Thread: A-frame ball joint

I managed to get a couple of quick measurements. Wont be 100% acurate, but should be close. I checked my bumpstop clearance, then took a measurement from the bottom of the chassis cross member that the LL mounts to and measured to a section on my Sals diff, which would approx follow the angle of mounting of the LL. I then jacked the vehicle up at the rear crossmember to gain approx 2 inch lift (more bumpstop clearance)

Note my bumpstops are 25mm longer than OEM

BS at ride height = 155mm
LL placement = 456mm

BS at 2 inch lift = 209mm
LL placement = 485mm

so for a 54mm spring lift, the LL only has to be 29mm longer, BUT there is more.

The cast section that is bolted in between the A frame arms and houses the main rear ball joint (for diff) changes angle with lift. At my static ride height its at 14 degrees. When it is lifted the 54mm it is at 10 degrees....So what does this mean you say. Well since the LL cast section has a goose neck that pics up the lower ball joint on the end of the LL shaft, this changes height as the angle of it changes.

I set it up in the BJ press jig. going from 14degrees to 10 degrees has a change of approx 5mm. It actually gets higher as the springs get longer. So this means you would take another 5mm of that 29mm.

So for approx 2 inch lift, the shaft of the LL only has to be 24mm longer.

Remember my static pinion angle may not be stock, and I already have 2-2.5 inch lift at static, so raising it another 2 inches from this postion may skew the results when compared to a stock height rig being raised just the 2 inches.

Atleast its a start.

Originally Posted by uninformed

I have to disagree with the above. I have seen plenty of rigs running 3 link + panhard and even double triangualted 4 link fronts and they flex very well, and NO they are not 50/50 weight balance.

Search around the net and look for pics of Safari Guards original 3 link 90's and 110's....these are full bodied LR with LR V8's in normal engine postion...front to rear flex is 50/50 balance.

The reason the fronts dont flex much on the LR is its the nature of radius arms to bind. They do have roll stiffness which is good. Its a combination of overall length, axle bush seperation and bush material/defelection. LR are better then Toyota and Nissan in this area simply for these reasons.

I personaly would be happy If I was alowed to make/get made, new longer arms using the stock bushes and bush spacing (this for a road going rig)

i agree extra length with same design RA's would be best of both worlds for street going applications...i would also think placement of mounts at chassis end with longer RA's would also dictate castor angle also...

Originally Posted by uninformed

I have to disagree with the above. I have seen plenty of rigs running 3 link + panhard and even double triangualted 4 link fronts and they flex very well, and NO they are not 50/50 weight balance.

Search around the net and look for pics of Safari Guards original 3 link 90's and 110's....these are full bodied LR with LR V8's in normal engine postion...front to rear flex is 50/50 balance.

The reason the fronts dont flex much on the LR is its the nature of radius arms to bind. They do have roll stiffness which is good. Its a combination of overall length, axle bush seperation and bush material/defelection. LR are better then Toyota and Nissan in this area simply for these reasons.

I personaly would be happy If I was alowed to make/get made, new longer arms using the stock bushes and bush spacing (this for a road going rig)

I think you have missed my point by a LOOOOONG shot.
I didn’t say don’t flex or anything like that.
I was trying to say that you are better off (in the first instance) spending time and effort with the rear flex before doing much on the front. Since the weight of the motor tends to keep both front wheels on the ground (unless heading up a hill)
And it is cheaper to get more flex in the back than the front anyway.

Since this thread started on a balljoint swap i have assumed ( maybe wronly) that we have been talking about a reasonably stock vehical and not some thing with major modifications.

As for A arm lengths i agree. While in Russia i added another pair of lower trailing arms to the top replacing the original shorter arms, along with 2 new mounts. This was a lada Kopec. The difference it made was astounding on ruff ice racing.