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Lonewolf1990

Axle swap

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Looks rad, why are we swapping axles? 

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2 hours ago, ]2eDeYe said:

Looks rad, why are we swapping axles? 

The truck feels sluggish when I try to push it white these wheels 

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On 10/23/2019 at 5:59 AM, datzenmike said:

 

 Tire choice is not going to affect your differential strength but being larger diameter will. You're asking your L20B to move the truck about 22% farther on each turn. That's a lot or extra work. You have a 4.375 differential gear, going from a stock 23.6" to a 29" wheel diameter, it will drive like you have a 3.56 ratio. The effect will be that you'll have a hard time driving into the wind, much slower passing times and harder to climb hills. Acceleration? well forget that. You would need a 5.33 ratio differential to correct this 

 

 

I would advise buying sensible shoes for your truck.

 

On 10/22/2019 at 5:35 PM, datzenmike said:

 If you mean larger diameter this would alter the effective gear ratio you have in the differential and it might feel a little sluggish taking off. Your stock tire is 23.65" diameter and you have a 4.375 ratio differential. If you were able to lift it and get 31" tires on it it would feel like the same as if you changed the differential to a 3.33 ratio. To correct for 31" tires you would need a 5.75 ratio differential.

 

On 10/27/2019 at 4:10 PM, datzenmike said:

I think you'll soon get tired of the shitty acceleration,

 

  Doesn't look as bad as I expected but you must already have taller tires on the front. How tall are they?Do they rub on turns?

 

You can get the acceleration back by going to a lower ratio differential like the 4.875 in the 521. Perhaps after market? You want about 5.33 or above if possible. Myself I would get a tire that's 12" wide but only 23" or 24" tall and avoid all this.

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40 minutes ago, datzenmike said:

  

 

 

 

  Doesn't look as bad as I expected but you must already have taller tires on the front. How tall are they?Do they rub on turns?

 

You can get the acceleration back by going to a lower ratio differential like the 4.875 in the 521. Perhaps after market? You want about 5.33 or above if possible. Myself I would get a tire that's 12" wide but only 23" or 24" tall and avoid all this.

 

They rub a bit when the truck leans on a turn but other then that it’s fine , I’ll double check on the front tires height 

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If you are just after gearing, a 72 or earlier truck diff will typically have 4:88.  

 

Any other axle is going to change the rear axle width as most are wider, a few are narrower.

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1 hour ago, ]2eDeYe said:

If you are just after gearing, a 72 or earlier truck diff will typically have 4:88.  

 

Any other axle is going to change the rear axle width as most are wider, a few are narrower.

Is there any that will just bolt up easily?

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Early 520/521 axles are going to be narrower, later 720 axles will be wider, but the gearing is interchangeable, the 1966 520 thru early 1969 521 have 4.88 gears, the late 1969 521 thru the 1972 521 have 437 gears, these gear sets are all interchangeable with your truck axle, it takes a couple hours to change them out and is much easier than changing out a complete axle that will likely have your tires/wheels either farther in your fender wells or have it sticking farther out of your fender wells which could result in you needing different flares.

This is what you need to change out for better gearing.

DSCN1636.jpg

 

DSCN1496.jpg

 

It has been mentioned that you will likely need 4.88 gears, they are a little harder to find, it would help to know what gearing you have now, 4.37 gears are much easier to find which you may already have in your truck, the 320 truck also has 4.88 gears, but the side gears would need to be changed out because the axle teeth are different.

It is expensive to ship heavy gear sets, they also need a very stout box, it can get spendy, but a complete rear axle will be even more expensive and cost a fortune to ship.

All Datsun/Nissan truck axles made from 1966 thru 1986 are interchangeable(bolt right in), but you need one the same width as the one you have, changing out the axle for another one the same width you have will not likely help you as it will likely have the same gearing you already have, fact is a Hilux axle of the same era will likely have around the same gearing as that gearing is what is needed to have a good all around derivable truck, when you changed your wheels/tires you changed the driving character of your truck that will take more than just changing out an axle, you need to change out your rear gears or go back to more stock sized rear tires.

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2 hours ago, Lonewolf1990 said:

Is there any that will just bolt up easily?

If what wayno described is something you wanna do instead of a full axle swap you can message me, I have a complete axle assembly from a 520 with the 4.88 gear set in it that I will likely never use......

Bought a bed that was made into a trailer for my 521...I kept the leaf springs and the axle ..... I'd like to keep the housing and axles but I'm more than willing to part with the center section .....

 

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5 hours ago, Lonewolf1990 said:

Is there any that will just bolt up easily?

 

The differentials are super easy to swap. Wayno posted some pics of them out of the housing. 

