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Attempted WD-22 rear disc brakes for the H-190

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Other than length/spline, will the D-21 Hardbody/Pathfinder axle (with disc brakes) and the wheel bearing fit the 620/720 H-190 axle tube??? They look like this:




Well I'm going to start pulling a Path 4.625 H-233 rear disc axle this w/end. It does not have the optional LSD. The yard owner is cool with that. I told him I need to remove and take a good look and do some measuring and then decide on it. Hopefully the pinion yoke fits the later 720 drive shaft, that would be a plus. I think I'll try the 4.625 to compensate for the 33" tires I'm using, stock was 4.375 but that rear lunched two years ago. I had a spare in my shed and had it almost in when I checked it... it was the 4:11 from the '82 axle I installed when I built the truck. Too much tire and too little gear makes mike a slow boy.


I don't expect to pull it completely on Sat but work is slow next week so maybe I'll get off early and go up and finish the job.....


Path rear end out... what a heavy beast! Mmmmm disc breaks! There's a sensor with wires attached to the pinion, some kind of speedo?? I like the E brake. Kind of like a mini drum brake inside the rotor and the cables could be grafted to an H-190.


There are two aims here:



Disc brakes on a H-190 (620/720) It may be as simple as swapping them off the Path axle onto the H-190 axle. If the C-200 axles are the same as the H-190 then this would work on the 4X4 C-200 as well.



A shortened Path rear end with disc brakes, LSD and 4.625 gears that will fit any 620/720. If the above works AND the splines are the same, the H-233 axle tubes could be shortened and the 620/720 axles with discs used.




First order of business would be to pull the H-233 and a 720 H-190 axle and compare the splines. If they are the same then the 720 axle will at least fit the H-233 third member.

Next the axle length. Remember the Path rear axle assy. is about 3" wider than the 720 axle. They might be the same length and the width increase could be all in the H-233 third member that holds the axles out further. If this is the case then there is no reason to swap the axles and the only way to shorten the width would be to shorten the axle tubes AND the axle. More than I want to attempt. NOTE: if they are identical to the 720 then they could be swapped in to give rear disc brakes.

Will the 720 wheel bearing fit the H-233 axle tube? Are the backing plates the same bolt pattern?


OK Good or bad here's what I got:



The Path axle is longer by at least an inch plus the wheel studs are very slightly longer making it hard to get a measurement. Could be 1.5" like I expected or close, but definitely they are longer. I didn't expect to get both axles out today so just took pictures.





The Path axles are thicker and 31 splines, the H-190 are narrower, and 29, so forget the axle swap, ain't happening.



The 720 axles will fit into the Path axle tube and the back plate bolts line up. Here's an '85 720 axle in the Path tube. Wheel bearings are the same part # too.





Get the Path disc (that also contains the drum parking brake) off and see if it will fit the 720 axle without the drum and shoes on it. It's still possible that the Path backing plate with all the disc brake stuff will fit the 620/720 axle. The bearing will have to be pressed off, the backing plate swapped (if it will work) and the bearing pressed back on. Pretty sure the longer E brake cable from the 720 will swap, It's pretty much in the same position too.


Here's the two E brake cables. The 720 axle is... uh just realized I have a pass side 720 axle and the Path is the driver's side. Anyway if you rotate them in your head you can see that they are positioned correctly. Crap I didn't see this earlier. No biggie the Path is clean and only takes 3-4 minutes to unbolt the axle. Should check the other side to be sure they are the same length L and R.




OK today I stripped the drum and shoes etc. off the 720 axle, likewise, I pulled the caliper and rotor off the Path. The Path also has a small drum on the front inside of the rotor with two shoes on it. Looks like a mini drum brake and is worked by the E brake cable. Even has the star wheel adjuster too.


Looks like there is extra space needed between the bearing/backing plate and the outer axle part where the wheel studs are to accommodate the E break n the Pathfinder. The Path disc brake stuff is about 1/2" wider than what the 720 axle has on it.


