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CV Axle Seperation

When I've swapped half-shafts in the past, it was always a with a lot of jimmying back and forth at the differential to get things in. Always! When I put the new differential in I had the axles in place and attached them to the diff just before raising it to final position. When the differential was swapped (previous thread) it was done by a shop so I didn't notice if there were any changes to spacing etc. When the first half shaft failed on the bump, it was quite the surprise and a relief when the swap went in so easily later that night. It was cold and I was not in the mood to fight this thing. Anyway, I failed to realize/consider/comprehend there might be spacing issues with the new differential which made the swap so easy. Well, on closer inspection today I discover that there is an issue.

Bad News: I have at least a .4" separation between the differential and inner CV hub. With the bolts inserted just enough to bite and hold, the calipers indicate .39" and I know there is a bit more. This is with the tire's / steering pointed straight ahead.
Good News: Anticipating just such an emergency, I have a spacer kit consisting of four 1/4" spacers and bolts, from Tuff Country.
Bad News: For the same reason I couldn't use the 2500 series CV Half Shafts Big-T gave me for cores/home gym, I can't use the spacers because they are for a 2500-3500 series truck and, therefore, the wrong diameter. Of course it says so right on the @#$%^&* box. "You [messed] up. You trusted us!"
Good News: The store that sold them is open on Saturday.
Bad News: (last one I promise) The correct spacer kits aren't in stock but will be in Tuesday.

At least I'm stuck in the office doing coordination work and any travel this week is will be in civilized areas.

So, I'll leave the truck on jack stands after I swap the passenger side (it's creaking in reverse) and wait it out till Tuesday.
 
Wonder if this was also some of the added "rolling resistance" Bill pointed out long ago. Hopefully 2 birds 1 stone, Idk just hoping.
 
Yes and no to the rolling resistance. Had that pretty much sorted out with the new parts and differential.
However, The right side CV is actually at a greater angle than the left one that's in need of the spacer. Trying to spin the axle while removing the inner hub bolts was met with resistance from the half shaft at the differential. Once removed, the differential spun free so, yeah, there's still some work to do there.
Probably need to get the truck level/even right side to left. Thought I'd done that but apparently the efforts came up short. Then get it re-aligned yet again as adjusting torsion bars messes things up...a bit.
Maybe when I come through Vegas again we can do another GTG at the Alignment shop in Henderson and let them sweat it out while we get something to eat.
 
"The right side CV is actually at a greater angle than the left one that's in need of the spacer."

Man your truck is skull $&@@ed
 
Now my feelings are hurt...
Actually, it's more of a case of having turned down the lift (adjusting the torsion keys) incorrectly. The truck appears to be higher on the right side although I have measured the ground to cross member clearances at the front and 'I thought I had it right." Apparently not but that's why they make wrenches and stuff right?
 
Paveltolz said:
Now my feelings are hurt...
Actually, it's more of a case of having turned down the lift (adjusting the torsion keys) incorrectly. The truck appears to be higher on the right side although I have measured the ground to cross member clearances at the front and 'I thought I had it right." Apparently not but that's why they make wrenches and stuff right?
Click to expand...

I'm sorry to have hurt your feelings. It just seems very strange to have one CV axle at a different angle than another.

Do you have a torsion key compression tool? I have one from when I did the bushings on Colby's front end. That said, when we were done, we took it in to the best alignment guy in Fullerton, told him the work we had done and specifically noted that the torsion keys/height needed to be checked and set.
 
The more I look at this set up and consider a few oddities etc. I'm fairly convinced I still have an issue with the Front Differential which is probably compounded by the torsion keys incorrectly adjusted. Either that or I've got a slight fitment issue with the differential being too far to the passenger side.

That creaking I hear while turning in reverse is more of a rattle and having changed the passenger side out yesterday I'm pretty sure its caused by the half shaft's inner bearing set "walking" against the differential. The old half-shaft came out with the grease cap pushed out. The new one pushed out the grease cap while installing it.

Coupled with the need for a spacer on the driver's side when one hasn't been needed in six years...more to follow I guess.
 
Pretty odd problem you seem to have there Paul.
Have a look at were the frame meets the cross member that hangs the diff.
I seen a couple trucks at the wrecker that had them badly cracked from the top down
 
Yeah something is up and idk if I would spend more $ on an alignment stuff yet. Unless Pete at the shop will do it for free, which wouldn't surprise me he's got a great reputation among shop owners and mechanics for honesty and fairness. Still why adjust it now if there is something else out. Did he say anything about frame alignment or axle displacement? Am I understanding right that your saying spacer on 1 side only-wtf? That's way wrong.
 
Thanks Bison, Over the years, this truck has had too many anomalies to account for. It's not a matter of being unique anymore. Definitely ODD which, anymore, is 'normal' for this truck.

There was previous owner damage to the front end discovered long after purchase. As it was a construction truck, I'm guessing they had whacked a stump or curb pretty hard to cause it to not take an alignment until after a shop recognized the right side was damaged.

