Ford 9"

aluke0510

Basic User
City
Arizona
State
AZ
#1
Anybody have any thoughts on a lighter yet stronger rear axle than the AMC 20? If I could drop 50lbs off it and be a bit stronger I would be happy. 50lbs may be hard though considering I think we are only talking about around 200lbs to start... But it is hope to get some weight off the back.

My thought is a Ford 9" with an aluminium third member. I saw the Currie aluminium centre section option but was a bit nervous about it. However it is hard to get weights. I asked Currie just hoping they could give me some numbers but didn't have anything to give me. I figure Ford is a good hope since it isn't a cast iron housing but welded steel centre section. Would be great if somebody made a good chromoly housing that wasn't built to be stronger than the standard but built to be the same strength thus lighter.

Other options Ford 8.8? Dana 44 lighter or heavier?

Thoughts?

Thanks
 

BRKLYNZ28

Scrambler Junkie
LIFETIME
CJ-8.com Member
City
BROOKLYN
State
NY
#2
guess the dana 60 is out of the question.. lol why do you want to lose unsprong weight? fuel
 

aluke0510

Basic User
City
Arizona
State
AZ
#3
Weight loss, want to keep the Jeep as light as possible. Allows for more payload without exceeding the GVWR by much.

Already looking at an aluminium block GM 5.3L v8 with AX15 tranny. Should result in about 150lbs weight loss (yeah I know it sounds funny upgrading to a V8 from the straight 6 to loose weight but hose are the numbers, aluminium v6 block is a bit expensive and it doesn't seem to easy to throw in an aluminium toyota v6). Lithium batteries which should net about 50lbs loss for the pair. Going to lighter front bumper (now it has a 3x6 x1/4" wall steel bumper) maybe drop 20lbs. Forged aluminium centreline wheels with slightly narrower tires (something like a 32x9.5 whatever that size was in metric... have 32 x 11.5 now and are getting to a point of needing upgrade) which should net a 70lb savings for all four. I can't think of many other upgrades that result in much substantial weight loss that are cheap, result in substantial weight loss or aren't already up for an upgrade...

So with those plans I should drop about 290lbs and loose no functionality, actually gaining some with the engine and batteries. If I can get another 50lbs off the back I would be happy. So far most of the weight savings is in the front with just the three tires in the back. I think I already need to look at a stronger axle in the back since there is the V8 and that is where most of the weight gets added at when packing for 2weeks bush. It's hard to keep the weight balance in check, the back will always be heavier than the front unless you move to something like the forward control... Thinking about mounting a storage box up front where a winch often goes to store tools and spare parts to bring some heavy stuff forward a bit.

So long story short I think the AMC 20 is borderline strong enough for V8, 32" tires and 2500lbs sitting on it bouncing off road. If I am upgrading I'd like to consider weight reduction options. Unsprung weight is a plus too.
 
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K9rockydog

Basic User
City
Glendale
State
Az
#4
Crazy obsession with vehicular "weight loss".. "this should lose this many lbs, that should lose that many"

You started out as a Street bike guy, didnt you..??!! I only say that, because I did.. and I know that is how we think..:thumbsup: :bacon: :headbang:
 

aluke0510

Basic User
City
Arizona
State
AZ
#6
Crazy obsession with vehicular "weight loss".. "this should lose this many lbs, that should lose that many"

You started out as a Street bike guy, didnt you..??!! I only say that, because I did.. and I know that is how we think..:thumbsup: :bacon: :headbang:
If I was a a street bike guy I wouldn't be wishing for an aluminium block 4.0 the same weight as a 2.4L... I would be going for the 5.7L without question. :)

No but when you start adding everything up for a 2 week trip in the bush it adds up.

15-20gal water, extra 20gal fuel there is 300lbs
50lbs camping gear
food 25lbs
25lbs camera equipment
100lbs tools and spares and jack
50lbs contengency

Not to mention the added weight of the larger tires and few mods I have done plus fluids weight adding an estimated 400lbs to curb weight plus a driver at 175lbs

So adding that up is 1125lbs and I think the payload capacity on a stock CJ8 with hard top and 258 was about 800lbs.

