Double Cardan Drive Shaft Solutions

[Nay]

Are the 3rd gen 4runner dc joints beefy enough for hardcore stuff?

So I’ve been wondering this as with a bit of extra lift it’s time for a rear DC. Not that I’m hardcore , there’s just no reason to spend extra money to trade down when you have a good driveline shop.

On Pirate, this shows up from a driveline guy:

“we even run toy c/v's oem and 1410 joints at the diff and its a toss up what will go”

So I just bought a 4Runner DC shaft with 58K miles for $88 and it’s going to mate with the spline side of my stock driveshaft that just got new u-joints.

I still have a trail spare OEM shaft, so no reason to not sacrifice one of them to keep the OEM diff end. I’ll report back.

 

[nukegoat]

So I’ve been wondering this as with a bit of extra lift it’s time for a rear DC. Not that I’m hardcore , there’s just no reason to spend extra money to trade down when you have a good driveline shop.

On Pirate, this shows up from a driveline guy:

“we even run toy c/v's oem and 1410 joints at the diff and its a toss up what will go”

So I just bought a 4Runner DC shaft with 58K miles for $88 and it’s going to mate with the spline side of my stock driveshaft that just got new u-joints.

I still have a trail spare OEM shaft, so no reason to not sacrifice one of them to keep the OEM diff end. I’ll report back.

I ran a toy cv in the rear and i do not believe it is as tanky as the folklore on pirate would have you believe. I run a 1350 cv now and it is definitely stronger.

Will the toy dc work? Yeah.

 

[baldilocks]

I ran a toy cv in the rear and i do not believe it is as tanky as the folklore on pirate would have you believe. I run a 1350 cv now and it is definitely stronger.

Will the toy dc work? Yeah.

What? You run a 1350 CV on the stock Toyota output?

 

[nukegoat]

What? You run a 1350 CV on the stock Toyota output?

Yes

 

[-Spike-]

I'm almost embarrassed to ask, gonna sound like a newbie, but why would anyone want/need to use a DC shaft in the rear of an 80? It's easy to adjust the pinion angle to match any lift with adjustable upper control arms, and there's no restriction due to camber, which is what makes a front DC necessary for some (me).

 

[nukegoat]

I'm almost embarrassed to ask, gonna sound like a newbie, but why would anyone want/need to use a DC shaft in the rear of an 80? It's easy to adjust the pinion angle to match any lift with adjustable upper control arms, and there's no restriction due to camber, which is what makes a front DC necessary for some (me).

Because even coplanar single cardan shafts will vibrate. Plus ground clearance

 

[-Spike-]

Ground clearance isn't an issue that can't be solved with a standard driveshaft. Mine has equal angles on both sides, not opposing. My pinion points above the transfer case output, no vibrations, no issues, several inches of extra ground clearance. More than a DC setup.

 

[baldilocks]

Once any driveshaft operating angle is beyond 6 degrees get it to run smoothly at all times can be very difficult not to mention the fact that at steeper angles a U-joints life is shorter.

 

[-Spike-]

Once any driveshaft operating is beyond 6 degrees get it to run smoothly at all times can be very difficult not to menetikn the fact that at steeper angnles U joint s have a much shorter life.

OK, but orienting the driveshaft in a 'broken back' configuration, as I have, reduces the angles as well.

The only concern I had when I did it was getting oil up to the pinion bearing. I ran it that way for 5 years or more before I regeared. The bearing was perfect at that time. Zuk added an oil slinger when he did the gear setup, sourced from Curt at Cruiser Outfitters when I bought the gears from him.

 

[baldilocks]

And what about your spring perches? Did you cut them off and rotate them so the spring would sit flatly on them and not be extremely curved.

With my pinion pointed directly at the transfer case, my springs don’t sit perfectly flat as they did before but it was not bad enough that I went to trouble of modding the perches/buckets.

Also, your rear sway bar must be bent to heck as even mine takes more hits than it did before.

I have zero vibes and that’s with a shaft operating angle of 13 degrees.

 

[Nay]

I ran a toy cv in the rear and i do not believe it is as tanky as the folklore on pirate would have you believe. I run a 1350 cv now and it is definitely stronger.

