posi-traction differential, which instead of outputs to left/right wheels, outputs to the front/rear driveshafts. If the cones are badly worn, the vehicle has trouble moving in the loose stuff. Engaging the "Emergency-Lock" is like an air-locker in a axle differential, it locks the differential in the transfer case making the front and rear driveshafts output match exactly. Not a good thing on pavement as severe binding will occur.
As long as the chain is in good condition, its a good unit. When the chain stretches beyond tolerances, it can slip over the teeth on the hubs it is supposed to drive, making a "popping" sound. Too much of this is obviously a bad thing......the real trouble is when too much slack occurs and the chain is jumping over the teeth, the chain can actually try to double-up and - due to lack of clearance - then blows a big hole in the side of the case.
Obviously, keeping the chain stretch with in tolerance is important. However, there is no adjustment or tensioner, only replacement. And new chains are no longer made by Morse, only option is China-sourced with a reputation for failing within 100 miles of use. Funny part is supposedly the same width/pitch of chain is still being used by the OEMs, but in a different length....might have to look into the option of how to shorten one of those?
All this makes the '79 somewhat undesirable in its current configuration.......so last week we brought home a T90/Dana Spicer 18 combination from a '47 CJ2A that was being parted out. Underneath the 2" of crud that made it an almost unidentifiable lump is a pretty nice unit internally. The model 18 transfer case is a gear drive and every part is available for them, likewise the T90 transmission is pretty bulletproof and compact. A nice surprise was finding an aluminum adapter on the front of the trans that I believe is to adapt a Ford 2000/2300cc 4-banger....further research is needed to be sure.
Anyways, the plan is to run the Quadra-trac setup until it dies, then decide which trans/engine to put in front of the Dana 18. Possible contenders on hand are TH400, SM420, T90 transmission. Engines could go anywhere from the 258 currently in there, to either a 2000 Pinto or 2300 pinto or a 2300 from a Ranger (if I can find a 7" deep bellhousing), or even to adapting something more modern.
Then 2 weeks later I happened on one of those deals just too good to pass up. Yeah, famous last words, I know.
A '79 CJ7 popped up within 1/4 mile..........pretty ratty, body made my '86 look like a showroom queen in comparison. But it was complete, unmolested and actually ran and drove pretty nicely.
Thinking it would be a good trial run at putting a 'glass tub on a CJ7 I grabbed it, bagged and tagged all the bits and pieces from the body, and proceeded to put them all on the new tub I had just picked up for the '86. Hey, I could just go get another new body after this '79 was sold, right?
Then marriage/kids/moving twice/etc all took place, moving both CJ7s to the back burner. Just last fall I sold the '86 to a good friend of mine - who was amazed that a splash of gas and a good battery were all it took to revive it after 7 years in the barn. One stuck rear brake drum was quickly dealt with (with the skid loader bucket) and he drove it home. Even more amazingly, he has driven it all over the place, 140 mile road trips with the occasional trip to a local mud pit and some massive snowdrift busting, and all it has needed was one rear axle bearing replaced. Great vehicle.
Kinda has me inspired to get the '79 out and finish it.
Now the '79 isn't quite as awesome underneath. It has the (upgraded option at the time) TH400 backed with the Quadra-Trac transfer case. While these were tough units they were new technology to the mechanics of the era, requiring special fluid and periodic chain stretch checking and replacement when that stretch reached a certain point, usually at 60,000 miles. The basic design was a chain drive down to a passenger-side drop with offset axles front and rear, reminiscent with the Dana 18 transfer cases that the military and civilian CJ2-CJ3-MB-JPW all used. In fact, the Dana 18 can be subsituted for the Quadra-Trac inasmuch as the driveshafts and axles are concerned. Adapting to the transmission and engine is the technical side of that swap.
The '79 also has the same front axle as the '86 (Dana 30) but instead of the Dana 44 the '79 has the AMC 20 rear, due to the offset pumpkin matching up with the Quadra-Trac rear output. These axles are the narrow-track versions, not quite as cool or good-looking as the wide-track stuff, but the AMC 20 rear is fairly tough and a 29 spline unit. Strong enough for our purposes.
Now as far as the TH400/Quadra-Trac transfer case is concerned.....we all know the TH400 is the strongest auto out there, right? This particular unit is a BOP case with the weirdo Quadra-Trac output shaft, very long course 10-spline shaft that of course can only be changed by completely tearing down the transmission as it is the first piece to go in the case. This particular transfer case seems to be in good condition, chain seems servicable and the clutch cones seem to be in good condition. You can kinda tell if they are shot, as the vehicle will not move unless the "Emergency-Lock" vacuum switch in the glovebox is engaged. What happens is the chain drives a cone-style posi-traction differential, which instead of outputs to left/right wheels, outputs to the front/rear driveshafts. If the cones are badly worn, the vehicle has trouble moving in the loose stuff. Engaging the "Emergency-Lock" is like an air-locker in a axle differential, it locks the differential in the transfer case making the front and rear driveshafts output match exactly. Not a good thing on pavement as severe binding will occur.
As long as the chain is in good condition, its a good unit. When the chain stretches beyond tolerances, it can slip over the teeth on the hubs it is supposed to drive, making a "popping" sound. Too much of this is obviously a bad thing......the real trouble is when too much slack occurs and the chain is jumping over the teeth, the chain can actually try to double-up and - due to lack of clearance - then blows a big hole in the side of the case.
Obviously, keeping the chain stretch with in tolerance is important. However, there is no adjustment or tensioner, only replacement. And new chains are no longer made by Morse, only option is China-sourced with a reputation for failing within 100 miles of use. Funny part is supposedly the same width/pitch of chain is still being used by the OEMs, but in a different length....might have to look into the option of how to shorten one of those?
All this makes the '79 somewhat undesirable in its current configuration.......so last week we brought home a T90/Dana Spicer 18 combination from a '47 CJ2A that was being parted out. Underneath the 2" of crud that made it an almost unidentifiable lump is a pretty nice unit internally. The model 18 transfer case is a gear drive and every part is available for them, likewise the T90 transmission is pretty bulletproof and compact. A nice surprise was finding an aluminum adapter on the front of the trans that I believe is to adapt a Ford 2000/2300cc 4-banger....further research is needed to be sure.
Anyways, the plan is to run the Quadra-trac setup until it dies, then decide which trans/engine to put in front of the Dana 18. Possible contenders on hand are TH400, SM420, T90 transmission. Engines could go anywhere from the 258 currently in there, to either a 2000 Pinto or 2300 pinto or a 2300 from a Ranger (if I can find a 7" deep bellhousing), or even to adapting something more modern.
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