Now I am sticking with the hard top but have been doing custom soft doors (well the Bestop tube doors closed in at the bottom with with cloth covered plastic and modifying the soft uppers to work with the hard top). (I do my own sewing) Heater is out as is the rear bumper switching to the bumperettes, windshield washer bottle and pump out, spare tire goes in bed without the tire carrier, etc. Figure with that I have lost about 150lbs.

Netting another 290lbs loss brings it to 440lbs loss brings it to 685 lbs or 115lbs under GVWR allowing a few more comforts or a passenger or longer trips.

Besides lighter weight is better performance. Less sinking in soft sand, better fuel economy, better braking, better handling. Just imagine a 4200lb scrambler outfitted to support 2 weeks fully sustained in the desert. With that 5.3L in it imagine the performance enhancement too. No pill can give you that.

*I have to admit these are all thumb suck numbers based on my estimates of the mods I have done and the mods I am planning and the estimated curb weight of a stock CJ8 with 258 and hardtop/doors. These numbers could be off by up to 100-200lbs...

I wish I had my own set of race car scales because then I would be getting accurate weight changes for each wheel with each change... BTW. I am an engineer.

Back on topic though I would feel a lot more comfortable with a stronger axle of the same weight or a lighter axle of the same strength. Want to avoid getting stranded, these weights are based on minimal spares and tools...

Edit: And I have obsessive compulsive disorder

Edit2: BTW I am so obsessive about weights and distribution that if there is no passenger the passenger seat comes out and jerry cans with water go in place. Better to get the weight farther forward and balance that side out.
 
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jims chop shop

Scrambler Junkie
LIFETIME
CJ-8.com Member
SOA Member
City
stafford
State
va
#7
You could "bob" the rear. !!
That will save weight and balance it out too. !!( wink )
 

BRKLYNZ28

Scrambler Junkie
LIFETIME
CJ-8.com Member
City
BROOKLYN
State
NY
#8
Wonder if the aqua body is lighter then original?. . U can take the power brake booster off as well for 5 lbs. Put aluminum rims instead of steel..

Sent from my SPH-L900
 

MrBeep

CJ-8 Vendor Supporter
CJ-8.com Vendor
City
Dillsboro
State
IN
#11
Sheet-metal Ford 9 inch, replace springs with coil overs / chrome molly 3 or 4 link. Save a good % of rear weight there. :wave:
 

Kane

CJ-8 Member
CJ-8.com Member
City
Berlin
State
ct
#13
I am a streetbike/trackday rider so I think the same way. My fiberglass body and front end are much lighter than the metal stock set-up. Pull the metal gas tank and metal skid if you have it and go plastic tank and aluminum skid. Go aluminum on the tranny skid and add synthetic winch line if you have one. Keeping the hardtop, go with soft doors or half door with soft wondows to lose 100 pounds or so.
 

aluke0510

Basic User
City
Arizona
State
AZ
#14
Wonder if the aqua body is lighter then original?. . U can take the power brake booster off as well for 5 lbs. Put aluminum rims instead of steel..

Sent from my SPH-L900
I don't think a new body is really in the scope I am looking at. From the plans I have now it isn't needed and will actually make my cost go way up given it isn't needed now and would be expensive to sort out and reconfigure the bed cover I already have installed now. Forged aluminium rims in my above plan already with slightly narrower tires should save about 75lbs so it takes 45lbs off the rear. Funny thing is most cast aluminium rims weigh the same as steel rims... But the power brake booster has to stay at least until I find out how the braking is fully loaded after all the weight reduction.

Given the thickness of aluminium they use compared to the thin sheet metal I don't know how much weight savings will actually be achieved if any. Only the really high strength aluminums actually exceed the strength/weight ratio of most common lower carbon non heat treated steels. The real weight savings is using medium carbon alloyed steels heat treated after fabrication. But talk about a price skyrocket...


