Trunnions (4 articles)

Lubricating trunnions

"The Trouble With Trunnions" feeding them!

And I've finally devised a simple (and cheap) way to force feed them their regular 5,000 mile dose of Cod liver oil ;-) ...or AMSOIL [or name your favorite] 90W gear oil.

Using a small "oral syringe" - no needle, just a plastic nib. I got mine (1 teaspoon) for free at the local pharmacy.

Put a rag under the trunnion to catch the extra fluid, so it doesn't run down the sidewall of the tire (if on). On the eclat/elite, it's easy to do with road wheel on, just turn the steering full lock and get to work...

Siphon up a teaspoon of gear oil, uncap the trunnion, put the nib into the hole and jam the front end tight against the trunnion, squeeze *quickly* and watch...

You should see some nasty old juice slip out from under the rubber top seal. Keep shooting until you do.

If you have trouble getting a pressure seal, slip a neoprene flat washer over the nib -- small enough to seal around the hole, big enough not to go in.

Remember to cap the hole again. Tada!!!

How to....

Good question about the trunnions --

One on each steering upright -- they are the lower swivel thingy, bolted to the lower suspension arm, carrying the upright base.

There's a rubber collar, like a dust seal, where it swivels, and just above that -- on the inside face (that faces the other side) -- there is a slender hex headed brass screw cap (probably a 7/16"). I had to crumble away some road dirt to find them this time ;-)

What I do... is just set the steering full-lock left, get in front on the left, clean around the cap and open it, inject the gear oil, and cap it. Then set the steering full right and do the right side. Don't even have to get "under" the car for that one. Use the same hypoid gear oil as in the differential.

Qs & As

I remember this being a hot topic for a while at Triumph, where I did my apprenticeship in the glorious days before it all crumbled into the Leyland / Austin / Rover hodge-podge. (As far as I know, I'm the only person who admits to working on the development of the TR7 - yet I promise I didn't do it single-handed - it takes a big group to create a car that awful....) The concern arises if a trunnion is filled with grease, and then neglected - if the grease sets and becomes sticky, it can tend to glue the trunnion to the upright. This can promote a torsional failure at the base of the upright, as the front wheels turn from lock to lock. Triumph strengthened the upright for the Mk 4 Spitfire, but I don't think any Lotus ever used this particular assembly - although Caterham adopted it on the Seven around 1978. If your trunnions have been filled with grease, I doubt that you will run into problems by then using oil - the oil should remove any tendency to sticking and creating torsional stress in the upright

They seem O.K. Are you saying that they will need to be stripped eventually ?

No... Unless there is something wrong with them... Just oil them, and if you ever do take the front apart, them clean/lube them or replace them. But if they are working now, they should work for long time... I haven't actually rebuilt them before. I got the full story about grease in trunions from a Triumph expert. Modern grease should provide every bit as much protection as oil for the trunions. That is unless one had added grease in the early days and trashed something. But then you would have detectable play in those trunions now. The recent comment about a rebuild by one of our Elan experts, either Tim or Rod , leads me to suspect that you wouldn't have to do more than replace any seals that might have died over the years.

It would seem that the P.O. has greased (i.e. NOT used EP90 oil) the front trunnions - which, as I recall from the list's recent discussion, is not a Good Thing.

1) Do I need to strip the trunnion ?

2) There were some differing views on grease versus EP90 - is it that serious and will it be O.K. to leave until the next service interval

It's not that serious. Oil them up and keep going unless they are too tight or too sloppy. The POs of my Elan either used grease or never touched them at all, and they worked just fine. I only replaced them because I was rebuilding the entire front end, but the trunnions were in good condition... It shouldn't be a problem. The original requirement for oil came in an age when grease was not as good as it is now. I think it used to shear more easily, not filling the voids that might occur due to the movement of the steering assembly.


Here are some favored eclat/elite U-Joints:
Spicer 5-153X (lifetime warranty) about $14 from NAPA.
Neapco (made in USA, try cross-ref.) available at Pep Boys.

The Neapco's have a neat feature: zirc nipple in one end cap. The folks at Dave Bean said theyv'e *never* seen Neapco fail. CAVEAT: Do not even look at UMB joints, no matter how cheap! Your life rides on these U-joints, since half-shafts also double as the "upper link" of the rear suspension (radial + axial loads).

Tips: Remember to pre-grease the caps before installing. (The assembly grease in new joints is only for shelf life.) Then shoot the crosses full after they have been mounted. A manual grease gun is best -- you can stop when you feel the resistance increase, just before the seals belch grease.

Six joints all, if you do the drive shaft, too. c/o Lotus Ltd, There was a tech article (H083) about drive-shaft vibes in eclat/elite.

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