Tri-axle Removal

There can be a number of reasons why you might want, or need, to remove the drive shafts from your car. The most common of these is likely to be that you need to replace the rubber gaiters.

Torn drive shaft gaiter

Over time these become perished and cracked or split. Particularly the inner gaiters closest to the gearbox. The gaiters need to be in good condition to keep the shafts lubricated and to prevent the ingress of dirt and rain and so prevent premature wear. 

It's necessary to remove the drive shafts to replace the gaiters. Additionally, you need to separate and remove the tri-axle joint (often simply called the 'tri-ax') from the end of the shaft. The tri-axle is a type of 'tripod plunge joint'  apparently. (I had to look it up). It has is a three-legged tripod with balls/ rollers, and this sits within a housing. It is able to roll and flex and so accommodate small changes in the length of the drive shaft as the car travels over bumps. 

Principles of a tripod plunge joint
(image copyright Pearson Education Inc.)

In my case the outer gaiters look okay but one of the inner gaiters has torn on the edges of the chassis 'tusks' after I rolled the engine-less car around the yard at the farm and then, later, brought it home.The other inner gaiter is cracked and so needs replacing at some point down the line anyway..... 

It's easy to tear the gaiters on the chassis

However I plan to repaint the engine bay and rebuild the front half axles before too long, so the hubs and shafts are going to come off now.

From, I think, March 1970 onwards, the design of the assembly was such that a steel tri-axle housing was bolted to the half-shaft on the gearbox. The driveshafts  - complete with tri-axle - could be slid out from the housing, and through the donut hole in the wheel hubs, simply by undoing two ridiculously small screws from the face of the hub. The tri-axle could then be removed from the shaft to fit new gaiters.

Prior to 1970 design change, the process was a little more complicated. I think there was an earlier design prior to 1966, but from that date (and so I'm guessing the introduction of the new engines) until 1970 the tri-axle housing was made of aluminium and was part of the driveshaft assembly. The size of the aluminium housing prevented it passing through the hole in the hub. 

It's simply not happening.....

The factory instructions for removing driveshafts is covered in Operation D.372-4 in Section one of volume two of manual 814. It covers shafts with an aluminium housing, and then those with the later steel housing. 

It's all in the book

For the earlier type of shaft with aluminium housing, the factory-recommended approach is to remove the hub with drive shaft in one go, then remove the tri-axle and housing on the bench.

The factory way. Part (3) is the tri-axle, part (2) is the housing

This is necessary when the engine is in the car as there is little working room to remove the tri-axle in situ. The factory way involves a lot of weight to be man-handled. 

The Dutch 'DS Technical Team' have produced a video with English subtitles (closed captions) that shows the removal of a hub and it includes removal of a later style drive shaft. You can find that video HERE.

Gavin Lane has also posted a couple of short videos on Youtube that chart his own personal voyage of discovery. You can find the first of them HERE.

If you are planning to remove your drive shafts, check what type are fitted to your car as it is possible to retro-fit the later style of shaft and housing on an earlier car and so you may avoid needing to remove your hubs. How can you tell? Well the types of gaiters are a good clue.

Gaiter for later style joint - large end is triangular in appearance
(photo copyright Dirk Sassen)

As are the housings themselves. Earlier style housings are chunky and ribbed. See (2) in the photo above.

In my case I have the earlier aluminium housings. But in my favour my engine was out of the car, so I had the luxury of being able to perch in the engine bay area and tackle the tri-axle in situ.

This was a very messy job with lots of grease over everything. First task was to lever-off the grease cap from the end of the tri-axle.

Removing the protective cap

This was packed full of grease. There was also a lot of grease around the tripod and it was difficult to see what was there.

The tripod and balls are in there somewhere...

With the cap removed, the aluminium housing was slid back (towards the wheel hub) from the tri-axle. 

The tripod exposed

I'd already been warned to be prepared to catch at least one of the balls (thank you Adie) which would fall of it's tripod leg - but still missed it! The balls shouldn't be muddled, and I was careful to lightly mark balls and legs so that they could be married back up later.

Wiping away the grease from the end of the drive shaft revealed a circlip This needed to be removed before I could tackle the tripod itself.