Only easy way would be to shorten to 620/720 axle length, trim the diameter and re-spline to 29. You would have to put the larger Path grease seals in the H-190 axle tubes because the Path axles are thicker. Now the Path axle with rear disc and E brake would fit the H-190 housing. It would be about 1 inch wider though. I'm bummed.


I would like to run the complete H233 axle assy. but it is too wide by 3", I would need to shorten the axles AND the housing tubes about 1.5" per side to fit and look right under my 620. I just dunnoh.

Edited by datzenmike
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Mike, You reallllllllly need to find a shop near you that does axle work. Do you have a six states near you? They do great work and not too expensive.

I checked into having a Dana 60 axle narrowed for my Jeep. It was only $55.00 to shorten to my specific length and respline. Another $50. to change the bolt pattern. Not sure if the last was to do the pair or just one.


How much would it cost you to purchase the H-233 of your choice? I would be willing to bet that the cost of an aftermarket LSD would be more than your price to mod a stocker that allready has disks and LSD.

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Mike, You reallllllllly need to find a shop near you that does axle work. Do you have a six states near you? They do great work and not too expensive.

I checked into having a Dana 60 axle narrowed for my Jeep. It was only $55.00 to shorten to my specific length and respline. Another $50. to change the bolt pattern. Not sure if the last was to do the pair or just one.


How much would it cost you to purchase the H-233 of your choice? I would be willing to bet that the cost of an aftermarket LSD would be more than your price to mod a stocker that allready has disks and LSD.



Lets see:

Pathfinder has rear disc brakes and optional 4.375 LSD on the 'Sports Package' but uses coil springs.

D-21 Hardbody has leaf springs, drum brakes and optional 4.625 LSD on the 'Sports Package'.


Ideally I need a D21 axle assy and swap in the Pathfinder axles with rear disc brakes and a Pathfinder with LSD and swap that in too. OR cut the coil spring and 4 link mounts off and add leaf spring perches for my 620.


I had no idea the re-spline was so cheap! If I have the axles shortened about 1.5" and I can cut the axle tube and re-welded the same amount I'm good to go.

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Mike, the sensor on top of the differential pinion is for the ABS system. Just snip that wire and leave the sensor plugging the hole, unless you want to add ABS to your truck.


I have wondered about the backing plate swap also. The book that i look in listed different wheel bearings for the disc brake rear axles. Drum brake axles all seemed to have the same bearing number for many years. 521-D21 i think it was.



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2eDeYe;84849'']Mike, how long is the splined portion of the pathy axle?


Thanks Steve I edited my post, had the wrong picture. Here's both axles:



I know what you are thinking. If I cut an inch off there wouldn't really be enough spline. Hummmmm.

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Looking at that picture, it appears the "splined" portion is bigger and then necks down for some dumb ass reason. If you shorten the Pathy axles will there be enough meat there to repline and still retain the diameter needed?

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Optical delusion. It's a digital pic so I blew it up so it looks like a soup can about 6' from your nose and the axle is a constant diameter with splines cut into it. The splines can be lengthened.


I also thought of something I forgot. I have an early '80s 'Yoda solid front axle and had some concerns when I built the truck because the front was an inch wider on each side than the 620 rear end. I used a 720 rear axle so would it be right to assume the 620 and 720 rears are the same width? Would be great if they are... this would mean the front is wider and putting the Path rear in would only make them closer in length. I wouldn't have to shorten it.

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620 rear housings depend on the year for width. The early 73-77 trucks were narrower than the 78/79 trucks. The difference in width is about 2.25". But i do not know the total width's. Maybe somebody can add that info to this thread. I think that it has been posted before, maybe it was on nwde.



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I measured and my front is 2" wider than the rear. This makes the front roughly, just under 58.5". The pathfinder rear is 59.1" so if I use it 'as is' it is closer to matching the front width than what I have now. This is great, no axle to re-spline and shorten.




