Trunnion Replacement

[Adrian Nugent]

Hi there,
I am planning to replace my lower trunnions.
I have looked online and found comprehensive guides but they all seem to be a bit in depth and only text. As a novice i may require some images and more of a basic guide.
I am aware there is some care to be taken with the torsion bar and the lower arm once the car is jacked.
If there are any guides floating around I would appreciate a point in the right direction.

Thanks

Adrian

[Chipper]

http://www.mmoc.org.uk/index.php?page=332

Ensure the jack used to raise the bottom arm is secure - most trolley jacks are pretty good for the job. Be aware that you have to jack up on the rear half of the lower arm, otherwise you won't be able to unbolt the front half!

[Adrian Nugent]

ok, the bottom of the arm I assume will be closer to the chassis?
I was thinking of jacking the car on the chassis leg with wooden boards in between to spread the load and then putting an axle stand in place of the jack and then another axle stand further up the leg (so i have one in front and behind the wheel arm).
then using the same jack on the arm to deal with the torsion bar.
does this sound reasonable or am i asking for trouble?

[Chipper]

Sounds like a reasonable enough way of going about it. If doing just one side at a time, I usually just use a trolley jack to jack up the car to a reasonable height, lower the crossmember onto an axle stand, then use the trolley jack to raise the lower suspension arm.

But your way sounds OK, so if you're comfortable with it, why not do it that way...

[bmcecosse]

That will be fine. Remember to remove the pin before unscrewing the trunnion!

[Adrian Nugent]

sorry bmcecosse,
the pin.... is that the one running through the lower trunnion itself? or is it attached to another part?
I know of the king pin but that is about it. Also will i have to do anything with the bolt running from the top trunnion or will I only have to deal with the bottom? sorry to seem dim, just my first time attempting this.

[chesney]

When I do this, I use a section of box section with a 'V' cut into one side.
I then refit the yoke for the tie bar onto the rear suspension arm (having removed the front arm) with the thread of the yoke sitting in the 'V' of the box, then lift the box section underneath using a jack. That way, it's near inpossible for the jack to slip off the suspension and causing damage/injury/worse...

[bmcecosse]

Yes - the pin running through the trunnion must be first removed. You won't need to touch anything else - but it would be a good chance to fit poly bushes all round!

[Adrian Nugent]

Cool, so it is just a matter of jacking the car correctly, getting that pin out and then unscrewing and replacing the unit. Would you say it is anywhere near as complex as the mmoc site would make it seem?
http://www.mmoc.org.uk/index.php?page=332

[Chipper]

No need to mess about with the brakes or hubs, if just replacing the trunnions. The lower ones are easily dealt with, by jacking up the rear half of the lower arm, having undone the four nuts and bolts on each side, lifting the front arm away.

Then, with the rear lower half of the arm still supported by the jack (raised enough to releive the torsion bar strain), gently pull the lower trunnion out, remove the fulcrum pin running through it, and unscrew it from the kingpin, noting the number of turns you need to undo it - refit the new one the same number of turns.

A new fulcrum pin is usually a good idea, unless yours is in good condition.

[bmcecosse]

Can you unscrew it without undoing the brake backplate? It's been a while...and when I did renew everything there I had the brakes off anyway......

[Budgie]

Just food for thought I replaced the whole lot i.e swivel arms/king pins, upper and lower trunnions on both sides after receiving the usual excellent advice from the guys on this site I know it might be a bit of a strain on the wallet but as was explained to me , better safe than sorry in the long run.

[bmcecosse]

It is a thought - because I was going to ask - how do you know replacing the trunnions is all that is required... The wear is usually 50/50 - trunnion/kingpin.....and a new trunnion on an old/worn kingpin may not last long.

[Adrian Nugent]

I am replacing it because the rubber seal broke and when I tried to buy a new one in my local classic car parts place they said I may as well replace the whole trunnion. I am looking at it as an excuse to get some hands on learning of how to change one, I think better to learn how to do it myself now instead of it being a surprise later down the road, but I will make sure I look into replacing the king pin at the same time.

thanks.

[bmcecosse]

I think they were 'pushing' their sales with that comment. Note - they are 'handed' - so don't get them mixed up......

[kennatt]

You can get the rubbers in a kit from traders,but just take the trunnion off and examine the threads,up a photo on,of both trunnion and pin threads,they may well be fine.If the tips of the threads are sharp,then both are done for,but if the tips are flat,then they will be fine.

[Adrian Nugent]

Here is a picture of my front suspension, i tried jacking it at the rear of the arm so that i could get the securing pin out of the trunnion but it wouldn't budge. I didn't want to try and hammer it out in case i damaged anything. Is there something I was doing wrong? also if I were to get the pin out would I need to disconnect the steering arm to pivot the kingpin out to unscrew the trunnion?

[Adrian Nugent]

https://www.tumblr.com/blog/nuggers123

here is a link to the images of my trunnions and king pin.

[Adrian Nugent]

Hi there,
I have attached some pictures of my trunnions, i have unscrewed the fulcrum pin nuts but cannot seperate my lower arms to unscrew the trunnion, I have absolutely no idea how to proceed, has anyone seen this setup before??
thank you [frame][/frame][frame][/frame][frame][/frame][frame][/frame]

[chesney]

I recognise that as the JLH suspension setup. You are very fortunate!
Maybe ask JLH themselves.