Trunnion maintenance

[Gridgway]

Probably a well trodden question, but I have realised that in my live axle car refurb, I thini I need to pay more attention to the trunnions than I was going to.

As it's new to me, although only having done 9,000 miles since new, I don't have any idea of the state of the trunnions, whether they are worn or not, oiled or greased or neither.

Any recommendations on what to do?  Are they easy to take apart, inspect, clean and put back together?  Anything to look for?

Cheers, Graham

[Englishmaninwales]

Remove, disassemble and degrease. Examine the threads on the upright and trunnion.Place the outer portion and check for any play.  Any wear, replace. Obviously if the thread on the upright is worn, this will require replacement. Replacements are available with poly bushes which are far better. Remember they are handed. Make sure the eyebolt is assembled anti -seize (Removal can be a problem if it was assemble without any last time!). Reassemble with EP 90 or grease (your choice, do a search, loads on this argument)

Malcolm

[Gridgway]

Thanks, I should have done this with the suspension apart (dampers went off to be serviced, did new bushes in the lower wishbone and refurnbed the calipers with enw seals!).  The good news is that I know it comes apart easily.

[Nigel Riches]

If your trunnions have a swaged in steel disc on the bottom you will probably find they leak if you use oil lubrication. However this can be remedied by degreasing and being scrupulously anal about getting any contamination out of the area where the disc is installed, being sure the area is dried thoroughly, then apply some wicking grade Loctite from the outside, around the swaged joint. I have done this and have no oil leaks.   

[Gridgway]

Thanks, that's helpful.  I'm feeling a bit annoyed with myself for coming back to it after having had the front suspension apart, but I need to check for lubrication and wear.

I'm minded to go for the upgrade kit to sphericals, but I don't know if it just fits into the Caterham lower wishbone and top balljoint.  Nor how hard it is to get the stub axle out to change over.

I think people on here have done it though.

[Gridgway]

Updating this, I took the front uprights off and apart to ge the trunnions off.  They were badly libricated with grease and seem to have wear and a lot of play.  Even though I quite like to keep it all original, I think I'll upgrade to the spherical bush replacement kit.

[Tazio]

The Canley Classic one?

[Gridgway]

Yes, that's the plan assuming they have stock

[Gridgway]

In an unexpected turn of events, Canley have siad that their kit is not suitable for the Caterham wishbones, it's designed for the Tirumph lower wishbone only.

I think I need to think again.  My race car fabricator can probably modify the lower wishbone to add a bearing carrier for a spherical bearing, then I can use the Canley upright/link.

Or I can buy some new trunnions and move on!

[Tazio]

Have a chat with David Sutton, Sooty on here, he's did the conversion about a year ago using the Canley kit.

Cheapest is new trunnions and this time lube them with EP90, not grease them, or you can go the whole hog, new uprights, new lower wishbones with spherical bearings, and if you have the classic upper wishbones replace them too. Not a cheap solution, but doable if you wait for the Academy guys to move from narrow track to widetrack, and get a set of wishbones cheap.

Alan

[anthonym]

I kept my trunnions because they are true to the era - and I gather cannon run on them and still work. - anthony

[Nigel Riches]

Trunnions  do you really need to splurge gazzillions of wonga on this.

Good old, in keeping with the period, trunnions do whats needed to accommodate suspension and steering movement, and in keeping with the vehicles age, just adding another mongrel aspect to a car design which has a long pedigree in this respect.

The spherical joints wear out if exposed to grit contamination, ok, no oiling, or greasing , if that's your thing, but not the be all and end all, get some new trunnions and use EP90 lube, they'll last a good deal of miles.

Buy some new trunnions, and move on. As you said.   

[Gridgway]

I'm there, the old ones weren't maintained.  The car has done 9,000 miles from new, so they have a short life if not lubricated, but that's really rather easy to do!

So yes I am going to just replace the trunnions (and the wheel bearings whilst it's all apart).

[Gridgway]

And I took the uprights apart all ready.  No big deal, but not sure I have any torque wrench settings for the stub axle into the upright and the stearing arm bolt.  Does anyone know them please?

[ECR]

I have 60 to 65 ftlb for stub to upright and 22to27ftlb for arm to upright 

[Gridgway]

Thanks ECR, sounds good!

[Terry Field]

Another vote here for EP90. I used to unscrew the grease nipple and simply squirt in EP90 using an oil can at various times between the annual servicing. It takes just a few seconds. Mine did 0ver 50k without any problems.

[john g]

Terry, that's a good idea...unscrewing the grease nipple. I've been using an oil gun.

[richardm57]

The  problem with trunnions apart from servicing is that they BREAK where the flanges meet the wishbones, so check very carefully at his point for cracks at side of weld.

[Gridgway]

That's interesting.  Just to clarify, it's the trunnions that tend to crack, not the wishbones?