There are 4-5 Pathfinders in the j/yard and I thought I checked them all but the one I pulled out with the disc brakes is a POSI LSD!!!!! Getting it for sure now! How I missed it I don't know. I was putting the backing plate bolts back on in preparation to setting it aside and maybe looking at it in the spring. Lot of money just for rear discs and 4.625 anyway. I tried turning the axle as I was bolting it up and the pinion was jammed against a tire and wouldn't move. This is odd as usually the other axle will just turn the other way. I checked and both turn the same direction.wtf? Maybe just tight. Tried to force the pinion to turn while holding the axle, no way. While wiping the dirt off the diff drain plug so I could remove and look inside I see this orange thumb nail sized paper sticker and so i wipe it off and in bold black letters are LSD! Made my day.

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Looking at that picture, it appears the "splined" portion is bigger and then necks down for some dumb ass reason.


That neck down is to reduce stress between the splined section of the axle to the main body. Allows the axle to twist more before breaking, otherwise it would snap when you downshifted into that parking lot.


Mike, you ideally want your rear axle narrower than your front for a better turning radius. But you could just bolt that in and go.


You can also upgrade to Yota IFS hubs down the road, which can give you 1.5" width per side to the front. Plus it adds vented rotors and bigger calipers.

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YES! I didn't mention that because I didn't think anyone would know about that. I have a set of '88 4runner hobs and vented disks. Apparently they bolt on but add some width so I've held off on that.


This w/end I'll remove the front rims and get a good width of the front and then I can compare it to the 150mm wide path rear. Mmmmm 4.625 rear disc LSD!

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did you grab the drive shaft too? Your gonna need it for that larger style flange on the pathy rear. peace.



I will... I do have the larger post '84 driveshaft from a 4X4 720 on there now. Will look into that though.

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Well I can now look out my bathroom window and see my H-233 4.625 LSD rear end with disc brakes! Fawking heavybitch! Driving the 'new' z24 motor again to-day and love the pulling power. Haven't even set the timing, just turned the dist till it ran good.

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2eDeYe;85474'']You'll want to tap the caliper to make them easy to bolt on, I plan to run a 1/2-13 helicoil. Still have to buy the right size drill bit...


Why would I tap the caliper? doesn't it just bolt on? or is there some issue with the caliper position on the vented rotors?


May work on it this winter. I have two new bearings (upper/lower) that support the weight in the knuckle? Figured to swap them when I swap the caliper/rotors while it's apart. I have the beginning of the 'yoda 'death wobble' at 30mph.

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The calipers get mounted to the other side of the caliper mount. Some guys have gotten away with just tapping the caliper with a 1/2" Fine thread, but I didn't like the thread height I got out of doing that. You can sqeeze a nut in there, thought that was a little to cluttered myself.


I also remembered that you need FJ60 rotors and something has to be done about the hubs as the stub one of the stubs has a bigger shaft. I already have mine on the shelf, still soaking parts and pining over the $ I'll have to spend on one bit :lol:


Here's a link with info on the swap. There is also a thread on marlincrawler.com forums but you have to join their forum. I highly recommend that though. The have a lot of tech on the yota solid axle and offer a lot of good parts.



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See if I got this right:


I have the wider calipers, the vented rotors and the hubs from an '88/'89 IFS 4runner. I just undid the wheel bearing and slid everything off and took it.


I have and early '80s solid front axle with single solid rotor.


Did I read right that I can't use the vented rotor but that I have to get an FJ60 rotor in order to use the 4runner stuff?

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OK I have my differential out.




This is not a clutch type LSD. Most open diffs have two side gears meshed with two spider gears. This seems to have two pairs or more spider gears meshed with the side gears.




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Well LSDs are available on this diff, and there is a sticker on it that says LSD, and I tried to turn one side backwards against the other with a long bar and it wouldn't, and if you turn the pinion, both wheels turn the same way.


I looked on a couple of D-22 sites and the term helical LSD is used. Nobody can explain it in a way that is understandable.

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