NicktheMillwright Posted April 3, 2023 Report Share Posted April 3, 2023 I know this may be a stretch, but does anyone have information regarding the weight of the rear axle that came with the 2WD 720's? Not super keen on removing the rear end to find this information myself. But I will if I need to. The goal is to axle swap a Isuzu Rodeo rear end. Its a Dana 44, Disk brakes, 6 lug, LSD, 4 Link, and can be re-geared to 3.7. I'm guessing it weights around 200lb. I want to know If I should look for the illusive Hardbody H-190 LSD rear instead. Quote Link to comment
datzenmike Posted April 4, 2023 Report Share Posted April 4, 2023 How does knowing the weight matter if putting a much heavier one in? Measure the WMS to WMS (wheel mounting surface) to make sure it's not too wide or narrow. Will your 14" rims clear the disc brake caliper? The D21 Hardbody H-190 LSD rear end was only an option on the '88-'93 4 cylinder 2wd trucks. It doesn't have disc brakes and has 3.889, 3.70 and 3.545 ratios. The 'third member' is removable so you don't need the axles and the housing. Easiest way to look for one is find 2wd, the year (88-'93) and four cylinder KA engine then look for the small orange sticker on the back side of the differential. Take a rag and good luck. Quote Link to comment
NicktheMillwright Posted April 4, 2023 Author Report Share Posted April 4, 2023 Regarding the weight. I'm trying not to add more weight that what I've taken away. Trying to add lightness and increase power. The rims I am planning on running do fit just fine, I did a test fit before pulling it. I have maybe 2mm of clearance between the caliper and the inner rim, that will be enough. 9 hours ago, datzenmike said: The D21 Hardbody H-190 LSD rear end was only an option on the '88-'93 4 cylinder 2wd trucks. It doesn't have disc brakes and has 3.889, 3.70 and 3.545 ratios. The 'third member' is removable so you don't need the axles and the housing. Yeah that checks out with my notes. I dont know the numerber of them that where equipt with the LSD but I can't imagine it was many. I'll do some digging Quote Link to comment
NicktheMillwright Posted April 4, 2023 Author Report Share Posted April 4, 2023 Mike it has just been brought to my attention that the HF37 axle code on my truck identifies it as a H190 Axle. There seems to be an LSD conversion available via Traction Concepts. The D21s and KA 1st gen Frontiers also used the H190 if I'm not mistaken? Both of which had LSD options, I know my 1st gen Fronty with the VG did not get such option. https://www.tractionconcepts.com/Nissan-H190-LSD-Conversion-Fits-H190-Open-Diffs-p/tcxni9301.htm I'm willing to bet that's a decent option if all else fails. I'll do more research Quote Link to comment
Crashtd420 Posted April 4, 2023 Report Share Posted April 4, 2023 I went down this road a little.... Anything v6 wont work... Different spline count and bigger differential in general..... Not 100% sure when they stopped using the h190 but it has to be a h190 differential I believe they went to the h233 next or something like that..... And stay away from the traction concept, I'm pretty sure it's the same as having a welded or locked differential... Straight line it's ok but no good in the turn.... There were a couple threads about the lsd and Detroit locker... I'll try to find an link those for you.... 1 Quote Link to comment
Crashtd420 Posted April 4, 2023 Report Share Posted April 4, 2023 Oh if you really want the weight I can get a ruff weight for you later tonight.... I have a disassembled housing in my basement... 2 axles ,diff, and housing... you'll have to add a couple pounds for the brake assembly... 1 Quote Link to comment
datzenmike Posted April 4, 2023 Report Share Posted April 4, 2023 8 minutes ago, Crashtd420 said: And stay away from the traction concept, I'm pretty sure it's the same as having a welded or locked differential... TC? Traction Concepts is I think what the old Phantom Grip changed their name to. Old wine in new bottles. Yes stay away. This is just a large spring forcing the side gears outward against the case. The friction of metal to metal somewhat locks the axles. As you can imagine the side gears and case were never designed for friction between them and why clutches are used on 'real' LSDs. You want LSD you have to pay for it. 720s don't need LSDs unless you live on dirt roads and see a lot of mud. The 720 certainly does not make enough power that an LSD is needed on pavement. 1 Quote Link to comment
