Originally Posted by Xtreme_Ford
Thanks TruBlu351. I'll check the bolts to see if they need tightening. I'll also check the uni joint for any obvious damage. If the uni joint does need replacing, will i have to realign the driveshaft once fitting a new uni joint? I've also had several opinions on how to replace a rear uni joint properly, but all sound risky. Do you know an appropriate method to safely and effectively replace one?
The rear uni is mounted to a flange which then bolts up to the diff pinion with 4 bolts (these may be loose). If so, should be an easy fix.
You may also have the design where the rear uni fits into a saddle on the diff pinion and is held in place by 2 U-bolts this is a 9" design, not sure if some stock late model Falcons have this too).
If you have to take the driveshaft out you should see 2 alignment paint marks on the rear uni setup. One on each of the 2 flanges that hold the uni. If you can't find it, either scribe or paint your own before removal. This is done for balance purposes. Just make sure you refit the flange to the driveshaft with the same orientation when removed and not 180* out.
Removing and refitting uni's takes a little practice, but is dead easy once you get the hang of it
1. Remove driveshaft (be prepared to plug the rear of gearbox to prevent excessive oil spill). If you jack the car way up from the diff (with axle stands), this sends most of the oil forward in the box.
2. Remove the 2 bearing cap snap rings on inside of flange (they tap out with a hammer and screwdriver). Some have circlips on the ouside. Get some circlip removal pliers.
3. Balance the driveshaft flange over some open vice jaws with one of the flange uni caps pointing up. Then get a socket (slighly smaller diameter than bearing cap) and hit the top cap, this will force the bottom one out and thru the vice jaws. You may need to get some grips to pull the cap out if it doesn't fall out.
***The caps are full of small needle roller bearings and could go everywhere if not careful. The grease inside should hold them in place.
Flip the driveshaft over and tap the protruding uni joint shaft (don't damage it) back down to pop the remaining cap out the other side. You should then be able to jiggle it out!
Inspect for cracks in the caps and broken needle roller bearings. If they're OK, fully clean them. Carefully replace all the bearings inside the cap, held in place with some grease. Refill with grease once refitted to car. You may just want to fit a new one anyway..........about $30.
1. Take caps off uni spider and slide spider into flange.
2. Get 2 caps at opposite ends and push them into the cap holes (opposite from removal), they'll only hand push in a little way. Then put the whole lot between some vice jaws and slowly compress the whole lot together, until the clip grooves are visible on the inside. Hardest part is not letting the uni spider dislodge the bearings as you compress the caps together. Helps if 2 people available. Make sure the uni has a smooth free movement. Don't over compress the caps.
3. Refit clips.
4. If the clips are on the outside of cap, then gently tap the cap in with socket until groove appears.
IF the caps don't compress at the very end by about 1-2mm, then there's a needle roller thats come loose! Remove and try again. The caps are stiff to fit, but avoid the sledgehammer
If have access to a "dial gauge" you could check the runout (alignment) of the driveshaft once its all back together. The rear driveshaft max allowable runout is 0.6mm. It should be OK though?? Unless there's vibration shouldn't need to worry.