Trunnions

[ronnie]

Hi I've ordered top and bottom trunions anything to watch out for changing them or is it straight forward
Thanks in advance

[bmcecosse]

Well -it's only worth changing them IF the threads on the king pin are not too badly worn...... Assuming the wear is accepetable - cleanliness and lots of grease (I use Moly Grease) is the way..... And remember to remove the bottom pin BEFORE trying to unscrew the trunnion - and fit the new pin AFTER screwing on the new one...... LH threads on the nearside kingpin........

[ronnie]

How will I be able to tell if the king pin threads are worn more than the trunion threads because at this point it's all stripped anyway ??

[simmitc]

When you see a new thread and a work thread side by side, then the difference is obvious. The thread should have a sharp edge and be cleanly cut, and even throughout. If the edges are flat then it's worn. Screw a trunnion on to the old pin. If it has tight spots or is wobbly then the pin is worn - the trunnion should screw on smoothly. It's generally good practice to renew the pin and the trunnions - you don't know how old they are, and whether they have been well maintained. In the old days when trunnions were worn, the threads on the key pin were re-cut slightly undersize and special oversize trunnions fitted.

[aupickup]

a good thread will have flats on the end

[ronnie]

Cheers for the info , are new king pins available off the shelf I

[bmcecosse]

Yes of course - at a price. And yes - I agree with Dennis - it's the worn out threads that are 'sharp'...... Trouble with fitting a new king pin is that you have to remove the steering arm from the old king pin.........

[ronnie]

Do you mean the track rod end ???

[bmcecosse]

No - the steering arm......which sticks out of the king pin, and to which the TRE connects!

[mike.perry]

The swivel pins used to come c/w steering arms.
I would advise removing the grease nipples, packing the trunnions with grease by hand, fitting the trunnions and then replacing the grease nipples. That way you are guaranteed to get grease in the trunnions, on your hands, the garage floor, on your clothes etc. etc.

[M25VAN]

And rinse them out first to remove any swarf/bits left over form manufacture.

[Declan_Burns]

And rinse them out first to remove any swarf/bits left over form manufacture.

Agreed-the ones I got were full of swarf. Might be easier replacing kingpin and the steering arm and TRE rathering than trying to remove the arm. They are not that expensive and then everything is new.
Regards
Declan

[ronnie]

Thanks everyone. I'm going to strip and inspect first and take it from there thanks

[Biggles1957]

I've just replaced both king pins and all trunnions on my traveller. Struggled a bit getting the steering arms out but blowlamp and PlusGas helped! Did have to cut one out with the angle grinder though...
Anyway, put it all back together and got the grease gun out. Pumped the old gun and out popped the end caps on the brand new trunnions!

I rang **** ***** where I had bought them from to be told that they take them to bits to clean them out and the lads obviously hadn't put them back together properly! Well it's nice that they clean them out - but more than a little frustrating that they fall to bits after you've spent half a day rebuilding the front suspension!! "Just tap them in with a hammer" he said - that's easier said than done because the brake back plate gets in the way (Wonderful Wolesley Brakes fitted - that's what stopped the Knackered bottom trunnion dropping off!) but I managed with a suitable soft punch. I think with the standard brakes you probably can get at the bottom trunnion end caps easily - but that's not really the point!

Just thought I'd mention it so you don't waste half a day fitting brand new bits that fall to bits as soon as you fill them with grease and which could have been so easily fixed if the muppets had bothered to put a little note in the box saying to tap 'em with a hammer! Grrrrrrrrr! Moral : CHECK THE END CAPS BEFORE ASSEMBLING THE TRUNNIONS ONTO THE KING PINS!

[bmcecosse]

Good story Biggles - and yes - another big advantage of the W front brakes is that the backplates 'trap' the bottom trunnion so it can't fall off the kingpin. A good safety feature! I think something similar could be achieved with the 8" backplate by fixing a short length of angle iron to the backplate - just under the trunnion.... But of course - with good maintenance there should be no risk of trunnions coming loose anyway.....

[M25VAN]

I rang **** ***** where I had bought them from to be told that they take them to bits to clean them out and the lads obviously hadn't put them back together properly!

Sounds like a feeble excuse! What's not to put back properly? Doesn't sound like the end cap was fitted properly during manufacture.
But yes, how many times do we forget to check something out before fitting it. Always best to do the manufacturers quality control for them at the earliest opportunity.

[mike.perry]

There was a kit to stop the trunnions dropping off available at one time, it may have been from Mr Grumpy

[kennatt]

There was a kit to stop the trunnions dropping off available at one time,

Is this whats going to be fitted come next year on pre 60,when no mot will be carried out