Thread: Suspension Question - Lowering and replacing 1 ton shackles

No, what you have done with the front is not correct. The front of the spring needs to be in the upper hole if the shorter shackles are fitted, and this matters at the front, as it changes the castor angle on the swivels. (It does not matter much at the back axle)

Why can't you get the spring into this position? Likely reasons are a build up of paint, or repairs that have left welds that need to be removed.

John

Problem at the rear is it may induce vibration by changing the pinion angle

Originally Posted by JDNSW

No, what you have done with the front is not correct. The front of the spring needs to be in the upper hole if the shorter shackles are fitted, and this matters at the front, as it changes the castor angle on the swivels. (It does not matter much at the back axle)

Why can't you get the spring into this position? Likely reasons are a build up of paint, or repairs that have left welds that need to be removed.

John

John thanks for this, what is contradictory/ confusing is that the workshop manual seems to shows the lower hole used along with the shorter shackle dimension. Which is what made me second guess what I had done ....

In terms of why I couldn't get the spring to go into the top hole, I think it's just too tight - so a tolerance issue rather than anything else. I'm using poly bushes from 4wd in Victoria - I should check the length against a conventional bush - the rears were very tight too if I recall.

Given it's ex mil it will have longer shackle plates and extended chassis plates. We made both of these by the dozen (access to gas profile cutter) and it's a simple process to lift without needing to change springs. You can slot the springs back into the upper holes but you'll also need the shorter shackle plates other wise you have the aforementioned castor issues.

In the manual I don't believe it would show the service spec suspension. I don't know if it was fitted factory to order for contract or done as an in service mod before they were released for use.

Originally Posted by clubagreenie

Given it's ex mil it will have longer shackle plates and extended chassis plates. We made both of these by the dozen (access to gas profile cutter) and it's a simple process to lift without needing to change springs. You can slot the springs back into the upper holes but you'll also need the shorter shackle plates other wise you have the aforementioned castor issues.

In the manual I don't believe it would show the service spec suspension. I don't know if it was fitted factory to order for contract or done as an in service mod before they were released for use.

Reread the original post. He has already replaced the longer 'One Ton' shackles with standard ones, and needs to move the front of the spring to the upper hole.

John

Originally Posted by shaunmax

John thanks for this, what is contradictory/ confusing is that the workshop manual seems to shows the lower hole used along with the shorter shackle dimension. Which is what made me second guess what I had done ....

In terms of why I couldn't get the spring to go into the top hole, I think it's just too tight - so a tolerance issue rather than anything else. I'm using poly bushes from 4wd in Victoria - I should check the length against a conventional bush - the rears were very tight too if I recall.

Try spreading it by putting a section of threaded rod through the lower holes with two nuts between the cheeks, and winding them apart.

I hope you don't have the axle U-bolted on to the spring - that just makes life more difficult, as, if you think about it, unless both side springs are at exactly the same height, they will be twisted by the axle. It is a lot easier to seat the axle once both springs have both shackle pins in place (but not tight).

John