Rear suspension ride height for new axle/beam

[ladderboy 0]

Got a 1994 1.9 in Sorrento Green :-). I know it's been lowered, so I really should have done some measurements before removing beam/axle :-(. Everything was seized to hell, so I ordered new axle from IMaxles. They're now asking what ride height I want it set to. I've got 17" alloys with 205/40 tyres on, and can JUST get my hand between tyre and arch trim at the front. Anyone give me a clue what I should tell them to set my new axle to so the rear matches the same ride height? They're saying they can drop it by 10-40mm. Thanks!

[jord294 92]

Why did you go to IMaxles when there are members on here that could of helped you out with a better built axle. 

Noone can give you a definite answer on what to get axle set to. 

I'd say get them to set it around 316mm and if its not right when fitted, ask on here ic someone can readjust for you.

 

Where you from?

[ladderboy 0]

I don't come on here that often, and I didn't know there were people who could offer new axles :-(. Are the IMaxles no good? I'll definitely disassemble it when I get it to ensure it's good and greased up, so easier to adjust if I need to. My old one was just seized and rusted and had been abused before. Ended up cutting both torsion shafts to get the unit apart!! That measurement you give, is that the shock bolts spacing? I'm just outside Bristol.   

[pug_ham 244 3 Cars]

You can adjust the beam ride height by the mm using the correct factory method and both ends of the torsion bar free from the trailing arm . beam tube.

 

g

[joris_andriesse 8]

What is the method/moment of measuring the hight?

Reason for asking is that I plan to take my beam off, refurbish it and replace the tb's and arb for a thicker version.

 

When placing the beam back, I would like the ride hight about 10mm lower than currently, what would be the best way to achieve this?

[welshpug 1,657]

lower   thats already too low.

 

rear ride height is set between the damper bolts with no tension on the torsion bars.

[wicked 103 3 Cars]

2 hours ago, joris_andriesse said:

What is the method/moment of measuring the hight?

Reason for asking is that I plan to take my beam off, refurbish it and replace the tb's and arb for a thicker version.

 

When placing the beam back, I would like the ride hight about 10mm lower than currently, what would be the best way to achieve this?

You measure the length of the damper, while damper is removed and axle is unloaded. Note that there is a ~2,5 ratio between damper length and ride height. 

 

If you swap for thicker bars, the old value is too high, as it will sit higher with thicker bars. 

[joris_andriesse 8]

Not sure whether I understand this correctly.
If I jack up the car and take of the wheels, that should be the moment to measure the distance between the damper bolts. Right? Why should I be measuring the damper lenght, while damper is removed?

With that 2,5 ratio, I guess I have to reduce the damper bolt distance with 4mm to drop the car by 10mm, right?

I understand that the thicker bars will make the car sit higher, so there will be some trial and error, I think I will give it an 10mm extra drop compared with the current hight. Preverably I'll set the beam as it is off the car, but I know I still might have to adjust when it's back on the wheels again.

[wicked 103 3 Cars]

The damper might press the arm down, depending on the type of shocks. 

 

Some searching on this might give you some values. I think I have 298 or 305mm with the 21mm bars. 

You just need to drill 2 holes in a strip of metal at that distance and fit it as damper. The fiddle the bar in and do similar on the other side. It also guarantees that you set both sides at the same height. 

[joris_andriesse 8]

23 minutes ago, wicked said:

The damper might press the arm down, depending on the type of shocks. 

 

Ah, I thought that you ment measuring the damper, which didn't make sense to me :p. Perfectly clear now

 

23 minutes ago, wicked said:

Some searching on this might give you some values. I think I have 298 or 305mm with the 21mm bars. 

You just need to drill 2 holes in a strip of metal at that distance and fit it as damper. The fiddle the bar in and do similar on the other side. It also guarantees that you set both sides at the same height. 

Will do some search. The idea of the metal strips is a great one!

[pug_ham 244 3 Cars]

10 hours ago, joris_andriesse said:

If I jack up the car and take of the wheels, that should be the moment to measure the distance between the damper bolts. Right? Why should I be measuring the damper lenght, while damper is removed?

No, that will be with the trailing arm weight on the torsion bar giving you the wrong measurement, especially if the rear shocks are still fitted.

 

You need to lift the arm to the mid point where there is no spring effect from the bars with the shocks removed & then hold the arm at that point to find your dummy shock length.

 

There area few topics on here with the dummy shock length for various thickness of torsion bars.

 

g

[ladderboy 0]

Can someone clear up my confusion re rear beam/axle components and assembly. I've read a couple of online explanations of setup, but due to inconsistent description of parts, I can't make full sense of them. Assume I've got the axle bolted to the car, trailing arms pushed in either end, but no torsion bars inserted. So which end do you insert torsion bars from, offset washer end or adjuster end? Once I've got the offset washer end in and tightened that end up, what goes on first at the other end, the adjuster or the domes/slotted bar end stop? Hex nut on the adjuster, does it go under or over the bar end stop? What does the ring of metal on the adjuster push against to draw the torsion bar into the trailing arm? When you're tightening to pull the trailing arms together, are you tightening the slot in the end of adjuster (looks easy to break) or something else? I'm sure once you've done one it all makes perfect sense!!

[petert 588]

You can only insert the torsion bar from one direction, as the two ends have different diameters. It's fairly obvious once you're into it. Only insert a torsion bar after you have set the shock absorber height. Only insert one trailing arm to begin with and get that set and locked up, before attempting the other side.

 

The adjusting screw is only used to set the preload/clearance. ie once the torsion bar is locked up by the torx countersunk set screw & offset washer on the other end, I wind the screw out until it touches the cup, then back off half a turn. There is no force on it at all.

 

Attached is a pic of my shock length tool.

Edited March 12, 2022 by petert

[Gohn 68]

On 3/11/2022 at 5:19 AM, ladderboy said:

I've got 17" alloys with 205/40 tyres on, and can JUST get my hand between tyre and arch trim at the front

if you swapped off what the previous owner put on and went back to a regular set of GTi 15" rims you could have a sidewall on your tyres

it would help to know what the car should feel like before making any changes and or setting your ride height

otherwise your setting up the whole thing around licorice strips

there'd be a big improvement in suspension/damping and ride

 

if that axle joint hasn't started on yours, go and literally grab it back off them

there are several members that have done thousands of rear beams and would have given good advice as well as a great axle

andy and tom are two and it really cant be that far to get it done right first time