1980 Jeep CJ5; Back to the beginning

[Pile of parts]

I'm thinking I can run a flywheel and clutch from a early 2000's 6.0 LQ4, NV4500 truck. Need to check the spline count for the disc though.

Yes, you can. However the clutch discs you will find for the sm420 will only contact about 2/3 of the newer flywheel. The center hole is dished out too much. It seems that many run it that way with no problem. I debated going that route but ended up buying a flywheel specific to the LS engine/old school transmission. Call it buy once, cry once or whatever... I just didn't want to wonder if it would be enough to not have it slip.

 

[Greg]

Yes, you can. However the clutch discs you will find for the sm420 will only contact about 2/3 of the newer flywheel. The center hole is dished out too much. It seems that many run it that way with no problem. I debated going that route but ended up buying a flywheel specific to the LS engine/old school transmission. Call it buy once, cry once or whatever... I just didn't want to wonder if it would be enough to not have it slip.

Good to know!

 

[Greg]

The next step was removing the hardtop & doors, they're pending sale and I really didn't like how it made the CJ look like a DJ... ... so, I got her topless. It looks 100x better without that top!!

Decided to roll a set of 35's up and see how they'd fit.... they look perfect! Hoping I can run a little more SUA lift using YJ lift springs and 35's with some trimming, keep it low with 'big' tires.

 

[Greg]

I need to come up with a specific plan for this CJ5 and seeing it without a top has really lit a fire under my ass. I love how it looks, it really reminds me of my old CJ5. I want to get it running and driving again, ASAP. It needs a new tub badly, but that can wait. I'm thinking about stabbing a stock Vortec 350 under the hood, using the stock SR4 transmission. Here's a list of parts and costs to get a 350 under the hood, done right and running.

Summit Racing 10.5" clutch kit $140 - https://www.summitracing.com/parts/sum-700802

Summit Racing 153 tooth flywheel, 29#'s $220 (I'd really like a heavier flywheel) - https://www.summitracing.com/parts/sum-700178/make/chevrolet

I'd get a 4bbl carb Vortec intake $185. - https://www.speedwaymotors.com/CROSSWIND-INTAKE-FOR-VORTEC,153332.html?sku=91011245-POL

Holley Truck Avenger carb ($600) for now, or Aces EFI (under $1000)? https://acesefi.com/products/killshot-ez-tune-efi-top-end-kit?variant=42085637128398

I think I'll try a shorty headers this time and keep the exhaust between the frameworks $250. - https://www.summitracing.com/parts/HED-69640

I'd need a proper radiator to keep the V8 cool, I'm sure there are plenty of options like this one for $190 on EBay. - https://www.ebay.com/itm/

Motor Mounts $140 - https://www.summitracing.com/parts/TRD-4563

Novak offers a universal Hyd Clutch kit that should do the job for $250. - https://www.novak-adapt.com/catalog/clutch/kit-hcr3/kit-hcrc/


This should get it back on the road, with a SBC!

The 2 piece AMC 20 shafts won't like it, but I'm not going to sink any money into that axle, unlike I did in the past. I'd love to build a Dana 60 with 35 spline semi-float 5x5.5 shafts for the rear and a Dana 44 for the front... eventually.

 

[Hickey]

I need to come up with a specific plan for this CJ5 and seeing it without a top has really lit a fire under my ass. I love how it looks, it really reminds me of my old CJ5. I want to get it running and driving again, ASAP. It needs a new tub badly, but that can wait.

I'm thinking about stabbing a stock Vortec 350 under the hood, using the stock SR4 transmission and getting a 10.5" 153 tooth flywheel and clutch kit.

I'd get a 4bbl carb Vortec intake, run a Holley Truck Avenger carb for now, with a small distributor HEI. Down the road, I'd love to add an Aces EFI TBI fuel injection setup. They're pretty affordable at around $1000.

This should get it back on the road, with a SBC under the hood. 😎

The 2 piece AMC 20 shafts won't like it, but I'm not going to sink any money into that axle, unlike I did in the past. I'd love to build a Dana 60 with 35 spline semi-float 5x5.5 shafts for the rear and a Dana 44 for the front... eventually.

An 8.8 would be more appropriate in that rear. I’ve got one buddy with an 8.8 in his TJ on 40” stickies. He wheels a TON and it’s only started having issues when he moved up from sticky 37’s.

