Trailing arm suspension flexing!!

[erik280i]

I made a cage from a piece of pipe 60 x 1.5 mm wich gives an inner diameter of 57 mm. I did cut out two pieces to leave two flanges wich i bend to the outside so the pipe fitted over the rubber and the flanges rested on the iron plate the rubber is mounted on. I then drilled holes in the flanges for the mounting bolts. Had it on for just over 2 years. Easy to make and cheap.

[mrzigazaga]

I wonder if a culmination of all three would make a huge difference?..Upgraded mounts, caged and then the stabiliser fitted..Might be worth looking into....cheers..Ziga

[adam quantrill]

Chimp of Overripe Bananas does seem to have some valid points, but in my experience of running on unmodified trailing arm wedges for many many years and miles, the bushes didn't get destroyed every year, far from it. So I think there must be something else going on too...

• Maybe the bushes are not as good quality as they used to be?
• Or they are being fitted with the wrong technique?
• Or there's some other fault that's causing it to fail prematurely?

Caging the bush would seem like a reasonable idea - anything to keep it from flexing about.

Can you get it up on some ramps with a suspension-flexing jack (the sort they use at MOT time) and jack the read suspension up and down to see where it's flexing? This should allow you to analyse it at your leisure.

[mrzigazaga]

adam quantrill said:

Or there's some other fault that's causing it to fail prematurely?

Hi Adam..Thats what's in the back of my mind!..The pins & Mounts came from RT and im sure he is not in the habit of selling shyte..So im wondering if at any time petrol has made its way onto the O/S bush and made it perish quicktime causing the other side to become worn quicker than usual?..I have had more than my share of fuel leaking..Anything is possible although the O/S old trailing arm pin was bent when Dan taylor replaced it..And its that side that is the worst again..Maybe its not just a coincidence..I will have a good look with Dan tomorrow and take some pics..Cheers..Ziga

[MJG280]

Here's an example from somewhere

[ChimpofDarkness]

RCK974X said:

Wow, that IS a complete rework.... not sure if I want go quite that far....
Great photo for info though....that rose joint should sort any flexing out, but I wonder if it might be a bit too harsh ??

Edited by RCK974X on Thursday 17th January 04:26

That's why I feel caging the original (or poly) bush is the most practical idea.

I wouldn't have thought the cages would work out too expensive, and no special tools or welding to fit them either.

No negatives, only benefits for just a little bit more money than just replacing the bushes, which will ultimately have quite a short life in their currently unsupported state.

If the cages were available as a kit supplied with new bushes, it would be an absolute no-brainer IMO.

[mrzigazaga]

Hi Peeps...Just got back from Dan taylor and the O/S Trailing arm bush is knackered albeit only a year old!..The one on the N/S is fine..He checked for play in the half shafts and lower suspension but its all good..We came to the conclusion that he may of spilt a little drop of petrol as he changed some hoses for me a little while back and there is one directly above it..I think i will go for the upgraded superflex bush and probably cage it..Dan also said that it might be an idea as there is a fixing above it to put a little shield over the top to stop any petrol from perishing it again..So all in all not bad news..Well done gavlar you got it right..Thanks to everyone else for their input,I will bookmark this post for future reference..Cheers...Ziga

Cheers for this link too...
http://superflex.co.uk/proddetail.php?prod=SF111-1...

PS:I wonder if a re-engineered mount with a smaller bush might be better?..Less surface area = Less movement.

MJG280 said:

Here's an example from somewhere

This is something we discussed earlier and it could actually be a good mod..You obviously need up and down movement but dont need sideways movement..I think its Something worth a little bit of research..

Edited by mrzigazaga on Thursday 17th January 15:47

[Wedg1e]

mrzigazaga said:

MJG280 said:

Here's an example from somewhere

This is something we discussed earlier and it could actually be a good mod..You obviously need up and down movement but dont need sideways movement..I think its Something worth a little bit of research..

That is an absolute waste of a Rose joint (I originally typed 'pile of sh!t' but this is a family forum )... the whole point of a 'Rose' joint is to ALLOW the shaft or beam to displace from the nominal axis. If you then go and constrain the lateral movement (the big washers either side of it, or at least I assume that's why they're in), you may as well not have used a Rose joint in the first place; something like the adjustable bit of an A-frame would be more appropriate (with a larger bonded rubber bush in it).
Aside from anything else, the threaded section of the rod end is likely to bend first...

Fundamemtally, the original bush TVR used was up to the job IF they'd supported it on both sides. It's exactly the same bush as use on the Esprit (with trailing arms) and those cars don't have the same rate of failure because uess what, the bolt goes through chassis plates on both sides.

It also doesn't help that since Metalstik don't make these bushes any more, the current issue ones are made in bloody India or somewhere from chewing gum and yak dung.

[mrzigazaga]

Wedg1e said:

Fundamemtally, the original bush TVR used was up to the job IF they'd supported it on both sides.

Hi Ian..So would it be better to cage the bush as some have done?..And if so can you machine some plates..I only need 2..

Wedg1e said:

The current issue ones are made in bloody India or somewhere from chewing gum and yak dung.