You could "bob" the rear. !!
That will save weight and balance it out too. !!( wink )
No, we are not chopping it! I need the space. I would have been a fan of moving the axle back another 6inches though.

How much does the roll bar weigh ?
About 60lbs. It is already out and I have a cage inside the cab. Net is probably about an additional 60lbs but it is moved a bit farther forwards.

Sheet-metal Ford 9 inch, replace springs with coil overs / chrome molly 3 or 4 link. Save a good % of rear weight there. :wave:
Pretty sure that will not result in weight savings. The weight of the 3 link may just offset the weight of the factory springs the weight of coil springs. When you look at it a standard disk brake conversion on the rear adds weight, about 10lbs I am told over drums; that is unless you pay $700 to get good forged aluminium callipers and drilled rotors.

I am a streetbike/trackday rider so I think the same way. My fiberglass body and front end are much lighter than the metal stock set-up. Pull the metal gas tank and metal skid if you have it and go plastic tank and aluminum skid. Go aluminum on the tranny skid and add synthetic winch line if you have one. Keeping the hardtop, go with soft doors or half door with soft wondows to lose 100 pounds or so.
Fiberglass isn't an option for me. If I didn't have the bed cover for security, a place to sleep, and a place to stand taller for better views this might have been something I looked at from the start. But not budgetable now not even for an aluminium tub. Custom fuel tank under there now, 1/4" aluminium with no skid and 40gal capacity... Aluminium tranny skid is a good option, something like a tube steel support covered with aluminium... No winch and not in the plans (there is a big weight savings). Current 5yr goals are deserts and often not to much to winch off of, better to learn how to back away or experience to not need one so you don't end up digging a big hole through rocks to burry a tire. Totally agree on the doors. Using tube doors but sealed up with light plastic and cover in cloth with soft uppers. Far lighter than Wrangler half doors but not as light as all soft doors. I need the rigidity of the tube doors to support a large camera...


I really do appreciate that people aren't flaming over trying to loose weight. I figured people would be up in arms over spending money to drop weight lower. It is nice to people appreciating it and supporting it. And people with similar thinking! Thanks for the support.

But I am still wondering about this axle thing. If there is an upgrade I can plan that will reduce weight or give more strength at the same weight. I hate how hard it is to get accurate weight figures on these things and that vendors don't know the numbers. You would think they would have close numbers from doing shipping... Need to sort out if it goes into the budget or not.
 

cbford

Legacy Registered User
City
CLT
State
NC
#15
The sheet metal 9" is lighter, stronger and will gain you over 1inch ground clearance.

Lose dash pad, dash panel. And mount gauges in plastic shhet screwed to a single small cross tube in place of solid panel.

Lose back glass in hard top. Strip floor to bare metal. Lose the upholstered, foam covered, steel framed seats and put molded plastic race seats in their place.

If you put a ford 302 in rather than a 5.3 it will save you another 40-ish lbs. a bit more if you use alum. heads.
 

aluke0510

Basic User
City
Arizona
State
AZ
#16
The sheet metal 9" is lighter, stronger and will gain you over 1inch ground clearance.

Lose dash pad, dash panel. And mount gauges in plastic shhet screwed to a single small cross tube in place of solid panel.

Lose back glass in hard top. Strip floor to bare metal. Lose the upholstered, foam covered, steel framed seats and put molded plastic race seats in their place.

If you put a ford 302 in rather than a 5.3 it will save you another 40-ish lbs. a bit more if you use alum. heads.
Thanks on the info on the Ford 9" any idea of numbers?

