Author Topic: 79 cj 5 build  (Read 13673 times)

sean1

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79 cj 5 build
« on: August 03, 2009, 09:19:52 pm »
would like imput.  i have a 79 cj5. bought another for parts that had a t-176 and dana 300.  258 motor.  bought full width one tons to go under it.  plan on doing a spring over and stretch the frame a bit.  would like to run 37 to 38 inch tires.  also plan to be street legal for the occasional sunday drive with the wife.  would  like anyones thoughts or imput of how i should go about this.  or if part of my plan is wrong feel free to give me your advice

                                                                          thanx

                                                                         sean

CJ8Ted

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Re: 79 cj 5 build
« Reply #1 on: August 04, 2009, 05:54:15 pm »
Are you going to wheel it?
If so what type of wheelin are you going to do? hill climbs, mud bogs, trails, rocks, (rock comp.) drags/figure 8 style racing,ect. 

Ted
85' CJ8 on 33s w/ 4.56s

sean1

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Re: 79 cj 5 build
« Reply #2 on: August 05, 2009, 06:37:42 pm »
yes i plan to wheel it.  but would also like to keep it street legal.  rocks, mud, trails.

CJ8Ted

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Re: 79 cj 5 build
« Reply #3 on: August 05, 2009, 09:12:06 pm »
At leased 4.56s in the diffs 4.88s or 5.13s if the axles will accept that low. 4 to 1 in the 300, YJ springs outboarded on the frame, Tj fender flairs, high steer on the front axle . Not sure if this info is the things you were looking for but its a couple things that came to mind.


Ted
85' CJ8 on 33s w/ 4.56s

sean1

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Re: 79 cj 5 build
« Reply #4 on: August 05, 2009, 09:57:03 pm »
thanx.  allready have a dana 60 front w/ high steer and a spool ( soon to be gone ) and a 14 bolt w/detroit.  alloy shafts up front.  curious how much strestch would be good.  i know you can get 10 inches out of dakota springs didnt know if i could get 15 some how with staying with leafs or maybe that is too much to get into?

Jeremy

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Re: 79 cj 5 build
« Reply #5 on: August 06, 2009, 12:39:05 am »
Spring overs have BAD axle wrap problems, especially with stock wrangler springs because the axle mounted under spring but leverage on the spring. A traction adding differential will make this worse yet. Sams' Offroad has a traction bar that can minimize this.

 Don't skimp on doing your steer correctly, a lot of guys try to get by on the cheap but I feel that this is dangerous and irresponsible.  A high steer or cross over is the appropriate way to go.  Also make sure you leave enough slack on your brake lines,  Spring overs have lots of travel in both directions since the stock wrangler springs are pretty flat.  Spring overs can also be a little squirrel on the road, I have had good luck with a spring shackle reversal on my jeep, this made the jeep ride a LOT  better and track better  than stock,  The disadvantage is you have to measure your front drive shaft very carefully and leave enough collapse to account for your suspension travel.

Make sure you can cover your tires with some sort of flare since you intend to keep this road legal.  You are going to gain a lot of lift with a spring over even stretching a cj5s wheel base a little may not be enough to keep U joints in it.  The U joints in your drive shaft will probably not be in phase, you may need a double cardan joint in your drive shaft as a result.  The T176/dana 300 is a fairly decent drive line but the T176 has a very high first gear (3:1 to 3.5:1) .so you will need some sort of lower range gears in the transfer case to compensate. 38" tires is about the limit that a T176 will handle assuming you keep the 258,  If you swap in a V8 it may scatter on you.  I am a firm believer in the 258cid I6 but the weight of 38" tires are going to make it feel a bit anemic. You may want to look at some engine mods to help out, but don't over do it or you will be back to stressing out the T176.  You should go a little lower in gearing to compensate for the weight.  Speaking of weight those big tires are tougher to stop too,  Some latter jeeps had a vacuum brake booster that should help the pedal pressure, you may need to adjust your proportioning valve and brake chamber anyway if you are  keeping the bigger brakes that are on your donor axles.

Also consider either heim jointed clutch linkage or swapping in hydraulic linkages.  CJ5s had pretty stiff springs to carry heavy loads but had a lot of flex in their frames.  Adding soft flexible springs + flexible frames = binding in the clutch linkage or worse yet the steering if that is not done right either,  (visions of a certain scrambler falling off the rock pile at the show one year,  eck)  Just something else to be aware of.

A spring over in a cj5........I would look at tying your roll bar into the frame and if possible adding a full cage. Even with the weight of those heavy full size axles and the extra width.  Even stretching your wheel base a little, going up and down some of the hills around here are a bit more of a thrill than I would be looking for. 

