front pinon angle

[gremlin boys]

ok guys dont shoot me but i have a Question i lifted my 85 chevy 3/4 ton she has 8 lugs, 4 inches, springs up front, blocks in the back, well the blocks came with a angle that made the drive shaft on the rear line up properly so no problem there, well what about the front i need to correct the front pinon angle so the front shaft lines up properly, do they make a small angled block to correct this?, oh does anyone have a longer front shaft ? i could buy? thanks Don

[rollen dean montoya]

you might try checking at a local off-road specialty shop to see what will be needed if you do need to correct the pinion angles. my guess is you might need to so you have less chances of binding at the pinion shaft to
driveshaft connection(the u-joint).
later, rollen

[tufcj]

DON'T change the front. Rotating the pinion up will also decrease the caster angle. The less the caster, the more likely the vehicle is to wander all over the street. Actually the correct angle is parallel to the output shaft of the t-case. Rotating the rear axle up is a band-aid fix for the rear shaft being too short. The only way to rotate the pinion up and keep correct caster is to grind the knuckles loose, rotate the axle and re-weld the knuckles. A lot of work.

For the smoothest operation, both u-joints should rotate in the same plane. That's why the t-case output shaft and the pinion should be parallel. The further away from parallel they are, the greater the chance for vibration. I won't go into a physics lesson here, but a U-joint doesn't spin at a constant speed, it goes thru an accel/decel cycle. When the u-joint at both ends of the shaft are parallel, they cycle at the same time and rate, and are smooth, change the angle of one end, and the cycle is thrown out of wack and vibrations occur. This is of course with standard u-joints on both ends, CV driveshafts are different.

If yours is part time, with lockout hubs, the front doesn't turn most of the time, and probably only gets used at slower speeds, like 'wheeling or bad weather, so it shouldn't be too big of an issue. If it's full time, maybe think about a part time kit.

Bob
tufcj

[gremlin boys]

thanks i drive this truck every day two to three hundred miles a week, it has lockouts and i have had it wheeling a few times last year but it needed a lift kit , this is the first lift i have done myself ,
i just wasnt sure about the front shaft.Don

[rollen dean montoya]

glad tufcj helped ya out. i was taking a guess only cause i have seen a few 4x4s lifted and have had their angles readjusted cause of the
insane lift that they had done.examples i have seen are a 86 toyota truck
88 chevy suburban and get this a 72 lincoln mark4 sitting on an f-350
4x4 frame.