 

[Greg]

An 8.8 would be more appropriate in that rear. I’ve got one buddy with an 8.8 in his TJ on 40” stickies. He wheels a TON and it’s only started having issues when he moved up from sticky 37’s.

My hangup with an 8.8 is the c-clip axles... I'd like to find a cheap Dana 60, narrow it and weld on bearing cups for 35 spline semi-float shafts.

 

[Hickey]

My hangup with an 8.8 is the c-clip axles... I'd like to find a cheap Dana 60, narrow it and weld on bearing cups for 35 spline semi-float shafts.

He runs the Yukon C-clip eliminator kit without issue. Has for many years.

 

[Greg]

He runs the Yukon C-clip eliminator kit without issue. Has for many years.

That could work, if I can find a 58" wide axle. It doesn't sound nearly as cool as a narrowed Dana 60 rear though! 😆

 

[Hickey]

That could work, if I can find a 58" wide axle. It doesn't sound nearly as cool as a narrowed Dana 60 rear though! 😆

No, but it has better clearance and easy disc brakes.

 

[bryson]

That AMC model 20 isn't nearly as crappy as everyone thinks they are - even with the 2-piece shafts as long as they're put together properly... Emphasis on that last part. They're not bulletproof especially when compared to a 60, but I'd argue they're every bit as good as any other axle that came stock in a CJ (1986 Dana 44 included). Remember that the center section of that model 20 is the same thing that the military runs in the Humvee, and while Humvees have plenty of issues, they don't typically break gears (I know they're portals and all, I'm just saying it's cool that they're the same parts...)

In stock form, if that flange nut hasn't ever been removed from the 2-piece shaft, you're good to go. If that flange nut and flange has been removed at any point in the Jeep's history, that's where you could have issues. The problem is that nobody bothers to reassemble and torque them properly, which doesn't seat the splines (flange to shaft) properly, and that's what causes the issues.

Read the gospel of Moses (Lundel):

Rear Wheel Hub Installation on AMC/Jeep CJ with the Model 20 Rear Axle

The axle shaft tapers have "teeth" that cut into the smooth surface of a new rear wheel hub casting. There is a minimum beginning axle shaft nut torque on Jeep CJs of 250 ft-lbs. For a new hub, this is followed by tightening the axle shaft nut further until you achieve the factory-specified stick...

forums.4wdmechanix.com

 

[Greg]

That AMC model 20 isn't nearly as crappy as everyone thinks they are - even with the 2-piece shafts as long as they're put together properly... Emphasis on that last part. They're not bulletproof especially when compared to a 60, but I'd argue they're every bit as good as any other axle that came stock in a CJ (1986 Dana 44 included). Remember that the center section of that model 20 is the same thing that the military runs in the Humvee, and while Humvees have plenty of issues, they don't typically break gears (I know they're portals and all, I'm just saying it's cool that they're the same parts...)

In stock form, if that flange nut hasn't ever been removed from the 2-piece shaft, you're good to go. If that flange nut and flange has been removed at any point in the Jeep's history, that's where you could have issues. The problem is that nobody bothers to reassemble and torque them properly, which doesn't seat the splines (flange to shaft) properly, and that's what causes the issues.

Read the gospel of Moses (Lundel):

Rear Wheel Hub Installation on AMC/Jeep CJ with the Model 20 Rear Axle

The axle shaft tapers have "teeth" that cut into the smooth surface of a new rear wheel hub casting. There is a minimum beginning axle shaft nut torque on Jeep CJs of 250 ft-lbs. For a new hub, this is followed by tightening the axle shaft nut further until you achieve the factory-specified stick...

forums.4wdmechanix.com

I've heard that same thing about the splined hubs, probably from that same article (in print) many years ago. The question I can't answer is, has anyone pulled the hubs on this 43 year old Jeep... and put them back together correctly??

With my first CJ5 and it's AMC 20, I upgraded to one-piece shafts and added a LockRite at the same time, keeping the stock 4.10 gears. It's funny that you mention the gears not breaking in H1's. Less than 3 months after the shaft & locker upgrade, I grenaded my gears (sheared 3/4 of the teeth of the ring gear) and had to put new 4.10 gears in (bought from Mepco, installed by Six States). By the time it was all done, I had over $1000 into my AMC 20.

