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85 720 spindle swap


Smiley720

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I wonder....... I should be able to use those spindles in a conversion for a 521 aswell considering the donor parts are from the same truck. Hardbodys are 6 lug aswell. Is there a way to convert the HB 6 to a yota 5 lug without doing the machining of the spindle to accept a yota rotor?

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This is what I have planned for my 620. Beebani makes control arms that can be used to convert a 620 or a think a 521 to ball joint using 68-69 620 ball joint control arms and 720 stuff.... Redeye has bought this 2 drop spindle on his 69 king cab with no probs! But the problem is that he is using a single piston caliper I think. I have been doing resercerch and this is what I think I have found...

 

You can convert a 620 to ball joints and use the 2 inch drop spindle from Belltech's from a hardbody... If you dont want the single caliper from the 720 or hardbody. You can upgrade I think using stock nissan parts. What you need is a Nissan hardbody 1993 hub from a 2wd which are plentyful. Buy the rotors for a 1993 v6 vg model and use the 2 piston caliper from any pathfinder v6 4x4 or 4x2. This will let you use I think better brakes and calipers. I have been to the dealer today! It looks like the v6 nissan hardbody with the better brakes "2 piston vs 1" uses the same hub as the regular l4 KAe hardbody spindle. The only diffrence is the rotor and caliper. The caliper uses the same part number on all pathfinders v6 4x2,4x4, and on the v6 nissan hardbody. Hopefully I can drop my car using the belltech drop spindles and have really good brakes... Any thoughts? Wish me luck!

Edited by Motavated
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couple things.....be careful when throwing out the 620 references .....bee's arms convert the drum 620, disc guys can simply swap the spindle assy's with the hubs/brakes.

 

The top hat height of the 720 and hardbody rotors are different, but the dimensions of the hub are the same. So.....if you're out getting hubs, try to find the 720 hubs, the centering nubs will fit inside more rims with out having to machine them or the rims. You can mount a 720 hub onto a hardbody with a hardbody rotor/caliper. Only worth it if you are getting parts anyway and you can find them easily.

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my 720 centering nubs are like 4" when i first tryed to fit my chevy wheels they woudnt fit.. Both my 84 and 86 hubs are the same.. Did 720's come with different hubs?

 

the mount is straight

 

My mount looks very similar to that but the arms arent straights there offset for caster..

Edited by RatRod25
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my 720 centering nubs are like 4" when i first tryed to fit my chevy wheels they woudnt fit.. Both my 84 and 86 hubs are the same.. Did 720's come with different hubs?

 

 

 

My mount looks very similar to that but the arms arent straights there offset for caster..

 

That is what I mean I put 79 620 control arms on a 520 that had king pins.I was told that wouldn't work because they were offset.But here I see the same thing done and yet it "works"?

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couple things.....be careful when throwing out the 620 references .....bee's arms convert the drum 620, disc guys can simply swap the spindle assy's with the hubs/brakes.

 

The top hat height of the 720 and hardbody rotors are different, but the dimensions of the hub are the same. So.....if you're out getting hubs, try to find the 720 hubs, the centering nubs will fit inside more rims with out having to machine them or the rims. You can mount a 720 hub onto a hardbody with a hardbody rotor/caliper. Only worth it if you are getting parts anyway and you can find them easily.

 

Sooo.... The 620 69 ball joint spindles can accept the harbody hub and 2 piston caliper? I can save some cash there.... Well I will try it out these coming days. 50% off at the junkyard this newyears.

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Ok I gots a question.....that looks like a 78 or earlier control arm....because the mount is straight but yet he has hardbody spindles on this and what appears to be newer control arms(non king pin)....how does this suspension work but yet it wouldn't work on the 520?

