Gs750 1978 front end juddering

To remove a 2008 Softail rear wheel FIRST block motorcycle underneath the frame so that theweight of the motorcycle is off of the rear wheel, remove saddlebags if equipped, remove the belt guard and the debris deflector from the rear fork, inspect the wheel bearing end play and service the bearings if and as necessary, label the wheel spacers for left or right locationand orientation i.e. fork side or wheel side, remove the rear brake caliper from the caliper mount and support it using an elastic cord or such,For the FXCW/C modelsthe nut retainer will remain in the axle nut and does not need to be removed and if it is removed it must be replaced. For all but FXCW/C remove e-clip, remove the rear axle nut, and for FXCW/C remove the rear axle nut, loosen both axle adjuster screws an equal number of turns to remove tension from drive belt, with a suitable drift or other tool tap the axle towards the right side and remove it, remove the spacers and the caliper mounting bracket, move the wheel forward and slip the belt off of the sprocket, raise the motorcycle to allow enough clearance for removal of the rear wheel and pull the wheel with the belt sprocket from the rear fork.

To install a 2008 Softail rear wheel FIRST apply a light coat of wheel bearing grease to the axle, to the bearing bores and to the bore of the inner sleeve, roll the wheel into place in the rear fork and slide the drive belt over the drive sprocket, position the left bearing spacer between the wheel and the fork, from the right side carefully insert the axle (with its washer for FXCW/C models) through the right rear fork, the short spacer, the rear caliper mounting bracket, the long spacer and into the bearing bore, continue sliding the axle through the wheel hub sleeve, the left side spacer and the left rear of the fork, install the washer, the axle nut, and the retainer, verify correct axle alignment and the check belt deflection, check the wheel bearing end play after tightening the axle nut to the specified torque because excessive end play can adversely affect stability and handling and insufficient end play can cause bearing seizure, tighten the axle nut to 95-105 ft-lbs (128.8-142.5 Nm), install the belt guard and the debris deflector, install the brake caliper and pads, install the saddlebags, if equipped, pump the brake pedal to move the pistons out until they contact both brake pads, verify the piston location against pads, verify the position of the brake pads against the brake disc, rotate the wheel to check for any interference(s) or misalignment(s) and test the brakes for proper operation.

clean the fuel system , carbs etc ! check your wheel bearings , headstock bearings and clamps are tight , tyre walls are ok and tyre pressure ok , i once used a metzler me33 and it was all over the place , bin'd it even though it was new as it nearly killed me ! put a bridgestone on and was perfect ! check your fork oil is good and correct level etc , fork springs are ok and same length and air pressure even ! frame clamps tight , no cracks etc !

check wheel bearings for failure. jack up front end till the wheels are clear from the ground try to move the wheel top and bottom and see if you can move the wheel in or out. excessive movement is bearings. check brake rotors (discs) for abnormal wear (no pads and surface of rotor missing

Are your bearings all fresh in your steering stem and front and rear wheels

Proper proceedure would include a 17 or 19mm allen socket for the end of the axle, but normally you can get the axle nut loose by leaving the 2 pinch bolts tight in that end of the axle. So, in order-
1-remove axle nut. 2-remove 2 bolts holding the brake caliper to the fork and tie it back out of the way.3 loosen the pinch bolts at the bottom of both fork tubes, this will allow the axle to slide out. There will be a spacer on the rotor side of the wheel for the bearing, remember this when you reinstall.
Installation-1-clean and lightly grease the axle and inside the bearing seals. 2-install spacer on rotor side of the wheel. 3-reinstall wheel onto the forks,tighten axle nut,leave the pinch bolts loose. 4-with the pinch bolts loose, compress the forks down-this insures that they are parallel to each other. If they forks aren't parallel, they will wear the bushings and fork seals prematurely. 5-tighten the pinch bolts to about 15NM. 6-torque axle nut to 40NM. 7-reinstall caliper.

Did you have the bearings checked? Was the tire balanced on the motorcycle?

Need to check the entire front end. Start at the Neck stem Bearings then fork straightness- Fork oil level- Axel straightness- wheel straightness-wheel balance.
Good luck.

Jack up the front end until the wheel is off the ground, then slowly rotate the bars from one stop to the other. If you hear noises or it feels rough, take the forks and wheel off, disassemble the fork head and inspect the upper and lower bearings and races for damaged surfaces. Clean and repack bearings with fresh grease. Reassemble the fork head and adjust the bearings to just remove slop. Recheck the rotation. When putting the forks and wheel back, check the shock action of each fork individually. If the machine has a lot of miles, drain the fork oil and recharge. Make sure that the axle is clamped tight as well as the fork head clamp and top bolts. Has the bike ever been hit hard in the front? If yes, it could have changed the fork angle making it unstable.

HAY YOU HAVE TO FOLLOW CERTIN GUDLINE TO TIGHT FRONT END BUT THE WOBBLE WAS NOT THER BE FOR CHECK THE TIRE EVEN LOOK OK YOU NEED TO CHECK BALANCING AND WHEEL BEARINGS YOU MAKE FRONT END ANY TIGHTER YOU CUOLD MAKE WORS HOPE THIS HELPS

remove front wheel
undo allen screw or bolt securing headstem to fork
remove headstem and handlebars
undo lock nut & ring retaining bearings, at top of fork tube, do not lose bearings which may be loose.
withdraw fork from fork tube, do not lose upper bearing race
remove lower bearing from old fork
install lower bearing on new fork (I prefer replacing bearings)
remove brake caliper from old fork install on new fork
insert fork in fork tube
install upper bearing (I prefer replacing bearings)
install retaining ring and lock nut on fork tube, adust untill there is no wobble, but free movement, too tight the bearings will collapse too loose the rider will fall off
tighten lock nut
install headstem
tighten headstem allen key - bolt
install front wheel