d70hd vs 60 vs d80 - Pirate4x4.Com : 4x4 and Off-Road Forum

JR650 · 03-17-2007, 10:30 AM

I am at the point in my build that i have to pick for sure which rear im going to run. its going in an SOA yj, 8" total susp lift, h1s with 39.5 iroks, 385 series ford/ np435/205. im running a dodge CAD 60 in the front, after looking for a decent HP ford front for about a year, i said piss on it and adapted this, kinda like the simplicity of the unit bearings, less to break. the engine is going to be a good solid 500hp with a 300 shot on top

. i dontthink that 60FF even with 35 splines is going to hold is it?? i also have in my posession a 70hd and the d80 that im planing to use from the same truck as the front axle. gear ratio is undecided at this point. i am a very right foot oriented kind of driver, not alot of rocks around here, lots of sand, mud, and snow, with some woods/logs and some rocks further north. the size of the 80 is the only thing that concerns me, the beef is undeniable. is that extra inch going to be worth the sacrifice in ring and pinion strength vs the 70?? i honestly would be suprised if its 50 lbs heavier. Im pretty well decided on the 80 but would like a second (or 10th) opinion. Any input is appreciated. Thanks, JR

TheRamChargerMan · 03-17-2007, 10:45 AM

It all boils down to weight and clearance.

All 3 axles use the same shafts if you go with 35 spline aftermarket.

The 80 should weigh about 75-100 lbs more than the 70 due to the size of everything, and maybe 100-125 more than the 60.

The ring gear/pinion size & strength is the only real benefit between these, but the gear/locker selection is almost non existent for the 70/80 when compared to the 60.

Not much help I'm sure, but it all depends on how much you think it will brake, and how easily will it be to replace parts.

I just decided to forego a d60hd w/35 spl & spool because I'm afraid it won't hold up behind my engine, so I am going 14b, even tho I have a d80 sitting right here.

JR650 · 03-17-2007, 10:56 AM

u can get an arb, detroit, and a couple different lunchboxes for the 70 or 80. locker selection isnt a problem.

Mr.N · 03-17-2007, 04:46 PM

The 60 is great for 34-39" tire. The 70U is better for 38-44" tire. I think the 80 is over kill for us...

If you can prove to me the 70 would have pinion deflection under load, then sure use an 80.

Gus310 · 03-17-2007, 06:41 PM

you probably dont want to hear it if you have been here a while but find a 14 bolt. they are cheap in junkyards, and the aftermarket id growing for them. they are easy to find and again, the aftermarket is growing. they are stronger than 60 and cheaper, find one, get some spares and come in cheaper than a single 60ff.

Ford_KTM · 03-17-2007, 06:50 PM

Run The 70, I Think You Wil Be Fine...i Dont Think The Ring Gear Will Be A Issue With It Whatsoever So No Need To Step It Up To A 80...

03-17-2007, 10:30 AM	#1 (permalink)
JR650 Registered User Join Date: Jan 2005 Member # 41529 Location: The Great Flat North Posts: 95	d70hd vs 60 vs d80 I am at the point in my build that i have to pick for sure which rear im going to run. its going in an SOA yj, 8" total susp lift, h1s with 39.5 iroks, 385 series ford/ np435/205. im running a dodge CAD 60 in the front, after looking for a decent HP ford front for about a year, i said piss on it and adapted this, kinda like the simplicity of the unit bearings, less to break. the engine is going to be a good solid 500hp with a 300 shot on top . i dontthink that 60FF even with 35 splines is going to hold is it?? i also have in my posession a 70hd and the d80 that im planing to use from the same truck as the front axle. gear ratio is undecided at this point. i am a very right foot oriented kind of driver, not alot of rocks around here, lots of sand, mud, and snow, with some woods/logs and some rocks further north. the size of the 80 is the only thing that concerns me, the beef is undeniable. is that extra inch going to be worth the sacrifice in ring and pinion strength vs the 70?? i honestly would be suprised if its 50 lbs heavier. Im pretty well decided on the 80 but would like a second (or 10th) opinion. Any input is appreciated. Thanks, JR __________________ 78 F250 supercab healthy 460 and 38" XMLs 91 YJ soa, 60front/80rear, locked, 38.5x16 TSLs on h1s, np435/twin stick 205, 385 series ford power

03-17-2007, 10:56 AM	#3 (permalink)
JR650 Registered User Join Date: Jan 2005 Member # 41529 Location: The Great Flat North Posts: 95	u can get an arb, detroit, and a couple different lunchboxes for the 70 or 80. locker selection isnt a problem. __________________ 78 F250 supercab healthy 460 and 38" XMLs 91 YJ soa, 60front/80rear, locked, 38.5x16 TSLs on h1s, np435/twin stick 205, 385 series ford power

03-17-2007, 04:46 PM	#4 (permalink)
Mr.N Registered User Join Date: Sep 2000 Member # 1635 Location: Minne-so-cold Posts: 3,959	The 60 is great for 34-39" tire. The 70U is better for 38-44" tire. I think the 80 is over kill for us... If you can prove to me the 70 would have pinion deflection under load, then sure use an 80. __________________ Proud Catholic \| My Dana Articles and Info -> http://77cj.littlekeylime.com/web_rs44.html

03-17-2007, 06:41 PM	#5 (permalink)
Gus310 Registered User Join Date: Jan 2006 Member # 65984 Location: Groton, MA Posts: 415	you probably dont want to hear it if you have been here a while but find a 14 bolt. they are cheap in junkyards, and the aftermarket id growing for them. they are easy to find and again, the aftermarket is growing. they are stronger than 60 and cheaper, find one, get some spares and come in cheaper than a single 60ff. __________________ Fez: SCARFACE makes you cry?!!? Ron: Yeah, when I think he got killed and left that big mountain of coke sittin' there... I mean, it breaks your heart!

03-17-2007, 06:50 PM	#6 (permalink)
Ford_KTM Registered User Join Date: Jun 2005 Member # 49754 Location: Reno, NV-Auburn, CA Posts: 488	Run The 70, I Think You Wil Be Fine...i Dont Think The Ring Gear Will Be A Issue With It Whatsoever So No Need To Step It Up To A 80... __________________ YJ 302 MOG 404's, fourlink 4.5 RE Coils, NP-435, 205, 42 iroks

03-17-2007, 10:45 AM	#2 (permalink)
TheRamChargerMan Registered User Join Date: May 2004 Member # 31352 Location: Newport News, VA Posts: 1,096	It all boils down to weight and clearance. All 3 axles use the same shafts if you go with 35 spline aftermarket. The 80 should weigh about 75-100 lbs more than the 70 due to the size of everything, and maybe 100-125 more than the 60. The ring gear/pinion size & strength is the only real benefit between these, but the gear/locker selection is almost non existent for the 70/80 when compared to the 60. Not much help I'm sure, but it all depends on how much you think it will brake, and how easily will it be to replace parts. I just decided to forego a d60hd w/35 spl & spool because I'm afraid it won't hold up behind my engine, so I am going 14b, even tho I have a d80 sitting right here.

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