Basically unbolt the 4 bolts holding the axle in on either side, pull them out ((brakes and all) until they come out of the diff, you will know....
Unbolt the driveshaft.

Then unbolt the 12 or so bolts around the diff and pry it out of the housing.

 

 

No axle will bolt right up other than maybe the 521, but your tires will hit the springs as it is narrower than the 620 axle. 

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So i might be sending lone wolf the diff I have.... are there things i can and or should check to make sure I don't send him junk?

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Backlash (end play) in the gear mesh

Gear wear - obvious chunks or pitting, heavy swirl marks on the ring gear

End play in the pinion gear

Sound - spin the ring gear and listen. A good gear mesh will have a nice whirring sound to it. A bad setup will sound bad. Like that old saying about rattlesnakes. You know it when you hear it.

 

I suppose you could even check the pattern with some paint, but if it looks and sounds good, then it probably is good.

 

Gear oil smells horrible when it gets burned, so stick your nose into it and take a whiff. Does it smell normal?

 

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3 hours ago, ]2eDeYe said:

 

The differentials are super easy to swap. Wayno posted some pics of them out of the housing. 

Basically unbolt the 4 bolts holding the axle in on either side, pull them out ((brakes and all) until they come out of the diff, you will know....
Unbolt the driveshaft.

Then unbolt the 12 or so bolts around the diff and pry it out of the housing.

 

 

No axle will bolt right up other than maybe the 521, but your tires will hit the springs as it is narrower than the 620 axle. 

 

I bolted up a 1986 Nissan dually axle to my 521 when it had a 521 frame/chassis, all the perches on the axles are the same width apart from the 1966 Datsun 520 thru the 1986 Nissan 720, the axle tubes/drums just stick out farther away from the perches the wider the axle, but the brake lines going to the rear are on opposite sides on the 521/720, so I had to reverse the brake lines on the axle.

 

 

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1 hour ago, Crashtd420 said:

So i might be sending lone wolf the diff I have.... are there things i can and or should check to make sure I don't send him junk?

 

If the pinion flange has more than an eighth inch play in it I would not send it to anyone, sometimes it is hard to tell when the gear set is in the axle housing, your feeling for the play in the ring and pinion, when the gear set is removed from the axle housing I want only a 1/16th inch play in the pinion flange.

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14 hours ago, wayno said:

 

I bolted up a 1986 Nissan dually axle to my 521 when it had a 521 frame/chassis, all the perches on the axles are the same width apart from the 1966 Datsun 520 thru the 1986 Nissan 720

 

 

 

Good info. B)

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22 hours ago, wayno said:

 

It has been mentioned that you will likely need 4.88 gears,......fact is a Hilux axle of the same era will likely have around the same gearing as that gearing is what is needed to have a good all around derivable truck, when you changed your wheels/tires you changed the driving character of your truck that will take more than just changing out an axle, you need to change out your rear gears or go back to more stock sized rear tires.

 

4.88 will help but I roughly worked out that you need about a 5.33 to get back to what you have now. The tire diameter has really affected you over all gearing.

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On 10/29/2019 at 5:39 PM, wayno said:

 

If the pinion flange has more than an eighth inch play in it I would not send it to anyone, sometimes it is hard to tell when the gear set is in the axle housing, your feeling for the play in the ring and pinion, when the gear set is removed from the axle housing I want only a 1/16th inch play in the pinion flange.

So what you're talking about is play in how much you can turn the pinion flange before it contacts the next gear tooth. This is called backlash and can easily be measured with a dial indicator on the ring gear (if the diff is out of the axle housing). Most factory settings are around .006"-.010".

 

When I refer to play at the pinion flange, I am talking about improper crush on the bearings. Play in and out on the flange means the bearings are either toast or the nut got loose, or for some reason the bearing cups settled in a bit.

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5 hours ago, Stoffregen Motorsports said:

So what you're talking about is play in how much you can turn the pinion flange before it contacts the next gear tooth. This is called backlash and can easily be measured with a dial indicator on the ring gear (if the diff is out of the axle housing). Most factory settings are around .006"-.010".

 

When I refer to play at the pinion flange, I am talking about improper crush on the bearings. Play in and out on the flange means the bearings are either toast or the nut got loose, or for some reason the bearing cups settled in a bit.

 

I was able to extract the diff fairly easily... I expected more of a challenge...

My initial impression is lonewolf is getting a differential that's in real good shape.... I still want to do those other checks you talked about but so far everything seems nice and tight and spins smoothly...... oil was pretty new and nothing smelled weird..... 

 

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7 hours ago, Stoffregen Motorsports said:

So what you're talking about is play in how much you can turn the pinion flange before it contacts the next gear tooth. This is called backlash and can easily be measured with a dial indicator on the ring gear (if the diff is out of the axle housing). Most factory settings are around .006"-.010".

