tail shaft spacers

[signmaster]

Hendo,
You could do it at home, you just need to drill out the hole in the caster wedge to accomdate the leaf pack centre bolt. Then mount the wedges between the diff and springs, with the thickest part of the wedge to the rear of vehicle.

Please correct me if I am wrong but after a lift the wedges should go in with the thickest part toward the front. As far as I can make out after reading numerous articles on the web the drive shaft out of the gear box should be parallel with the pinion on the diff. This is true for both split tail shafts as per the Hilux and single tail shafts. When the rear is lifted, this would vary depending on the shape of the springs but all things being equal a lift would tend to rotate the pinion side of the diff up, taking the pinion and the drive shaft out of parallel. So putting in a wedge with the thickest part facing toward the front would angle the diff down therefor returning the pinion and gearbox shaft to their parallel position. Then perhaps fit a spacer onto the centre bearing to even out the split tail shaft and reduce any excessive universal joint angles. I believe that the spacer on the center bearing will have little effect on vibrations but is only important to even out the universal joint angles.
Any feedback on the above comments would be appreciated as I am having a small vibration/drumming problem after a 2" lift see this thread. http://www.newhilux.net/phpbb/viewtopic.php?f=28&t=11105

[scottsr20]

Both are correct. The gearbox flange and the pinion flange should be parallel as stated, so the wedge needs to be positioned to correct which ever way the springs have thrown it out. The symptoms crossport had to deal with( shudder slowing down and dissappears with a load on) would suggest it is opposite to the more common situation that the lifted leaf spring on a sprung over vehicle will need a wedge with fat end at the front. If your shudder is worst on take off or with a load in the tray, then the pinion flange is too high initially and needs a wedge to lower it.

[J&L]

Guys, just remember to grease the universals at least every 5000km. With a lift they work harder and soon cause vibrations as well. To test the wedge angle is easy. Check the gap at the top and bottom of the universal mounting at the rear propshaft. They should be equal. If not, add wedge angle.

[Hellbound]

Hendo,
You could do it at home, you just need to drill out the hole in the caster wedge to accomdate the leaf pack centre bolt. Then mount the wedges between the diff and springs, with the thickest part of the wedge to the rear of vehicle.

Please correct me if I am wrong but after a lift the wedges should go in with the thickest part toward the front. As far as I can make out after reading numerous articles on the web the drive shaft out of the gear box should be parallel with the pinion on the diff. This is true for both split tail shafts as per the Hilux and single tail shafts. When the rear is lifted, this would vary depending on the shape of the springs but all things being equal a lift would tend to rotate the pinion side of the diff up, taking the pinion and the drive shaft out of parallel. So putting in a wedge with the thickest part facing toward the front would angle the diff down therefor returning the pinion and gearbox shaft to their parallel position. Then perhaps fit a spacer onto the centre bearing to even out the split tail shaft and reduce any excessive universal joint angles. I believe that the spacer on the center bearing will have little effect on vibrations but is only important to even out the universal joint angles.
Any feedback on the above comments would be appreciated as I am having a small vibration/drumming problem after a 2" lift see this thread. http://www.newhilux.net/phpbb/viewtopic.php?f=28&t=11105

I have to disgree with you and agree with crossport on this one. Look at the rear diff from side on, installing the wedge with the thick part at the front will rotate the diff anti-clockwise but you dont want that because you are then moving the centre of the tailshaft on more of an angle to the centre of the diff input shaft. Whereas you what you want to happen is for the rear section of tailshaft to meet the diff input shaft straight on, and not rotated anticlockwise more as that will be more of an angle for that universal joint to operate at.

Thats why you would install is with the thick part of the wedge at the back, so that the diff rotates clockwise (from side on ) and becomes more inline with the centre of the tailshaft.

[scottsr20]

It depends on the angle you created by lifting the car. Mine definitely needed the thick part at the front. I put a dgital level on each flange to check the angle at the gearbox output and diff input flanges . If you did your lift just with leaves ( I used different leaves and extended shackles ) that could be why the two cars need different wedging to correct the angle .

[signmaster]

I have done a bit more research and I believe I am right. I will actually have to rotate the diff down which will increase the angle between the diff and tailshaft but this will make my pinion shaft exactly parallel with the drive shaft from the gearbox.
The reason for this is that the velocity transmitted through a universal joint is not constant and must cancel out by having two (or 3) universal joints. If the angle of the pinion shaft and the drive from the gearbox shaft are not the same the velocity changes within the universal joints will not cancel out and you will get vibrations. Having said that the universal joint angles should not be more than 3 degrees (some say 6 degrees max). If you have everything lined up exactly, all in a straight line there will be no rotation within the needle rollers and you will be transmitting all the power of that D4D engine through a single roller causing the universal joints to develop pitting and premature failure. The ideal angel is 1.5 degrees.
I think the curve of the new springs can vary and some people may have to fit the wedges the other way around to make the input and output parallel. I measured the angles with my iPad, so I hope it is accurate enough.
I have ordered a pair of 1 degree wedges and will fit them as soon as I have the time, will let you know how it goes.


