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Centre of Gravity


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Hi Guys

 

My new scissor lift has arrived, the operating instructions state that the centre of gravity of the car must be positioned over the centre of the lift. Does anyone know the position of the centre of gravity of a TR6? I suppose the position will vary due to amount of fuel and items in the boot.

 

Thanks for your help

 

Bill

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Hi Bill

 

Centre of gravity is usually around the gear lever or slightly further forward of that point. If you lift it very slowly with wheels just lifting off the ground, you will be able to see where the CoG is as it'll have a tendency to go light on all four wheels.

 

You'd probably need a set of wheel scales to work it out exactly.

 

Kevin

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Hi Bill,

 

the generally accepted figure from back in the day for weight distribution is 52%F / 48%R based on standard kerb weight.

 

The weight of additional items, thinking particularly of tools and spares in the boot, will increase the rear weight and reduce the front % load.

 

In reality, I would simply line up the lift with the approximate centre line of the car, ie midway between the two axle lines, half the wheelbase if you prefer. The TR6 is sufficiently close to 50/50 that an odd inch either way is not significant.

 

Cheers

 

Alec

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The new MOT rollers weigh the axles when in use and my 4a with a 16st MOT man in the driving seat comes out near as shove it 50/50.

Stuart.

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Bill,

 

I wouldn't worry too much about the exact centre of gravity. If your scissor lift looks like mine in the thumbnails then the main headache is getting the car exactly central across the lift frame from side to side. Because the TR6 wheelbase is pretty narrow by modern standards if the car is too far forward or back even when perfectly centralised, the main frame of the lift will contact the inner edge of the tyres. As you can see I position the arms and pads under the rear trailing arms and front chassis rails. I frequently have the car on in either direction depending what I'm working on. It will be impossible to position the car in such a way that an excessive imbalance occurs and still be able to lift it. If your lift is different then disregard this drivel !

 

Having said all that, the lift has been a wonderfully useful bit of kit. Best thing I have bought in recent years. I sunk mine 6in into the floor so when not in use it's covered by scaffold boards and can be driven over. Clearly working underneath is not really practical other than at the front and rear overhangs (oil changes are easy for example) but just to raise the car a couple of feet to save the ageing back when doing simple underbonnet stuff is a great asset. One of those stools on wheels and the ability to raise the car three or four feet makes suspension and brake work a doddle. It's also great for polishing the sides if that's your thing!

 

Not sure why the second image is on its side. Clearly I'm a bit of an attachment virgin.

 

Hope you find it as useful as I have.post-13887-0-81837900-1518525822_thumb.jpgpost-13887-0-93791900-1518526057_thumb.jpg

Edited by Mike Herlihy
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Thank you gentlemen for your help especially Mike, today I finally got the lift working (I bought the E4G MR06GR Portable Mid-Rise Scissor Lift - 2.7 Ton, 1ph from Equipment4garages https://www.garageequipment.co.uk/Garage-Lifts/Mobile-Scissor-Lifts/E4G-MR06GR-Portable-Mid-Rise-Scissor-Lift---27-Ton). My TR6 is quite low and although the lift is only 116mm high fully lowered I had to buy a couple of scaffold boards so I can park over the lift and position the lifting arms.

 

I chose this lift because it only has one cross member and 1300mm lifting height, access looks pretty good but I have not actually worked on the underneath of the car yet.

 

Thanks again gentlemen your help, much appreciated.

 

Bill

 

post-1193-0-42710000-1518811435_thumb.jpgpost-1193-0-10530200-1518811465_thumb.jpg

 

Sorry can't get pictures vertical!

Edited by wheeler
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Hi Bill now you have got your lift I think the first job to do would be to alter the angle of your oil filter adaptor or put a slightly shorter filter on as it appears to be hanging down below the chassis rail & looks very vulnerable especially if the car is very low .

Chris

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