 

When I refer to play at the pinion flange, I am talking about improper crush on the bearings. Play in and out on the flange means the bearings are either toast or the nut got loose, or for some reason the bearing cups settled in a bit.

 

I guess I should have given a little more information, when I go to wrecking yards I always check the tags in the 720 engine compartment or the tags on the hardbody driver side door to check the gearing as I am always looking for 3.3 gears, and I always turn a wheel on every H190 axle I see as I am looking for LSD gear sets also, if I find something that interests me I grab the pinion flange and twist it to see how much play there is as this is an indication of how wore out the gear set is, if it has a quarter inch of play or more before a wheel moves I generally move on unless it is possibly a LSD, the LSD I found several years ago had quite a bit of play in it, but it was possibly an LSD so I pulled it expecting to find welded up spider gears and you can only imagine what my face looked like when it dropped out and it was an LSD, I was stunned, at first I didn't even believe it was an H190 LSD, there was a 620 across the row so I took the gear set out of it and put this LSD in that housing and the axle dropped right in so I just bought it and brought it home, I checked the pinion flange play at home and there was only a 1/16th inch play so it was good, but some are just wore out, too much backlash or the bearings are wore out so the pinion flange twists/moves more than an eighth inch and I don't know how to set up gear sets, and people that do want a lot of money to do it, so I pass on open gear sets and find a good one some where else.

I always check the play after I remove a gear set and almost every one is good, but a couple have been worn out and I didn't buy them, but it is hard to tell when they are in the axle at a wrecking yard so I pass on anything with more than a quarter inch play before the wheel/drum moves, and I am talking about twisting the pinion flange.

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I suppose that test is ok for a wrecking yard quick inspection, though it may be misleading due to the numerous variables involved. Add in the R&P backlash, the spider gear back lash, and the play in the axle splines and you could get a lot of play before a wheel turned.

 

Setting up gears is simple. The only tools you need are a rattle gun and the correct size socket for the pinion flange nut, a heavy drift, a hammer, some pieces of tubing (to fit the pinion bearing over the shaft) a bearing splitter, a torque wrench and that's about it. A press is nice but not required and a big bench vise helps to hold the diff while setting it up, but again, not required.

 

My basic method for setting up gears is to always try the original pinion shim first (the one that came off the original pinion gear). 99% of the time, the original shim gets you close enough. You may have to remove the pinion shim a couple times to get it right, but if you use anti seize on the shaft when installing the bearing, it makes it easier to get the bearing off to change the shim. If the side bearings (carrier bearings) have threaded adjusters, this makes it stupid simple to set the side bearing crush and gear lash. Almost all aftermarket gearsets come with a setup guide and bearing kits are usually supplied with various shims. You should try it sometime.

Edited by Stoffregen Motorsports
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Ring and pinion lash on an H-190 is 0.006" to 0.008" or a little less than one and one half, to two thicknesses of a piece of paper. Side to pinion mate lash is 0.004" to 0.008" or one to two thickness of paper, actually just slightly less. So if both sides of the side gears, and the R&P were at max clearance that's 0.016" or half the thickness of your index finger nail!

 

If the R&P had enough wear to allow 1/4" of back and forth the teeth would be worn off. The slack is likely the side gear and pinion washers are worn allowing them to move more than usual. These gears only turn when going around a corner, and likely you aren't on the gas too much anyway and all the slack is removed.  

 

 

Never seen a differential without 'lots' of play on the driveshaft end.

 

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Sometimes I can feel the backlash of the ring/pinion, sometimes I can't with the drive line connected to the pinion flange, so that is why I picked a 1/4" play before the drum/wheel moves, all them different things going on can add movement to the pinion flange twist, but an LSD or 3.3 gear set gets removed and I check it out of the axle housing where I can see what is going on, also I forgot to mention that I stick my finger into the drain hole and check the color of what is left of the oil, if it is silver I move on unless an LSD or 3.3 gear set.

I used to buy gear sets at the wrecking yards for guys when they were cheap and ship them all over the country, I also would change out the 320 side gears into better ratios gear sets for 320s, this is how I learned what was good and what to walk away from, why waste time when there was another 720 over there that has a tight gear set, but now even 720s are getting hard to find in wrecking yards and they want a lot of money for them.

As for setting up gears, I have all the good ones I need now, I will likely never have to worry about not having what I need for my trucks again.

The whole point is if a gear set is out of the axle housing and you have a lot of play(backlash), it is not worth shipping anywhere.

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Well I went out to my H-165 3.70 differential and turning the pinion and I can just barely get it to rattle. Maybe 1/16" of back and forth. Side and pinion (spider) gears are snug. So maybe the splines add some?  Because in vehicles they move a lot!

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