Project Marina, Front Suspension Rebuild – Part 1

In typical old car fashion, what was meant to be a simple and easy job kinda spiralled out of control.

I had a plan. It was a good plan. Replace the bushes in the front end of the Marina, because they were all perished. I also wanted to replace the top ball joints and clean out the trunnions and grease them.

I knew the top shock eye bushes weren’t in good shape. I had noticed them a while ago and knew I had to replace them as they wouldn’t pass a WOF inspection like this

These are fairly important as they are joining the top of the upright to the shock (which doubles as the top arm). If these are worn or perished it can cause play in the top of the upright, which is no good at all.

The next bush that needed to be done is the eye bolt bush. These were also visibly perished. Apparently upgrading these to poly bushes makes for a good upgrade to handling. This bush is what locates the inboard end of the lower arm.

The final bushes are the pair on each of the tie bars. On most cars upgrading these is also a good idea since these bushes control forward and aft movement of the lower arm when accelerating or braking.

That’s it for bushes in the front suspension. It’s a very simple setup, but does mean that the bushes that are there are all crucial to suspension operation.

The plan was to replace the tie rod and eye bushes with polyurethane bushes and replace the shock eye bushes with an uprated kit that replaces the bushes completely with a steel insert.

Disassembly although messy, was quite straightforward. I started by splitting the tie rod end balljoint with one of the splitters in my kit.

It’s a shame that I have to disconnect the brake hose from the caliper to remove the caliper (as the hose is mounted to the upright), but it’s the only way to remove the hub and disk.

I then undid the eye bolt nut and removed the tie rod and front of the lower arm

To remove the upright you need to split it from the shock. This is done by undoing and removing the pad on the top of the assembly. This is screwed to the top of the balljoint that goes through the hole in the shock arm (and through those ugly perished bushes). I couldn’t undo this on the car, so ended up removing the balljoint from the upright and leaving the balljoint in the shock. You do need to keep upwards pressure with a jack on the assembly during this, otherwise the torsion bar will keep trying to pull everything down and makes it harder/potentially dangerous when it gives way.

And that’s the upright removed, in all its filthy glory.

Of note here is the fact that despite my car being a 73, it has the much more substantial upright, spindle and trunnion as used on the later six-cylinder Marina. Everything here other than the top ball joint is completely different to the UK cars.

This is where it all started to go pear-shaped. The trunnion wasn’t looking too hot, covered in grease and dirt. It did spin freely on the upright, which was promising. The pin was stiff and seized though.

Removing the trunnion showed that although the grease was filthy and old, the thread on the upright was in good condition.

The threads had some wear on the upper threads as to be expected, but were tight with no play. You can see the wear as the peaks of the thread on the LH side are squared off a bit.

The problem was the trunnion. The cap on the bottom had been blown out and was missing. This was letting grease out, and dirt/water in.

I also managed to extract the pin and wasn’t happy with what I saw.

The bushing in the trunnion wasn’t looking great either

I tried cleaning the pin up, but it was a lost cause

All that was left was to move on and remove the shock

I jammed the locknut in the vice and used a hammer and spanner to knock the pad free

These are the bits removed from the shock. Lots of grease and perished rubber. The top pad is retained, but everything else is scrap now.

I planned to flush the oil in the shock and replace it with a mono grade 30W engine oil, which should stiffen it up slightly (but anything is usually better than the old oil in them).

The top cover is held on with a series of screws, and once removed gives access to the main chamber of the shock. Annoyingly I suspect someone had been here before, as the oil was full and although a lot of sludge had settled on the bottom, the oil was clean.

To flush and bleed these units you need to pump the lever arm up and down a few times. I couldn’t do that. The arm was so stiff even with no valve or oil in the shock that it was almost impossible to move by hand. I ended up putting the whole shock in the vice and swinging off the arm to get it to move, and when it did, it was anything but smooth. It felt like needle bearings had pitted their race and you thumped over them, it was very jerky.

I closed it up and left it.

The final thing I wanted to do for the day was to remove the eye bolt holder so I could press the bush out. There is one nut to remove on top of the chassis rail in the engine bay, and then you should be able to knock the eye bolt holder through. It is held in with a tapered spline so it doesn’t turn.

I suspect that tapered spline was my undoing. I couldn’t get the thing to pop, no matter how hard I hit it or what fluids I soaked it in. I tried for a couple of days and then gave up.

So in total, I had one trunnion that was trash, a shock that was stuffed, and an eye bolt I couldn’t remove to press the bush out. Not winning.