Trunnions

Let’s not argue about the spelling…….. They are the swivelly [sic] bits at the top and bottom of the front legs of your moggie. There’s a top trunnion and a bottom trunnion and they are very different but do the same job. One thing they need is grease. The owner’s manual probably says something like 10,000 mile intervals but believe me, I do this three or four times a year on my 5000 allotted miles. It’s not a hard job to replace them but it’s a real pain of odd sized sockets, ring keys and open ended, 15mm and 16mm split pins to drill out and replace and a steering arm to heat up, cool down, heat up, cool down, bash out and hope you haven’t wrecked the threads, grease nipples to clean out, packing pieces to make if they’re lost, rubbers to grease and split pins to find. It’s much simpler and easier to look after your Trunnions!!

Jack up the car a side at a time and remove the front road wheels. Support the car with stands under the chassis and let the bare hubs just hang. There is a grease nipple at the very top of the leg, probably covered in grunge and another at the bottom, just behind. Various sizes have been fitted and retro fitted clean the surrounding area and use a pair of pliers to unscrew them. Clean the nipple. You don’t want any road grit to find its way in with the grease. Test the little ball in the end of the nipple isn’t rusted solid by holding the nipple against the delivery nozzle of the grease gun and squeezing the gun just a little until you get a half inch of nice clean grease through it. Screw them back in and now they are nice and clean, nip them up with whichever spanner. [Wipe any grease on to a convenient brake pipe, not your overalls!] Any that won’t let the grease come easily through should go in the bin.

Order new nipples and they should be with you the next day in the post. www.tomroy.com or similar. It’s not a second mortgage. Hold the delivery pipe against the top one and squeeze the handle until clean new grease appears in a wave at the rubber three or four inches down the leg. Do the same at the bottom and the wave of grease should appear at the rubber sleeve at the top of the trunnion of the swivel pin, much the same as the top one. Sometimes the grease will also appear at one side of the trunnion cross piece where it meets the bars from the torsion bar. This is normal and at least you now know the pin isn’t seized solid. If it’s been some years since the last greasing you might have some difficulty. At the top, recon Trunnions tend to allow grease out in a circle around the nipple. This is bad machining of the trunnion and there isn’t a lot you can do except strip off the trunnion and apply grease manually on to the swivel pin threads.

If the grease simply won’t go in but squirts out of the side of the nipple then try warming the trunnion with a blow lamp, gently at first and then more positively but not so low down that
you singe the rubber bush where it meets the leg. Let this cool a little and then try again. Several attempts should get it. Same at the bottom. If your wave of grease comes out only at the bottom warm it a little above and try again. But while you’re there………. The track rod end has a grease nipple on the top………….