Friday 30 June 2023

Drive shafts and hubs

 Just a quick one this, although I did do it very gradually and over the course of a year or so.
 
Drive shaft (and engine!) refitted
As my car is from 1968, it has aluminium tri-ax housings. The size of these means that the drive shafts cannot simply be pulled out through the middle of the hubs. Instead, you first need to remove the ri-ax so that you can remove the aluminium housing. I did that back in April 2020 and you can read about it HERE.
Tri-ax removal
 A common problem you find on Ds is that people over-greese through the nipple at the hub end of the shaft. This provides grease to the double Hook joint. They are apparently "greased for life" - so why have a grease nipple at all? Well the grease nipple doesn't directly feed the bearings apparently. It just supplies a little grease that gets thrown around the joint to help lubricate it.  If you over-grease, all that happens is that you end up with grease sprayed all over the inside of the wheel rim. And wider if it's seriously over-greased.
An over-greased Hook joint.....the nipple is by the Ligarex strap
Perhaps part of the problem is that people think the whole joint - and the rubber gaiter - needs to be filled with grease. It doesn't. The space is there within the joint to allow it to flex, and the gaiter is really just a dust and grit shield. My wheel rims were coated, so I knew I needed to remove excess grease from my joints. I laid each shaft out on a sacrificial plastic sheet and then used compressed air to loosen and force out any excess grease. I used a spatula to scoop out gloops of grease. I removed most of what I could but left a little there. Hopefully there is so little that it won't spray everywhere once the car is on the road.
 
While I'm on this themes, I don't know why, but Citroen seem to be very stingey with their grease nipples. The hubs and shafts have one grease nipple each, and then plugs (looking like slotted screws) where the other nipples fit.
A plug and a grease nipple
They are proper 'things' and are in the parts catalogues, though not shown as being fitted to the shafts - just the steering relay arms - part 18 below.
Plug screw instead of a grease nipple: part 18
I also found that for each pair of ball joints on the hubs, there was one grease nipple and one screw.... The idea is that (when you want to grease the car) you remove the plug, borrow a nipple from wherever it's fitted, grease, and then put the plug (and nipple) back...... I couldn't be doing with all that, and decided to remove the plugs and fit extra grease nipples. I'm sure you can pick them up anywhere but, (being a bit anal!) I bought some original Citroen grease nipples. They were 2 Euros for eight of them - so hardly expensive.
Who says 'new-old-stock' parts have to be expensive?
More recently, I cleaned up and painted the hubs and  drive shafts.
 
A job I'd not been looking forward to
The hubs were carefully cleaned up and de-greased. I masked off the ball joints and the centre, rotating part of the hub and just prepared to paint the outer cast steel part of the hubs. 
Degreasing everything took ages.....
I was pleased with the results.
Painting the drive shafts and associated parts
I refitted the rubber dust covers over the balljoints of the hub - packing them with grease. You are advised not to put too much grease in, but I think at least two of mine look to 'plump. Removing any excess grease is simply a case of removing the retailning clip and squeezing a little of the grease out from the dust cover. I was re-using the original dust covers. I'd been careful not to tear them when removing the ball joints but could see small holes in them. I fixed these with Superglue. partly because I didn't have any alternative ones to fit and partly because I wanted to keep using the original ones for aslong as I could. I don't trust modern reproduction rubber, and here is why:
 
 I'd bought some new triax gaiters several years ago as part of an order from a foreign supplier. The supplier sold cheaper versions of lesser quality - but they also sold more expensive ones that were supposedly 'best quality'. That's what I paid for. Now I came to fit them I found that the two gaiters for the tri-ax ends were completely different. There are no makers marks that I could see and the moulding seem to be the same, however one was flexible, dull in colour and rubbery. The other was stiffer - more like plastic - and shiny
Chalk......and cheese
I concluded that whether by mistake or through laziness, I'd been supplied with one cheap and one expensive - but which was which!  I decided to keep the ones I'd bought as spares and start again: I bought new gaiters from Citroen Classics. I think Darrinn said they are made of neoprene and are hard wearling.

I slipped the gaiters, hub and tri-ax housing over the drive shaft and prepared to rfit the tri-ax. I had previously marked up the tri-ax so I knew which shaft it matched to. And (for what it's worth) I'd even marked the shaft so that I could align the triax back to the same splines as before. I've since been told that the tri-ax can simply be hammered back over the end of the shaft using a suuitable drfit and brute strength. Possibly so, but I had found mine hard to remove and expected them to be a tight fit going back on. The advice I had been given, was to heat them slightly to cause them to expand a little.
 
With the shaft, gaiters and housing standing vertical on my bench, I suspended the tri-ax above it. The tri-ax parts seems to have a different profile on each side and I wasn't sure whether this would aid or hamper the fitting of the circlips that secure them. Studying old photos from when i removed them, I suspended the tri-ax the same way round - just so I could be confident the circlic would go back on.
Getting ready to heat the tri-ax
I applied a little heat just to the main body of the tri-ax and, when I thought I'd applied enough heat, quickly lowered it onto the shaft. I'd already found a suitable socket to use as a drift and it only took a gentle tap with a hammer for the tri-ax to be fitted home on the shaft.
'Landing' the tri-ax on the shaft
You know it's fitted when you can clearly see the groove where the circlip will need to fit.
 
Retaining circlip fitted under the splines
I was surprised at how much heat was then transfered into the shaft and it was a while before I could refit the securing circlips. One cool, it was time to fit the rollers and secure the gaiters. The alloy tri-ax housings have three steel sleeves for the rollers. A common problem is that, as the joints wear, the sleeves develop a bit of a groove and the joints become stiff and/ or noisy.  Several of my sleeves were starting to show wear. 
 
Tri-ax sleeve - with signs of wear
A quick and easy solution is to swap the sleeves fromthe hosuing on one side of the car, to the housing on the other side of the car. A bit like swapping carr tyres over to even up the wear, swapping the sleeves in this way means that the rollers in the joints are no longer contacting the part of the sleeve that was showing signs of wear.
 
I had been told not to muddle up the balls, tri-ax ends and sleeves, but now that I had swapped the sleeves around, I judged that all bets were off and just re-assembed things. I was (am!) relying on new grease helping to slow future wear. 

The joints have to be generously greased. Each of the aluminium housings needs 200g of CV joint gease. With the shaft/ hub assembly still standing upright on the bench, I smeared some grease around the backs of the sleeves and fitted them in the housing. I then put about 100g of grease in the receeses where the rollers would fit. I put more grease on the roller shafts and fitted the rollers. With the housing pulled over the rollers, I redistributed the displaced grease and used up the remainder of the alloted 200g. I fitted new paper gaskets before capping off the housings. With the housings fitted to the shafts, I fitted Ligarex banding to secure the gaiters.
New gaiters fitted.
All ready to fit back on the car now - giving me, once again, a rolling chassis. I will need that if I'm going to get the engine back in this summer.
 

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