Will the toy dc work? Yeah.

How’d we determine definitely stronger? I take it all with a grain of salt, but there seems to be no dispute that the OEM Toyota is a lot stronger than a 1310. Also, part of what is discussed is the strength of the DC side housing and yoke alloy in Toyota vs. Spicer and the joints don’t change that.

To more general comments:

I’m only looking at this in terms of the typical 1310 shafts people buy, and is that the right compromise vs. additional custom spend vs. sourcing a Toyota shaft and having a shop do the work since I have a shop that has done great reasonably priced work for me for years.

I’m not a all parts must be Toyota type, although with extensive Spicer experience in in the past (think getting to the point of a Currie HP Ford 9”) I will say they are a lot more tolerant of operating angle and minor phasing issues in terms of vibration.

It’s that tolerance I think that gets a lot of people to put up with the minor decel noise or whatever noise they have that isn’t really the classic oscillation vibes, but I cannot keep this damn thing quiet or from being randomly grumbly and I’ve had enough. I put in new u-joints even though my shop said the original were fine (no binding or catch spots by hand), and it quieted things down a lot but not fully. I bet a ton of us are in boiled frog stage where things just get a bit louder over time and we don’t notice the increments.

It’s easy enough for me to compare. I have a 3rd gen 4Runner on a 3” lift that is driven by one of my sons, and there is zero driveline noise. That’s a 1999 Limited, hardly a bastion of modern technology and certainly not babied, but it sure doesn’t make all the freaking driveline noise my 80 does.

This is all also in part because with the new Dobinson Flexi 4” it’s really dialed and that opens a bit more speed on long highway trips. Look ma, full passenger and gear load and no front swaybar! (my wife took these pics) (no nuns were harmed in the making of this post)

Now I need to figure out why adding 3/4” of rear lift made my rear locker light come on and stay on.

 

[-Spike-]

And what about your spring perches? Did you cut them off and rotate them so the spring would sit flatly on them and not be extremely curved.

With my pinion pointed directly at the transfer case, my springs don’t sit perfectly flat as they did before but it was not bad enough that I went to trouble of modding the perches/buckets.

Also, your rear sway bar must be bent to heck as even mine takes more hits than it did before.

I have zero vibes and that’s with a shaft operating angle of 13 degrees.

My spring perches are nowhere near flat, the springs don't mate with them well. However, that hasn't caused any issues, I've never unseated a spring.

I don't have a rear sway bar after snapping mine in half, so retaining one of those might be a reason to use a DC shaft. However, several other people who have good rear flex and no mods to the pinion angle have destroyed the rear sway bar, so I'm not convinced that the pinion angle is responsible for my sway bar getting destroyed.

 

[Nay]

OK, but orienting the driveshaft in a 'broken back' configuration, as I have, reduces the angles as well.

The only concern I had when I did it was getting oil up to the pinion bearing. I ran it that way for 5 years or more before I regeared. The bearing was perfect at that time. Zuk added an oil slinger when he did the gear setup, sourced from Curt at Cruiser Outfitters when I bought the gears from him.

Going broken back like the stock front shaft is an interesting approach. I’d have also been concerned about proper oil distribution, but if we’re honest that FUD has been pitched for DC shafts for forever. As if the oil stands there in a pool while the R&P rotate.

Still, I think the whole “standard shaft is better” argument is another strange hive thing here. A zero degree operating angle for the diff side is the strongest possible configuration and the DC side is sharing load between two joints.

The idea that a DC is a harder trail fix makes zero sense to me given that not carry a spare rear driveshaft and only carrying spare joints assumes that only the joints will fail when most of us damage our driveshafts by physical rock contact.

Either way, literally the entire point of owning an 80 is that a serious build still runs easily on the highway and that should mean it is relatively quiet at the basic level of smooth driveshafts.

We have this huge gift of a broken back front that can be converted to DC while fixing caster at the same time. I just haven’t wanted to spend the money, but the 4Runner DC plus Metal Tech upper adjustable arms should be around $500 so trigger pulled.

If anybody wants a set of almost new OEM upper rear arms, hit me up. Price will be compelling since your original bushings are toast.