 Perhaps Rick will chime in since I think his jeep's set up is a little closer to what your are intending.  Honestly,  You are planning a ambitious project,  I think it will be more expensive than you think,  But I have seen it done before on cj8, cj7 and YJ  wranglers before but most of these ended up being trailer queens as they tend to be a handful on the road at speed. Since you are planning for driving this beast on the road a more moderate build up may be better for your use. 
Jeremy Meehan

Rick_Bear

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Re: 79 cj 5 build
« Reply #6 on: August 07, 2009, 10:02:04 am »
Your intended project is a good bit of work, but not impossible. I personally think 37's and/or 38's are too big, I wouldn't go larger than 35's. The driveline in a SOA needs fully adjusted from front to rear or it will not last very long. My CJ5 is not sprung over, but does carry a bit over 6" of lift.

This is long, but should be quite helpful:
Courtesy of : John Nutter

Springs
The rear springs used in CJs and YJs are the same width, so the rear springs bolt right in. The YJ front springs are a little longer and wider than CJ front springs. The fixed spring hanger for the CJs front spring is the correct width because the CJ front spring uses a wide bushing in the back. It is the shackle side of the CJ that is not compatible with the YJ front springs. For the shackle end of the front springs, CJ rear spring hangers are the right width and only cost about $14.99ea new. They need to be moved forward so that the rear hole in the spring hanger goes where the old front hole used to be. There is a rivet in the frame at the location where the new front hole needs to be. The rivet holds the cross member in place. I welded the cross member to the frame, ground the heads off the rivets and punched them out. The bolt holes lined up perfectly. The picture to the left shows where the front spring hanger needs to be modified. The red arrow points to the rivet to be removed and the blue area shows where to weld. Weld before removing the rivet so everything stays in place. The rivet hole will be used for the forward bolt on the spring hanger. Moving the hanger forward leaves a space between the steering box bracket and frame where the back part of the spring hanger used to be. I cut off a piece of the old spring hanger and used it as a shim. The red arrow points to the spacer for the steering box made from the old front spring hanger. The rear hangers do not have an extra hole to clear the rivet that you knocked out, so they are much stronger than the stock front spring hangers. This swap makes expensive after market hangers unnecessary.
Bushings
I used polyurethane bushings meant for the rear of a CJ in the frame part of the shackles and the fixed spring eyes on both the front and rear. I left the factory rubber bushings in the shackle ends of the springs, but I will probably replace them with polyurethane eventually. The shackle end bushings for CJs and YJs can be purchased separately or about $1 or $2 a piece, so it won't cost much.
Shackles
For shackles I used 2" x 3/8" bar stock all the way around and I made the bolt holes 4" between centers. The shackles have a good rake forwards on the front and rearwards on the rear, but because the YJ springs are flat they shackles move inward on both compression and extension and the rake is actually an advantage since it gives them more room to move and less chance of getting stuck over center.
U-bolts and U-bolt Plates
If you have kept the stock Dana 30 you will probably need to fabricate some spring plates to accommodate the wider YJ springs, but your stock U-bolts should still work. If you have gone to a Dana 44 FSJ spring plates work well and U-bolts can be purchased locally at a good auto parts store. Mount your shocks parallel with the bottom of the axle tube and for early CJ 7's you will want to change to the later CJ7 shock towers to allow a longer shock, FSJs also use the same towers and are good donor vehicles. Lower sway-bar mounts from a FSJ fit between the springs and spring plates and have worked out very well for me.
Brake Hoses
If you want your CJ to ramp over 1000, you'll need to give some attention to brake hoses. If you use stock hose in their stock locations, it is very likely your hoses will limit travel. To complete the swap full size Jeep (FSJ) or Chevy Blazer brake lines relocated to mount off the bottom bolt of the shock tower work well.
Drag Link and Tie RodSince the CJ drag link attaches to the knuckle and the lift will cause it to run at an angle, it will most like hit the spring if left in stock form. There are several potential solutions to this problem. One is to convert to a custom "Y" style tie rod and drag link similar to what is used in the Wrangler YJ and other vehicles. Another solution is fabricate a bracket to move the drag link over the spring.
For my personal project I converted to spring over steering. Because of the serious nature of steering work I'm going to say "If you have to ask how you shouldn't try to build it yourself." Although I designed the arms myself I enlisted the help of a fellow 4 wheeler who is also an expert machinist to do the actual work. Many of the companies that make custom width front ends are selling similar spring over steering kits. The kits consist of steering knuckles from a '74-76 FSJ or Chevy and some custom steering arms that bolt to the flat area on top of the knuckle. These kits put the tie rod about as high as the top of the diff cover, which works out perfectly for SOA with YJ springs. By custom designing my steering arms I was able to retain the use of stock wide track CJ linkages even though my Dana 44 front is 2" wider than my Dana 30 was. This gives me extra tire clearance and makes finding spares easier.
Spring Wrap and Wheel Hop Control
The biggest problem with a spring over conversion is spring wrap and the resulting wheel hop. The problem is accentuated with soft, flat springs that articulate well. You will need some kind of spring wrap control or you will break u-joints, drive shafts, and even yokes. When the spring wrap unloads, it causes wheel hop which can cause a roll in an off-camber situation. Some sort of anti-spring wrap measures must be taken. I used a ladder bar with a shackle and threaded section on the leading side and a fixed mount to the axle tube on the trailing side. It controls axle wrap and wheel hop completely while still allowing full articulation. My ladder bar does this by controlling the pinion angle while still allowing every other type of movement including twisting. If the pinion angle can't change the springs will not wind up and wheel hop is prevented. I bent my ladder bar and broken the axle tube mount by testing on pavement and rocks, but even in this half functional state it still worked fine. I've been driving with this setup for a whole season already and so far I've experienced no wheel hop. I fabricated the axle end mount for the ladder bar to put the bottom bar only an inch or so below the axle tube and the top bar about 8 inches above. The front end of the bar mounts to a frame cross member I built, but many people mount them to their skid plate. All three points of the ladder bar and the other end of the shackle have polyurethane bushings to somewhat absorb shocks. The bottom tube of the bar runs parallel to the rear driveshaft but about 1" below to protect it from logs and rocks.
Spring Rates and Sagging
A common complaint of CJ owners who have used YJ springs SOA is that they are too soft or sag easily. I suggest using YJ 5 leaf rear spring packs for both the front and rear of your CJ. Mine haven't sagged after a season of 4 wheeling. If sagging becomes a problem or if more lift is desired add-a-leafs can be purchased from many lift kit manufacturers or made from another YJ spring pack. Try to buy or make add-a leafs that are as long as the main spring in the pack and put them in the second position. If this isn't high enough or stiff enough you can add even more leafs further down in the pack.
Conclusion
The end result with my CJ7 was RTI scores over 1000 by using springs that someone gave me for free and no expensive conversion kit. The SOA leaves plenty of room for tires, my 33s don't rub at all and it looks like there is plenty of room for 35s.
Do Your Duty And History Will Do You Justice...!
06' Wrangler Rubicon Unlimited, Clayton 4" Long Arm Suspension, Clayton Full Skid Plates, AtoZ Fabrication Rock Sliders, AtoZ Fabrication Cage Addition and More modifications to come...

