Today I did something to my car (volume 2)

MetzgerMeister

M Performance Pedals fitted during the week.

Before:




After:

zurbfoundation

new gaskets for the manifold, had some leakage there - the exhaust manifold gasket and the gasket between manifold and down pipe - much quieter now and i don't get any fumes when stopped at the lights :-)

Toyotafanboi

Best - engine - ever!

Black_Knight

Not today, but at the weekend I did some more investigation into my GFs Mini fuel gauge problems.

The good news is, it appears the problem might be limited to a single bad (single core) wire! :cool:
If I can find a replacement wire with the connectors, great! If not it'll be a hacky DIY job. Just needs to work, doesnt need to be pretty.

nd

There was a leaking rear shock in the Primera I bought a couple of weeks ago. I said it'd be wise to change both rather than one.

So these arrived today



old ones



I used Jou's ratchet strap idea to compress the springs.


installed

5W30

nd wrote: »

I used Jou's ratchet strap idea to compress the springs.

Although I've seen worse, lads impacting the nut off whilst holding the spring with their feet on the ground Works when changing for smaller springs which don't need to be re-compressed to screw the nut back on.

I wouldn't do it either way. You only have to buy spring compressors once

You seem like a bodge fan with the bodge compression method and bodge higher trolley jack :pac:

nd

I disagree that the jack is a bodge. It works. And imo safely. And on this occasion the straps worked. And again safely as I never put my fingers somewhere that if they failed I'd get injured. Imo sometimes people trust the "proper tool" more than they should and put themselves in danger because they think it's can't fail.

Imo it's a good idea to use tools whether "proper" or not with the mindset that even if they fail you can not get injured.

I've seen a qualified mechanic under a transit with nothing holding it up other than a jack. But it was a proper jack so I'm sure he was grand :pac:

Toyotafanboi

5W30 wrote: »

Although I've seen worse, lads impacting the nut off whilst holding the spring with their feet on the ground Works when changing for smaller springs which don't need to be re-compressed to screw the nut back on.

I wouldn't do it either way. You only have to buy spring compressors once

You seem like a bodge fan with the bodge compression method and bodge higher trolley jack :pac:

I don't think it's too bad, particularly on the rear springs on an older model primera. They aren't under a mad amount of compression, look at how the spring is wrapped by the strap in the new shock, how would he have removed the strap at all if the compression was huge? it would be pinched tight between the spring and shock cup.

I know no two cases are the same and I wouldn't automatically try a "bodge" method, but on a few older jap models i've seen you can just hold the spring with your hand, it barely even flinches when you open the shock top.

5W30

You'd be a bit mad to assume a spring isn't really compressed just because it's on an old Japanese car...

I personally wouldn't fcuk around with springs. I've seen a few flying away from mechanics and it's not pretty.

Toyotafanboi

Well, I agree asumptions lead to errors. At the same time, time the springs in the rear of an old, light car will most likely not be under huge compression. Take it on a case by case basis, but the rears on my old starlet for example, when the weight of the car was taken off of the shock you could squeeze the spring with your hand. I've seen plenty of springs shooting off on youtube and i'm sure it can and does happen, but looks like the lad got away grand in this instance.

joujoujou

5W30 wrote: »

[...] I've seen a few flying away from mechanics and it's not pretty.

^^This!^^


...leads directly to a conclusion - a tool used is only as intelligent as the person using it. So actually no ratchet strap is more dangerous than a spring compression tool, especially if inappropriately used.

5W30

joujoujou wrote: »

^^This!^^


...leads directly to a conclusion - a tool used is only as intelligent as the person using it. So actually no ratchet strap is more dangerous than a spring compression tool, especially if inappropriately used.

That does not mean you use your t-shirt to compress a spring and put it all down to your "skillz"

joujoujou

Who said it does?

5W30

joujoujou wrote: »

Who said it does?

joujoujou wrote: »

So actually no ratchet strap is more dangerous than a spring compression tool, especially if inappropriately used.

^

But let's not ruin an interesting thread.

All that matters is that it worked!

colm_mcm

joujoujou wrote: »

^^This!^^


...leads directly to a conclusion - a tool used is only as intelligent as the person using it. So actually no ratchet strap is more dangerous than a spring compression tool, especially if inappropriately used.

Ratchet straps aren't nearly as strong as spring compressors and can easily mis-shape and break under pressure.

Using ratchet straps to compress springs is by definition inappropriate use.

That said some springs are shorter than others, some shocks are longer than others etc

Ded_Zebra

Most ratchet straps that sort of size are rated for at least 1000kg, could even be 2000kg. I would trust them 100% to compress a spring and probably more so than some spring compressors.

