Psykovertible Posted October 2, 2005 Share Posted October 2, 2005 not finding much info on this. i have access to a dana 44 with a 3.73 gear cheap but not sure if it is a waste. how strong are they stock? if i put a bunch of money into axles and gears maybe i should buy a 12 bolt or a 9" instead. anyhow, sbc 400 should push 400-500 hp. car is light... really light, and i am mostly sure i will be using an auto trans. i just got that "back-half" chassis from the classifieds that shoud beef the car up and looks like ladder bars will be used. planning on big sticky tires. any info? Quote Link to comment Share on other sites More sharing options...
Psykovertible Posted October 14, 2005 Author Share Posted October 14, 2005 bump on dana 44 info request Quote Link to comment Share on other sites More sharing options...
Guest Phil1934 Posted October 14, 2005 Share Posted October 14, 2005 That was rear in '55-'57 Chevy and we blew a half dozen with a 301. Quote Link to comment Share on other sites More sharing options...
Tim240z Posted October 14, 2005 Share Posted October 14, 2005 I would go with the 9". More choices on gear sets, lockers/spools etc and more aftermarket support. Get a full floating rear as they are stronger. If you are going to go through all that effort, might as well use the most effective parts.... Quote Link to comment Share on other sites More sharing options...
auxilary Posted October 14, 2005 Share Posted October 14, 2005 i think this post needs to be in drivetrain section... Quote Link to comment Share on other sites More sharing options...
JMortensen Posted October 14, 2005 Share Posted October 14, 2005 I betcha there's been a lot of development of the D44 in the last 50 years... D44 is the rear of choice for the smaller Jeeps, CJ, YJ, XJ, etc. for rock crawling which is REALLY hard on diffs. You guys think drag racing is tough, you ought to see these guys stuck on a rock and literally bouncing the whole rig up and down on 38" tires with 8 lbs of air in them. Talk about shock load... Not to mention the D44 comes in the back of the Viper and older Vettes. The diff Scottie went 10 secs on was a D44 or a D36, I am pretty sure his was the D44. You might want to try and compare the two, or at least find out the max potential of both. The thing to do for a solid axle D44 is start looking at off road magazine articles and websites and see what people are doing to beef them up. I wouldn't count the D44 out, although the full floater 9" that Tim suggests is basically a NASCAR rear end and is going to be stronger and maybe even cheaper with the number of circle track guys out there. Check circle track magazines and suppliers for the 9" stuff. Quote Link to comment Share on other sites More sharing options...
5foot2 Posted October 14, 2005 Share Posted October 14, 2005 I'd look at the 8.8 LSD rear end out of a early 90's mustang. It's pretty strong, lots of brake options and you can do the MM ford 5 lug brake/hub conversion to match. One other thing I like about the 8.8 in the mustang, it's located by a triangulated 4 link setup, so it has the mouning lugs on the diff for the upper bars. If you wanted to run the triangulated 4 link this will help out a bunch. When you start to measure for the back half, you'll see you don't have much room behind the seats, traditional ladder bars are going to be tough to install. Quote Link to comment Share on other sites More sharing options...
Scottie-GNZ Posted October 14, 2005 Share Posted October 14, 2005 Not to mention the D44 comes in the back of the Viper and older Vettes. The diff Scottie went 10 secs on was a D44 or a D36, I am pretty sure his was the D44. That is correct. I ended up using a c4 Corvette D44 diff, same as the one used by Vipers. However, mine was IRS with 3" steel halfshafts so not sure I can comment on the axles to be used in a solid D44 rear. I would say if you have a need for a D44, 12-bolt or 9", you are probably also not using the stock axles that came with it. In a light Z car any D44 with aftermarket axles should be more than strong enough unless you are launching a mega-HP car off the line with a manual tranny. As a comparison I was launchng a 600lb/ft torque turbo engine at about 4800 off a transbrake. HTH, Quote Link to comment Share on other sites More sharing options...
