M
Mac
Guest
Curious if running 0* is bad on front pinion angle on Dana 30? Tires seem to be wearing fast. Would this cause excessive wear. I have no DW, bumpsteer, vibes etc. Drives fine on the pavement.
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- Location
- Terra Firma
Pinion angle affects drive shaft u-joints and vibrations, not tire wear. Check your toe-in.
RCP Phx
NAXJA Forum User
- Location
- Phoenix,Az
Spobi Alert!!
While pinion angle by itself cant cause tire wear,the relationship it has to castor can!If yours is a daily driver adjust for castor,if its mostly an offroad rig adjust for pinion angle,(all within reason).
BTW:You don't want 0*,you need to be under that to account for axle wrap!
While pinion angle by itself cant cause tire wear,the relationship it has to castor can!If yours is a daily driver adjust for castor,if its mostly an offroad rig adjust for pinion angle,(all within reason).
BTW:You don't want 0*,you need to be under that to account for axle wrap!
Right now you have about 9* of castor wich isn't too ideal. Having too much castor will make your steering wheel whip back to centre after turns and possible make the handling kind of sharp. The downside is that it is putting stress on your driveshaft u-joints as was mentioned above, but also stress on your pinion seal and pinion bearings. I think that if you set your castor to 5-6* you will like the handling better and it will be better for the running gear.
M
Mac
Guest
I remember when I had my alignment done the castor was around 2.5*. How could my castor be at 9*. I'm not experienced in this so someone set me straight. I could take it back to the alignment shop and have them tell me castor but I'm pretty positive it was 2.5*. Am I doing something wrong when I measure pinion angle. I put the angle finder on top the flat part of the pumpkin. I've heard to put it on the knuckle or on the flat part on the alxe tube next to the pumpkin? It drives fine on the road. Not a daily driver but I put about 9k on year on it just driving weekends and to offroad events. Thanks
MaXJohnson
NAXJA Forum User
- Location
- The Kansas Rockies
The mis-information is starting to pile up here.
There is a fixed relationship between your castor and pinion angle so changing one will change the other a similar amount. In any case, as Eagle mentioned, it should not have a noticable affect on tire wear. If your figure of 2 1/2° of castor is correct, your pinion angle would be around 6 1/2° to 7° on an older XJ(high pinion axle); a few degrees more than that on a late model XJ (low pinion axle). The most convienient place to measue pinion angle is off the cast in circles on either side of the front differential cover. The most accurate would be to remove the driveshaft and measure off the machined face of the front pinion yoke. Remember, if you use the first method, compare your reading to 90° or vertical.
A pinion angle of 6 1/2° is a good target whether at stock height or lifted. 1/2° to 1° of operating angle is a good setting for the front u-joint. Operating angle is the difference in the pinion angle vs the drive shaft angle. 3° deg as mentioned by Gojeep is generally considered the maximum permissible operating angle, not the optimum. 1 1/2° to 1° is just enough to keep the bearing needles moving for proper lubrication. Not having leaf springs on the front eliminates axle wrap as a factor. Even the small amount of movement allowed by rubber bushing compliance in the front suspension won't matter as the front axle typically isn't under power most of the time unless you are in the habit of driving in full-time 4 wheel drive.
The degree to which you can achieve these angles depends on the amount of lift you're running and whether you have the high or low pinion axle housing. Most of us have to find a compromise.
There is a fixed relationship between your castor and pinion angle so changing one will change the other a similar amount. In any case, as Eagle mentioned, it should not have a noticable affect on tire wear. If your figure of 2 1/2° of castor is correct, your pinion angle would be around 6 1/2° to 7° on an older XJ(high pinion axle); a few degrees more than that on a late model XJ (low pinion axle). The most convienient place to measue pinion angle is off the cast in circles on either side of the front differential cover. The most accurate would be to remove the driveshaft and measure off the machined face of the front pinion yoke. Remember, if you use the first method, compare your reading to 90° or vertical.
A pinion angle of 6 1/2° is a good target whether at stock height or lifted. 1/2° to 1° of operating angle is a good setting for the front u-joint. Operating angle is the difference in the pinion angle vs the drive shaft angle. 3° deg as mentioned by Gojeep is generally considered the maximum permissible operating angle, not the optimum. 1 1/2° to 1° is just enough to keep the bearing needles moving for proper lubrication. Not having leaf springs on the front eliminates axle wrap as a factor. Even the small amount of movement allowed by rubber bushing compliance in the front suspension won't matter as the front axle typically isn't under power most of the time unless you are in the habit of driving in full-time 4 wheel drive.
The degree to which you can achieve these angles depends on the amount of lift you're running and whether you have the high or low pinion axle housing. Most of us have to find a compromise.
Roanoke XJ
NAXJA Forum User
- Location
- Roanoke, VA
So what is the most accurate way to measure caster (minus a machine). I pulled my Jeep into the garage, which I assume is almost nearly flat (new house). I place the ange finder on the bottom of the spindles and adjusted them between 2* and 3*. Just to clarify.
I measured on the Cast circles beside the diff cover. It measured 10*. When place the angel finder on the flat part under the spindle, I get 3*. Now that 3*, I assume would be a negative 3*, meaning the spindle is rotated toward the rear of the Jeep 3*.
Is that the correct way to measure? Do I need to adjusted it to a positive 3*, meaning rotation of the axle until it is 3* past 90* towards the front of the vehicle??
Thanks for the help.
I measured on the Cast circles beside the diff cover. It measured 10*. When place the angel finder on the flat part under the spindle, I get 3*. Now that 3*, I assume would be a negative 3*, meaning the spindle is rotated toward the rear of the Jeep 3*.
Is that the correct way to measure? Do I need to adjusted it to a positive 3*, meaning rotation of the axle until it is 3* past 90* towards the front of the vehicle??
Thanks for the help.
