double ended double cardan joint - anyone know ?

[Shayne]

OK i'm going the silly route with suspension on my 80 just because i can , and seeking problems before i start reveals some (not all) suffer serious vibration as a result of going too high and putting prop shafts at extreme angles .

I'm aware custom arms and drop boxes , gearbox drop plates etc but as a fail safe back up i've been looking at how some cured the vibration with a double ended double cardan joint prop .

This is not something i wish for and i sincerely hope i never need it , but it would be nice to know there are solutions out there should it turn out that spending too much on suspension ruined my truck , so ..........

All references i've found to this problem are incomplete in specifics , all say the double DC's available have a very short life expectancy and reading between the lines at stuff unsaid i get the feeling penny pinching incomplete suspension set ups are the cause of vibration in any case .

But anyway

Successful cure is claimed several times by taking the double DC prop from a Hilux and having it shortened to fit .

My question is which Hilux ?

 

[Chris]

I contacted a propshaft company in Nottingham and they quoted me about £600 to make a bespoke DC prop for the front. I know that's not what you asked, I'm just chucking that in there for reference.

As you may recall, I spent hours and hours on this. Here's a distillation of what I leaned.

When the drive line isn't 'in line' you need a UJ. Of course. But in fact you need two UJS one at each end... Well this isn't strictly true. If the input flange of your front diff is in line with the shaft of the prop, but the output of the transfer box isn't then you actually only need one UJ. Well guess what, on a standard 80, the diff and prop ARE in line. So, the second UJ barely does anything other than when you go over bumps and thing. The phasing of the prop just doesn't matter because the movement of the joint at that end is so small that phasing isn't necessary. Now, when you put a great big lift on (like I did) the axle twists so much from its original castor that suddenly you need a UJ that works. Hence all my difficulties. What the DC joint does is effectively cancel out the 'bend' in the T box joint to make the shaft align with the T box and NOT the front diff. So the front UJ is back to playing on its own again. If you did some castor correction you shouldn't need a DC joint. But if you DID add one, I can't see any earthly reason why it would wear out unduly. In essence it would be correcting something that wasn't actually there in the first place.

Where I was getting vibration was in the diff end UJ that was out of phase. They only phase in two ways on these props. The first is totally aligned, ie both ends the same, which is wrong by 100% or opposed completely. I counted the splines did the maths and you simply cannot have them what I'll call 1/4 phased, then 180, then 270 then back to 360. The splines will not allow those increments. The reason that some 80s have badly phased props but don't have an issue is, as I said, because only 1 of the UJs is doing any work and that is well within the 'bend' angle of a joint. So you can phase the second joint anywhere you like.

DC would be short and very heavy probably giving a very smooth drive. I have had a prop made in Rotherham (not collected it yet) because the splines on my old one were so badly worn, the prop was whipping on over run and making a terrible noise. They couldn't rebuild it so have made a custom heavy duty prop for me for £264

Sorry Shayne, I don't know which Hilux it is.

 

[Shayne]

Thanks Chris , because your answer provoked thought , all i have read is little better than hearsay and the some do some don't question is never asked never mind answered .
So i'm wondering now if the double ended double cardan actually corrects a poorly balanced prop , and if so its an overly complicated answer to a simple problem .

The Hilux (solution?) was arrived at by want of Toyota quality from those complaining that they are tired of replacing custom made double DC props .

Maybe im just struggling to accept the suspension will cost me more than my stepdaughters whole car

 

[Firewout]

Last year the farmer next door was complaining about his hilux; he had to replace the double dc joint......

 

[Chris]

Now this might be incorrect, but I am not aware of a DC Hilux joint as such but they DO have a very long prop with a centre support bearing in there halfway along which is prone to problems. I have a Hilux so I know this is how they are set up. I know several people who have had this replaced. It's not a DC UJ, it's a support bearing with a sort of joint which is needed because the Hilux is the length of two aircraft carriers.

Not saying there's no case where a DC is fitted, but I know that people have confused the centre bearing with being a UJ

 

[AndycruiserguyLomas]

The Colorado has a DC joint on the transfer end of the rear prop.

 

[Chris]

Yes it does.

 

[clivehorridge]

I’ve a reasonable lift on mine, and assuming some sag, it’s got to be 4” - 5”. I’ve now got castor correction plates, but the ideal and “proper” way would be bespoke radius arms.

