Haynes Roadster Crush Tubes

[Guest b3nny]

Managed to take a side apart today and from what I have read the Haynes locost chassis is supposed to have 44mm crush tubes these are 41mm and the bracket looked slightly bent in taking up the extra 1.5mm each side, I measured a rear bracket and this would accept a 44mm tube with around 0.5mm clearance, am I right in saying thenI just need to order the 44mm crush tubes? When the Bush was assembled the tube ssat flush if not a little inside the Bush.

 

It also creeks when going over speed humps and I think I read this is due to the crush tube being to short?

 

[Guest iank]

That is quite likely to be the cause of your creaking.

 

When assembled the washers at each side of the bush should tighten down on to the crush tube not the bush, i.e. the clamping pressure is on the tube

 

So the poly bush rotates on the crush tube.

 

If the tube is too short the clamping pressure is on the bush, this wears the bush and puts unnecessary load on the mounting since there is nothing to rotate around .

 

Ian

[Guest b3nny]

Exactly what it was doing, so are you saying there should also be washers inside the u clamp? Clamping onto the crush tube as there wasn't any?

 

 

You could actually see some of the red colouring on the u clamp as well.

 

The handling is also VERY stiff doesn't hold the road well at all I had a geo setup last week and he advised there was no movment in the wishbones at all and with them moving freely this would help no end!

Edited July 7, 2014 by b3nny

[agent_zed]

you don't have to have washers they just take up any slack so you don't bend the brackets in. If the crush tube fits tight and there is about 0.5-1mm (can others confirm this?) or so each end of the bush, it is fine without them. You don't want the bush too loose on the sleeve either as it could move forward and back.

 

If it was me i would cut the sleeves to fit the bushes (with a bit sticking out each end). Then offer up the wishbone and pack with washers if necessary so that the bracket doesn't have to move when you bolt up tight and everything is still square.

 

hth

[agent_zed]

oh yeah i also packed my tubes with copper grease so they don't rust to the bolt and make remove in a few years time difficult.

 

Also put lithium grease in the gap in between the bushes to keep water out.

[Guest b3nny]

My trouble is the sleeve is already to short, I'm guessing a square black and some ruff paper would be a bodge if I sanded the Bush down?

 

I can get a complete set of crush tubes for the haynes for £40.

 

Am I likely to get away using the bushes that are there?

[Guest b3nny]

I'm looking to place the order this morning for either the crash tubes or a complete set of tubes and bushes,would it be recommended to get the whole set or would I just get away with the tubes? I'm not sure how long they have been on the car as it was like it when I bought it, they are poly bushes that are in there would they be likely to be worn enough to replace due to the way they have been fitted?

[Grim]

save yourself some heartache and get stainless crush tubes from wisbech engineering, less than a couple of quid each. The tophat bushes are about 60p each from there (don't know if the size is right for you).

[Longboarder]

Ahh, the crush tube debate. Different schools of thought and different types of bush. Many OE suspension bushes come with a crush tube with the bush bonded to it (and possibly and outer bush bonded on also). These are designed to have the crush tube and outer bush pressed or clamped rigid in position with the suspension at rest and rotation movement is all in the 'rubber' twisting. No great debate here. Crush tube bolted up tight.

This is not what you have on your car. You have a crush tube not bonded to the rubber/plastic/nylon/polywhatsit which is also not bonded to the wishbone housing but a moderate press fit, So it has three options of where the rotation can take place. Crush tube can rotate round the bolt, bush can rotate round the crush tube or bush can rotate in the wishbone housing.

You have to decide which you want to happen. You can rule out the last option. The debate is do you want the first (metal on metal rotation) or the second (bush on the crush tube rotation) to be the way your suspension works.

Once you decide you should build the suspension so that it is held, and shimmed, properly in position without distortion or significant slack to work the way you want it.

 

Nigel

[Guest b3nny]

As I'm still very new to this I'm not sure how the builder had designed it to work, as far as I can make out he's basically followed the Haynes book (ron Chapman), to me it seemed the crush tubes where to small as they sat just inside the Bush or dead flush and was just tight end up crushing the Bush causing it to be absolutely solid! So I was hoping it would just be a case for me to buy new tubes and bushes with tubes the right size and get them on and hopefully it would be night and day difference.

[Longboarder]

Choice is yours. Pic of the options and what not to do below. Personally I would go for a rotating, lubricated, well fitting crushtube on the mounting bolt and a good locknut or better drill and pin the nut. Shim to within a few thou of the space so the wishbone cannot move significantly fore and aft. Obviously the third example with the distorted bracket is what not to do.

 

Nigel

Edited July 8, 2014 by Longboarder

[Guest b3nny]

Great help thanks very much!

 

I'm not sure shims is a option as from what I remember when I looked last night the brackets will only just accept the 44mm crush tubes.

[Guest davidimurray]

b3nny - I take it you are running a Haynes Roadster? What are your handling worries? Mine handles beautifully - fantastic grip around corners the rear tyres start to squeal before the back end starts to break loose. Nice and stable on motorways. The only issue I have yet to dial out is a bit of bump steer that can be a un-nerving on a striaght bumpt road.

 

What are your geo settings? What springs are you running? What are your ride heights?

[agent_zed]

just thinking if you do plan on turning down the bushes slightly (if you have access to a lathe) i'd pop them in the freezer first to make sure they are hard. When i turned mine a bit they were hard going when they were soft.

 

remember they do shrink when frozen so take that into account if cutting.

 

Also freeze them before fitting as again they will be smaller

[Guest b3nny]

b3nny - I take it you are running a Haynes Roadster? What are your handling worries? Mine handles beautifully - fantastic grip around corners the rear tyres start to squeal before the back end starts to break loose. Nice and stable on motorways. The only issue I have yet to dial out is a bit of bump steer that can be a un-nerving on a striaght bumpt road.

 

What are your geo settings? What springs are you running? What are your ride heights?

 

I'll take a picture of the geo settings later, I'm running gaz coilovers and ill measure the ride height shortly when i go out to the car.

 

The car is absolutely rock solid no movment anywhere, on B roads it's very uncomfortable and throws you around literally, it's also very twitchy changing gears at high speeds haves you zig zagging just doesn't fill me confidence at all.