..I make you right mate....Cheers...Ziga

[mrzigazaga]

Hi Mate..Those bushes sound great as they are resistant to petrol..The only problem is i cant find any with the correct plate that fits TVR's..
http://www.google.co.uk/url?sa=t&rct=j&q=s...

Perhaps a cotton reel type of kit or something like the ones in the link below..If they could be pressed into a plate that might be a better design..I might try modding the old mounts when they are off the car although im not sure about testing them on the car!!..I will rig something up indoors...Perhaps one on each corner of my bed as im a right fidget and i weigh a ton!...

http://www.ebay.co.uk/itm/Landrover-Rear-Trailing-...

[ChimpofDarkness]

This is what you need if you want to go poly:

http://superflex.co.uk/proddetail.php?prod=SF111-1...

However, being more resistant to petrol shouldn't be your reason for selecting poly over rubber, your car really shouldn't be leaking petrol in the first place Zig.

I still have some doubts over the durability of poly bushes, personally I'm very much with Wedg1e on this one.

Wedg1e said:

Fundamemtally, the original bush TVR used was up to the job IF they'd supported it on both sides.

Couldn't have put it better myself.

New standard rubber bushes, new pins & the (IMHO) essential bush supporting cage and it should perform very well & last for years.

Just keep in mind, a petrol leak is unacceptable for a list of way more obvious reasons that bush life.

Please remember anything you change on brakes & suspension should be done in pairs, it's an essential basic rule that ensures both sides of the car are in balance

Keeping costs down is all well & good but I was always taught:

"Do it properly & you'll do it once".

Your extended tyre life alone will pay for the bush cages alone!

Good lick with it Zig, you have the perfect opportunity here to make a significant handling & safety improvement to your car

[mrzigazaga]

Cheers Dave..I would prefer to go for the original bushes as they are a bit cheaper but i dont want them to fail again..Petrol or not!!..The cage idea makes sense but my engineering skills are limited and would much prefer someone making them who is a skilled machinist and has all the gear....
..IAN..... ..For beer tokens at BBWF2013....Obviously only if you have time.

Of course i will change them in pairs..Even though the N/S bush is ok...Cheers...Ziga

[erik280i]

[quote=RCK974X]

Erik280 - have you got any photos please ? A picture is worth a thousand words and all that..

I don't have any photos but i can mail you a sketch if you like.

Erik

[RCK974X]

Yes Please !! all photos,pics,sketches welcome - I think between us all we should be able to come up with a definitive answer = "this is the way to go, and it's reasonably simple..."

Interesting what you say about polybushes....I've put some in the tie bars, as I couldn't find original bushes easily...but they don't seem to handle the distortion/angles very well. On one side though, mine had NOTHING left, just a bit of powder !!

[adam quantrill]

That's why there's that f-ing big heavy washer on there, so if the rubber disappears, the arm won't come out of the general location of the mount.

[mrzigazaga]

Hi Peeps..I have received a trailing arm kit from Superflex..The next day i might add..And they look a better quality rubber..The mount is shaped differently but shouldnt think that poses a problem..The kit also comes with the steel inserts and some grease..Ok they are more expensive than the ones from RT but so far i have had to change the ones from RT twice in one year!..I hope they are not old stock or factory originals...As i believe they might be..Anyhow i will report on my findings and submit the part number to the wedge parts list...Overall im impressed so fart.....Whoops i meant far..Cheers...Ziga

[Danny Hoffman]

And they are shinier

[Mr Tank]

mrzigazaga said:

Hi Mark

One of the Bushes looks OK!

The distorted one is that the same side which distorted last time? Because you said in Jan that the N/S was OK!

If it is, then it maybe something else causing the distortion than a faulty bush!

Andy

[mrzigazaga]

Hi Andy..I was reading from the start of the post and i think i either didnt put the conclusion up or i started another post..(More than likely)..But it came to light that the O/S bush that went previously never got changed as Dan looked back through his job sheet and there was an advisory as regards to it..I think i must of forgotten about it..Anyway the last time i had the pins and bushes changed on both sides was around three months ago, Dan used a pry bar and went all round the rear end of the chassis and hubs and nothing was moving abnormally..Then he checked again after he had fitted the bushes..I also went through an MOT recently and he did the same and found nothing..Since then both have failed with the rebuilt engine..Not with the blower fitted so i can only assume that the bushes being sold by RT are not up to standard..I dont want to be derogatory towards richard as it might be a case of someone selling him old stock..When the new bushes get fitted i will post up the pics of the recently fitted orginal type bushes..But if they have failed then maybe the superflex will be a better part for anyone in the future..However im now wondering if the diff cradle could be broken..What would be the symptom of that?..Although as i say there is no obvious movement anywhere...Cheers..Ziga

[Engineer1949]

As part of the rebuild to my wedge i have now finished the design for the upgrade to the rear end basically it starts with a four bolt 20mm selfaligning ball race with triple seals to replace the rubber bush, the pin connecting the bearing to the trailing arm is threaded to allow a decent amount of adjustment to allow the toe in to be adjusted, the lower link is also having a left and right handed adjuster so camber can be adjusted without the need to fit or remove shims to the drive shft plus all this can be adjusted with the car on the ramp,pictures will follow as the build takes place will be a little while as have just had my pacemaker replaced.


John