Anyway, more to the point, as Chris said, the UJ at the diff is doing very little as the joint is running almost straight. Of course the Tbox UJ is doing plenty, but I have no vibration issues.

BTW, there’s a plausible theory that because the diff UJ is almost stationary (meaning the needle roller bearings in the cups) it will likely fail before the Tbox UJ that looks like its doing overtime... So dont be surprised if the diff UJ fails prematurely.

I have no idea whether there’s a connection between it not being worked very much and vibrations.

If I was starting from scratch like you are Shayne, I’d want bespoke radius arms. The not only correct caster angle, but they maintain stock wheelbase. I would also go with adjustable Panhard rods and the Panhard angle correction brackets. They bring the Panhard rod back to almost horizontal as it is on stock suspension, avoiding excessive side-shift on flexing.

Good luck Shayne, and paint everything well on the bench before fitting, these so-called plated steel brackets rust like a rusty thing on rust day, and quickly...

 

[Firewout]

Hilux Ln 106 front driveshaft : https://goo.gl/images/pXbqYF

 

[Chris]

Nice. I bet that's not far off. I tried a 60 series one which would have been great - if it had fitted!

 

[Iwan]

The early D4D hilux 2004 single cab that I had, had a DC front and rear. On the front transfer connection it's too small and the bolts dont line up for the front of the 80 transfer.

The rear DC is just after centre support bearing. It does fit the front transfer on the 80 but as the prop tube is flared it doesn't allow for shortening the hilux prop tube. The DC is the same size as the sliding joint on the 80 front shaft so a new tube at the correct length is required to make it work. Thats as far as I got with it. The parts are in my workshop, I'll try to get a picture up of them....

 

[frank rabbets]

I would go with what Chris has successfully done (? Chris). If go somewhere different and get a vibration you may probably never sort it out. Been there once and it took me months to sort it and several bottles of brain morphine.

 

[StarCruiser]

IIRC you already have one of these, albeit only one DC, on the rear of your Collie don’t you Shayne?

 

[Shayne]

Well at least i didn't get shot down in flames for over thinking things .

It's the warning from the people selling the arms that started my investigation Clive
"Constant 4x4 vehicles may require Part time front hub kit or double carden front tail shaft"

These people were often mentioned http://www.4xshaft.com/Toyota.asp

As your playing with this idea Iwan i must guess you do have some vibration on deceleration and so i will say it has crossed my mind while considering the "some do some don't" question , who might consider simply swapping the prop with one from another 80 if only to rule out the possibility of worn splines being the cause .

 

[clivehorridge]

You’re welcome to borrow mine Shayne, any time you’re passing by...

 

[Iwan]

As your playing with this idea Iwan i must guess you do have some vibration on deceleration and so i will say it has crossed my mind while considering the "some do some don't" question , who might consider simply swapping the prop with one from another 80 if only to rule out the possibility of worn splines being the cause .

I had quite a lot of rattle before fitting the drop boxes, but now I only get the rattle on deceleration on the motor way or above 75mph.

I have an auto front prop on as it's about 20mm longer than the manual one that belongs to the transmission. It's still too short so I started to look into the rear hilux DC. It will work just am a bit too busy with a big oak frame restoration job at the moment.

I tried to upload some pics yesterday but as I've given up smart phones (because they command too much attention), it's not as easy as it used to be to share pictures!

 

[frank rabbets]

" GIVEN UP SMART PHONES". That's quite a statement Iwan. Will you always be an addict and have to attend an anonymous group so you don't slip back ?

 

[Chris]

I made a spacer for my front prop so that less of the splined section was exposed and more spline was engaged - obviously. To get the prop length back to where it was this required somewhere around 15mm which is quite a bit. No I am not going into production, but it was a thing of beauty and precision. There's an insert that goes in the middle so that the spacer centralises on the flange/spigot thing not the bolt holes.

 

[nielsc]

I have 4" OME springs, and never had any caster correction, never had any vibrations, only sometimes it wanders on rutted roads, therefor I fitted Pedders rubber caster correction bushes, guess what; lots of vibrations after fitting those. Explain that ?

 

[Chris]

Got my new prop today. Very nice. It's fitted with (apparently) one of the most commonly found spider bearings in the known universe. That's handy then. Certainly no slop in it!