Will L. said:
Yeah something is up and idk if I would spend more $ on an alignment stuff yet.
Click to expand...
I'm thinking a trip to a frame shop is in order. It took a couple of years to identify that the reason it wouldn't take a computer alignment was because there was actually some front end frame damage (previous owner I swear) that an alignment shop pulled out. Apparently, not enough or correctly. Pete did say the right side was now at the limit of adjustment but he got it to run straight. Yet another clue discovered in hind sight.

Still, Like I've said, this current issue has never presented itself until now and so, to me, the new front differential is suspect but I'm still taking it to a frame shop just the same. I know there are tolerances in the design and build of these things and yet a quarter of an inch suddenly making itself an issue is just ODD.

Will L. said:
Am I understanding right that your saying spacer on 1 side only-wtf? That's way wrong.
Click to expand...

You're understanding things correctly. Driver's side has more than enough room for a 1/4" spacer. Passenger side is fine if not a little too tight allowing for the shaft end to make contact with the differential axle hub (hope that term is correct) and is making rotating the assembly by hand quite difficult.

Thanks all for putting up with this new lesson in 6.5 addiction/learning. I'm not intuitive so new stuff doesn't present cause, effect and solutions in one easy step.
 
Definatly odd. You need some good messurments to compair to a know "normal" truck or a manual. Seems like someone posted years ago a coach builders manual. It had every messurement on the frames.
 
Paveltolz said:
Thanks Bison, Over the years, this truck has had too many anomalies to account for. It's not a matter of being unique anymore. Definitely ODD which, anymore, is 'normal' for this truck.

There was previous owner damage to the front end discovered long after purchase. As it was a construction truck, I'm guessing they had whacked a stump or curb pretty hard to cause it to not take an alignment until after a shop recognized the right side was damaged.


I'm thinking a trip to a frame shop is in order. It took a couple of years to identify that the reason it wouldn't take a computer alignment was because there was actually some front end frame damage (previous owner I swear) that an alignment shop pulled out. Apparently, not enough or correctly. Pete did say the right side was now at the limit of adjustment but he got it to run straight. Yet another clue discovered in hind sight.

Still, Like I've said, this current issue has never presented itself until now and so, to me, the new front differential is suspect but I'm still taking it to a frame shop just the same. I know there are tolerances in the design and build of these things and yet a quarter of an inch suddenly making itself an issue is just ODD.



You're understanding things correctly. Driver's side has more than enough room for a 1/4" spacer. Passenger side is fine if not a little too tight allowing for the shaft end to make contact with the differential axle hub (hope that term is correct) and is making rotating the assembly by hand quite difficult.

Thanks all for putting up with this new lesson in 6.5 addiction/learning. I'm not intuitive so new stuff doesn't present cause, effect and solutions in one easy step.
Click to expand...
I think would cut 3/8" off the splined end of half shaft.
 
I was under the truck making observations. No cracks observed so that's good news.
Differential: The holes holding the differential to the passenger side frame mounts are ovals allowing for an estimated 3/4" play. The bolts are resting against the inside meaning if it could shift to the drivers side some, it would help alleviate some of the gap on the driver's side and compression on the passenger's side half shafts. There isn't a means of moving the whole unit though as there are no provisions for it on the driver's side. I got in there with a pry bar and ratchet straps to give it a little assist. Got a little movement out of it and the passenger wheel spins without having to be hand cranked over. I'm betting some of the 50 or so miles of bone rattling washboard I drove over caused some of this and the effects of that speed bump put the icing on the cake. Great! So, once I get the spacer set (tomorrow) I'll be able to drive it to a shop and have it gone over and, hopefully, repaired. I'd rather get that differential centered but according to the PDF file, it is already. Weird.
 
I wonder if these rubber differential mounts on the dr side have the steel bolt bushing out of center as a means of rotating the rubbers to facilitate centering the differential to the frame.
It is common to have slotted holes on lots of places to allow for shifting of a component for best fit.
You mentioned front end damage on this truck,..maybe the dr side differential frame brackets got bend over a bit to the pass side shifting the whole thing to the right
 
I think your assessment of the underlying cause as the previous damage to the front end is spot on. That and the fact that while the initial fix was to sort out the alignment, it wasn't sufficient. At the time it was 'good enough' but now that is proving to be problematic. It wasn't good enough and it was strong enough, apparently, and wear and tear since has begun to manifest itself. Hopefully the frame shop will find damage that can be repaired. That's a strange thing isn't it...hoping they find damage. Such is the nature of 6.5 addiction.
Thanks Bison, appreciate your observations.
 
Paul, I observed the same when I was removing the Lower Control Arms on Colby's to replace bushings. Passenger side mount holes were oval slots, driver's side round. I had undone everything trying to shift the differential so that I could get something between the frame and the CV mounting plates on the differential. It ended up there being minimal to no movement available and I had to go a different route.

Still can't believe I did that job and the way I ended up doing it, but the end results were good.
 
Don't remember if you said, but did you lower the diff? There are kits that will lower it. Not sure if it will help, but it seems like it would.
 
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