CIP4

Ded_Zebra wrote: »

Most ratchet straps that sort of size are rated for at least 1000kg, could even be 2000kg. I would trust them 100% to compress a spring and probably more so than some spring compressors.

From an engineering point of view I wouldn't even slightly trust it. Firstly that's a 350 kg ratchet standard for that size you hardly think that tiny ratchet would support a car or more hanging out of it.


Based on hookes law F = -kx,

k = 100000 N/m conservative enough for a car Spring constant
X = displacement of Spring from neutral position i.e. With no weight on it.
F of the strap = 350 by 9.81 = 3433.5 newtons. This is the force the ratchet can take.

At x = 30 mm

F = 3,000 newtons

At x = 40 mm

F = 4,000 newtons

At x = 50 mm

F = 5,000 newtons

So stating the obvious no it's not grand your fairly dam near the breaking point of the ratchet strap even if the k value is abit lower your still close and that's not even adding in a factor of safety.

It was fine this time but maybe not the next time your playing very close to the limits and things don't like being pushed to there limits. Anyway what's done is done but I wouldn't be calling it a safe alternative.

nd

My question is, what do you think happens if it breaks? In my case I used it to compress the spring less than an inch to allow the nut on to the top of the shock. That was with the shock and spring totally off the car. No fingers ect. could have been trapped. If it had snapped I'd to have found another way of compressing the spring. In this instance I don't see how it could have been dangerous.

Nor in Jou's case.

CIP4

nd wrote: »

My question is, what do you think happens if it breaks? In my case I used it to compress the spring less than an inch to allow the nut on to the top of the shock. That was with the shock and spring totally off the car. No fingers ect. could have been trapped. If it had snapped I'd to have found another way of compressing the spring. In this instance I don't see how it could have been dangerous.

But if any of the metal components in the ratchet broke of and struck you in the face or eye chances of it happening maybe aren't huge but the ratchet mechanism is rated to 350 kg and as you seen you could easily go over it. Wouldn't of been as bad if the strap failed but with the ratchet that's a good bit of energy your letting out of the system if it snaps potentially leading to high velocity metal.

Look I wasn't trying to pick you out as there is a few that have done it. But sometimes people forget how easily things can go wrong or how close they are to its limit.

rizzee

Bulbs and plates.

Ded_Zebra

CIP4 wrote: »

From an engineering point of view I wouldn't even slightly trust it. Firstly that's a 350 kg ratchet standard for that size you hardly think that tiny ratchet would support a car or more hanging out of it.


Based on hookes law F = -kx,

k = 100000 N/m conservative enough for a car Spring constant
X = displacement of Spring from neutral position i.e. With no weight on it.
F of the strap = 350 by 9.81 = 3433.5 newtons. This is the force the ratchet can take.

At x = 30 mm

F = 3,000 newtons

At x = 40 mm

F = 4,000 newtons

At x = 50 mm

F = 5,000 newtons

So stating the obvious no it's not grand your fairly dam near the breaking point of the ratchet strap even if the k value is abit lower your still close and that's not even adding in a factor of safety.

It was fine this time but maybe not the next time your playing very close to the limits and things don't like being pushed to there limits. Anyway what's done is done but I wouldn't be calling it a safe alternative.

CIP4 wrote: »

But if any of the metal components in the ratchet broke of and struck you in the face or eye chances of it happening maybe aren't huge but the ratchet mechanism is rated to 350 kg and as you seen you could easily go over it. Wouldn't of been as bad if the strap failed but with the ratchet that's a good bit of energy your letting out of the system if it snaps potentially leading to high velocity metal.

Look I wasn't trying to pick you out as there is a few that have done it. But sometimes people forget how easily things can go wrong or how close they are to its limit.

Firstly it may interest you to know that I am also mechanical engineer, It's nice to see a bit of maths going on on the forum

I have no idea what those ratchet straps are rated for (neither do you). ND will probably be able to tell us a it is usually written on the label. Just eyeballing it to a similar strap that my dad was using last weekend (to lift the body of a toyota MR2 actually, temporarily) which was rated to 1000kg not the 350 you have quoted. The reason I would prefer to use them over some cheaper spring compressors is tat the spring compressors have a tendency to slip on the springs to suddenly let them go. The straps are less lightly to slip.

Unless ND confirms the rating of the strap we won't know.

5W30

rizzee wrote: »

Bulbs and plates.

Doing that myself soon enough. I already ordered the LED bulbs.

Need to order pressed plates. Looks good though!

