Starting Car on Jack Stands? Safe/Unsafe?

[xRUSTYx]

Hey Guys ...

Car's been on jack stands for the past two weeks. Have tires incoming and decided to update the exhaust while I was at it ... Change oil, diff, and tranny fluid as well.

Couple Things:
1) I want to heat up the oil to make it come out a bit better.
2) I also need to start the car and allow to heat up to check exhaust fitment & side sill fitment.

Now, The car is sturdy. I've tried bumping it rather hard, and it doesn't move. Jack stands are on flat concrete. Safe to start? I wouldn't rev, just start & idle to heat up oil/exhaust.

Thanks guys!

 

[CPPRHD265]

Personally, I won't do it... especially if you have solid motor mounts

 

[Torquemonster06]

I wouldnt do it myself. I would hate to see it fall off. Personally I would just lower and jack it up as needed to get those things right. Two jacks makes it alot easier. IMHO.

 

[Steve-Indy]

You may want to read this thread...a few more hazzards:

http://forums.viperclub.org/threads...-maybe-you-can-help?highlight=carbon+monoxide

 

[xRUSTYx]

Personally, I won't do it... especially if you have solid motor mounts

Hmmmm... You have me thinkin!

I wouldnt do it myself. I would hate to see it fall off. Personally I would just lower and jack it up as needed to get those things right. Two jacks makes it alot easier. IMHO.

I could do this as well, but then changing all the fluids while warm would be a bit more difficult.

You may want to read this thread...a few more hazzards:

http://forums.viperclub.org/threads...-maybe-you-can-help?highlight=carbon+monoxide

Steve, are you telling me I need to take off the drivers door ahead of time? haha ...

The exhaust vents to the open air (rear end is 12 inches from the opening of the garage)

Appreciate that thread though. Never would have thought pulling a fuse would fry a PCM!

 

[AviP]

I do it all the time. The chassis is so stiff, at times it seems that the 4th jack is not needed. I have jacked it up completely with 3 jacks. Freaky cool! So to worry about it's stability is a joke. It's going nowhere unless you jacked it wrong. Be safe.

 

[TrackAire]

I've done it multiple times and with multiple different cars. Very common at the track. On a Viper, it is very important that you have the contact points all evenly loaded because the frame is so stiff, you could have 3 points holding 90% or more of the cars weight and you might not know it if you don't pay attention. Most normal cars have so much flex that even if all 4 of your jackstands are not making great contact, the car flexes enough to weigh down each contact point very well.
Again, make sure you have the jackstands in the rigth place and that they are connected to the frame/jacking points correctly, other than that it's no big deal IMO.

I've also seen mechanics start cars on two post lifts (four contact points, just like you have now) and sometimes those cars are 5 or 6 feet in the air.

Cheers,
George

 

[xRUSTYx]

I do it all the time. The chassis is so stiff, at times it seems that the 4th jack is not needed. I have jacked it up completely with 3 jacks. Freaky cool! So to worry about it's stability is a joke. It's going nowhere unless you jacked it wrong. Be safe.

Good to know ... and yes, only 3 jack stands are holding mine up. The 4th is about 1/2" from being used. Its still under the jacking point however, just in case LOL.

I've done it multiple times and with multiple different cars. Very common at the track. On a Viper, it is very important that you have the contact points all evenly loaded because the frame is so stiff, you could have 3 points holding 90% or more of the cars weight and you might not know it if you don't pay attention. Most normal cars have so much flex that even if all 4 of your jackstands are not making great contact, the car flexes enough to weigh down each contact point very well.
Again, make sure you have the jackstands in the rigth place and that they are connected to the frame/jacking points correctly, other than that it's no big deal IMO.

I've also seen mechanics start cars on two post lifts (four contact points, just like you have now) and sometimes those cars are 5 or 6 feet in the air.

Cheers,
George

Thanks George ...

My passenger side jack stand is not touching the triangle on the passenger side. Its about 1/2" short. Would you recommend I use the actual jack so that jacking point is indeed taking some of the load?