Psykovertible Posted October 15, 2005 Author Share Posted October 15, 2005 yah.... thanks for replies first of all. it took a few minutes for e to find this post today cause I was looking around in the drivetrain forum. duh. Nevur sayd I was uh jeanious did eye... Jake Quote Link to comment Share on other sites More sharing options...
dr_hunt Posted October 15, 2005 Share Posted October 15, 2005 The 4x4 guys say that the dana 44 is good for about 400 HP in stock form. The 9 inch ford is almost bulletproof. My 3800 lb monte has launched with the left front in the air several hundred times over the last 3 years with a 9 inch. The z launches with both wheels in the air and has stock resplined axles, also 9 inch. The 8 inch Ford rear parts are expensive, the 8.8 has come along way and is a real nice piece, the 9 inch will always be king of the hill but costs alittle extra HP to run than say the 12 bolt which is another fine choice. All of this is my opinion only. Your going to spend some $$ anyway, I'd go with the 8.8, 12 bolt or the 9 inch, with any of these you won't go wrong. Quote Link to comment Share on other sites More sharing options...
JMortensen Posted October 15, 2005 Share Posted October 15, 2005 The 4x4 guys say that the dana 44 is good for about 400 HP in stock form. Agree with everything you said Doc, but 400 hp in a 4x4 which again is going to run big tires, probably a locker or a spool and go mudding or rock crawling is worth quite a bit more hp in a light sports car, even one that drag races on slicks. Also just cause I think it's interesting I thought I might mention that the new Nissan Titan truck has a D44 in back. Quote Link to comment Share on other sites More sharing options...
dr_hunt Posted October 16, 2005 Share Posted October 16, 2005 Might be, let's talk apples and apples. Depends on the axles, I believe that the D44 came in 27, 29 and 30 spline versions depending on the application and year. Certainly the 29 and 30 spline version are the ones to use and the 27 spline is one to stay away from. Dirt doesn't hook like slicks on pavement and if somebody was going to do a solid axle conversion then it would seem appropriate to get the best rear available unless they just had one laying around. I've blown several D44 to pieces even in the dirt in my 4x4. A 400 lb-ft torque engine, which is common for a modded V8 with a 700R4 or 200 4R trans and a 4.11 rear diff will generate 4571 lb-ft of torque on the axle without taking into consideration the torque multiplication factor of the converter, which for a good high stall converter can reach 2. So if you use the light duty 27 or even the 29 spline axle in the D44 it probably won't last very long, whether it is a light car or not, cause the torque will never change only the time it is loaded to the maximum value will, which will decrease with time sooner than if it were in a heavier car, since the lighter car will start moving sooner and travel quicker. When I got my 9 inch for the Monte from Moser engineering, I bought their super duty axles, which are mondo and the diameter of the axle is based on the torque output of the engine only! Ditto for the axles in the z, based on engine torque not vehicle weight. So, if we are talking apples and apples then I'd say pick the rear based on the amount of torque and HP you plan on trying to plant, not on preference of diff's and what may or may not be the most reliable while offering the best availability of parts and goodies. Of course we could just do a winters quick change and eliminate all doubt and have gear chang capability in 30 minutes or less! Quote Link to comment Share on other sites More sharing options...
JMortensen Posted October 16, 2005 Share Posted October 16, 2005 Just like for the 9" there are chromoly aftermarket axles for the 44 that are much stronger than the originals. Definitely want the highest spline count you can get for sure. The axle length in a Z is going to be significantly shorter than that in a 4x4, and that makes them stronger. One more comparison point. What are people putting through the 27 spline MM stub axles? Compare that to what they can put through a straight axle with a full chromoly 30 spline axle, with no CV joints. I think the D44 would be a lot stronger... About your traction in dirt comment. I don't even agree about the traction thing if you're talking plain ol dirt. Think about the size of the tire. That gives it a LOT more leverage on the axle shaft itself than a smaller drag tire on a street car. But then you get into these rock crawling guys, who are BRUTAL on the diffs, and I would argue that they can put maybe 2 or 3 times the torque to the diff that a drag racer can. When the vehicle is on a 45º slope bouncing up and down trying to get over a big rock that's a LOT of stress on the axles. Whole lot of stress. Oh, forgot to mention that the off road truck is generally close to twice the weight of a Z. Let me put it this way. I've seen a lot of diff carnage. The carnage I saw when I worked for Randy's Ring and Pinion was almost all 4x4 stuff. I'd say 90%. I've seen a driveshaft for a 4x4 that was twisted into a screw shape. I've seen axles twisted off at the carrier. Ring gears with 1/2 their teeth sheared off. Etc, etc. The stuff from the cars was usually a couple pinion teeth broken or the U-joints busted or burned up gears. I still agree that a 9 would be the strongest build (with an upgraded 3rd member), followed by a 12 bolt, followed by an 8.8, followed by the 44. It's definitely not the strongest thing out there. I'm just saying that I think you're underrating the 44. Quote Link to comment Share on other sites More sharing options...
