# Chassis seam and jacking point - is this normal over time?



## Suberman (Aug 16, 2010)

For some reason, i took some underbody pictures (chassis seam and jacking points to be exact) and was quite shocked with what i saw. Bumps on the skirts are the jacking point on the pinch weld.

Is this normal? 

FR









FL









RR









RL









They all look like they've been jacked up with iron blocks or something? The seams even though welded together seem to have gone a bit random!:doublesho Car is a STI hatch with about 45k miles.

AFAIK, the car has always been jacked up with either a 4 post lift with rubber pads or a trolley jack with a piece of (rather mashed up- which makes a better cushion than a fresh piece?) plywood from my regular tyre shop.

Either this - trolley jack with plywood









Or this









Please correct me if i'm wrong, but do cars with side skirts generally have less mashed up jacking points? Doesn't seem like it in this case.

Is this inevitable even with proper jacking and lifting procedures and tools?


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## Wally (Sep 2, 2006)

I drive an Impreza for over 10 years, what I do is jack up the rearside on the diff case.
Jack up the front on the chassis beam itself, a good 30 cm further inwards of the normal jacking point.44The points you show here are just for occasionbal use, changing a flat or so. Regulary using those points will indeed damage the coating, but is looks normal to me....


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## Suberman (Aug 16, 2010)

Wally said:


> The points you show here are just for occasionbal use, changing a flat or so. Regulary using those points will indeed damage the coating, but is looks normal to me....


Aren't these the "jacking points" for a proper vehicle lift as well? A proper 4 post vehicle hoist lifts up the car from these points as well.

AFAIK, all proper workshops use a vehicle lift which uses these points for oil changes, tyre rotation etc. How will these be for occassional use?

I'm not referring to the slightly scraped off underseal, but the pinch weld/chassis seam all seems to be slightly bent.


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## Sirmally2 (Feb 28, 2011)

That can be caused by somebody using a jack. Its quite easy to bend them


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## Suberman (Aug 16, 2010)

What type of jack are you referring to?

Like i said, the ONLY jack this car sees is a trolley jack with with a piece of wood or a 4 post lift with a rubber pad.


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## Sirmally2 (Feb 28, 2011)

Have you had the car from new? Does it go into a dealership for service? Ive found that when dealerships check brakes etc they use a trolley jack and depends on the experience of the user if they hit the jackpoint bang on.

Failing this i couldnt really say what has caused it. My jack has slits in for it to sit in, yet they still do get the occasional knock and easy to bend out of shape


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## Suberman (Aug 16, 2010)

Sirmally2 said:


> Have you had the car from new? Does it go into a dealership for service? Ive found that when dealerships check brakes etc they use a trolley jack and depends on the experience of the user if they hit the jackpoint bang on.
> 
> Failing this i couldnt really say what has caused it. My jack has slits in for it to sit in, yet they still do get the occasional knock and easy to bend out of shape


Yes mate, had it since new. It did go into the dealership for the first 3 oil changes and some stuff that only they can rectify, other than that, it's always been to my regular workshop that uses a 4 post lift.

Can a trolley jack with a piece of wood cause this problem? Because the 4 post lifts i know all have rubber pads.


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## Sirmally2 (Feb 28, 2011)

I would say it pay possibly be the wood.... May be worth investing in some of the same material thats on your 4 post lift for your trolley jack? But it may also be possible that it has been done while in dealerships as many of them have apprentices which are obviouslyy not as expereinced as the time served mechanic


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## herbiedacious (Sep 27, 2010)

They obviously haven't got any of these:
http://www.detailingworld.co.uk/forum/showthread.php?t=185071&highlight=pinch+weld


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## Suberman (Aug 16, 2010)

Sirmally2 said:


> I would say it pay possibly be the wood.... May be worth investing in some of the same material thats on your 4 post lift for your trolley jack? But it may also be possible that it has been done while in dealerships as many of them have apprentices which are obviouslyy not as expereinced as the time served mechanic


I do have an adaptor for my own jack.

Here it is.

















Hmmm....I'm thinking that maybe the rubber pads that most workshops use are not too friendly on the pinch welds/seams as well as they do not have the slit for the seam to sit in 

These are the commonly used ones. 