Dash pad is out but that was more of a cosmetics thing, it only weighs like a pound. Eh, I need the strength of the steel dash, and that would honestly probably only loose like 3 pounds. Can't loose the glass in the hard top gut I have done a lot of thinking about how one could implement a vinyl window there. I have also thought about some of these more modern plexiglass scratch resistant coated windshields to use at the back. I think we still have to keep our heads about comfort, on a two week bush expedition trip the last thing you want is excessive noise and uncomfortable seat causing fatigue. If going to spend 4-5hrs a day in it for 2weeks then you can't loose all the creature comforts, have to retain the critical ones. But I do pull seat and bracket out of passenger side generally. What I was seeing was 500lbs on the fords, GM's all aluminium 5.3 v8 is 400lbs... Lighter than a 2.5L diesel.
 

cbford

Legacy Registered User
City
CLT
State
NC
#17
It is not a huge weight savings, maybe 8-10 lbs. But you will get an extra 20+% in deflective resistance strength plus tapered bearings, stronger attachment points and potential of larger fluid reservoir depending on housing shape you choose.

I suggested plastic race seats as they will likely be more comfortable from a support perspective than the stockers in addition the being stronger and lighter.

And I am not guessing, I can tell you from personally reading the scale; an L33 - 5.3 weighs 460 lbs. with accessories and a stock 5.0 with iron heads and accessories weighs 425. Remember, the 5.3 is physically larger than the 5.0. And in terms of rotational parts - the 5.3 crank/rods/journals/bearings are good up to 1k hp whereas the ford stockers might make 600 and live. That means they are beefier.
 

Bad Karma

Captain Sarcasm
LIFETIME
CJ-8.com Member
City
Garden Hill, Ontario, Cana
State
da
#18
My Scrambler weight 5200 lbs trail ready without anyone in it. Mind you I have 60s, iron block 5.3L, nv4500... etc etc...
 

aluke0510

Basic User
City
Arizona
State
AZ
#19
It is not a huge weight savings, maybe 8-10 lbs. But you will get an extra 20+% in deflective resistance strength plus tapered bearings, stronger attachment points and potential of larger fluid reservoir depending on housing shape you choose.

I suggested plastic race seats as they will likely be more comfortable from a support perspective than the stockers in addition the being stronger and lighter.

And I am not guessing, I can tell you from personally reading the scale; an L33 - 5.3 weighs 460 lbs. with accessories and a stock 5.0 with iron heads and accessories weighs 425. Remember, the 5.3 is physically larger than the 5.0. And in terms of rotational parts - the 5.3 crank/rods/journals/bearings are good up to 1k hp whereas the ford stockers might make 600 and live. That means they are beefier.
Great, mildly lighter or equal with quite good strength increase. Enough for me to put into budget. Currie or go have shop shorten junk yard and change out gears if needed?

Seat isn't planned for now. I have a smittybuilt seat with acrylic canvas and sheepskin upholstery. Very comfortable even in 110F and 5hrs. If I am desperate for weight later I will take a look.

Interesting on the Ford. I think a GM is an easier swap though with more support for instal and wiring. But I could be wrong, never looked too much past the weights and was getting a lot more info on GM's. Fuel economy compared? Considered a 2.5L Toyota diesel for a bit. Slightly less HP but more torque at 450lbs. But also factoring in less fuel requirement for the same distance knocks more weight off. Parts have to be imported 95% of time, techs to troubleshoot and repair would have to be excellent as it would be an engine that would have never seen here before. And more expensive. Plus would need to sort out everything for transmission adapt or using a toyota transmission and transfer case... Complicated as all.

My Scrambler weight 5200 lbs trail ready without anyone in it. Mind you I have 60s, iron block 5.3L, nv4500... etc etc...
I think that means my 4200-4400lbs target is realistic then. Yours is quite a bit more built than mine with larger tires, axles, winch, lift, cage, seating, heavier engine/transmission, batteries (it is amazing how much weight can be saved just with going to lithium, expensive but last better, better power range, and far lighter), etc. When you say trail ready how much fuel, water, camping gear, spares and tools, etc. are you talking about?

Wondering what fuel economy to expect? Seeing anywhere from 17-22mpg highway. I get about 17 now with 358 and howell injection.
 

John N

Addicted....Ex-SOA VP
LIFETIME
CJ-8.com Member
SOA Member
City
Rockville
State
VA
#20
This shows what mine weighs on race car scales, specs below.......

 
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