Front end clunking

[Gary Schulz]

In the process of driving the new restoration around a bit and I have been noticing a subtle clunking noise in the left front suspension. I was guessing it had something to do with the drive shaft because the splines were a bit snug on the U-joint (even though they were repeatedly cleaned and I ran the axle in and out before installing). It looks to me like the drive shaft circlip is popping in and out of position as the suspension moves. I presume the following pictures shows that the large ring is not bottomed on the inner CV race so this means the axle is not in the correct position then?

Is there any "easy" way to take care of this without breaking the ball joints? I hate to pull this all apart again!

20200614_102639.jpg

[360gts]

I suspect the issue is the circular wire clip that is on the outer end of the shaft. Maybe someone else can verify if the inner cage is different on the inside....
other words......is there a difference in which way the cage is installed with the ball bearings...if that makes sense! Something I never looked at as the CV joint always comes pre-assembled....just a thought!

Regarding pulling it apart...you might be able to disconnect the HD joint and slide the shaft back enough to see what has happened the wire clip.
Other than that...it the ball joints!
D

[Gary Schulz]

Thanks Dermott,

I believe the issue is with the outer wire circlip popping in and out of place as the suspension moves because the axle is captive in the splines on the inner UJ. I used all new parts on the inside UJ and the splines were basically "zero clearance".

[iain1967s]

The inner end of the splined driveshaft is supposed to be a sliding fit in the Hardy Spicer couplings. Maybe take a fine file and bevel the edges of the splines and/or grooves in the coupling?

[Dearg1275]

If you have “ zero clearance” on the Hardy spicer end splines they are not going to want to slide as they should. This is the end that is meant to slide freely. The forces involved are high and will take the path of least resistance. That the outer circlip has let go means this end is easier to move.

To my mind it’s a case for taking the whole drive shaft out and sorting out that tight inner sliding joint otherwise it will happen again and the shaft can come right out of the CV at the most inconvenient/dangerous moment. Replace that outer clip too it may have been weak or now be weakened.

And how many flats have you turned up on that ball joint lock tab? Again huge forces at play here.

D

[Gary Schulz]

I found the problem... The drive shaft spline that fits into the UJ coupling is machined wrong! I compared the fit of the UJ coupler with another drive shaft I had laying around and the other drive shaft allows the coupler to slide fully onto the shaft. My new shaft would jam on the coupler when at maybe 2/3 engagement. The old one would slide all the way (and beyond). The old shaft is shown on the top in this picture for comparison-

20200614_150730.jpg

Here is the maximum drive shaft engagement between the two of them-

20200614_150839.jpg

Not sure of the exact machining process used here (broaching and/or grinding) but the tool comes up and out too early so the spline near the root actually tapers to a wider dimension causing the shaft and coupler to jam together- Here is the shaft as produced by whomever makes them for MS-

20200614_154352.jpg

I fixed this by using a fine abrasive cutoff blade on my Dremel and lightly touching up the splines near the root of the drive shaft. This gives clearance and the coupler now slides fully onto the drive shaft.

20200614_155345.jpg

I don't think the exact shape matters here because all I needed to do was relieve the interference fit...

Not really very happy with these drive shafts I guess!

[Dearg1275]

Why are you replacing the drive shaft?

D

[Gary Schulz]

Why are you replacing the drive shaft?

D

Not replacing the drive shaft. Just fixing the drive shaft so it slides 100% onto the spline. The other older drive shaft was shown as a comparison.

[Dearg1275]

Why are you replacing the drive shaft?

D

Not replacing the drive shaft. Just fixing the drive shaft so it slides 100% onto the spline. The other older drive shaft was shown as a comparison.

No, why are you replacing the “older” driveshaft? Also in your photos above the out put yokes are missing their closing caps on the inner end. Perhaps you are not using these on the car.

D

[Gary Schulz]

I could use old shafts. These came complete as a set with new S CV joints many years ago and I am only just getting things put together now. This yoke had a closing cap on it however I removed it to be able to properly clean the yoke. With the cap on it has a "blind" end which makes for difficulty in cleaning thoroughly. Just about every yoke I have has had the caps removed and I can see why... Once it is confirmed to be OK then I may reinstall the cap (or maybe not)...

EDIT: I can put new caps on using this method- viewtopic.php?f=3&t=27637

[CooperTune]

There is another thread on the board about drive shafts. If your old axles are org. from your early Cooper S do they have
the small raised area as pointed out as Hardy Spicer shafts in the other thread? I once had a set of Hardy Spicer posi
output shafts which would not engage the posi. Took them to Newport Cutter Grinding and they set up and skimmed the
sides of the splines and all was well. Steve (CTR)

[Gary Schulz]

Actually the old axle shown is from a drum braked car (850) so there are no raised sections like the newer axle has. It sounds like I wound up doing something similar to what you described. I am still surprised that these are made incorrectly. The reason I didn't fix this before installing the first time was I thought they didn't engage as far as they do when installed on the car.

It is frustrating to have to completely tear apart the front end on a brand new car!

I didn't want to see the car like this for quite a while

20200615_100211.jpg

[CooperTune]

Last friday I pulled and repaced the complete left front suspension and brakes on a mini that was dropped off at my shop
due to a 1 qt. every 45 minutes oil leak while driving. I threw away the jeans and shirt I was wearing when done. Want to
trade jobs? I'd be happy to work on something that clean. Steve (CTR)