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Acute uni-joint angle - Cheap solutions?
Posted: Sat Nov 25, 2006 6:56 pm
by UZJ40
flex up the rear of my truck today to make sure my park brake cables were ok, which they were, but instead found that the top uni binds up.
i know i can get a custom shaft from Dobbin for about $800, but the budget is getting very tight now trying to finish it for tuff truck.
any sugestions for a cheaper alternative, using a cv or cardin joint, that i can do?
Posted: Sat Nov 25, 2006 7:17 pm
by andrew e
die grinder in the flange and limiting straps would be the cheapest by far.
By the way, thats a good use for junk mail, make trailing arms out of them. now all you need is a johova's wittness as a transfer case and you'll be set.
good luck at TT07
Andy
may not have to worry
Posted: Sat Nov 25, 2006 10:46 pm
by Nelso
Usually one wheel will be up while the other is dropped, so you won't ever put the uni through that angle. Wait until you ramp it to see if it binds and then, if you need to, you can run a limiting strap to the middle of your diff.
Posted: Sat Nov 25, 2006 11:01 pm
by Gribble
Double cardan off a Hilux front shaft. Dont run a limiting strap, its like tying one hand behind your back.
Posted: Mon Nov 27, 2006 5:20 am
by redzook
Gribble wrote:Double cardan off a Hilux front shaft. Dont run a limiting strap, its like tying one hand behind your back.
pretty sure the single uni he has on there now will operate at a higher angle then a double cardan
can you explaing why a limiting strap is no good?
Posted: Mon Nov 27, 2006 8:18 am
by PJ.zook
Wouldnt double cardan be better though, as its two uni's joined together?
Also yeh why is limiting straps bad? They stop the shocks taking all the pressure at full extension etc dont they?
Posted: Mon Nov 27, 2006 8:24 am
by Jimbo
HOw about the CV in the tailshaft of a commodore (vn-vp).
Posted: Mon Nov 27, 2006 11:08 am
by Guy
A limiting strap in the middle will stop dropout like that but will not affect side to side articulation much if anything. so you can still get you diffs all crossed up like \ or / but not _
The rear of that tub is also looking quite cool ...
Posted: Mon Nov 27, 2006 11:32 am
by Reddo
You might get more travel out of the UJs by easing out the 'gussets' with a die grinder, but not that much to fix the angle you have there I suspect, and under load the whole lot is likely to fail cause of the acute angle.
Double C joints will give more angle and are stronger cause they spread the load across two UJs. 60 series DS might be worth a go.
Another option is to make up your own CV-based drive shaft, or to limit full drop as already said.
Posted: Mon Nov 27, 2006 6:56 pm
by Rhett
use a uni out of a independant lux with a cetre limiting strap. I think those unis have somting like 35 degree working angle. You will never flex up the truck like that anyway
(unless bellyed out or jumping.)
Posted: Mon Nov 27, 2006 8:48 pm
by Gribble
redzook wrote:pretty sure the single uni he has on there now will operate at a higher angle then a double cardan
can you explaing why a limiting strap is no good?
It will be crap because the 2 shafts are so far out of sync, you will end up destroying the joint in no time flat.
A limiting strap is no good because it does excactly that, limit the suspension. However, in Mark's situation its a good tempory fix if he cannot fix the driveline issue. If it was my 40 and had no budget restraints I would fix the driveline issue and leave the suspension to do its thing "unlimited".
Posted: Mon Nov 27, 2006 9:35 pm
by FireTruck
...I have one of those 'dobbin' style shafts sitting on the floor of my garage... well, bits of one anyway.
I have the CV end, including the (massively long!) slip joint. Also have a spare CV. Those should be the expensive bits I reckon. You'll have to get it built to suit though.
If you are interested in buying them PM me.
S.
Posted: Mon Nov 27, 2006 9:38 pm
by Tojo
A limiting strap is no good because it does excactly that, limit the suspension. However, in Mark's situation its a good tempory fix if he cannot fix the driveline issue. If it was my 40 and had no budget restraints I would fix the driveline issue and leave the suspension to do its thing "unlimited".
good point. There is barely enough suspension droop as it is. Limiting it by an inch or so to stop the unis binding will make a huge differance to the trucks performance
Posted: Mon Nov 27, 2006 10:14 pm
by zzzz
How about some offset U-joints?
