Driveshaft reassembly difficult at rear slip joint
My brother owns a 2002 4x4 2500HD crew cab short box, 8.1L/Allison with approximately 96k miles on it. One of the original U-joints went bad and while he was inspecting the driveshaft still on the truck, he noticed the carrier bearing rubber was starting to go.
He brought his truck over to my house and we removed the shaft, threw it into the back of my truck and ran it over to my father-in-law's to use his shop press. I marked ALL the pieces of the driveshaft with a paint pen before we started the tear-down to index all the pieces for reassembly. In order to remove the carrier bearing, we had to split the shaft at the rear slip joint (carrier bearing area) - it was no big deal getting it apart; the female stub shaft slipped off the splined male shaft without having to use 'the persuader'.
I pressed out all the u-joints and pressed the new ones back in. I pressed off the old carrier bearing and after some creative thought, figured out how to press the new bearing back on all the way. Up to this point, everything was going A-OK... I went to reassemble the stub shaft but no matter how I clocked it on the splined shaft, it did not want to slide back on easily. At best, the stub shaft would go on the splined shaft maybe 1/2-3/4" before it decided it didn't want to go any further. As I applied pressure to make the stub shaft slide back on (remember, I indexed all the pieces and I had the lines matched back up for reassembly), the female stub shaft splines started digging into the blue spline lube on the male splined shaft and actually removing some of the blue material.
After fiddling with it for some time and needing to get his vehicle back on the road today or else (truck is his wife's daily driver/grocery getter when it's not pulling his 5'th wheel), we ended up having to tap the stub shaft back together with the help of the persuader. I realize this is not ideal - the female stub shaft / male splined shaft interface is the primpary slip joint for the rear axle and with the amount of force required to reassemble the joint, I don't think it's slipping. Anyhow, it is apparent that during our reassembly, we collapsed the slip joint about 3/4" shorter than it was when it came out of the truck (I'm guessing at this figure as there is about 3/4" of front stub shaft sticking out of the transfer case which was in the t/c when we started as witnessed by the shiny band aft of the t/c rear seal).
If it were my truck I would pull the rear slip joint back apart and make sure I got it working the way it is intended before running it; my brother figures it is "good to go" as-is.
Any ideas why the slip joint did not reassemble easily??? This is not my first time doing this type of task but it is the first time I have had this kind of issue. Moreover, with the rear slip joint not being operational, will carrier bearing durability to be compromised (the front slip joint on the transfer case should still work but the carrier bearing will need to slide fore/aft inside the carrier bearing rubber to accomplish that). Might the slip joint come back into service on its own as the truck gets used and some torque and jounce loads get imparted to the joint?
I am certain we did not damage the male or female splines of the joint and there was no particle contamination on either. My brother did apply some light grease on the ID of the stub shaft after we tried to assemble it without but the grease didn't help so we wiped it back off before reassembling the joint.
This is one reason I hate helping other people with their stuff - now I have his vehicle woes on my mind...
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