Rear Trailing Arms

[Paul]

I've got the opportunity to have some new trailing arms made for the back of my 110 for free, but it needs to be done by someone remote me, so he needs details of the length and angle I want them bent to. Soooo...can anyone tell me what angle they should be bent, where along the length the bend should be and what the resulting length should be? This is assuming a 2" lift from standard.

I know I could probably work out the angle roughly by eye to get the chassis end bush unstressed, but I was hoping someone might have already done this for a 2" lift and save me from guessing wrong.

The arms are going to be made from 44mm dia solid bar (because that's what he's offering for free) if that makes any difference.

Paul

[simonr]

I've got the opportunity to have some new trailing arms made for the back of my 110 for free, but it needs to be done by someone remote me, so he needs details of the length and angle I want them bent to. Soooo...can anyone tell me what angle they should be bent, where along the length the bend should be and what the resulting length should be? This is assuming a 2" lift from standard.

I know I could probably work out the angle roughly by eye to get the chassis end bush unstressed, but I was hoping someone might have already done this for a 2" lift and save me from guessing wrong.

The arms are going to be made from 44mm dia solid bar (because that's what he's offering for free) if that makes any difference.

Paul

Don't know precisely, but lets work it out!

Let's assume standard arms are X cm long and that on a normal height vehicle they are horizontal.

If you lift it by 2", you have a right angle triangle (roughly) with one side 5cm, one side X cm, so by pythagorus, your new length Y will be:

Y = Square root ((5 x 5) + (X x X))

The bend will not be absolutly at the chassis end (probably 10cm away towards the axle or so). Lets call this distance away from the chassis mount Z.

The angle of the bend A will be:

Tan A = 5/(X - Z)

or

A = ArcTan(5/(X-Z)) degrees

If you measure the length of your existing arms, from the middle of the chassis bush to the middle of the axle bush (the two points around which it rotates), I or someone else will calculate it for you if you like.

Si

[dollythelw]

send me your email address Paul

[Hybrid_From_Hell]

Y = Square root ((5 x 5) + (X x X))

The bend will not be absolutly at the chassis end (probably 10cm away towards the axle or so). Lets call this distance away from the chassis mount Z. The angle of the bend A will be: Tan A = 5/(X - Z) or

A = ArcTan(5/(X-Z)) degrees

The other 'low tech' option is :

a chalk mark on the floor, a pipe bender, 4 grunts 17 pumps and a f*rt then check the bend

Nige

[landyliam]

how about a set of these

[Paul]

Don't know precisely, but lets work it out!

Let's assume standard arms are X cm long and that on a normal height vehicle they are horizontal.

If you lift it by 2", you have a right angle triangle (roughly) with one side 5cm, one side X cm, so by pythagorus, your new length Y will be:

Y = Square root ((5 x 5) + (X x X))

The bend will not be absolutly at the chassis end (probably 10cm away towards the axle or so). Lets call this distance away from the chassis mount Z.

The angle of the bend A will be:

Tan A = 5/(X - Z)

or

A = ArcTan(5/(X-Z)) degrees

If you measure the length of your existing arms, from the middle of the chassis bush to the middle of the axle bush (the two points around which it rotates), I or someone else will calculate it for you if you like.

Si

Thanks Si, I think I must have been on the right track then using pythagoras theorem.

My existing arms are approx 30", lets say 76cm. So for a 2" lift, the extra lenth required would be naff all then, less than ¼" ?

Unfortunately the calculator I have here at work can tell you the value of an annuity in 25 years time, or the internal rate of return but doesn't have any scientific functions, so can you help me out with the angle?

Paul

[rick]

or, you could just get them made dead straight and instal a Rangie Spares/Les Richmond Automotive taper shim between the chassis outrigger and the bush, or use one of Rangie Spares new 15* offset angled bush.

Just to throw more options up and give you more decisions to make

[Paul]

or, you could just get them made dead straight and instal a Rangie Spares/Les Richmond Automotive taper shim between the chassis outrigger and the bush, or use one of Rangie Spares new 15* offset angled bush.

Just to throw more options up and give you more decisions to make

The taper shim thingy from Rangie Spares was exactly what I was going to do Rick, but they cost about $100. I can get the new ones made up and set at whatever length I want, and bent to whatever angle I want, all for free, so long as I tell him length and angle etc. I'm thinking why pay $100 if I can get them bent when they're made?

Yes I know, I'm starting to sound like an accountant or something.

Paul

[rick]

<snip>

Yes I know, I'm starting to sound like an accountant or something.

Paul

not at all, sounds like a decision any of us would make.

[Revor]

Since the Pinion Angle is Improper from the get go I usually make mine between 10 and 15 mm longer than stock after I bend them about 50 mm behind the leading edge of the tire about 15 degree so that you relieve some stress on the frame bushing and keep the arms out of the rocks..

Of course it depends on the application.. 110's are different..

Keith

[Turbocharger]

To improve the pinion angle at the propshaft, wouldn't you have to make the arms shorter, to pull the bottom of the axle forward and point the diff nose more towards the gearbox?

[Paul]

Well, they're done. In the end I kept them straight and opted to try out some offset bushes. If they don't do the job properly, then I can get the arms bent at a later stage.

Here they are before fitting. Being 44mm solid bar they're fairly heavy, but no more than the front hockey sticks. Some of the remains of the skinny original arms show for comparison:

The offset bushes compared to standard:

The new arms installed:

The bush angle looks about right now:

Hopefully they should do the job. If I bend these then I'm in real strife.

Paul

[Mark90]

Ooo they look nice B)

[cols110]

Hmmmmm, very nice.

[LR90]

Looks neat and those bushes are a nice alternatice to cranked arms (unless of course you're cranking them to get them up out the way of rocks).

[orange rover]

like the offset bushes, neat alternative to new arms, who sells them?

[Paul]

like the offset bushes, neat alternative to new arms, who sells them?

They've been made up specially by an Australian mob, Les Richmond Automotive in Melbourne. Sorry, don't know if you can get them anywhere in Blighty.