 

That upper arm mount is angled. That's a stock 620 disc suspension, but with a dropped spindle. That's why I cautioned about using 620 info generically without specifying disc or drum. I've only been working with the discs for the 521's for about 7 years and I'll be the first to admit that I don't know everything about these setups. I'd love to see someone else step up and spend some time and money testing this stuff! :) I've also found that sometimes, there's a HUGE difference between what I consider safe and acceptable and what most other guys are willing to accept. If you're frustrated by my information or answers, please...by all means....take a tape measure and some tools to the s/y and check it out. Over the years, I've easily got about 40hrs in the s/y and hauling parts back and forth that didn't work. I've got hundreds of hours into R&D and I can still say without a doubt, I have not covered all possibilities. So, I've gotten the info I needed the hard way, but most of it was done years ago and my memory of the details is fading. Some fresh input would be great!! There was a ton of info on the old NWDE site...which is gone now. Anyway.....Seriously, I'm not trying to be a jerk about this or anything.....I would seriously like to see someone pick up the ball on this and get fresh info. I've already done it once, so I can promise you it won't be me back in the s/y this time! :) I may still have the info from the NWDE thread....I should probably try to add it to olddatsuns.com so that it's easier to find :)

 

 

 

my 720 centering nubs are like 4" when i first tryed to fit my chevy wheels they woudnt fit.. Both my 84 and 86 hubs are the same.. Did 720's come with different hubs?

 

 

 

My mount looks very similar to that but the arms arent straights there offset for caster..

 

I should have clarified....early 720. I don't know what the year split was, but the later 720's use the same hub as the hardbody, while the early ones are more similar to the 620. 620 hub would probably be the best.

 

 

 

That is what I mean I put 79 620 control arms on a 520 that had king pins.I was told that wouldn't work because they were offset.But here I see the same thing done and yet it "works"?

 

Do you have pics or a thread on the control arms you put on the 520? I've seen two other 521's with the 620 arms bolted on....both had negative camber and positive caster. One of the rigs was in the scrapyard so I got a really good look at how things were. The other was on a rig a guy was driving. He said he couldn't let go of the steering wheel or it would go in the ditch......but he thought that was acceptable and a good trade off to have discs instead of drums. He daily drove the rig....I wouldn't have taken it to the end of the street.

 

So you did actually put the arms on....upper and lower?

 

Again...his upper mounts are at an angle, so you're not actually looking at the "same thing"

 

 

Sooo.... The 620 69 ball joint spindles can accept the harbody hub and 2 piston caliper? I can save some cash there.... Well I will try it out these coming days. 50% off at the junkyard this newyears.

 

No.....the calipers won't mount. What I said was the spindle assemblies would swap. You can take a hardbody(late 720) spindle/hub/rotor/caliper and mount it to the 620 balljoints and tierod.

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Holy Shit, this thread is so full of poor information concerning the disk brake conversion that it should be deleted to stop further confusion.

 

Guys, this has been covered so many times before, why are we making a crap thread like this.

 

Motavated, not to be a dick, but you know what years 620's were made. Yet in both of your posts your gave wrong information. And why the messy list of shit to try to find parts from?

Pick a 2wd HB that you want to use--single piston or dual piston and use everything from one vehicle. Everything that you need can be pulled from a 2wd truck. Yes you can get calipers from the 4x4 also, they are the same.

 

 

Yes, you can physically bolt late 620 disk stuff to a 520,521, and early 620. BUT, take it to an alignment shop when you are done--it is an absolute fuckshow. No way in hell could it drive good, and it will be absolute dissaster to your tire wear.

 

I would also recommend avoiding the disk brake calipers/rotors from the 78-83 trucks with the solid rotors, i personally would prefer good working stock drums over those calipers.

 

 

----EDIT----

I have added a reasonably long list of parts for this conversion further down in this thread, hope it helps somebody.

Edited by yello620
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Aww shi! I dont know.. Just trying to make it work with what a have I guess. I dont want to buy parts I don't need from the yard. I guess I will just go with the hard body spindle with the better calipers to not confuse myself and others.

 

What I currently want to try is use the 79 620 spindle and see if I can use a 92 hard-body hub on it. They use the same bearings? HA! Just want to make things complicated I guess....

 

I also list a mess of parts so that me and others can find parts I guess. Sometimes you just cant find a V6 hardbody 4x2 in the yard. I needed to find other cars like the pathfinder who have the same part.

 

Yeah to much info was posted and gladly it was pointed out that it was wrong. That is why I posted what I know so that someone like you man could set me straight. I will post what I do find soon.