 

[-Spike-]

Going broken back like the stock front shaft is an interesting approach. I’d have also been concerned about proper oil distribution, but if we’re honest that FUD has been pitched for DC shafts for forever. As if the oil stands there in a pool while the R&P rotate.

Still, I think the whole “standard shaft is better” argument is another strange hive thing here. A zero degree operating angle for the diff side is the strongest possible configuration and the DC side is sharing load between two joints.

The idea that a DC is a harder trail fix makes zero sense to me given that not carry a spare rear driveshaft and only carrying spare joints assumes that only the joints will fail when most of us damage our driveshafts by physical rock contact.

Either way, literally the entire point of owning an 80 is that a serious build still runs easily on the highway and that should mean it is relatively quiet at the basic level of smooth driveshafts.

We have this huge gift of a broken back front that can be converted to DC while fixing caster at the same time. I just haven’t wanted to spend the money, but the 4Runner DC plus Metal Tech upper adjustable arms should be well under $500 so trigger pulled.

My only 'standard shaft is better' argument is that converting to a DC shaft is more expensive and more prone to wear failure (at least in my experience with Spicer joints in the front driveshaft, haven't had any issues since converting a Tundra shaft, even though I had to use the old dc joints as there aren't any new ones easily available), plus the fact that the broken back configuration addresses all of the problems a DC shaft addresses and adds even more clearance. It can be done for the cost of the adjustable control arms, which you need anyway to run a DC shaft. I don't buy into any arguments about trail fixes being easier or harder since I've never broken a shaft and if I did I'd just pull it out and continue on down the trail, possibly with the help of a strap and a willing friend. I don't carry any spare parts, other than a few electric odds and ends.

Anyway, I get that we all solve issues in different ways, I was just wondering if I was missing something important and should think about running a rear DC shaft. Those that already run them don't need to run out and swap in a stock shaft, but those contemplating how to fix their vibrations might read all this and realize there's more than one way to skin a cat. My way isn't without compromises, so as usual there's no 'right' answer.

 

[nukegoat]

How’d we determine definitely stronger? I take it all with a grain of salt, but there seems to be no dispute that the OEM Toyota is a lot stronger than a 1310. Also, part of what is discussed is the strength of the DC side housing and yoke alloy in Toyota vs. Spicer and the joints don’t change that.

I've read all the posts by Jess (and his followers) from High Angle Driveline. I think the cast Neapco and other junk flanges are worse than the steel Toyota flanges, but you don't have to use cast flanges.

Other than difficult-to-verify claims about the u joint being some magic alloy, the fact remains that 1350 joints are bigger in all dimensions. This means less deflection, less stress on yoke ears, etc.

To more general comments:

I’m only looking at this in terms of the typical 1310 shafts people buy, and is that the right compromise vs. additional custom spend vs. sourcing a Toyota shaft and having a shop do the work since I have a shop that has done great reasonably priced work for me for years.

I’m not a all parts must be Toyota type, although with extensive Spicer experience in in the past (think getting to the point of a Currie HP Ford 9”) I will say they are a lot more tolerant of operating angle and minor phasing issues in terms of vibration.

Toyota joints don't operate under different mathematical principles than Spicer u-joints. So saying that one kind of u joint deals better with poor operating angles than another is a little... psuedosciency.

 

[baldilocks]

I've read all the posts by Jess (and his followers) from High Angle Driveline. I think the cast Neapco and other junk flanges are worse than the steel Toyota flanges, but you don't have to use cast flanges.

Other than difficult-to-verify claims about the u joint being some magic alloy, the fact remains that 1350 joints are bigger in all dimensions. This means less deflection, less stress on yoke ears, etc.


Toyota joints don't operate under different mathematical principles than Spicer u-joints. So saying that one kind of u joint deals better with poor operating angles than another is a little... psuedosciency.

I run Spicer 1310 CV’s on both drive shafts with the zerkless Life Series joints. I’m geared down, triple locked, and run 37’s. Rubicon style wheeling is what I do a lot of. The front shaft has almost 4years on it and rear about 2 years and quite a few trail runs. I’ve had zero problems thus far and will be the guinea pig here as I promise to openly admit to the Mud masses when I break one or wear one out in a less than acceptable time frame. I don’t drive my 80 a lot of miles so if a 1310 wears out in 50k that’s about a ten year life span in my rig. Last year, I converted to part time so the front gets used even less now.

