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Parker Transmission and Gear rebuilt my 727 with quality clutches and a TransGo Reprogramming kit which reduces the overlap between shifts, especially the 2-3 shift. I also picked up a low stall torque converter for a song which should help improve compression braking downhill. With an RV type cam in the motor, I'm told performance will be fine.
What worked: I notice a substantial difference in compression braking on the road and on the trail. It shifts much quicker now but not harshly at all.
What didn't: I had a weird slippage problem when I manually downshift to 2nd under load for awhile. It's since gone away. Possibly a stray air bubble. Performance off the line seems slightly worse but a better choice in cam and better carburetor / tune would surely help.
Recommendations: if you want a rebuilt trans, go to Parker Transmission. Run a low stall converter in a trail rig if you have $300 to blow, otherwise, stick to a stock 1500rpm converter.
I swapped out my New Process 228 transfer case for a New Process 208 part time case.
What worked: I liked pulling out 50' of vacuum tubing. It freed up a little space where the SelecTrac switch used to go. I like using mechanical levers to select mode and range. I like the idea of getting home in front wheel drive if I ever need to. I have found the NP208 does shift on the fly.
What Didn't: Doesn't seem to do as well in light snow. The SelecTrac shift on the fly switch was easier to get to than the floor lever.
Recommendations: If you want to handle Colorado style snow (shallow, spotty, etc), keep the 219, 228, or 229. If you want to lock in hi and don't mind wearing out your front axles, run a 219. If you don't want to smoke your viscous coupler, run a 228. The 208 is probably best for trail and deep snow.
I chose to use 80's Cherokee Widetrack axles because they offered the enhancements I wanted while still being bolt-in replacements. Running 33" tires, I switched to Precision Gear 3.73:1 gears, front ARB and rear Powertrax Lock Right. The rear AMC20 tubes are stitch welded to the housing.
What worked: I gain a tiny bit of articulation, much better turning radius, decent clearance, and increased stability. The Lock Right rules. I haven't used the ARB yet. I'm sure the welding will prevent tubes spinning off-road. BJ's Offroad supplies alloy AMC 20 WT axles now.
What didn't: Try to find junkyard 80-83 WT Cherokee axlesÑespecially if your Jeep club thinks this swap is a good idea and starts hoarding them too. They are rare which sucks. Do me a favor and keep your 80+ narrowtracks or use a J axle in the rear. Besides, the AMC20 has pretty crappy clearance. I saw an article in a 4x4 magazine saying you can shave 'em. A rear D44, maybe from a J10, would help, but requires new mounting brackets. You could do a 70's WT D44 but then you have pumpkins that have opposite offsets. That is NOT ideal. Converting to 70's front D44 would be work.
Mixed bag: The gears are on the tall side. I like running lower highway rpms. Unfortunately the gears don't mix well with the cam and I'm painted into the corner of lower rpm torque. Cruise is 2000-3000.
Recommendations: Have Predator 4wd in Colorado Springs do your axles. They are stellar. Run a rear locker if you plan to do moderate to difficult trails. A flexy lift and open diffs will do more than you think.
Overview
- Rebuilt Jeep A727 with TransGo reprogramming kit
- Custom-built 1100 rpm low-stall torque converter
- Widetrack Dana 44 Front; ARB Air Locker
- Widetrack AMC 20 rear with stitch welded tube, housing; Powertrax Lock-Right
- Differential gears are Precision Gear 3.73:1
- New Process 208 transfer case
Transmission
Parker Transmission and Gear rebuilt my 727 with quality clutches and a TransGo Reprogramming kit which reduces the overlap between shifts, especially the 2-3 shift. I also picked up a low stall torque converter for a song which should help improve compression braking downhill. With an RV type cam in the motor, I'm told performance will be fine.
What worked: I notice a substantial difference in compression braking on the road and on the trail. It shifts much quicker now but not harshly at all.
What didn't: I had a weird slippage problem when I manually downshift to 2nd under load for awhile. It's since gone away. Possibly a stray air bubble. Performance off the line seems slightly worse but a better choice in cam and better carburetor / tune would surely help.
Recommendations: if you want a rebuilt trans, go to Parker Transmission. Run a low stall converter in a trail rig if you have $300 to blow, otherwise, stick to a stock 1500rpm converter.
Transfer Case
I swapped out my New Process 228 transfer case for a New Process 208 part time case.
What worked: I liked pulling out 50' of vacuum tubing. It freed up a little space where the SelecTrac switch used to go. I like using mechanical levers to select mode and range. I like the idea of getting home in front wheel drive if I ever need to. I have found the NP208 does shift on the fly.
What Didn't: Doesn't seem to do as well in light snow. The SelecTrac shift on the fly switch was easier to get to than the floor lever.
Recommendations: If you want to handle Colorado style snow (shallow, spotty, etc), keep the 219, 228, or 229. If you want to lock in hi and don't mind wearing out your front axles, run a 219. If you don't want to smoke your viscous coupler, run a 228. The 208 is probably best for trail and deep snow.
Axles
I chose to use 80's Cherokee Widetrack axles because they offered the enhancements I wanted while still being bolt-in replacements. Running 33" tires, I switched to Precision Gear 3.73:1 gears, front ARB and rear Powertrax Lock Right. The rear AMC20 tubes are stitch welded to the housing.
What worked: I gain a tiny bit of articulation, much better turning radius, decent clearance, and increased stability. The Lock Right rules. I haven't used the ARB yet. I'm sure the welding will prevent tubes spinning off-road. BJ's Offroad supplies alloy AMC 20 WT axles now.
What didn't: Try to find junkyard 80-83 WT Cherokee axlesÑespecially if your Jeep club thinks this swap is a good idea and starts hoarding them too. They are rare which sucks. Do me a favor and keep your 80+ narrowtracks or use a J axle in the rear. Besides, the AMC20 has pretty crappy clearance. I saw an article in a 4x4 magazine saying you can shave 'em. A rear D44, maybe from a J10, would help, but requires new mounting brackets. You could do a 70's WT D44 but then you have pumpkins that have opposite offsets. That is NOT ideal. Converting to 70's front D44 would be work.
Mixed bag: The gears are on the tall side. I like running lower highway rpms. Unfortunately the gears don't mix well with the cam and I'm painted into the corner of lower rpm torque. Cruise is 2000-3000.
Recommendations: Have Predator 4wd in Colorado Springs do your axles. They are stellar. Run a rear locker if you plan to do moderate to difficult trails. A flexy lift and open diffs will do more than you think.
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