The trolley jacks are not supposed to be used on the seams even with a piece of wood are they? Unless i it's used with an adaptor like the one i shown above?



herbiedacious said:


> They obviously haven't got any of these:
> http://www.detailingworld.co.uk/forum/showthread.php?t=185071&highlight=pinch+weld


They don't mate. Most workshops i know use either a 4 post lift with a rubber pad or a trolley jack with some wood as a cushion.


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## F1 CJE UK (Jul 25, 2010)

I had the same on my subaru, got the dealer to fix them and then got a puck made from the guy on here.


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## badman1972 (Jun 24, 2010)

I'm pretty sure you would find it is quite common but agree that it isn't really acceptable


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## Suberman (Aug 16, 2010)

F1 CJE UK said:


> I had the same on my subaru, got the dealer to fix them and then got a puck made from the guy on here.


Your current Subaru? How did the dealer fix it? Did they do a good job? Was any painting involved?


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## R2P (Dec 25, 2010)

Had this problem on every car I have owned, I just got them seem welded. So now trolley jack goes on something strong like subframes or axles themselfs to prolong rusty sills I also jack it up myself in any tyre shop.
Mot man is the only only person who raises it with the jack on the ramp but thats still on sub frame


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## andy monty (Dec 29, 2007)

Suberman said:


> Your current Subaru? How did the dealer fix it? Did they do a good job? Was any painting involved?


Clean the area with something like surfex and PW

Rinse really well and ideally allow to dry (at this time of year however that might be a problem) :lol:

then treat with Dynax s50 inside the sill if you can get in this will creep along and pour out of any gaps sealing them..

then belt and braces treat the outside with Dynax UC give the area a swill down with white spirit (this will clean and drive out any moisture)

Give the guys at Bilt hamber a ring

http://bilthamber.com/pro-introduction.php?cname=Corrosion Prevention&name=dynax S50

http://bilthamber.com/pro-introduction.php?cname=Corrosion Prevention&name=dynax-UC

I use the workshop jacking points where i can rather than the sill


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## F1 CJE UK (Jul 25, 2010)

Suberman said:


> Your current Subaru? How did the dealer fix it? Did they do a good job? Was any painting involved?


Well I say they fixed it, they reshaped the sill and gave it a quick paint. I only take my car to RCM now and they take care with it.

:thumb:


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## Suberman (Aug 16, 2010)

andy monty said:


> Clean the area with something like surfex and PW
> 
> Rinse really well and ideally allow to dry (at this time of year however that might be a problem) :lol:
> 
> ...


Cheers for that Andy. I know BH makes some great stuff and I'm very keen to try out their dynax UC, but unfortunately (i should've said earlier) i'm not from the UK, so shipping of these products is impossible!


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## Suberman (Aug 16, 2010)

Thanks for all the replies fellas, but i need to know what could've caused this. So i can avoid it like the plague

I can't really pinpoint exactly what caused this but i do know that my car has been lifted by trolley jacks with wood as cushion (as shown in 1st pic). There is no groove on the wood for the sills to sit in, could this most likely be the cause?

Other than that, it's always been jacked up by a proper lift with rubber pads like what i've shown. But those rubber pads do not have a groove as well. Could it be the cause as well?

Also, is it normal if the front suffers more than the rear? Because of the weight up front?


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## moosh (May 8, 2011)

Jacking it up on those points has caused that mate.

I would always try to lift a car further under the car on the chassis rails or subframe.

The block of wood wont be helping as they can split or compress, they do help to a certain extent.

But yes the problem here is the jack and the ramp and solution would be not to jack it at these points.

Those points are designed for the little jack you get in the boot that locates in the correct position but sill damage is sometimes un avoidable and frustrating.


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## Suberman (Aug 16, 2010)

moosh said:


> Jacking it up on those points has caused that mate.
> 
> I would always try to lift a car further under the car on the chassis rails or subframe.
> 
> ...


Yes, i think you are right mate. The trolley jack with a piece of wood is just going to flatten the sills with time as the car is jacked up 1 side at a time which put alot of stress on each jacking point i think.

What this tyre shop have done is, they've attached a piece of wood to all their trolley jacks' cup, so when the lift is occupied they rely on trolley jacks on the factory jacking point.

So i guess the factory jacking point is strictly for use with the factory jack that comes with the car or a trolley jack BUT only with a suitable adaptor like the hockey puck. Wood will still flatten the sills!

Brings me to my next question. What about 4 post lifts with rubber lift pads that do not have a slot or groove on it for the sills? Will those flatten the sills as well?


