jack shaft question

[1Lzook]

my jack shaft is on a lean down to my transfer case like nearly maxed out, i know this will flog my unis out over time but that doesnt worry me, my concern is at a higher rpm my shaft gets a pretty bad vibration in it, can the shaft be rebalanced to suit the angle that it is on ??

[christover1]

my jack shaft is on a lean down to my transfer case like nearly maxed out, i know this will flog my unis out over time but that doesnt worry me, my concern is at a higher rpm my shaft gets a pretty bad vibration in it, can the shaft be rebalanced to suit the angle that it is on ??

It is more than likely the problem is the two flange angles not on same plane.
But if not, I'm sure tailshaft repairers could balance it.
Could be that the unis got worn into the old angle, the new angle finding the problem.

I am just guessing, hope ya get a better tech response.

christover

[Vineboy]

I'd be surprised if it's out of balance because it's pretty well tucked up and out of harms way. What makes you think the vibration is coming from the jackshaft?

[1Lzook]

the transfer case has never made a vibration and without the jackshaft in there is no vibrations coming from the gearbox

can the shaft be on to much of an angle ??
would a custom shaft fix this ??

["CANADA"]

what have you done to put it on that angle?

[1Lzook]

its got the 1.6 motor and where the motor ended up getting mounted the gearbox is sitting to high

["CANADA"]

its got the 1.6 motor and where the motor ended up getting mounted the gearbox is sitting to high

is there anyway you can drop your motor a few more inch's??

[christover1]

its got the 1.6 motor and where the motor ended up getting mounted the gearbox is sitting to high

You can lift the transfer case up about 20mm with a 1.0 litre set up, with no major mods. Not as easy as a 1.3 because crossmembers are different. I have a body lift, tho.
I used stock engine mounts, which are 20 mm thicker than the originals.
that may help, as it also slides it back 15mm, relieving the angle.
Better ground clearance, too.
christover

[1Lzook]

unfortunitly it was the only thing i didnt check when i put the motor in, i made sure that it fit but i didnt think that the shaft angle mattered so much, i have tried to life the transfer up as high as i can but 20mm still isnt enough, is there anything they can do to the shaft to make it beable to handle the angle

i rang universal drive shafts at geebung and he reckons he mite be able to put a knuckle joint in, but he has to see the car first which means trailering the car there, so if there was an easy solution i would jump at it but yeah doesnt seem to be so far,,

any other suggestions ?

["CANADA"]

unfortunitly it was the only thing i didnt check when i put the motor in, i made sure that it fit but i didnt think that the shaft angle mattered so much, i have tried to life the transfer up as high as i can but 20mm still isnt enough, is there anything they can do to the shaft to make it beable to handle the angle

i rang universal drive shafts at geebung and he reckons he mite be able to put a knuckle joint in, but he has to see the car first which means trailering the car there, so if there was an easy solution i would jump at it but yeah doesnt seem to be so far,,

any other suggestions ?

drop your motor a few inch's!!!!!

do it properly the first time..less the angle the longer the uni's are going to last...

[christover1]

Did you mount the motor at same height as the 1.0?
Why I ask is: the 1.0 litre mounts sit on top of chassis, but 1.3 engine mounts sit inside the chassis, lower down.
1.6 needs mounts in same plane as 1.3.
I bolted a plate to original 1.0 mounts, and bolted the engine mounts lower on the plate.
Maybe motor is way too high?

Did you use 1.6 sump?
If you put on a 1.3 sump with its oil pick up, you may be able to lower engine without it hitting diff pumpkin?
I'm not sure on this, I haven't tried to fit a 1.6, just read up a little.

A lower engine is better for C.O.G but higher has more clearance.

There are special drive shafts for high angle needs, but not cheap, and I don't know much about them.

But there is lots of info on Outers about them
Double Carden I think is one type

christover

[Gwagensteve]

Chris, a double Cardan driveshaft has two universal joints back to back and as such cancels all velocity variations out through its travel. In this sense it is a kind of CV joint.

To use a double cardan joint, ALL of the angularity has to be borne by the double Cardan joint. The "normal" uni jointed end must have as little angle as possible or you will actually get worse vibration.

If the output shaft of the gearbox and the input of the transfer are parallel, the best solution is just two run of the mill unis.

1Lzook - the only real way to fix this is to get the engine/gearbox position right.

Interestingly, Greg's 660 conversion sits the back of the gearbox quite high, his jackshaft is on quite a steep angle. Doesn't really vibrate too bad, but the car is pretty rough/noisy.

Steve.

[Vineboy]

Have you always had the vibration or just since you put in the 1.6? just trying to rule out other possibilities.

[1Lzook]

yeah only since i put the 1.6 in
the other possibility i have is that i have not used this shaft before, its a 1.3L shaft that has had the uni changed at the transfer case end so it would bolt up to the 1L transfer case, after fucking around with the motor pissing about will all the different positions i found this seemed to be the best spot for it, i mite have a bit of a play with the gearbox mount, i may be able to get it to drop about an inch at the gearbox end without to much trouble, hopefully then the rattle mite go,

unfortunitly the moded engine mounts have already been welded into position the car has been fully wired, had all custom hoses made and moving it would just be a night mare, so hopefully i can come to some other solution,

the only thing i can think of doing is actually moving the transfer case back a bit that way the shaft coming from the gearbox wont be on such a steep angle because it has further to travel, obviously that means 3 new shafts which i really dont want to do, but if nothing else can be done ill just have to do that

does anyone else have any info on the driveshafts that can handle big angles ?

[christover1]

I reckon lowering the rear of gearbox sounds like a good idea.
It would have minimal effect on the motor end.
That and a small change in t-case position (new shafts not needed if change small enough) I use stock shafts.

Also check unis haven't seized on one axis.

Also make sure jackshaft isn't too tight, this can cause probs. Shaft at box end needs room to slide forward and rearward, so roughly half way inserted.
(mine was too tight with the 1.0 jackshaft, but is great with a 1.3 jackshaft now fitted)

christover