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Lower trunnion and lock stop


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When I rebuilt the front suspension on my 5 I noticed that the rear of the lower trunnion was touching the outside edge of the spring pan. I assumed that when the chassis was loaded with the engine and gearbox this would change and create some clearance. Engine and gearbox are now on the chassis but there is still contact, although slight, on the spring pan. So do I file a small amount off the rear of the trunnion, ignore it and let it wear itself a clearance, or what?

All contributions gratefully received as always!

Many thanks,

Tim

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Tim,

it could well be that your shocks are too long, mine were, which resulted in binding of the trunnion to the pan, but only with wheels off the ground, so with fully extended damper.

I sent the dampers back to the supplier, and ordered others (I went for Konis but orhers are available). There is a post about this on the TR6 forum some 2-3 years ago.

Not sure if your issue is caused by that, mine only had this in fully extended position.

It is important to solve this issue, as it will give very high stresses on the vertical link.

Waldi

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These still touch with the wheels on the ground! 

They were supplied by Moss or TR Shop so surely would be right!

Tim

Edited by Tim T
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Hi Tim,

that doesn;t sound right!!!

If the pan is touching the trunnion with the damper in a neutral position it could get quite stiff if and when the damper is extended.

The issue, a couple of years ago, was that the standard (cheapo) damper was found to have grown over the years by about 30mm.

When the front of the car was elevated the longer length of damper allowed the angle created by the damper and wish bones to close up such that the spring pan was pressing on the trunnion and making turning very stiff.

So was it the longer damper that caused the problem. It certainly added to the problem. But !! - Koni and all the pother struts can also be a little too long and these also touch (on the very few that I have looked at).  

So what to do.  I would suggest that unless you can create a gap at the pan/trunnion by moving something then I would remove metal from the pan so it is clear what ever extension the damper has.

Roger

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Thanks both. My feeling is investigate a little more tomorrow with a few to creating enough clearance. Should only be a couple of thou. The only new items in the set up are standard springs, standard shocks, and poly bushes. Everything else is original off the car.

cheers

Tim

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Thanks Roger for the clear explanation of my earlier issue. My new Koni’s solved the issue (which in my case only was an issue with shocks fully extended), they had the correct lenght.

Tim,

it looks like you have a different issue if the trunnion is binding in neutral position too.  It will need further inspection of the components for damage, past modifications, size, correct fitment/orientation etc.

I raised a PQI which was investigated by Roger&Co. My too long shocks came from TR-shop, but other suppliers had the same ones. 

Regards,,

Waldi

Edited by Waldi
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Can anybody confirm what the length of the standard shocker should be and also what sort of clearance should there be between the rear of the trunnion and the spring pan please. Do you know when the TR Shop withdrew their units and are the Moss ones ok?

Thanks again!

Tim

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Hi Tim,

the lenght should be 300 mm, the too long ones were 330 mm. This is effective length, not overall length. But as said, if tou have this issue also in the neutral position this is not your issue.

I raised the PQI in December 2016 and ordered these shocks in November 2016.

Roger and Ian approached several suppliers. I was positively surprised by the good response, follow up and feed back from Roger and Ian, so can recommend anyone to raise a PQI if you cannot come to an agreement with the supplier on a technical issue with a part.

TR shop binned their remaining stock, Rimmers did not see an issue and continued selling their stock which surprised me and Moss was interested to understand the issue and thought it could be related to the top ball joint (which I think is not the case but that is a different story), and Moss indicated they would further study the issue. But they took the issue serious.

Guess which seller did not sell anything to me since...

Regards,

Waldi

 

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Many thanks for your comments Waldi and Roger. Having had a further chat with Stuart I think that I am going to ignore to issue until the car is fully loaded and see if it changes, then investigate further. What is odd is that the only new elements in the set up are the bushes, springs, shocks and top ball joint, trunnions and vertical links are all Stanpart originals.

Many thanks for your time and interest.

Tim

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Final update then. Took Stuart's advice and left the issue alone. Whilst rolling the chassis back and forth during the day to create a bit more space I noticed that the issue had resolved itself giving a clearance of about 3mm on each side. Moral being be patient and don't panic too soon!

Thanks,

Tim

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