With the plan for a V8, manual transmission & 35's I just don't see the sense in keeping the AMC 20 and spending that kind of money on it again.

I really want a slightly wider set of axles as well, around 58" WMS. I also think it would be fun to build a rear Dana 60 and 44 for this CJ5. Yeah, they're probably both overkill and I could get away with lesser axles, but what's the fun in that? I do want this thing to be quite capable on the trail, I'd love to wheel harder stuff with it and having it built stout would nice for peace of mind on the trail.

 

[RockChucker]

I seem to remember that an 8.8 out of an exploder is just over 58” wide. I had to run spacers so the tires would clear the spring buckets in the frame on my TJ back in the day. I’d 2nd the 8.8. There is nothing wrong with c clips….until you break a shaft. But with the plans you have for this rig, I don’t think you’d ever have a problem breaking an upgraded chromo shaft, even without eliminating c clips.

 

[Pile of parts]

I ran exactly, what you're wanting to build, in my CJ5. Dana 60 from a late 60's ford 1/2 ton. Many referred to them as super 44s because the ring and pinion was dana 60 but they were a semi float with shafts the size of a Dana 44 and 5 on 5.5 lug pattern. Width was about 60". I upgraded them with dutchman 35 spline shafts. The front was probably a '77 or so wagoneer 44. It was not the wider Cherokee chief so the width matched the rear. Changed it to 5 lug and upgraded the shafts to Alloy USA when they first came out. No questions asked lifetime warranty but I never used it. I ran a 304, t-18, 4.88 gears, 38s and Detroit Lockers. I sold those when I went to one tons to @UNSTUCK and he either sold them or put them in @Jay5.9L jeep, I believe???

 

[Greg]

I ran exactly, what you're wanting to build, in my CJ5. Dana 60 from a late 60's ford 1/2 ton. Many referred to them as super 44s because the ring and pinion was dana 60 but they were a semi float with shafts the size of a Dana 44 and 5 on 5.5 lug pattern. Width was about 60". I upgraded them with dutchman 35 spline shafts. The front was probably a '77 or so wagoneer 44. It was not the wider Cherokee chief so the width matched the rear. Changed it to 5 lug and upgraded the shafts to Alloy USA when they first came out. No questions asked lifetime warranty but I never used it. I ran a 304, t-18, 4.88 gears and Detroit Lockers. I sold those when I went to one tons to @UNSTUCK and he either sold them or put them in @Jay5.9L jeep, I believe???

That's pretty awesome! Funny that you've BTDT. 😎

I've been reading about 35 spline semi-float D60's with discs from Ford E350's. It would be too difficult to chop the tubes to narrow it, order cut to length shafts and run it.

 

[I Lean]

Have you considered a semi-float 14 bolt instead?

 

[Greg]

Have you considered a semi-float 14 bolt instead?

I heard they were junk...

 

[Hickey]

Have you considered a semi-float 14 bolt instead?

That would make a sweet mowing implement to pull behind your CJ5 in your back yard.

 

[1969honda]

My first summer working at Camp Williams a group of green berets shredded (6) AMC 20s in two days. Granted they were trying to learn how to brake/throttle modulate to get the lockers working properly, but the anemic 6.2 diesel still shucked the teeth like they were nothing.

 

[Greg]

My first summer working at Camp Williams a group of green berets shredded (6) AMC 20s in two days. Granted they were trying to learn how to brake/throttle modulate to get the lockers working properly, but the anemic 6.2 diesel still shucked the teeth like they were nothing.

🤣

When I forcefully removed the teeth from the ring gear of my AMC 20, I side stepped the clutch on the 1-2 shift with the built SBC at around 6k RPM. I wasn't easy on that drivetrain and I'm surprised I didn't break more parts, to be honest.

I had to lock the hubs and drive home in 4 high... with the rear-end making terrible noises the whole way.

I was trying to impress a girl... I don't think it worked. 😆

 

[mbryson]

🤣

When I forcefully removed the teeth from the ring gear of my AMC 20, I side stepped the clutch on the 1-2 shift with the built SBC at around 6k RPM. I wasn't easy on that drivetrain and I'm surprised I didn't break more parts, to be honest.

I has to lock the hubs and drive home in 4 high... with the rear-end making terrible noises the whole way.

I was trying to impress a girl... I don't think it worked. 😆

I was worried about similar at BeWilder the other night in the Buick