Thread: extended rear shock mounts?

I made adapter plates out of 10mm steel plate to raise the original mounts, if i had them i could measure them for you but someone stole them and stuck them on his rangie (rovercare), think i raised them 40mm

my understanding which can be corrected is all you would need is to make up a adpator plate ...1" seems too much as this is approx 25mm
i would be going around 10-15mm
Vern says his 10mm raised it around 40mm

be carefull! you could buy 10 different 10 inch travel shocks and they would all be different lenghts

measure full open and fully closed length and then cycle your axle full up and full down and build mounts to suit

cheers, Serg

ps remember that when you bottom out at speed or under load you will compress the bump stops more than you think so build some safety into the up travel/closed length of shock so not to kill your shocks

You can buy 2 inch raised shock mounts from LRA. About $85 a side. They have a front and back plate for each side of the chassis and a box section that goes over the chassis.

Angus

Originally Posted by disco_thrasher

my understanding which can be corrected is all you would need is to make up a adpator plate ...1" seems too much as this is approx 25mm
i would be going around 10-15mm
Vern says his 10mm raised it around 40mm

No, its made out of 10mm thick steel plate, bolts to the side of the chassis where the old shock mount bolted, then the old shock mount bolts to it , just 40mm higher

Originally Posted by uninformed

be carefull! you could buy 10 different 10 inch travel shocks and they would all be different lenghts

measure full open and fully closed length and then cycle your axle full up and full down and build mounts to suit

cheers, Serg

ps remember that when you bottom out at speed or under load you will compress the bump stops more than you think so build some safety into the up travel/closed length of shock so not to kill your shocks

I was going to say this exactly but you beat me to it mate, IMHO this is the best way to set your suspension up that way you are getting the most out off the shock length.

no worries, thanks guys, guess im heading down the get some 10mm plate tomorrow

as for cycling the axle up and down, is that the sort of thing that can only be done with a forklift or something similar?

i have also been thinking of rotating the mount 90 degrees so the top eye is in line with the chassis, to reduce strain and binding of the top eye, any suggestions regarding that?

Originally Posted by jazzaD1

gday, in my disco i have a 2" lift consisting of dobinson coils and lovells shocks (from Shane at Suspension Stuff), in the rear they are extended a further 2" than normal, in order to gain the full amount of travel, and to avoid bottoming out the shocks, i need to fabricate some new rear upper mounts

here is where my confusion begins (im sure im overthinking it)
since the shocks are 2" longer than normal does that mean i need to raise my mounts by 2" or just by 1" since it includes up and down travel?

i thought i had it sussed out (thinking 2") until a mate of mine told me that it would mean it only needs the mount raised 1" (he is a landcruiser driver though haha)

can someone please clarify this for me?

does anyone have any CAD drawings or even measurements to start from? i have seen some people have used adapter plates to raise their standard mounts

thanks

Originally Posted by jazzaD1

no worries, thanks guys, guess im heading down the get some 10mm plate tomorrow

as for cycling the axle up and down, is that the sort of thing that can only be done with a forklift or something similar?

i have also been thinking of rotating the mount 90 degrees so the top eye is in line with the chassis, to reduce strain and binding of the top eye, any suggestions regarding that?

As Serg said, measure closed and extended lengths as they vary between manufactures. Bilsteins will usually be longer when closed because of the way they separate the gas from damper oil inside the body.

You need to ensure they don't bottom out of full bump as Serg explained.

If everything else is equal, increasing a shockies travel by 2" will require a 2" increase in the body length (for piston travel) and thus the closed length.

If the closed length is 2" longer, then the top mount needs to be 2" higher to have the same safety margin against bottoming out.

If the closed length is less than 2" longer, then you might get away with the reduced safety margin - you need to check this.

You will not be able to raise the rear upper mount by 2" unless you have a body lift (front mount can be raised without a body lift).

The rear upper mount could be layed further forward, but remember you will need to put crush tubes into the chassis rails.

The other option to raising the upper shockie mount is to lower the bump stops.

Do not change the upper mount to rotate the shockie eye 90*. The stock setup is not ideal for lifted suspension, but this would worsen the problem.

The rear axle articulates about the ball joint on the upper A-frame. Because the lower shockie mount is well below the height of the ball joint, and behind the upper mount, it shifts forward and inward as that side droops and backward and outward as it rises. When you lift the suspension and extend shockie travel, this becomes worse. It results in bending flex of the rod of the shockie, but thankfully most don't break or stay bent (some do).

To minimise this problem, you need to have sufficient flex in the shockie rubbers. Rubber distorts but it's volume does not change - therefore to have sufficient flex there must be space for the rubber to distort into. Discos have separate issues at the top and bottom rubbers.

At the top, a nut and washer are tightened up against the rubber, confining it to the eye of the shockie. IMHO it is best to use early rangie top mounts - these had a washer that is retained by a split cotter pin, which allows better flex.

At the bottom, cups were welded to the mount to locate the rubbers. Remove the cups and use shockie washers to locate the rubbers (same as early rangies).

Edit: if you lift the body up far enough on stands, remove the wheel on the side to extend down, and the spring on the side to go up, then you can cycle it with a jack under one side of the axle. Remember what Serg said about compression of the bump stop.