Caster wedges/shim... Which way

[axeten]

Hi all,

Can someone please confirm for me which way the caster adjustment wedges get installed after a 2" lift.

I have put them in with the fat end to the back to tilt the diff flange up.

But now i am reading on all kinds of sites that they go the other way. Every thread i have read has someone saying fat end to the back and then someone else saying fat end to the front???

Can someone tell me the actual correct way to install them?

Also, how can i measure the pinion angle that will determine how much caster adjustment i need?

[07luxyTD]

You want to tilt the front of the diff up so big bit at the back little at the front, so taper starts at the front and biggest at the back. The reason people say the other way round is because there springs are most likely under the diff not on top of the diff e.g Landcruiser

[09lux]

The diff pinion has to be parallel to the output shaft on the gear box to be eliminate all vibrations.

[axeten]

You want to tilt the front of the diff up so big bit at the back little at the front, so taper starts at the front and biggest at the back. The reason people say the other way round is because there springs are most likely under the diff not on top of the diff e.g Landcruiser

Yeah thats what i though, and how i have installed them. There are threads on here that have people saying both ways. Some say bring the diff up and other say to make it more perpendicular to the ground. It was getting a bit confusing.

It did seem to make a bit of a difference how i installed it so i'll leave it as is a drop the center bearing a bit.

[StevenS]

depends on the ute really. Best way is to measure the flange angles and determine from that which way the diff needs to roll to make them parallel. It would also show whether a 1 degree wedge would be enough.

[axeten]

depends on the ute really. Best way is to measure the flange angles and determine from that which way the diff needs to roll to make them parallel. It would also show whether a 1 degree wedge would be enough.

So the flange on the rear diff facing the front of the car. And the flange on the transfer case that faces the rear need to be parallel? Is that right? where each end of the 2 piece shaft bolts on?

[StevenS]

depends on the ute really. Best way is to measure the flange angles and determine from that which way the diff needs to roll to make them parallel. It would also show whether a 1 degree wedge would be enough.

So the flange on the rear diff facing the front of the car. And the flange on the transfer case that faces the rear need to be parallel? Is that right? where each end of the 2 piece shaft bolts on?

yep. If you have an Iphone running the latest IOS then it has a built in level as part of the compass app that you can use.
Android phones probably have hundreds you can download. This is how I measured the angles on my ute and found I almost could have gone with a 2 degree wedge but a 1 degree wedge sorted out the vibrations so I didn't stress.

[axeten]

depends on the ute really. Best way is to measure the flange angles and determine from that which way the diff needs to roll to make them parallel. It would also show whether a 1 degree wedge would be enough.

So the flange on the rear diff facing the front of the car. And the flange on the transfer case that faces the rear need to be parallel? Is that right? where each end of the 2 piece shaft bolts on?

yep. If you have an Iphone running the latest IOS then it has a built in level as part of the compass app that you can use.
Android phones probably have hundreds you can download. This is how I measured the angles on my ute and found I almost could have gone with a 2 degree wedge but a 1 degree wedge sorted out the vibrations so I didn't stress.

Awesome, that's what i wanted, an explanation that made sense rather than 2 people saying to install the wedges in different ways because "their mate told them".
Thanks heaps, will let you know how it goes.

Alex

[axeten]

Thanks again StevenS.

I installed an angle meter in my phone and held it against the transfer case flange. Pressed the "Zero" button and then held it against the diff flange where it read -2 degrees. I'd installed the 1 degree shim already and had to drop the diff 2 degrees to make the flanges parallel. Turned the shim around (fat end to the front), which made the difference 0.1 degrees.

Dropped my center bearing a few mm with a fat washer i had and the shudder is almost gone. Will play around with the center bearing spacing a bit more and see how it goes.

Thanks again

[StevenS]

Thanks again StevenS.

I installed an angle meter in my phone and held it against the transfer case flange. Pressed the "Zero" button and then held it against the diff flange where it read -2 degrees. I'd installed the 1 degree shim already and had to drop the diff 2 degrees to make the flanges parallel. Turned the shim around (fat end to the front), which made the difference 0.1 degrees.

Dropped my center bearing a few mm with a fat washer i had and the shudder is almost gone. Will play around with the center bearing spacing a bit more and see how it goes.

Thanks again

No worries. My shim went in the same way. I've spaced down the center bearing a bit but never found it made much difference, never got a straight answer myself on how important it was/wasn't.

[llough10]

I am currently going through the same situation - I put the fat end at the front and it reduced vibration significantly.

Tossing with the idea of spacing the centre bearing but unsure at this point. Time to search the forum!