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## moosh (May 8, 2011)

Suberman said:


> Yes, i think you are right mate. The trolley jack with a piece of wood is just going to flatten the sills with time as the car is jacked up 1 side at a time which put alot of stress on each jacking point i think.
> 
> What this tyre shop have done is, they've attached a piece of wood to all their trolley jacks' cup, so when the lift is occupied they rely on trolley jacks on the factory jacking point.
> 
> ...


They also dont have the grooves dude on the four poster ramps and if they adjustable pads on the lift are not all at the same height that will also cause in some cases a little bit of damage.

Its a manufacturing issue though as these garages obviously do there very best not to damage the sills but if the car maker hasnt made provisions for jacking pads them the garages can only do there best.

Its a pet hate of mine when they jack the car on the sill and ruin it.

On the actual jacking point of the car there is a structural piece of steel which is thicker at the part of the sill than anywhere else on the car so that when the car is jacked up it transfers the load to the other structural parts of the car. The steel on the sill infront of it (actual sill below the cover) is only mild steel and has no structural performance same goes for the floor so the only issue i would have with using a slotted puck or slotted piece of wood is if it doenst rest or touch the structural part it will cause damage to the softer areas i.e. floor pan and sill.

Solution on your car as has been said is jack the car up on the central diff skip pan or at the front on the subframe :thumb:


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## Suberman (Aug 16, 2010)

moosh said:


> The steel on the sill infront of it (actual sill below the cover) is only mild steel and has no structural performance same goes for the floor so the only issue i would have with using a slotted puck or slotted piece of wood is if it doenst rest or touch the structural part it will cause damage to the softer areas i.e. floor pan and sill.
> 
> Solution on your car as has been said is jack the car up on the central diff skip pan or at the front on the subframe :thumb:


There are 2 humps on the floor itself (behind the factory jack points) I believe those are one of the reinforced areas that will hold the car's weight?

These









The owners' manual states that the factory jacking point is to be used when lifting a car with a 4 post lift, but the picture clearly shows a lift pad with a slot in it to fit over the sill. If rubber lifting pads also may slightly flatten the sills why do the manufacturers of these lifts even make them?! 

I can't do an oil change by just jacking up the front or rear. The shop that does it for me uses a 4 post lift. There must be a way out for for using a lift with rubber lift pads? Maybe position the pads where the humps are?


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## Bero (Mar 9, 2008)

Having sold a few of these lifting adapters/pucks i understand the problem well!

I think it's worse using a hand jack as opposed to a 2 poster/4 poster with lifting beam. 'Proper' lifts lift at 4 points simultaneously and act directly up. A trolley jack lifts one corner and tends to try and pull the seam weld out as the jack pad moves in an arc up and towards the jacking handle due to the design of hand operated jacks.


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## Suberman (Aug 16, 2010)

Bero said:


> Having sold a few of these lifting adapters/pucks i understand the problem well!
> 
> I think it's worse using a hand jack as opposed to a 2 poster/4 poster with lifting beam. 'Proper' lifts lift at 4 points simultaneously and act directly up. A trolley jack lifts one corner and tends to try and pull the seam weld out as the jack pad moves in an arc up and towards the jacking handle due to the design of hand operated jacks.


No more hand jacks to be used on any of my cars from now on even with wood or rubber as i think it'll still damage the sill somewhat, unless it has a proper adaptor/puck.

Have you had any issues with bent or damaged sills with a proper adaptor/puck with a handjack?

What about lifts with rubber pads without a groove or slot in them? Do these go over the sills or inside behind the sills? Although rubber, they seem quite hard really, will they flatten the sills as well?

This is the rubber pad that my tyre shop uses. Is this ok? Doesn't look too sill friendly TBH.


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## Bero (Mar 9, 2008)

Suberman said:


> No more hand jacks to be used on any of my cars from now on even with wood or rubber as i think it'll still damage the sill somewhat, unless it has a proper adaptor/puck.
> 
> Have you had any issues with bent or damaged sills with a proper adaptor/puck with a handjack?
> 
> ...


I've not had any issues and of the 100+ i sold on DW all the feedback over 320 posts was positive.

Looking at the marks on the pad your tyre place uses I'd say they jack up right on the seam (look at the multiple straight line marks across the pad).

As for 'Is this OK?'.......I guess it depends on your definition of OK. The bigger the pad the better, each one will be lifting 300-400kg and it's better the spread that over a big pad.....but it's still a lot of weight resting on an edge.


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