sean1

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Re: 79 cj 5 build
« Reply #7 on: August 09, 2009, 10:17:44 am »
thanks for all the info guys.  very helpful.  the reason i was thinking about the large tires was due to the size of my axles in order to get the ground clearance needed.  that 14 bolt is  pretty big.  the axles already have the high steer components on them.  i would have picked a longer cj but this one was basically given to me.  thought about a nice fix up just to drive on the streets but i want to wheel it and have some fun.  fix it too nice a i wont want to scratch it up. 

ddechri

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Re: 79 cj 5 build
« Reply #8 on: August 31, 2009, 10:17:04 am »
While the D60 and 14 bolt are great, indestructable axles, they are definitely overkill for the 258. Perfect for rock buggies and trailer queens especially when you try to cover them for legality. In fact, as Jeremy points out, you would blow the tranny first anyway. Start small and work up to the beast if you figure out you need it. A CJ-5 with 4 inches and 35's will go almost anywhere while being a very friendly street machine. The springs you can find used on the forums. An early '70 D30/D44 set will give you 3.73's and a D44 rear that practically bolts-in. There are always 35's on the forums left over from upgrades. Wheel it, drive it, then see where you want to go with it.

On the otherhand, if you want to proceed with your plan, find someone who did it already and learn from them. Maybe even drive their rig. Someone has got to know a friend of a friend who did this.

- Dave
Dave DeChristopher
'79 CJ-7: 4.0L, T18, bronco geared Dana 20, D30/D44 (locked), Warn 8274
'60 Willys PU: IH 304 V8, wide T19, Dana 18, OD, PTO Winch, SOA D44/D53(Power Lock) w/4.27's, 33's,
'68 CJ5 - Dauntless, SM420 (project)
'98 Dodge Ram 2500 12V CTD QC LWB
"Where ever I go, there's I AM"