On the rear, I put the floor jack right under the pumpkin of the axle. On the front, because of the weight of the engine, I jack at the bottom of each I beam as close to the tire as I can while still getting good grip (on a 2WD like ours...)

Floor jacks are imperative. I lost an uncle back in the 60s to a floor jack that ruptured an o-ring while he was under the vehicle for a "quick check".

 

Floor jacks are imperative. I lost an uncle back in the 60s to a floor jack that ruptured an o-ring while he was under the vehicle for a "quick check".

I think you meant to say "Jack stands are imperative"

Harbor Freight has the big 6 ton stands, anyone using those?

 

Thanks, RT. So sorry for the loss of your uncle. I bought some jack stands last year for our travel trailer and also plan to use them on our truck when I do the job.

 

Do you have actual jack stands that are designed for trailers or ones that are designed for cars and trucks?

When it comes time for saftey under or around a vehicle you need the right ones.

 

Oops. Great catch. Distracted typing.


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Do you have actual jack stands that are designed for trailers or ones that are designed for cars and trucks?

Your right they are different. the trailer ones are generally screw type with a small flat circle at the top, and the automotive type have notched stops and a "U" shaped head. I wouldn't use a trailer type on an automobile, but I would use an automotive type on an RV.

Harbor Freight has the big 6 ton stands, anyone using those?

I have a couple of 2 ton sets that have served me well for over a decade. I used a pair of 12 ton to hold the front axle of a '72 Winnebago, 37" off the ground to drop an engine. That 454 would lift the front end of that 27' motorhome off the ground when I was done. :thumbsup:

 

On the front I jack my truck up with the floor jack under where the spring crosses the axle tube. On the rear the same thing. I never, ever, jack any unit up with the jack under the gear box or "pumpkin" as some call it. For those that do just take a step back, look at the leverage you are putting on the connection of the tubes and the center section, or better yet take the rear cover off and put a dial indicator on the gears when you do it, it flexes. I would agree that jack stands are a must. A jack stand won't leak down or drop on you suddenly. Safety and sense.

 

I never, ever, jack any unit up with the jack under the gear box or "pumpkin" as some call it.

I don't mind putting a jack there on an unloaded vehicle but I wouldn't on a loaded one.

 

Yes I see that a lot, there that pumkin is, it looks like the best spot and it certainly is the most convenient / easy spot to place your jack. It is unfortunatly one of many spots absolutly not intended to support a vertical load of the units weight front or back. Think leverage multiplication.

 

True - and I wouldn't think about doing it on a vehicle that had any significant weight in the back. On a pickup, usually you can get two guys named Bubba to pick the back up without jacks. To pick the back up with no torque applied to the axle tubes, you'd need two floor jacks one under each leaf spring lifted exactly the same amount at the same time. Just lifting one side at a time would exert a lot more force on the components than lifting it in the center.

 

True - and I wouldn't think about doing it on a vehicle that had any significant weight in the back. On a pickup, usually you can get two guys named Bubba to pick the back up without jacks. To pick the back up with no torque applied to the axle tubes, you'd need two floor jacks one under each leaf spring lifted exactly the same amount at the same time. Just lifting one side at a time would exert a lot more force on the components than lifting it in the center.

One of the fun things to do on this forum is split hairs, it is just that kind of media. We expand upon many things past a practical mechanical purpose sometimes, but this is not one of them. RT, you are a smart guy but are just defending a poor mechanical practice on this topic in my opinion. I think that if you re-read you own post above you will find where I base that.

 

I have four jack stands intended for vehicles that I also use with our travel trailer. They are rated at four tons each.

 

I worked in auto repair shops, that had no lifts, for about 20 years. There were at least 10-20 vehicles per day that were jacked up by placing the jack under the center of the differential. That's 50-100,000 vehicles without any issues. I'd guess there are 1,000's of other people with like experiences. I'd also guess there is someone somewhere that has seen some damage by doing this.

I'd also guess there is someone who always leaves his window down so he can get into his car because he once slammed his finger in the door.

 

I worked in auto repair shops, that had no lifts, for about 20 years. There were at least 10-20 vehicles per day that were jacked up by placing the jack under the center of the differential. That's 50-100,000 vehicles without any issues. I'd guess there are 1,000's of other people with like experiences. I'd also guess there is someone somewhere that has seen some damage by doing this.

I'd also guess there is someone who always leaves his window down so he can get into his car because he once slammed his finger in the door.

You make a good point just not supporting your own analysis, how often did you check a vehicle for internal gear box damage after you did this manuever that NO gear box manfacturer recommends that I know of, or did you like many make an assumption? Are you writing from personal experience about your window?

 

OK, you guys haven't convinced me that this is the right way to do things, in fact it is recommended by differential manfacturers that you don't do it. But you have convinced me that the subject does not attract open minded people. Sometimes when a shadetree practice gets ingrained it seems justified, or just must be justifed by those that practice it, that is the case here. I actually have opened up differentials and found damage that in my opinion was caused by jacking under them. Some of the imaginary statistics being quoted above to justify the practice are really funny. I can quote my own, I personnaly have never damaged a differential by this poor practice. I KNOW this because I just don't do it that way and don't have to makle up skewed testimonials or statistics and imaginary "millions" of differentials. I don't have a problem with spending a few minutes doing it correctly, but I guess low attention to detail is not one of my problems. It is in my opinion the practice of people or businesses that either don't have the right equipment or are not willing to put out the effort to jack a vehicle up the safest way the produces no negatives without questions.

 

I actually have opened up differentials and found damage that in my opinion was caused by jacking under them.

Be more specific or I'm calling BS on this one. And don't make up the specifics.

 

I just put a bottle jack under the axle as close to the wheel as possible but once up i put it back down on top of a couple 6x6s. I have had cars fall off jacks and believe it or not your initial reaction is to try to catch it...

 

The "link" to the manufacturers recommendation is in your owners manual. It states to NEVER use the center of the diff. either front or rear.
As far as the lug nuts are concerned I would like to here how many use an air impact to tighten there wheels or a torque wrench? I personally use a torque wrench.

 

The "link" to the manufacturers recommendation is in your owners manual. It states to NEVER use the center of the diff. either front or rear.
As far as the lug nuts are concerned I would like to here how many use an air impact to tighten there wheels or a torque wrench? I personally use a torque wrench.

99% of the time when a owners manual tells you not to do something like jacking a truck up by the center of the diff is because they are thinking that you are doing it with a stock jack.

I have blown apart a dozen stock jacks just trying to change a tire on a loaded truck and would never think of trying to lift the whole rear off of the ground with one.

As for using a torque wrench to tighten your lug nuts, how many people out there re torque them after a few miles as manuals suggest?