Note the circlip on the end of the splined shaft

I had been warned that the tripods were extremely tight on the drive shafts and could either slowly pull off the splines of the shaft or, after no movement, could release suddenly with a 'bang'. I was also advised that the 'weapon of choice' was a hydraulic puller. 

(Relatively) cheap hydraulic puller

With the drive shaft held in a vice for stability, a three legged puller can do the job too, but needs to be quite a substantial size. 

Using a three-legged puller on a tripod
(Image copyright Gavin Lane)

The beauty of a hydraulic puller set was the range of attachments that came with it. I was able to rig up two half-collars behind the tripod that eliminated the risk of the puller jumping or slipping off. 

Use of a puller

The tri-axle is starting to move

It took a surprising amount of pressure and, sure enough, the tripod released with a 'bang'.

Tri-axle removed

With the tripod removed from the shaft, the aluminium housing (and gaiter) could be removed. The last task was to peel back the outer gaiter on itself so that the shaft slid through the hub.

I'm not doing the gaiter replacement job just now. I will save that until I'm well into the rebuild. I just need to find some more storage space now. 

Tucked away

Front Jacking Point Replacement (Part 3) - Left Hand Side

With the tips I picked up while replacing the right hand jacking point, I moved on and replaced the one on the left side. While the jacking point itself looked deceptively sturdy, the closing panel behind was clearly in a poor state. In for a penny, in for a pound.....

The rust was hidden under the underseal

The three screw holes you can see in a horizontal row in the photo above, are the mounting point for mudflap. Those mudflaps mask the jacking point areas and you don't realise how bad they can get until you look really closely....

I proceeded as I did for the right hand side. The welds were exposed......

Welds Exposed

......and I used the spot weld drill to drill them out. I only drilled an initial pilot dimple to steady the drill and took things slowly to avoid drilling too deeply and into the underlying flanges.

The jacking point on this side was very stubborn and I had to remove it in pieces to give me access to the diagonal flange.

Some bits practically fell off......

....others had to be surgically removed

Overall things worked well and there was less damage.

Less damage this time.......

The flanges tidied up quite nicely

Inside, the box sections were in very good order and a testament to the Waxoyl I applied back in the mid 1990s. Though after 20+ years it was dried, curling and cracking on the bases - so I scraped that out and will apply some more wayoyl or Dinitrol in due course.

Box sections look good inside

Disassembly went well then. Reassembly, on the other hand was far trickier than on the right hand side. The panel was a poor fit to the flanges that it needed to be welded to. In particular, there was no contact with the the two angled faces of the diagonal flange and also along the top horizontal flange at the footwell edge. Taken together, it meant that I would not be able to get adequate welds  on a significant proportion of the panel. Something that was not going to be acceptable (or safe) for a jacking point. The old panel I had removed made contact in these parts, but it was now too damaged, twisted and cut-up to reveal any of it's secrets. 

It all came off like a jigsaw

I spent quite a long time gently coaxing the replacement panel and flanges together where I could. In other areasI resorted to a hammer to encourage the panel to meet the flange.

One of many trial fits

I was more careful in removing paint only around the plug weld holes. I drill a mix of 5mm where the weld would be to a fairly flimsy flange and 6.5mm holes where the weld would be around the edge of the panel and to more substantial flanges.

Weld-thru primer over the plug weld holes

A much better fit now

My plug welding needs to improve. I was still leaving significant domed heads on the welds through my efforts to pour heat into the weld to ensure the metal fused. My penance would come later with the much-loathed grinding off of the welds......

Nearly there......

It all seems to have worked out okay in the end. I had used weld-through primer on the surfaces before I welded. As well as smelling foul when it burns, I 'm also convinced that stuff causes the MIG welder to spit more. What's that they say about a workman blaming his tools?

Grinding back the welds. I HATE that job.....

Now that it was all back together, and the welds were ground down, I thinned some zinc primer and liberally painted that on the seams and joins in the hope that it would wick into the gaps. That's just for now. I will eventually get around to sealing the seams, painting and finishing with either undersea or schutz.

A thing of beauty!