 

[TowDawg]

As long as you have the jack stands in the right place and it's balanced, it's no problem. I've done it with mine plenty of times.
I also have rubber covers over my jack stands, so it helps isolate any vibration that could possibly cause metal on metal to move around and possibly be an issue.

 

[xRUSTYx]

As long as you have the jack stands in the right place and it's balanced, it's no problem. I've done it with mine plenty of times.
I also have rubber covers over my jack stands, so it helps isolate any vibration that could possibly cause metal on metal to move around and possibly be an issue.

This is a good idea. I have some pretty thick foam padding I could cut and put on each jack stand to make sure nothing slips! Thanks!

 

[ViperTony]

Can't say I've done this with 3 jack stands but certainly 4. I've never had issues running the Viper on jack stands and movement, etc. But I use 12 ton jack stands which gives me about 19" clearance under the Viper without having to raise the jack stands at all. Sturdy....it's not going anywhere.

 

[TrackAire]

Good to know ... and yes, only 3 jack stands are holding mine up. The 4th is about 1/2" from being used. Its still under the jacking point however, just in case LOL.





Thanks George ...

My passenger side jack stand is not touching the triangle on the passenger side. Its about 1/2" short. Would you recommend I use the actual jack so that jacking point is indeed taking some of the load?

I always have at least 4 contact points. I make sure there is weight on each jack stand (I use the scientific test of grabbing the jack stand and giving it a good shake, lol...you will be able to feel if the jack stand has a lot of weight on it or if it can stand to be raised another notch). If you're in between notches, you can always use a small square base of plywood of different thickness to take up the slack and get a very even weight on the jack stands.

I will say this, be careful about using the all aluminim jack stands made by Torin as your only support. They have a round tube design with one very small bolt holding the vertical tube to the baseplate. I would not trust these as your main support. I have a set of four that I use when traveling to track events as a backup to my 4 scissor jacks. They are very light weight and easy to handle but if holding up the entire car, I would only use a more traditional jack stand with a wide base that slopes up like a pyramid. No proof that these have failed, but they are made in China out of who knows what quality aluminum so better to be safe than sorry IMO. I use them as a backup safety precaution which I feel they are well suited for (when used with my 4 screw jacks this gives me 8 points of contact and stability...mainly used when not in the shop but at the track, etc where I don't have my normal tools and don't want to deal with the weight and awkwardness of the traditional jack stand).

Cheers,
George

 

[xRUSTYx]

Thanks George!

I'm using the TORIN Double Locking 3 ton Steel Jack stands. These: http://www.northerntool.com/shop/tools/product_200305225_200305225

Bit weary of using a wood block right under the triangle? Doesn't seem too sturdy to me?

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[TrackAire]

Thanks George!

I'm using the TORIN Double Locking 3 ton Steel Jack stands. These: http://www.northerntool.com/shop/tools/product_200305225_200305225

Bit weary of using a wood block right under the triangle? Doesn't seem too sturdy to me?

You must be registered for see images

That is the jack stand design I prefer.

Regarding wood, I'm talking about a sheet of plywood, maybe 1" bigger on all sides than the base of your jack stand. Maybe get something that is around 3/8" thick to use as a base. This will allow you to fine tune the height of the jack stand since a lot of garage floors, etc are nowhere near flat to begin with.

Take your time, double check everything and you'll be good to go.

Cheers,
George

 

[Viper Specialty]

Have done it a thousand times. I do prefer however to have two hydraulic jacks lightly on the front lift points as well, as the best points for jack stands on the front are rather close to center line of the car.

 

[xRUSTYx]

Did it this evening ... No Issues

Thanks for all the responses guys!

Another Question, this time, an exhaust questions.

I've read I can either tack weld, or use self tapping set screws. Thinking about going with screws for a couple reasons

1) The car is still on jack stands, and I've been unable to find a mobile welder locally
2) I don't feel like grinding off welds should I decide to change something.

So ... I figured a single set screw through each Band Clamp ... Anyone know a good length/size to use?