Can you safely jack up at the center of the axle?

[mainemike]

What I like about using a heavier jack stand is the base (footprint) gets much larger. I also do not like having to raise the jack stand very far using the extension - the heavier stands are taller. This is all good for peace of mind. Once you get used to using a 6 ton or larger the smaller ones look like twigs. (sort of like the axles on a heep)

 

[rove_mcanus]

It works better if you jack from next to the diff center

 

[96r50]

I don't know about the CDL bit. Aren't you relying only on the Park pawl to hold the truck then? That doesn't inspire that much confidence for me. And yes you better have a good parking brake, but that seems kinda necessary anyway. If not only for regular driving, at least to pass the safety inspection at events...

I just always put big chocks anytime I lift a vehicle up. And whenever I can, I'll also put something big underneath a solid part just as backup.

I don't like to lift off the diff housing too much. More unstable than the side tubes and could put undue stress on the 3rd member bolts possibly. Done it though.

We rely on the parking pawl the other 364 days of the year to hold the truck in place (sometimes in less than ideal circumstances), so why not? I haven't heard of any parking pawl failures, including trucks that have been hit (and pushed) while in park, so I trust it. I'm not arguing that this is better than the parking brake or chocks, it's just what has worked for me in the past. The parking pawl is designed to keep the truck from rolling forwards or backwards while in park, so why shouldn't that apply when the CDL is locked (eliminating the VC from the equation), and one axle is on jackstands?

Obviously the ideal situation would be to use the parking brake, chocks, parking pawl and CDL, as well as strapping the truck in between two large immovable objects and banning gravity from the workspace around and under the truck. However, I don't think any of us have that much time (or mad skillz) on our hands when we want to change a tire or do a knuckle repack.

X2 on putting the removed tires or other solid objects under the frame/sliders as a backup.

 

[shfd739]

I jacked mine up from the rear diff last week to do rear brakes. I have a Craftsman professional floor jack (paid a chunk of money for it but the ease of use and big rating were worth it over a dinky trolley jack) that I placed under the center of the rear diff. Once up jack stands went under it and once I settle the truck on stands I keep the jack up just incase the stands give out it will catch it; or at least give me enough time so I can get out from under the truck.

I figure our mechanic at work lifts 13,000 lb ambulances from under the rear diff that it should be fine on the Cruiser.

 

[firetruck41]

We rely on the parking pawl the other 364 days of the year to hold the truck in place (sometimes in less than ideal circumstances), so why not? I haven't heard of any parking pawl failures, including trucks that have been hit (and pushed) while in park, so I trust it. I'm not arguing that this is better than the parking brake or chocks, it's just what has worked for me in the past. The parking pawl is designed to keep the truck from rolling forwards or backwards while in park, so why shouldn't that apply when the CDL is locked (eliminating the VC from the equation), and one axle is on jackstands?

Obviously the ideal situation would be to use the parking brake, chocks, parking pawl and CDL, as well as strapping the truck in between two large immovable objects and banning gravity from the workspace around and under the truck. However, I don't think any of us have that much time (or mad skillz) on our hands when we want to change a tire or do a knuckle repack.

X2 on putting the removed tires or other solid objects under the frame/sliders as a backup.

I never trust my truck to the parking pawl. One of the first things I learned in drivers ed (many years ago), was to set the parking brake, then place the car in "park". This way the parking pawl does not have any pressure on it. I do this every time I turn off the car, or ambulance at work. Drives some of my coworkers crazy to find the "emergency" brake on when it is parked in the safety of a flat truck bay. I have also had coworkers who did not have that habit ingrained in them, get to an emergency scene, and in their excitement forget to put the ambulance in park, and never think about using the E-brake, when they step out, they find the ambulance driving away from them...

 

[wxm]

I have been using a pair 4-ton rated Craftsman from Sears (Craftsman Professional 4 -Ton Jack Stands, One Pair - 50163 at Sears.com), thinking 8000 lbs would be enough for our truck. Never taken consideration of one side yield its way. Though I always kept the lift in lock position as safety backup. Maybe I should pick up a 6-ton pair from HarborFreight...

 

[Tenzig Norgay]

Just jack it up, put it on stands and get to work. You thought you were jacking up the taj majal or something.