Sent from my iPad using Tapatalk

[Hazeyboy94]

I have done a bit more research and I believe I am right. I will actually have to rotate the diff down which will increase the angle between the diff and tailshaft but this will make my pinion shaft exactly parallel with the drive shaft from the gearbox.
The reason for this is that the velocity transmitted through a universal joint is not constant and must cancel out by having two (or 3) universal joints. If the angle of the pinion shaft and the drive from the gearbox shaft are not the same the velocity changes within the universal joints will not cancel out and you will get vibrations. Having said that the universal joint angles should not be more than 3 degrees (some say 6 degrees max). If you have everything lined up exactly, all in a straight line there will be no rotation within the needle rollers and you will be transmitting all the power of that D4D engine through a single roller causing the universal joints to develop pitting and premature failure. The ideal angel is 1.5 degrees.
I think the curve of the new springs can vary and some people may have to fit the wedges the other way around to make the input and output parallel. I measured the angles with my iPad, so I hope it is accurate enough.
I have ordered a pair of 1 degree wedges and will fit them as soon as I have the time, will let you know how it goes.


Sent from my iPad using Tapatalk

I was just reading this thread and it ended with you waiting to fit a pair of 1 degree wedges. Just wondering if you have fitted them and did it solve the problem? Cheers.

[Hellbound]

I fitted mine the seemingly incorrect way with the wedge with thick end to the front. Was instructed by Crossport to do so when he sold them to me and shes all good...

[Hazeyboy94]

I fitted mine the seemingly incorrect way with the wedge with thick end to the front. Was instructed by Crossport to do so when he sold them to me and shes all good...

Sounds good. I just fitted a TJM 2" lift kit and i noticed vibrations like what's been mentioned. I first thought it was brake or clutch shudder but now realize what the issue is. Can the part be found at most suspension shops? And is the part just called a "1 degree castor wedge?" I live in NZ, so i'll look around here, but if i can't find the part, how do i get them from Crossport?

Cheers mate.

[Hellbound]

Yeah i just PM'd him and got each others email and went from there. They arrived pretty quickly, just have to drill a hole in the centre of the wedge in order for it to fit over the spring locater bolt that goes through the centre of the leaf pack. Maybe just double check with him about the orientation of the spacer just to be sure which way its meant to go...

[Hazeyboy94]

Yeah i just PM'd him and got each others email and went from there. They arrived pretty quickly, just have to drill a hole in the centre of the wedge in order for it to fit over the spring locater bolt that goes through the centre of the leaf pack. Maybe just double check with him about the orientation of the spacer just to be sure which way its meant to go...

I PM'd him and another member a week or two ago and no reply. I have had no luck finding them here in NZ. Thankfully i've found them selling Hilux 1 degree wedges on Ebay. They are already pre-drilled to, so i'm going with them

[Hellbound]

sounds good matey, let us know how you get on ok -

[Hazeyboy94]

I had the 1 degree castor wedges fitted & because the shudder was on slowing down i got them fitted with the thick part of the wedge to the rear.

It solved most of the shudder, but i still get some shudder when slowing down changing it from 4th into 3rd at around 40kmh. It's nowhere as bad as before, but it still bugs me. Any ideas anybody?

Cheers.

[Hellbound]

Man, im getting so confused now - i recently upgraded my rear leaves and seeing as i had the 1' wedges already fitted i thought i was ask my suspension guy about which is the true direction to install them. Has told me that the thick end points towards the front of the car.

Now i had them installed before on the old set of leaves where the lift was the same 40-50mm but was a result from airbags and had some tiny vibration but not really. Wedge installed with thick end to the rear of the car.

So in goes the new leaves and i thought ok i swap it around so the thick end is now pointing towards the front and blow me down theres some weird vibration going on at all speeds thats not terrible but noticeable. just wondering do i take it out again and swap her over so that the thick end points to the rear!

Can anybody say for sure which ends points where and actually eliminated the vibration caused by lift???

Ultimate are you around to confirm this!

[Tiprat]

Hi guys, just wondering at what kph are u guys getting this vibration? cheers tiprat.

[wld_64]

The way the wedges go in and which degree is differant for every vehicle, check the pinion angle and purchase wedges to suit or you are wasting your money as you won't know which way your pinion is out ( up or down ). I did a 4 inch lift got a vibration at low speed, measured and needed 6 degree wedges inserted big end to the back, still had a small vibration, checked uni's and replaced with heavy duty ones and checked tailshaft balance at 1200 rpm it nearly jumped off the bench! Rebalanced, sweet now. Don't leave a vibration in the driveline or it will flog pinion, trans and center bearings and distroy uni's in no time.

[tulula]

Guys im running a 12"lift with about 3 degree of caster. Thick part of wedge def needs to go towards the front of the truck. The idea is to keep the diff assembley as horizontal as possible. Increases the ujoint angles but reduces shudder vibrations. Also running a 40mm tailshart spacer, and a 1" drop spacer for the center shaft bearing. Works for me, pretty sure i heard it from Allan Gray from Terrain tamer and 4wd action magazine.

[tulula]

Sorry guys actually its more like at least 10 degrees of castor. But no vibration or shudder here.

[meh gang]

hi guys where do you get tail shaft spacers from,thanks

[toyboata]

hi guys where do you get tail shaft spacers from,thanks

Just use a few washers or find one about 5-10mm think depend on lift.

I never installed my castor wedges so got a spare new set if anyone after them $40 plus post if anyone keen .
I would have thought with any lift you'd want fat end of wedges at rear so as to tilt pinion upwards and re align with tailshaft which now has increased angle upwards due to lift.