Crashtd420 Posted April 4, 2023 Report Share Posted April 4, 2023 Although the last two new ones available were sold there is some good discussion here too... Quote Link to comment
Stoffregen Motorsports Posted April 4, 2023 Report Share Posted April 4, 2023 Weight - probably around 150 pounds. 1 Quote Link to comment
NicktheMillwright Posted April 4, 2023 Author Report Share Posted April 4, 2023 On 2/5/2023 at 9:00 AM, datzenmike said: Oh man. Any info is good info even if it gets off track. Someone in the future may come looking for H-190/H-233 information. Yes that would be me, among many 6 hours ago, Crashtd420 said: Okay so I gave this a good read. And from what I understand, stock 720's don't benefit from LSD's However the Z24 I am building for my truck is spec'd to push 14psi of boost, so that changes things a bit Additionally I am building a 4 Link, which is why I want to get a potential axle swap or diff swap understood and on paper before I do such a thing I guess what I'm asking is, is it even worth swapping to an LSD? This truck will never be a race car, mostly for fun because we all need a project. However being able to fool around would be nice. 5 hours ago, Stoffregen Motorsports said: Weight - probably around 150 pounds. Thanks for the info Stroff 6 hours ago, datzenmike said: TC? Traction Concepts is I think what the old Phantom Grip changed their name to. Old wine in new bottles. Yes stay away. Roger that. 1 Quote Link to comment
datzenmike Posted April 4, 2023 Report Share Posted April 4, 2023 Well it, (LSD) increase traction to both rear wheels and resists the engine spinning the tire with the least traction. Invaluable if in mud or have enough power to spin the one rear tire if drag racing (In a straight line) and more traction needed. It does have the ability to break away or slip when turning tight corners when there is sufficient traction as in on pavement. However if off pavement the LSD won't allow slip and it will act like a welded differential. There is a slight tendency to plough ahead when turning as the rear wheels resist turning at different speeds. LSDs have increased tire wear on the rears. The higher the break away torque needed to allow the clutches to slip, the more traction to both tires, the more tire wear and the more the vehicle wants to go straight when turning. It's harder to regain control in an over steer condition if you have an LSD. Quote Link to comment
Crashtd420 Posted April 4, 2023 Report Share Posted April 4, 2023 So I weighted the axle housing, with both axles and differential but with no brake parts.... I was very surprised it was only 100 lbs... 1 Quote Link to comment
wayno Posted April 5, 2023 Report Share Posted April 5, 2023 (edited) I recently went thru this, I had an LSD in my 521 kingcab SD25 turbodiesel, it was the 3.545 version, I did not like it but it is a 2wd and light in the back because it has a stepside box, I found making left turns in traffic to be scary in wet conditions, if I had to get it moving because a car was coming the backend would more often than not start coming around on me, but the worst was when I was entering a freeway on right turn ramp where the road was tilted to the left because it was a left turn going uphill, if the tires broke loose the rearend would start heading at the cement wall/barrier, it is tough to get it moving uphill in this scenario, in traffic others are annoyed because I was not keeping up with the vehicle ahead of me, one time I believe I heard a horn honk, I got lucky and a 3.3 gearset came available at the local wrecking yard and I installed that and have never regretted it, 3000rpms is about 80mph or maybe slightly more now, I drove it long enough to get used to the LSD, but the lure of 3.3 gears was too great. I found that LSD in an unmarked 1993 hardbody axle, I did not believe it was really an H190 LSD, I thought when I got it out it would be a Lincoln Locker, I was stunned when it came out of the axle housing, I actually walked away from that earlier to get something more important to me as I did not believe it was an LSD(not marked like Dmikes photo), I pulled C200 carrier out of a 4wd to repair my dually axle and pulled a 521 windshield then went back to that axle as I just had to find out if it was welded. Edited April 5, 2023 by wayno 1 Quote Link to comment