 

[e9999]

I never trust my truck to the parking pawl. One of the first things I learned in drivers ed (many years ago), was to set the parking brake, then place the car in "park". This way the parking pawl does not have any pressure on it. I do this every time I turn off the car, or ambulance at work. Drives some of my coworkers crazy to find the "emergency" brake on when it is parked in the safety of a flat truck bay. I have also had coworkers who did not have that habit ingrained in them, get to an emergency scene, and in their excitement forget to put the ambulance in park, and never think about using the E-brake, when they step out, they find the ambulance driving away from them...

agree.

I don't know what's with folks not using the parking brake. It's more than just an emergency brake. In fact, I have used mine a million times as a PB but never ever that I recall as an EB besides playing with it once or twice for fun. Not only do I use both PB and Park (obviously the latter since i want the key), but I also very much do the PB first and then the Park, for the same reason given above - less stress on the pawl. In fact, had to remind my new driver teen to do that a few times but I think the torch is now passed safely...

 

[hawaiicruz]

It is dangerous Eric and I probably shouldn't have mentioned the spacer.

Certainly, nobody should ever get underneath (even for a short time) any vehicle that is supported only by a jack even if it us a good jack. But sometimes you need to get the truck higher than the jack will lift (mine has a 20" lift) and I will use a 4x4 as a spacer while I ratchet up the jack stands another 4" or so. Again, not a great practice but I try to do it as safely as possible.

I also shove a tyre+wheel underneath the slider on each side if I am working under the truck.

If I was going to skimp on something, it would NOT be the jack stands. I want those to be tall and heavy duty... way more HD than the weight of the truck and plenty tall enough to get the truck high enough to do the job.

-B-

I personally would never try to lift a vehicle from the pumpkin it's just not worth the risk and x3 on sticking the tire underneath just in case
and and always use e-brake
and chocks if you can
its one thing if your just changing the tire and leaving the truck on the jack, but if your working on it PLEASE have it properly supported I also carry 2 pieces of 2x12 so I can use them as supports UNDER the jack just in case
( I do alot of wheeling in soft sand)

 

[Doc]

as the previous poster has already stated. Propper support surface is the key. It doesn't matter if your using 6 or 12 ton jack stands if they sink into the dirt.

I had the front end of my 80 up on stands doing my first birf job. My driveway is gravel, and was dry when I started the birf job. No problems. Until I found out I forgot to buy certain parts. It stayed on jack stand until the parts arrived, about a week later. Then it rained, and one morning I came out to find the nose of the cruiser on the ground. The jackstands had buried themselves in my driveway. Now I always place at least a 3/4" plywood sheet (2 foot x 2 foot) under each jack stand.

 

[woody]

I've jacked up my rig from just about every part of the truck....

the key is the PLATFORM...any point solid enough to keep the truck suspended is solid enough to jack from...frame, control arms, pumpkin, housing, etc. The constant force applied by a jack is SIGNIFICANTLY less than that from daily driving, and that is far less than the stresses of wheeling.

My rig is on 3 wheels now (see my other thread)...the truck slid off the back of the flatbed wrecker into my driveway...I put a jack under the center of the housing (left of the pumpkin, it was too close to the ground), got it high enough to put a jack under the passenger side outer edge of the housing, then repositioned my Sears floor jack under the pumpkin....

I then drove it into the garage....3 wheels and one wheeled floor jack...yeah, I had a buddy 'steering' the jack, or it would'a steered itself...

I'm far from a safety poster child, but am conscientious when it comes to jackstand placement, floor jack use, etc...now if I was just better at preventative maintenance

 

[80t0ylc]

I think we kinda drifted away from the OPs question about jack placement, but still related and worth mentioning. Jackstands and their weight rating. Been doing a little web surfing and came up with these conclusions:

1. Higher rated (6 ton & up) are not that much more expensive and well worth the difference in cost for both safety and height of lift.
2. Inspect your jackstands for cracks and rust near welds that could lead to failure.
3. The surface that jackstands are placed on is as important as the rating of the jackstands. Concrete is best, pavement is almost as good. Jackstands have been known to sink into pavement in hot weather and not always evenly. Gravel & dirt can become swampy with wet weather. If used on surfaces other than concrete, either limit time on jackstands or beef up support under jackstands. Sheetmetal on wood can prevent jackstand sinking into the wood.
4. MOST IMPORTANT: I saved the best for last. Before you start your work under rig on jackstands, grab the rig and try to shake it hard! If it's gonna come down, you want to know before you get under it. Do this each day before work and even after long breaks on same day. This is especially important if rig is jacked up on anything but concrete. If you feel any instability at all, fix it before proceding.

PS: You can not be too safe. You are the final judge when it come to your safety, don't take shortcuts in this area.