10 degrees more per joint than standard and you can get a little more if you get busy with the grinder
http://www.4xshaft.com/Super-Flex.html
Posted: Tue Nov 28, 2006 5:45 am
by redzook
Gribble wrote:redzook wrote:pretty sure the single uni he has on there now will operate at a higher angle then a double cardan
can you explaing why a limiting strap is no good?
It will be crap because the 2 shafts are so far out of sync, you will end up destroying the joint in no time flat.
A limiting strap is no good because it does excactly that, limit the suspension. However, in Mark's situation its a good tempory fix if he cannot fix the driveline issue. If it was my 40 and had no budget restraints I would fix the driveline issue and leave the suspension to do its thing "unlimited".
lol
u notice it is at full droop how often do u think it is gunna be at full droop not very often so i dont think he has to worry about destroying the uni
have u eva seen a limit strap being used ? set up properly the only thing it stops is droop wich is what he needs
also go to a werock event every buggy has a winch on the front and most on the back to hold the diffs from drooping to far
but they must have just went this way cos they couldnt afford a good shaft eh
Posted: Tue Nov 28, 2006 7:41 am
by Tiny
redzook wrote:
also go to a werock event every buggy has a winch on the front and most on the back to hold the diffs from drooping to far
but they must have just went this way cos they couldnt afford a good shaft eh
yes a winch not a strap
this alows the driver to vary how much the diff is limited to control body roll, tramp etc. you can not creat a prellell to a winch on the front of a buggy and a strap on the rear of the 40 to stop the uni binding.
That said, I think a strap is the cheapest easiest short term solution
Posted: Tue Nov 28, 2006 11:26 am
by RUFF
Gribble wrote:Double cardan off a Hilux front shaft. Dont run a limiting strap, its like tying one hand behind your back.
A Hilux DC joint wont go to the same angle as a stock Cruiser Uni so that isnt going to fix it.
DC joints are not usually made to run at higher angles but to help take out vibrations from shafts running at higher than normal.
You will notice that there are not many vehicles with big flex running DC joints.
Grind the Ears of the shaft and run a limmiting strap in the centre.
Or convert to an early range rover Square flange shaft with a Tom Woods Offset SuperJoint 1310 uni. ZZZ posted the link above. With a small amount of machining on the back of the toyota flange and re-drilling it will fit. I run one of these in the back of my buggy with 18" shocks and get full droop out of it.
Posted: Tue Nov 28, 2006 11:34 am
by noelb1
love_mud wrote:A limiting strap in the middle will stop dropout like that but will not affect side to side articulation much if anything. so you can still get you diffs all crossed up like \ or / but not _
The rear of that tub is also looking quite cool ...
Posted: Tue Nov 28, 2006 12:13 pm
by Gribble
redzook wrote:Gribble wrote:redzook wrote:pretty sure the single uni he has on there now will operate at a higher angle then a double cardan
can you explaing why a limiting strap is no good?
It will be crap because the 2 shafts are so far out of sync, you will end up destroying the joint in no time flat.
A limiting strap is no good because it does excactly that, limit the suspension. However, in Mark's situation its a good tempory fix if he cannot fix the driveline issue. If it was my 40 and had no budget restraints I would fix the driveline issue and leave the suspension to do its thing "unlimited".
lol
u notice it is at full droop how often do u think it is gunna be at full droop not very often so i dont think he has to worry about destroying the uni
have u eva seen a limit strap being used ? set up properly the only thing it stops is droop wich is what he needs
also go to a werock event every buggy has a winch on the front and most on the back to hold the diffs from drooping to far
but they must have just went this way cos they couldnt afford a good shaft eh
I said its not a bad soloution but its not the best. What if he bellys out and the limiting strap doesn't allow both rear wheels to reach far enough downwards to get some forward traction happening? Theres one scenario where a limiting strap is bad.
Posted: Tue Nov 28, 2006 12:36 pm
by FireTruck
I run Tom Woods Super Flex joints (1350's) on the FireBug too... on the diff end of both the front and rear shafts. Got them through Sean at ABT4x4.
Without them, with the 16" shocks fully edxtended, the uni joint binds and goes bang... ala WE Rock finals this year...
S.
Posted: Tue Nov 28, 2006 5:50 pm
by mattyd
I very much doubt that these guys offer a cheap solution.... but I thought I would share with everyone something that we might be seeing in high-angle applications in the future.
http://cvcoupling.com/
They are based in Orange, NSW, and have a potentially very usefull invention.
Matt
Posted: Wed Nov 29, 2006 8:22 am
by Jimbo
So why cant u use a Cv out of the rear of a commodore? Surely it could handle tighter angles than a standard uni?