I’m returning to work this week on Scarlet’s (1959 Austin-Healey “Bugeye Sprite) front suspension and brakes. In Pt. 1 Renovating Scarlet's Front Suspension, I removed the springs, shocks, control arms, kingpin and steering rack. It’s taken a significant amount of time to disassemble, clean and paint the various components in anticipation of their rehab and rebuild.
To make some space on the workbench, I’ve decided to complete the assembly of the right-side brakes and control arm/kingpin assembly. Once complete, I can clean up my workspace and move on to the left-side components.
I previously ordered a swivel pin repair kit (264-185) from Moss Motors. The kit included new swivel pins, fulcrum pins, bushing, washers, shims etc. As soon as the kit arrived, I took inventory of the parts as there are some pretty tiny bits and pieces that would not be easy to source locally should they be missing.
Learning from others, I put the three cork washers into a plastic baggy filled with oil. Others have complained that trying to mount “dry” cork washers would result in them splitting during the mounting process.
As explained in Part 1, I encountered difficulty in removing the fulcrum retaining pin and the fulcrum pint itself. Thankfully, the repair kit included those parts. Before installing the fulcrum pin, I coated the threads with Permatex anti-seize copper grease and coated the center portion of the pin and king pin with red grease.
There’s a small lip in the inside of the control arm, where the fulcrum pin resides, that will help locate the oil-soaked cork washers. The cork seals are there to help retain grease, pumped in from the end of the fulcrum pin. There must be some long-standing engineering reason for the use of cork? I would think that a rubber/poly-type seal would provide a better seal and be longer lasting.
With the fulcrum pin inserted through the control arm and the bottom of the swivel pin I was able to insert the wedge-shaped locking pin, making sure to insert it from the top (nut and washer on the bottom).
The Restoring Sprites & Midgets book by Grahame Bristow, (page 38) provides some excellent tips on assembling the swivel pin (kingpin). Below is an excerpt from page 38:
"Assembling the Kingpin:
1. fit a new O ring into the base of the stub axle, note that it has a circular cross section, the upper seal (which fits under the trunnion) has a square cross section.
2. Locate the dust tube and spring assembly. Smear some water repellent grease onto the kingpin and then fit into the stub axle.
3. Fit the upper O ring, thrust washer, shims and top trunnion. This is best done with the assembly mounted in a vice. Firstly, put on some of the shims, fit the trunnion and rubber seal and using the old nut tighten down the trunnion.
If the assembly locks, add more shims. If the assembly is loose and the stub can be felt to move up and down on the king pin, remove some shims. When there is slight resistance, you've got it right."
A couple of notes from my personal experience:
- My swivel pin repair kit from Moss came with three cork washers. Two identical cork washers are fitted on the fulcrum pin on either side of the swivel pin. The third cork washer is smaller and presumably is fitted at the bottom of the swivel pin in place of the O ring mentioned in #1 above. In my case, the 3rd cork washer was set aside.
- Two brass swivel pin (king pin) bushings were also included in the kit. These would need to be reamed and fit to the new swivel pin. In this case, I was lucky. I test fitted the new swivel pin into the stub axle and there was no play and the existing bushings were in good shape.
Roger Williams said on the Austin Healey Bugeye Frogeye Sprite 1958-1961 Facebook forum:
”I have been working on sprites for 45 years. The first time I rebuilt a front end I replaced the bushes without checking for wear and had to ream them to fit. The second time and all times after that, I installed the spindle over the new king pin and found it to fit perfectly. It turns out that there was no wear on the bushing. It is the kingpin that wears. I have not found a worn bushing in a spindle ever. Your results may vary.”
Kenith Smith, on The Austin Healey Experience forum posted his experience in 2015:
”Peter C at World Wide Imports http://nosimport.com/ will ream and size the bushings and fit to the swivel pin. I sent to Swing Axle, Swivel pin, and all of the rest of the piece parts from the Major Suspension Kit to Peter C. His guys reamed the bushings and set them all up for clearances so all I needed to do was bolt the assembly to the wishbone and reassemble. Cost about $50 plus postage and turned around and going back to me the same day”.
- Four thin metal shims were provided in the Moss kit. As noted in #3 above, these are intended to provide adjustment for any play in the swivel pin’s up and down motion. I installed the swivel pin in the stub axle and followed Mr. Bristow’s instructions in #3 above. In my case adding shims made the axle more difficult to swivel. I ended up with no shims needed which is the same way they came apart.
With the swivel pin and stub axle assembly completed, I was able to reinstall the previously restored brake backing plate, shoes and cylinders. With the assembly still on the bench, I greased the swivel pin’s zerk fittings using my new LockNLube grease coupler.
The Restoring Sprites & Midgets book by Grahame Bristow on page 197 suggests fitting the stub axle and control arm (wishbone) to the car separately due to its weight. That would require fitting the swivel pin’s cork washers (personal experience #1) while on the ground. Uggggg! I’m going to try suspending the stub axle/control arm assembly from the damper and then mounting the rear of the control arm to the frame. That seems far less “fiddley” to me. If it doesn’t work out on the left side, I can try Mr. Bristow’s method on the right.
Conclusion: To do it right, a front end rebuild is probably one of the more expensive parts of the mechanical restoration phase, after an engine rebuild. My thinking is to do it right and enjoy a safer and better handling Bugeye for years to come. Part 3 of this series will be delayed as the engine bay MUST be refreshed and painted before I can re-install the front-end suspension.
Here are a few of the online resources that I used in preparing for my project:
A detailed look at how to disassemble a Frogeye Sprite's front suspension -Econobox - Bugeye Build Episode 22
Front suspension on MG Midget explained (Worn bushings & parts) – John Twist – Episode 203 MG Tech
Front suspension rebuilt by a newbie – Keith Smith – Austin-Healey Experience – Episode “Start-Stop”
Kingpin Rebuilt (Rubber Seals) - Front suspension rebuild : MG Midget Forum : The MG Experience