Need Help With Grinding Sound After Suspension Lift

[dasnoboarder]

Awesome, thanks daisy

[geeves]

just a thought based on an earlier description of the problem If the axle tipping forwards is the problem then longer rear shackles will tip it back. Also a fix and more lift

[dasnoboarder]

That could be the issue geeves, and it may be made worse by my new shackles (5mm shorter than factory ones).

Would adding longer shackles help by rotating the diff up a little, or make things worse by adding more lift?

This is my current shackle angle, ok, but not that good. The angle is vertical or a little toward the axle:

How much would be a good shackle extension to help the diff angle, help the shackle angle, while not lifting it too much?

Also, how much lift can the driveshaft take before falling out under flex? (mine's the slip-yoke style)

[geeves]

Your limited flex wise by the shocks Even if you do get longer ones the way they are fitted prevents the axle twisting much further than standard. Shakle angle is ok as they would of been pointing backwards with the old springs. Once they settle the shackle will be straight up and down

[dasnoboarder]

Thanks geeves, I thought shackles looked a little too far forward, but it's a good point my old springs were quite sagged.

I haven't found spring wedges in NZ yet, rang the Shock Shop in Glenfield, and they hadn't heard of them.

With about 11mm drop on the rear crossmember/gearbox, all the bad vibration has gone.

When driving motorway speed it still has a little vibration, but no where near as much.

I'm going to leave it as is for a while, see if little vibration goes away, and test the setup offroad to see how the front driveshaft feels, then decide if I want to drop the box by another 5mm or look into getting hold of small degree spring wedges.

Cheers!

[sprey]

Hmm come to think of it with mine, ever since ive had the car its had a big of a clunk even when changing gear from R to D etc. so yea prob replace the uni joints soon then hopefuly the sound is gone.

Im guessing this wedge thing doesnt affect me as i have coil spring in the rear

[dasnoboarder]

No wedges for you mate, they go between the leaf spring and axle.

To tune coil sprung rear suspension you need longer/shorter upper/lower arms. Or get adjustable ones!

[Demonic]

That could be the issue geeves, and it may be made worse by my new shackles (5mm shorter than factory ones).

Would adding longer shackles help by rotating the diff up a little, or make things worse by adding more lift?

This is my current shackle angle, ok, but not that good. The angle is vertical or a little toward the axle:

How much would be a good shackle extension to help the diff angle, help the shackle angle, while not lifting it too much?

Also, how much lift can the driveshaft take before falling out under flex? (mine's the slip-yoke style)

From what i know the angle of the shackle should be at a 90deg (or a close to that) to the eye to eye of the spring, have a look at a stock set and u will see what i mean.

[dasnoboarder]

Yea, optimum angle is like this:


Mine are a bit far forward, but should hopefully get closer to that after a while on new springs.

[MrBIGHORN]

You mite need to mod a wedge from a truck.
Contact some one that does steering on trucks as my isuzu 550 has them on the front axle

[dasnoboarder]

Thanks for tip, might be cheaper than importing them from Aus!

[daisy]

Yip do the spring wedges im running those rear leafs too and thats how i fixed it not sure what degree the wedges are they were just the ones i had at the time. ive got a mate that owns a SHOCK SHOP ill go see him tomorrow and find out the degree of the wedges i think i need a bit more than what ive got cause i still get a bit vibration over 100km

My spring wedges are about 3 degrees and he thinks i could go 5 degrees he thought the leafs would settle more than they have and its been over a year now
but il wait till i make up new draws in the back (more weight)
he get his wedges made up from the local engineers

[dasnoboarder]

Thanks mate, I guess it would cost about $250 to get them made from scratch?

[dasnoboarder]

Found this from the old forum, about converting the 2.8 slip-yoke driveshaft to the 3.1 fixed style:

Tom, great work, looks great. But out of curiosity did you know the later MUA5 trans mission in Jackaroos and MUs have eliminated the slip yoke already!

You just need to source the extension housing etc and change them over. I think someone did that when they went to install the Terra Low gears and found the kit is different with the slip yoke trans.
The later models just have a flange end and the slip joint is in the prop shaft.

Matt.

Is the extension housing just the back of the transfer case? How many parts are needed, would it be an easy job?

Also, I've found one gearbox/transfer case breather, a plastic cap to the left of the 5-speed gear-stick boot, can anyone tell me where the other one is?

Cheers,
Andy

[jezza]

would just be easier to fit a 3.1 gearbox as it would be a easy job of just swapping boxes instead of stripping them down.
There will be one breather on the gearbox and one on the transfer case

[dasnoboarder]

Only way I can see that doing a complete swap would be feasible is if the wreckers would do an exchange deal...

Would it be just as easy to swap transfer cases? I have an reasonably new exedy clutch in my 2.8 and don't wanna mess around with that (3.1 has different clutch assembly?)

Don't have the money to buy a whole new box or the space to have a spare one sitting around haha.

[dasnoboarder]

Can someone tell me if a 3.1 transfer case will do a straight swap with my 2.8 one? Same bolt pattern onto gearbox & crossmember etc?

[dasnoboarder]

Right, I've found that 2.8 and 3.1 MU transfer cases can bolt to the same gearbox,
And might have found one I can use...

Can anyone help me on these questions?:
A case from a 3.1 manual Bighorn will also bolt on?
Is the 3.1 driveshaft from a SWB Bighorn the same as the 3.1 MU?

Cheers,
Andy

[Pissy]

Please let US-me know so I can do a FAQ on the subject,........as I too get the same issus ?

[holden]

http://www.offroadspecialties.co.nz/node/138 Shim Set 6 Degree