Having searched for as much information as I could on AWD failure I concluded that the sleeve that mates the transmission output to the angle gear input shaft was probably worn, not surprising on a 120,000 mile AWD Volvo. VIDA dice unit couldn’t find any faults with the AOC so I want ahead an ordered a service kit (31256246) which hit my wallet to the tune of £122. This comprises of an improved sleeve with nitrate coating, two seals (9143911 and 9143885), o-ring (didn't use), lithium based grease for splines (1161748), and five replacement bolts for the angle gear.
Other supplies I bought were 2 ltrs of gearbox oil – API CL-4 75W-90 (M66 transmission) and 1 ltr of transmission/angle gear oil – 1161648.
You will need fresh gearbox oil because as you pull the driveshaft it will start to leak out. Plus, with all the activity surrounding the sleeve replacement metal fragments (angle grinding) and debris will enter the gearbox.
Before I begin explaining the task in hand I would like to thank members on this forum and others online who have completed and documented this DIY – without it the main dealer would have had my business.
Now for the fun part: let’s get the collar off.
Pull R/H driveshaft:
Up on home made ramps; loosen R/H wheel nuts and axle bolt.
Jack up suspension, remove wheel and axle bolt.
Move brake caliper and suspend out of way. Remove brake disk.
Remove track rod end from hub carrier, remove the two strut-to-hub carrier bolts. This allows rotation of the hub carrier so the driveshaft will pull free of the hub. Be careful do not allow axle to flop around as this could cause damage to the outer CV joint.
From under car, undo two bolts and remove the driveshaft support cap.
An extra pair of hands is helpful now as the driveshaft is pulled from the transmission. The CV joints will need to be prevented from flopping around.
Get ready to lie under the car for hours.
Remove angle gear:
Remove downpipe to gain better access to prop shaft. No need to remove full exhaust.
Remove the head shielding above the downpipe-to-catback flange. When you do this you allow the prop shaft centre support to move freely – important for the next job.
Remove the six bolts from the angle gear output/end cap on prop shaft. Pull free and rest on anti roll bar.
Remove five angle gear/ transmission housing bolts. Start from the awkward top bolt which is out of sight.
Pull angle gear off transmission – it doesn’t require much force – and remove. It weights about 12kgs
Not disappointed, this is what I expected to find - the collar gear splines that mate to angle gear input shaft were completely worn. The splines on the angle gear input shaft were in good condition - replacement angle gear not required thankfully.
This is the point were the job got difficult. The sleeve is bonded to the transmission with epoxy from the factory – pretty much designed in mind with it staying put. Angle grinder deployed and rough holes cut to allow the three legged puller to grab. Used a socket placed inside the sleeve for the puller to brace against.
Remove the two seals – replacements are in service kit – they only get in the way.
I drained the gearbox oil before removing the large of the seals (9143911).
After pulling, hammering and levering on the sleeve for 5 hours resulted in zero movement.
Started afresh the next morning with a few weapons at my disposal: heat (propane torch), hammer drill (from tool hire shop) and a determination to get this damm thing off. I was past the point of no return because the sleeve was that badly damaged.
Another couple of hours spent in the routine of pull, heat and hammer produced nothing.
I tried a new technique which wasn’t neighbourhood friendly (drill was so loud) but it worked to pop the sleeve off in less than 10 mins. Right, this is what I did: heated the sleeve and then attacked it with the hammer drill in short burst where the rough holes were cut. Spin the sleeve on the transmission and repeat.
There wasn’t lots of room to position the drill because it’s very long and the sleeve doesn’t stick out far. I found the best method was to lie on my side and hammer up in a manner to force it off the transmission output shaft.
Remove the remainder of the epoxy off transmission output shaft, then grease the splines supplied with the service kit. Grease the splines on the angle gear input shaft too.
Before fitting the new sleeve clean the seal seats then replace the two seals, ensure they are inserted the correct way round (embossed part numbers face out).