dr_hunt Posted October 16, 2005 Share Posted October 16, 2005 Well, if he's going to go crome moly axles, then why bother with the Dana 44?There is a corresponding torque level that all diffs will handle on a regular basis, the D44 is kind of on the lower end. No matter which rear, they all will have to be shortened so the length of axles would be the same, so the mathematical equation simply is reduced to axle diameter, don't you agree? Inversely proportional to length, directly proportional to diameter. I was talking stock and I think that the original question was whether he should bother with a stock 44 unit cause it was available cheap. And stock 9 inch 28 or 31 spline axles are bigger diameter than the D44 and if you get pre '79 then they can be shortened and resplined for a fraction of the cost of aftermarket axles, like $45 versus $279 for axles. So, really, his question is "Do I bother upgrading and shortening a D44 for the z with a 400-500HP sbc or do I go 12 bolt or 9 inch?" So as a recomendation I'd personally go with something other than the "stock" D44. Doesn't make sense to me to put all that $$$ into the 44 when he could easily spend less and go 9 inch, 12 bolt or 8.8. For me it's just my preference as insurance and really what would be up to the task, yeah, the 44 might work fine, the 8.8, 12 bolt or the 9 inch will definately be better. Nobody likes to do it twice at twice the cost, better to do it once even if it costs more than cutting corners would. Quote Link to comment Share on other sites More sharing options...
JMortensen Posted October 17, 2005 Share Posted October 17, 2005 Doesn't make sense to me to put all that $$$ into the 44 when he could easily spend less and go 9 inch, 12 bolt or 8.8. For me it's just my preference as insurance and really what would be up to the task, yeah, the 44 might work fine, the 8.8, 12 bolt or the 9 inch will definately be better. Nobody likes to do it twice at twice the cost, better to do it once even if it costs more than cutting corners would. True enough... Quote Link to comment Share on other sites More sharing options...
Psykovertible Posted October 17, 2005 Author Share Posted October 17, 2005 well..... dont have to narrow the D44 cause it will fit in there with about a 8-10 inch wheel as is. however, talking with my dad he mentioned to make sure it has 3" axle tubes or I will have to custom make suspension brackets for the 4link/ladders (whatever) i use. i will likely use the Jegster suspension thats been talked about here. cant think of the user name right now but chatted many times and he loves it. cross between 4link and ladders that are fairly short front to back and are simple. they are called ss bars. Quote Link to comment Share on other sites More sharing options...
Pop N Wood Posted October 17, 2005 Share Posted October 17, 2005 I always thought the longer the shaft, the higher the torque capacity. At least that is what the Navy thinks when rating propeller shafts. Quote Link to comment Share on other sites More sharing options...
JMortensen Posted October 17, 2005 Share Posted October 17, 2005 I always thought the longer the shaft, the higher the torque capacity. At least that is what the Navy thinks when rating propeller shafts. If the shaft were longer it would be less stiff. Maybe they're counting on a torsion spring type action from the prop shaft??? Just a SWAG. Quote Link to comment Share on other sites More sharing options...
Pop N Wood Posted October 17, 2005 Share Posted October 17, 2005 Yes, that is exactly the reason they gave. There is more rotational give in the shaft before it snaps. Quote Link to comment Share on other sites More sharing options...
dr_hunt Posted October 17, 2005 Share Posted October 17, 2005 Nope, I believe that there is an equation for elastic deformation and one non-elastic deformation. Jmortensen is probably right, for a given torque, a longer shaft will provide more elastic deformation so that would be a plus in that application. Quote Link to comment Share on other sites More sharing options...
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