Wildcat Walker Posted April 5, 2023 Report Share Posted April 5, 2023 10 hours ago, wayno said: I recently went thru this, I had an LSD in my 521 kingcab SD25 turbodiesel, it was the 3.545 version, I did not like it but it is a 2wd and light in the back because it has a stepside box, I found making left turns in traffic to be scary in wet conditions, if I had to get it moving because a car was coming the backend would more often than not start coming around on me, but the worst was when I was entering a freeway on right turn ramp where the road was tilted to the left because it was a left turn going uphill, if the tires broke loose the rearend would start heading at the cement wall/barrier, it is tough to get it moving uphill in this scenario, in traffic others are annoyed because I was not keeping up with the vehicle ahead of me, one time I believe I heard a horn honk, I got lucky and a 3.3 gearset came available at the local wrecking yard and I installed that and have never regretted it, 3000rpms is about 80mph or maybe slightly more now, I drove it long enough to get used to the LSD, but the lure of 3.3 gears was too great. I found that LSD in an unmarked 1983 hardbody axle, I did not believe it was really an H190 LSD, I thought when I got it out it would be a Lincoln Locker, I was stunned when it came out of the axle housing, I actually walked away from that earlier to get something more important to me as I did not believe it was an LSD(not marked like Dmikes photo), I pulled C200 carrier out of a 4wd to repair my dually axle and pulled a 521 windshield then went back to that axle as I just had to find out if it was welded. 83 Hardbody? 83 720 maybe? or 86 Hardbody? I am currently deep in the rabbit hole of narrowing an H233B LSD to suit 620. I invested a great deal of time and money and let a well known manufacturer work on my first unit (1995 Pathfinder). The shop ruined the axles, welded the housing ends on crooked, and didn't cut anything to the correct length. Since I needed to get 2 more axles, I opted to get an Xterra 33 spline LSD unit. The Xterra LSD unit is stacked in such a way that the breakaway torque is useless, but everything in the 3rd member except for the 33 spline side gears is interchangeable with the pathfinder LSD 3rd member. I am now narrowing the housing myself and have sent the axles to Dutchman in Idaho for a cut and re-spline. Fingers crossed that the axles get re splined correctly. Quote Link to comment
datzenmike Posted April 5, 2023 Report Share Posted April 5, 2023 There were no D21 Hardbodys till '86.5 when the 720 stopped production. From '86.5 till '89 the Z24i engine was used and KA24E after. The H-190 LSD option was from '88-'92 on 2wd trucks with four cylinder engines so it overlaps the two engines by one year. As I remember it the WD21 Pathfinder did have a stout break away torque but this was later reduced to near uselessness and probably continued into the Xterra. Can only assume soccer mom's were irritated by the tire chirping turning in and out of driveways on a vehicle that almost never went off pavement? Quote Link to comment
Stoffregen Motorsports Posted April 5, 2023 Report Share Posted April 5, 2023 17 hours ago, datzenmike said: It's harder to regain control in an over steer condition if you have an LSD. Pedal to the metal and steer into the drift. Smoke the tires and hopefully someone got it on video. 1 2 Quote Link to comment
wayno Posted April 5, 2023 Report Share Posted April 5, 2023 11 hours ago, Wildcat Walker said: 83 Hardbody? 83 720 maybe? or 86 Hardbody? I am currently deep in the rabbit hole of narrowing an H233B LSD to suit 620. I invested a great deal of time and money and let a well known manufacturer work on my first unit (1995 Pathfinder). The shop ruined the axles, welded the housing ends on crooked, and didn't cut anything to the correct length. Since I needed to get 2 more axles, I opted to get an Xterra 33 spline LSD unit. The Xterra LSD unit is stacked in such a way that the breakaway torque is useless, but everything in the 3rd member except for the 33 spline side gears is interchangeable with the pathfinder LSD 3rd member. I am now narrowing the housing myself and have sent the axles to Dutchman in Idaho for a cut and re-spline. Fingers crossed that the axles get re splined correctly. I goofed, it was a 1993 Hardbody I found the H190 LSD in, I will fix that goof if I can. 2 Quote Link to comment
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