Our rally XR4Ti has pretty standard, bolt-on, 6-balls-per-joint CV Axles in the back, like this:
I have 4 pairs of them. Not all have seen rally use, but every last one- including a pair recently rebuilt by me (which looked fine when disassembled), a pair of remanufactured ones with one rally on them, a pair of ancient used ones with several rallies on them, and a pair of rusty ones that have been out of service for over a decade- have some rotational play. I'd say a few degrees. How concerned should I be about this? Do I have 8 bad CV axles or is a few degrees of slop expected? The rule of thumb I've always heard is that any play like this is bad, but I have a whole lot of them which move this way but haven't failed... yet.
I've been down this road with GM FWD axles. Every one I've ever had my hands on had some (more than I'd like) rotational play. I've only ever checked used or reman'd parts though, new OEM was outside my "buy one and see" price range.
Honestly, I've used any that didn't have torn boots and didn't have any radial play. I've only had one axle break on me and that was an OEM with ~80k on it, broke it making a hard left (120+ degrees) from a stop sign, inside axle + light throttle = POP!
I've also towed 3500+# behind a 4000# car that had 150k+ miles on reman'd axles and never broke one despite MANY full throttle pulls with 300 ft-lbs on tap.
All of my experience is with DDs though, certainly rally axles are subjected to much more impact/shock loading.
Is the play in the ball tracks, or is it in the inner spline? I have seen the inner track split from spline play, or at least I think that was the failure origin. It was a DNF. A little play is better than a tight joint that introduces extra oscillating loads on the diff and wheel bearings. One of the suppliers of lightened joints for formula cars failed to re-hone the outers after the lathe, and they got real tight from stress relief contraction. We saw many failures.....When you rebuild your own, put the micrometer on your new balls, I just bought a set that were almost a whole thou oversize when the supplier speced +/- .0002.
In reply to TurnerX19 :
The play is in the track/cage, the splines on all of them are tight as far as I can tell.
In reply to ¯\_(ツ)_/¯ :
Oversize balls are an available thing, which you need anyhow to drive stage rally! Seriously +.001 and +.002 are listed for many sizes. A big surprise to me when I did my X1/9 last month was that the balls were .500", yes inch.
Do you mean you can buy bigger balls?
I actually happen to have a pair of brand new, never used, OEM subaru axles out in the garage. I can check them to give you some kind of reference. I'm expecting zero play in them though.
jimbbski said:
Do you mean you can buy bigger balls?
got a link? I need some of those for rally. I'm too slow.