I agree with the school of thought that the reason to build an 80 rather than something lesser (4Runner, jeep of any flavor, etc.) is to ride in comfort as much as possible so there are certain things I have no problems with spending the necessary funds on to achieve this. I hate driveline vibrations. Admittedly, I have my own unfounded reservations about the 1310 equipment because it is smaller than the over sized driveline components that were in the rear from the factory. That’s why I spent the cash to have a second complete 1310 CV/stock Matsuba rear drive shaft built. It’s clamped up to the front side of the 4x4Labs rear bumper using muffler clamps I welded on.

I will gladly let any of you rent it, I mean borrow it, if need be, to get your rig safely off the trail.

 

[Nay]

Toyota joints don't operate under different mathematical principles than Spicer u-joints. So saying that one kind of u joint deals better with poor operating angles than another is a little... psuedosciency.

It’s just experience. I have spent over $10K on a project getting to happy driveline angles with proper geometry. 80’s are exceptional in this regard, because it’s the single biggest impediment to bigger lifts.

The Spicer joints have shown almost no tolerance for being out of phase or even running nicely once you get past a pretty low degree of operating angle. The simple fact that u-joints operating at an angle travel in an elliptical path suggests that tolerances are going to matter, pseudosciency or not.

That’s also why size isn’t everything - if it was, none of us would be running an 8” front R&P. Toyota carrier tolerances are vastly superior to Dana, and it’s flex that blows stuff more than straight shearing. I’d rather have the clearance that comes from better engineering than having to compensate with Dana 60’s.

A Toyota u-joint obviously can’t rotate in a different ellipse arc than it’s angles prescribe, but they don’t complain in the same way, at least in my experience. None of that matters with a DC shaft unless you don’t set up pinion angle properly since a zero angle u-joint travels in a circle - it is 100% a strength discussion.

But it’s worth noting in making decisions since the Toyota parts route is relatively inexpensive:

~$75 for the parts yard DC
Your OEM driveshaft for free
~$125 to retube and balance

That’s fairly bueno in the scheme of things.

 

[baldilocks]

@Nay- you lucked out finding a Toyota DC that has such low miles. Most out there have high miles and the joint itself isn’t all that wears.

As I’m sure you know, the Toyota drive shafts are not designed to be torn apart like you plan. They are schwaged together. Yes, I know people have done it.

 

[-Spike-]

@Nay- you lucked out finding a Toyota DC that has such low miles. Most out there have high miles and the joint itself isn’t all that wears.

Meh. I got a Tundra dc driveshaft with 125K on it, took it to the driveline shop and they said it was in great condition and 'Run it'. So I did.

In the Tundra and my big Mitsubishi box truck (and I assume other typical OEM installations), the dc shaft is used to give a little flex to a very long and fairly straight driveshaft, not to overcome extreme angles, so the wear is insignificant. They generally have a single u-joint at each end and the dc joint near a carrier bearing in the middle or so. The single joints cancel each other, and each of the two joints at the dc joint cancel each other in theory, although there isn't much of an angle there to cancel in practice. That's how driveshafts are supposed to be set up, with pairs of u-joints. The way we use dc joints is technically incorrect, but it (usually) works because the single joint is (supposed to be) at zero angle.

 

[baldilocks]

Meh. I got a Tundra dc driveshaft with 125K on it, took it to the driveline shop and they said it was in great condition and 'Run it'. So I did.

In the Tundra and my big Mitsubishi box truck (and I assume other typical OEM installations), the dc shaft is used to give a little flex to a very long and fairly straight driveshaft, not to overcome extreme angles, so the wear is insignificant. They generally have a single u-joint at each end and the dc joint near a carrier bearing in the middle or so. The single joints cancel each other, and each of the two joints at the dc joint cancel each other in theory, although there isn't much of an angle there to cancel in practice. That's how driveshafts are supposed to be set up, with pairs of u-joints. The way we use dc joints is technically incorrect, but it (usually) works because the single joint is (supposed to be) at zero angle.

Right mate.