Top Trunion and Bottom Trunion

Post by **londonboy** » Tue May 19, 2009 1:04 pm

Hi I have to change both the top and bottom trunion on both sides of my car. Morris Minor 2 door 1971 can some one tell me the easy way to do this. I have read so many different ways of doing this job but they all seem to go about it a different way
Thanks

Post by **mike.perry** » Tue May 19, 2009 1:42 pm

It would take a lot of writing to go through the instructions. You are better off following the instructions in the workshop manual. There probably are different ways of doing the job but they all achieve the same result.

Post by **londonboy** » Tue May 19, 2009 4:09 pm

That is true but if you wanted to take the M/C and and were to follow the book you seems that you have to take every thing a part.

Post by **Matt** » Tue May 19, 2009 4:39 pm

you need to drop the suspension to get the bottom trunnion off, you need to disconnect the lever arm from the top but you might get away without removing the track rod end

Post by **davidpidge** » Tue May 19, 2009 5:28 pm

Good timing! I'm about to attempt a bottom trunion replacement. My mechanical knowledge is nill but it looked pretty straight forward. I was goin to jack up the front end, take of the wheel and start un-skrewing bits. I don't have a workshop manual but I have got an 'exploded diagram' and a haynes manual. Anyone tips...other than take it to a mechanic?

cheers!

Post by **mike.perry** » Tue May 19, 2009 5:38 pm

Support the chassis corner on axle stands and when you have removed the tie bar link and front of the lower suspension arm keep the rear suspension arm supported on a jack as it is still under load from the torsion bar. When you have removed the bottom trunnion then you can lower the jack until the load is off the lower arm.

Post by **kennatt** » Tue May 19, 2009 6:04 pm

whatever you do DON'T just jack it up and unscrew everything. As mike says you must suport the rear bottom arm ,the one that is attached to the torsion bar,If you just unscrew without doing this you could well lose a finger,there is still quite a bit of force left in the torsion bar even with the car jacked up.

Post by **kennatt** » Tue May 19, 2009 6:05 pm

whatever you do DON'T just jack it up and unscrew everything. As mike says you must suport the rear bottom arm ,the one that is attached to the torsion bar,If you just unscrew without doing this you could well lose a finger,there is still quite a bit of force left in the torsion bar even with the car jacked up.

Post by **MarkyB** » Tue May 19, 2009 6:12 pm

Even with the suspension at it's lowest point the will still be plenty of tension on the torsion bar.
I used to use a trolley jack and a bottle jack but I've mislaid my bottle jack and made do with a suitable lump of 6x3 timber (don't use a brick as it may well crumble

)
jack up the front of the car on the side you are changing. Take off the wheel then lower car until the rear ( cast ) suspension arm is supported by the jack/ lump of wood and the top arm just moves off the lower stop.
Then remove the front part of the lower arm and the nut on the back of the bottom trunnion.
Pull the suspension leg away from the rear arm.
Now jack up the car until the block/jack is free.

Hey Presto, now you can have your way with the trunnions etc.

To replace the rubber bushes on the top trunnion or the trunnion itself I normally take off the large nut and wriggle the bushes off the pin then use a minimal amount of brute force to get the new bushes over the pin.
Reassembly is the reverse process etc.
Be aware that a good chunk of the weight of the car is stored in the torsion bar and it could bite, work on a nice level sound surface.
A brick size or bigger bit of wood is about right.
Your mileage may vary but this is the way I do the job and it works for me.
If you want to replace the rubber bushes I have a way of doing that too.
Unless there is a pressing reason to actually remove the torsion bar I wouldn't ,trying to mark it to go back in the right place I find very tricky but someone else may have a method?

Post by **bmcecosse** » Tue May 19, 2009 7:12 pm

Be aware - that if top and bottom trunions need replacing - there may well be significant wear on the king-pin it's self. And so new 'trunions' may not make that much difference ! Best to inspect before investing in trunions - you may need complete new king-pin assemblies - and unfortunately there are no new ones to be had!
The top trunion bushes are very much better if replaced with polyurethane rather than rubber - even if you leave all other bushes as rubber - these ones are a MUST for poly!!

Post by **aupickup** » Tue May 19, 2009 7:40 pm

no new kingpins !!!!!

i have several in the for sales all new old stock

Post by **bmcecosse** » Tue May 19, 2009 10:02 pm

Crikey - I thought these would have been snapped up ages ago Dennis - especially as the much promised 'new' supply still seems to be as far away as ever!
But actually - I did rather expect you to jump in to the thread - and you did!

Post by **aupickup** » Tue May 19, 2009 11:31 pm

only one pair left tho now

Post by **londonboy** » Wed May 20, 2009 1:45 pm

Thanks to you all for your help.

Post by **davidpidge** » Wed May 20, 2009 10:11 pm

Thanks everyone. I succesfully changed my lower trunnion today and it passed it's MOT! Now she has to make it to Newquay tomorrow!

Post by **bmcecosse** » Wed May 20, 2009 11:38 pm

Well done - good luck with that run. Enjoy!