iwan's hdj81

[frank rabbets]

And a nice picture of a double cardan here.

http://www.therangerstation.com/Magazine/summer2008/ujoints.htm

 

[frank rabbets]

It's very easy to shorten a prop shaft by cutting a piece out of the tube and then cleaning up the yolk and welding the shorter piece back on. I did this with just a hacksaw through the weld, a jubilee clip round the tube to give a right angle line to saw at and a very crude welder. I took it to GKN for balancing and it did not need any weights!!

 

[Chris]

Yes the double cardan would be a nice feature. Ran out of time for a test drive today. But will give it a spin tomorrow and we'll see if the dub dub dub speed related noise has gone. Ideally I'd like to get the input and output flanges vertically parallel with each other.

 

[Iwan]

Thanks Frank for the very informative information on the props. There's more to it than I imagined and expected..

For leaf sprung stuff the wedges are just the ticket to regain the angle. The double cardan joint is the way to go Chris. The 6" slee lift kit includes one... a quick note from my experience... if you want to go the double cardan route. The early 4 speed 60 series front prop has a double cardan and i believe the same flange fitment. Wount be the right length but could be re tubed. ..

 

[Iwan]

Here's an interesting thread on ih8mud about castor measurement. .

http://forum.ih8mud.com/threads/how-to-measure-castor.188460/

Hope the link works..

 

[Chris]

It does, but I am still not a great deal wiser. I understand all the principles, I just don't know which one I am suffering from, why and what to do about it. The truck drives absolutely fine. I have a level truck, steers great, flies at great speed with no vibration. OK so you say 'Great, leave it the F*** alone then' but the anal retentive in me says ahh but it simply feeling fine doesn't mean that it is. I think that caster, when it's wrong is detectable in the way it drives. Mine is good, but it seems to have created this angle in the props that I don't understand. I am going to try Steve's 45 degree rotation next.

Oh by the way my front prop was also on the other way around to the green one. The fat part of the prop was at the diff end on the grey one but on the green one the slip yoke was at the diff end. It all seems very random and no help from the FSM. Anyone got a Max or Haynes?

 

[frank rabbets]

On the standard 80 the front slip is on the dif and the rear slip is on the gearbox.

 

[Chris]

Cheers for that Frank. That's the way I now have them. But the front was the other way around

 

[Iwan]

60 series out of phase front prop as standard.


Diff points up on these. Wish i checked my 80 before I started.

 

[Chris]

It's not much out is it. Only a few splines. Have you got a smartphone with angle app?

 

[Iwan]

It's not much out is it. Only a few splines. Have you got a smartphone with angle app?

I got the pic of the web. But i am keen to get to my 60 and angle measure.. but yes like you say not much of a turn.. i have a digital angle finder so can get the angle from the vertical. ... all good stuff... been going back over leaf sprung Soa procedures... interesting stuff!!

 

[Chris]

I think where my mind is struggling is that these UJs whilkst adjustable on the splines must SURELY have to be off set by an angle divisible by 4. So in line, 45, 90, 180 etc. If you offset one end by lest say 3 splines and 15 degrees or something random, that doesn't come around evenly in each rotation. In a phased prop you get 1,2,1,2,1,2 or you could get 1,2,3,4,1,2,3,4. Maybe even 1,2,3,4,5,6,7,8 like mini shockwaves But a bit like you'd get in an obscure time signature in drumming, wouldn't you end up with something odd like 1,2,3,1,2,3,4,5,1,2,3,1,2,3,4,5

See what I mean? I can't get my head around having one flange that's not parallel to the other being countered by some weird random alignment.

 

[Iwan]

I thinking that looking at it as 90 degrees or 1/4.. The other 270 degrees or 3/4 is relative in their own sectors. So only upto 90 degrees of adjustment.

From SOA research today the cardan joint is mainly used on big lift cut and turn with the diff flange facing up to the transfer case. But set sightly lower out of direct line to account for reversing and full spring compression. Most use the standard front prop with phasing corrected.. so fine with the lift size on younger brother 80!

Spring over axle conversion threads show a hell of a lot of detail regarding castor, pinion etc and a lot of info on it out there...

 

[clivehorridge]

Sorry for eavesdropping, but I'm following this with interest, but with nothing to add....

I did see this though, and thought it interesting.... I'm sure you guys will have seen it...

 

[frank rabbets]

The picture of that shaft shows it half way between out and in phase doesn't it ?

That Thompson coupling man said there were no load bearing sliding surfaces on his joint. Well there are not any on birfield joints either. He also blamed a cvj for having resistance but forgot to mention that he had not taken the rubber boot off which was causing it. Also his rotation video comparing flailing shafts shows the hardy spicer joint revolving slowly but his own joint running more rpm. The higher the rpm the truer any brocken shaft will run. Any jointed shaft will drop in the end when the rpm drops low enough. We had prop shafts with hardy spicer joints break on PTO's but they always span true until the rpm was so low it was not a real danger. He's a nasty man and needs ...............

 

[clivehorridge]

I didn't take to him either Frank, but the joint looked cool. No explanation as to how it worked.

 

[Iwan]

Just been out to lock the dog up.. couldn't resist checking the front props on the cruisers!

60 series same as the earlier picture..
red lj70 90 degrees out of phase. .
81.. auto in phase..
junk truck front and rear in phase.. wtf?

 

[Iwan]

It's not much out is it. Only a few splines. Have you got a smartphone with angle app?

I got the angle for you Chris. The pinion angle is 10 degrees upwards from vertical.

I managed to dig out the Double Cardan 4 speed front prop I mentioned. They are 20 spline shafts so thinking 18 degrees per spline.

The flange ends are the same pattern as a 80.
I am not qualified to do any calculations but interested in what you think

 

[Chris]

Wow, short little thing isn't it. (fnar fnar)

Hmm, have to think about that. I measured it bly placing the fixed end main yoke flat on the deck so that read zero basically and then turned the other main yoke (starting at zero as well) until I got to where I am now. I could not get 45 degrees. It was either 30 something or 50 something. No spline in between. So as I was already at the 30 something, I went to 50 something and that seems smoother.

 

[Iwan]

Thats the one 36deg and 54deg.. glad you shifted the donk donk!!

Short gearboxes the 4 speed H42!!