Driveshaft Trouble

[TJ Chaddy]

Hi Guys,

Over the weekend i have destroyed my rear driveshaft for the 2nd time.

1st time i was climbing beer o'clock hill at the springs when i completely snapped a bolt on the diff side. this then threw my driveshaft everywhere and destroyed it.

On saturday I snapped a uni joint, which then tore out the ring where the uni joint sat in. (also broke an upgraded U-bolt kit) Its starting to become an expensive excercise as these parts dont come cheap.

does anyone have any suggestions or recommentations.

(im running 15x8s with 32x11.5x15 cooper STT tyres on standard gearing)

pics to come tonight

[carlosprite]

Too much wheel spin, and when it gets traction it snaps?

Are all your angles set up correctly?

[TJ Chaddy]

thats what generally has happened (wheel spin) but not enough to do that kind of damage. Im not sure if my angles have been setup.

[hophoar]

have you got any sort of transmission spacers /motor mount lift or adjustable control arms to help elieviate the angles on the unis.

[TJ Chaddy]

have you got any sort of transmission spacers /motor mount lift or adjustable control arms to help elieviate the angles on the unis.

no transmission or motor mounts. i dont believe i have control arms. ill be going to the brisbane jeep club toolbox on saturday so hopefully someone there can talk to me about it.

[Kiwi Jeeper]

Just so that I understand, you are running 3" lift with no changes to motor mounts, transmission skid, slip yoke, and rear control arms. If all you have done is lifted it 3" with no other modifications to compensate and correct driveline angles, driveshaft u-joints would be excessive stress when rear axle cycles through the motion range. Add wheel spin to mix, something has to give. Usually the weakest link breaks.

[Tassie Jeeper]

Just so that I understand, you are running 3" lift with no changes to motor mounts, transmission skid, slip yoke, and rear control arms. If all you have done is lifted it 3" with no other modifications to compensate and correct driveline angles, driveshaft u-joints would be excessive stress when rear axle cycles through the motion range. Add wheel spin to mix, something has to give. Usually the weakest link breaks.

thats my thoughts too as i wouldnt beleive an open diff with that size tyre should brake them regularly then again i have mechanical symphony and havent broke a driveshaft or axle in the three years iv had it and wheeled the crap outa it too

[Toff]

Probably bent the output shaft which in turn would be killing the unis.
Stock gearing doean't help - but lack of attention to the driveline angles is probably the main problem.

[sssadamsss]

You need a sye, double cardon driveshaft and adjustable control arms.

[Mangler]

You need a sye, double cardon driveshaft and adjustable control arms.

Adjustable Rear upper control arms would be the minimum but ideally rear uppers and lowers.

There is a set of rear uppers (Currie I think) in the for sale

[TJ Chaddy]

Just so that I understand, you are running 3" lift with no changes to motor mounts, transmission skid, slip yoke, and rear control arms. If all you have done is lifted it 3" with no other modifications to compensate and correct driveline angles, driveshaft u-joints would be excessive stress when rear axle cycles through the motion range. Add wheel spin to mix, something has to give. Usually the weakest link breaks.

I have a SYE, double cardon driveshaft, not sure about the control arms. Ill defineatly look into getting motor and transmission mounts. Im in the middle of saving for 4.11 ratio change and air lockers.

[james]

Dont get air leakers

Sent from my dieing HTC Un-Desire half smart phone

[Cornelius]

Did you get a bit of drivetrain vibration while on the blacktop ? Like a droning noise under load or decelleration ? I'm getting that at the moment after a 3 " lift install. Advice from Wooders via Superior Engineering is that I need adjustable rear uppers to correct the angle of the SYE double cardan rear tail shaft ...........else uni's will snap and stuff will wear out and the car would continue to drive like sh@t. So the adjustables are on order .........more money down the Jeep hole ............

[Cornelius]

Hahahaahaha James looks like you are in the market for an I-phone !!!!!!!!

[Aaronsjeep]

looks like you need a few upgrades,as people mention in above posts
sye, new shaft to suit, 4.11 gears to suit 32 inch tyres, or 4.56 may be better imo.

or drop your jeep back down to 2 inch lift. make sure driveline angles are all ok.

[bonza]

I have a SYE, double cardon driveshaft, not sure about the control arms. Ill defineatly look into getting motor and transmission mounts. Im in the middle of saving for 4.11 ratio change and air lockers.

adjustable control arms to dial in the correct angle of the rear drive shaft are essential

so is regearing. basic mechanical engineering really, with a higher diff gear ratio, that means more strain on the drive shafts, transfer and transmission. regear the diffs to a lower ratio and the strain is greatly reduced. I assume you have 3.07 diffs so going to 4.11 will reduce the strain and effort by well over 30%

think of it as a lever trying to prise a large 1 tonne rock using a crow bar 2 meters long, takes a lot of exertion to move the rock and you would probaly strain a muscle (your drive shaft). use a 4 meter crow bar (regearing) and it suddenly becomes easy on the muscles

[TJ Chaddy]

Did you get a bit of drivetrain vibration while on the blacktop ? Like a droning noise under load or decelleration ? I'm getting that at the moment after a 3 " lift install. Advice from Wooders via Superior Engineering is that I need adjustable rear uppers to correct the angle of the SYE double cardan rear tail shaft ...........else uni's will snap and stuff will wear out and the car would continue to drive like sh@t. So the adjustables are on order .........more money down the Jeep hole ............

There used to be a slight vibration at high speeds even though my wheels and tyres are balanced. and it does feel like its coming from the driveshaft. so maybe i need the same thing. Ive noticed last night when i was under the car that the angle of the driveshaft in comparison to the diff is quite substancial. im looking at getting a tummy tuck also so maybe when i get that, i look at getting engine and transmission mounts. Diff hangs too low too :P