Edited by Motavated
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OK, short list of parts for the brake conversion.

 

Option one.

Single piston caliper option.

Take everything from a 2wd 4cylinder hardbody. This means the spindle assembly. You still need lower control arms, tension rods from a 78/79 620, and custom upper control arms.

 

Option two

Dual piston caliper option.

Take everything from a 2wd V6 hardbody. This means the spindle assembly. You still need lower control arms, tension rods from a 78/79 620, and custom upper control arms.

 

As mentioned, 2wd V6 trucks are hard to find.

 

So, option three.

Take everything from a 2wd 4cylinder hardbody except the rotors and calipers. Get calipers/mounting brackets from a 4x4 hardbody or pathfinder, and order new rotors for a 2wd v6 truck and you have option two with new rotors. This means the spindle assembly. You still need lower control arms, tension rods from a 78/79 620, and custom upper control arms.

 

 

Rotors from the 4x4 will NOT fit.

 

Master Cylinders, these bolt directly to a 620 booster, i do not know about the master cylinder install on a 520/521.

7/8" master from a 280z, designed for front disc/rear drum.

15/16" master from early 280zx, designed for front disc/rear disc.

 

Ball joints

Upper ball joints are the same part number from 78 to 97(end of the HB). 2wd and 4wd. TRW part number 10424

Lower ball joints are the same part number from 78-10/85, TRW part number 104234

Then lower ball joints changed 11/85-97(hardbody), TRW part number 104139.

 

However the lower ball joint part number change did not change the stud dimensions at the spindle mount. The change was how they mounted to the control arm.

 

Outer tie rod ends,

Nothing really interchanges from early(521) to late trucks(hb). But all of them seem to share the same stud taper specs at the spindle. Which is the part we need to worry about when swapping disc spindles to an early trucks tie rods.

 

This step always seems to get missed when people talk about disc swaps. The tension rods. Your tension rods from a drum brake truck do not work. I have not found a bolt on junkyard item that will work without modification. I used 78/79 tension rods that i had shortened, then i rebent them to fit stock early 620 frame mounts. This was way easier than it sounds too.

 

Another note about this conversion. The control arm method means that you must use the upper control arm cross shaft from a 78/79 620(maybe 78-85, but i cant verify that, HB will not fit). Some people may not like how this fits the frame, it bolts on just like it did in the original truck, but the drum frames used a 12mm bolt and the disc cross shaft has a 14mm hole because the factory disc truck used 14mm bolts. It would be adviseable to have something taking up that space, or better yet drilling and tapping the frame for the larger bolts(i havent tried this and it may not work).

Edited by yello620
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You would have to make custom arms to run toyota spindles, cando specialties make arms to lay 20's with a toyota style ball joint.. I bought my spindles from aim for 200 bucks.. I have had them on my truck 5+ years with no prob..

 

Granted this is a slight tangent from the main topic, It seems like a good place to ask. Does the yota spindle swap with the 720 spindle? Both height and ball joint moints would need to match. I doubt it, otherwise we would have likely heard of it as an easy 5 lug swap a long time ago.

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Granted this is a slight tangent from the main topic, It seems like a good place to ask. Does the yota spindle swap with the 720 spindle? Both height and ball joint moints would need to match. I doubt it, otherwise we would have likely heard of it as an easy 5 lug swap a long time ago.

 

Ratrod25 said you would have to custom fabricate the arms to run yota spindles. I installed the complete spindle/caliper/rotor from the E25 Caravan which is .25" bigger than stock for the 720 and is dual piston. Had the system from and E24 Caravan before and converted for better braking. It works with the B14 master cylinder also. BTW I own an 85 720.

Edited by flinterman2000
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  • 5 years later...

Beebani offers custom adjustable upper and lower control arms for the Datsun pickups and Nissan hardbodys. Pm him on here or look for his eBay listings of the LCA/ UCA, coilover mounts, 5 link rear and disc brake conversion brackets. His eBay name is Beebani1028

 

I really hope the OP found the answer to his needs sometime before the 6 YEARS inbetween when he asked and you answered had passed...

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