5W30

OSI wrote: »

That's probably the best way to do it

CIP4

Ded_Zebra wrote: »

Firstly it may interest you to know that I am also mechanical engineer, It's nice to see a bit of maths going on on the forum

I have no idea what those ratchet straps are rated for (neither do you). ND will probably be able to tell us a it is usually written on the label. Just eyeballing it to a similar strap that my dad was using last weekend (to lift the body of a toyota MR2 actually, temporarily) which was rated to 1000kg not the 350 you have quoted. The reason I would prefer to use them over some cheaper spring compressors is tat the spring compressors have a tendency to slip on the springs to suddenly let them go. The straps are less lightly to slip.

Unless ND confirms the rating of the strap we won't know.

Well I'm 99% sure they are lidl / aldi which if you look them up they are 350kg I didn't pick the number out of the sky. I've never seen a strap that size rated to 1000 kg but maybe you can get them. Any one ton straps we have at home are a lot bigger than that and 2 ton a lot lot bigger than that. But Ye obviously without it being read of the strap everyone is guessing to a certain extent.

Look I am not trying to show up ND up or anything I mean ultimately nothing went wrong but I still think you are working close enough to the limits far ale bough if there 1 ton straps and your only compressing the spring by 30mm or so. Nice to put a bit of maths behind what I'm saying but if your a mechanical engineer obviously you know to get a fully correct answer I'd need to calculate k using diameter, G etc but as I don't have the spring plus I think that would be going a bit far.

Toyotafanboi

Can't bate a bit of hookes law there must somehow be a way to involve youngs modulus, afaik it's the way to solve pretty much every engineering problem ever.

nd

250 daN/kg lashing capacity straight pull, 500 daN/kg round pull

And there were of course 2 in my case. 4 in jou's. I know that 2/4 isn't 2/4 times the capacity. But they obviously help each other.

Ded_Zebra

CIP4 wrote: »

Well I'm 99% sure they are lidl / aldi which if you look them up they are 350kg I didn't pick the number out of the sky. I've never seen a strap that size rated to 1000 kg but maybe you can get them. Any one ton straps we have at home are a lot bigger than that and 2 ton a lot lot bigger than that. But Ye obviously without it being read of the strap everyone is guessing to a certain extent.

Look I am not trying to show up ND up or anything I mean ultimately nothing went wrong but I still think you are working close enough to the limits far ale bough if there 1 ton straps and your only compressing the spring by 30mm or so. Nice to put a bit of maths behind what I'm saying but if your a mechanical engineer obviously you know to get a fully correct answer I'd need to calculate k using diameter, G etc but as I don't have the spring plus I think that would be going a bit far.

Life is always more exciting close to the limits!!! I would also hazard a gess that they make those straps with a fairly big factor of safety because they know people will be idiots with them!

Straps like that are actually a lot stronger than they look. Seatbelts for example are tested at 9.8kN and have an ultimate tensile strength a hell of a lot higher than that!

joujoujou

Precisely.

AFAIK all mechanical devices (whatever you call them) are tested well above their "official" load capacity.

Whatever it is - a ratchet strap, a bridge or a crane - load limit is not a real limit. Obviously nobody should ever go over the limit.

Finally, whatever your opinion is, it worked perfectly.

5W30

joujoujou wrote: »

Precisely.

AFAIK all mechanical devices (whatever you call them) are tested well above their "official" load capacity.

Whatever it is - a ratchet strap, a bridge or a crane - load limit is not a real limit. Obviously nobody should ever go over the limit.

Finally, whatever your opinion is, it worked perfectly.

I agree but personally I'd rather keep my fingers/face/arms/bollocks rather than the 40 quid it costs for a decent set of spring compressors :eek:

CIP4

Ded_Zebra wrote: »

Life is always more exciting close to the limits!!! I would also hazard a gess that they make those straps with a fairly big factor of safety because they know people will be idiots with them!

Straps like that are actually a lot stronger than they look. Seatbelts for example are tested at 9.8kN and have an ultimate tensile strength a hell of a lot higher than that!

Ah Ye look fair enough I'm not trying to turn it into a big dangerous the straps would have a factor of safety added but if there 250kg straight capacity as ND said with a factor of safety of two they are still only 500kg. Anyway it doesn't matter it worked I wouldn't personally do it but maybe I'm over cautious. We shall move on I don't want to turn the thread into pages of this.

In other news I need to do something to my car to post it here I honestly haven't touched it mechanically since before the summer. I bought it but a new air filter in it, replaced dips to H7 night breakers changed number plate bulbs to slightly more led look bulbs. Replaced a few missing screws in parcel shelf support and that's literally it in 6 months. Probably a bad thing I miss doing the small jobs.