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joshs1ofakindxj
07-01-2009, 08:57 AM
So how are you guys lifting 4.0L I6's out of Jeeps?

Last one I did, I pulled with the transmission and t-case still attached so I just threw some chains around everything and pulled it without much trouble but for moving them around the barn and pulling the next one I wanted to have some of those eye-nuts that thread onto the studs on the top of the motor. Are these studs rated for the weight of the whole drivetrain? I would think they would be. They're 1/2-13 correct?

Looks like McMaster-Carr has some eye nuts but none that are long and would clear the valve cover. Anyone know where to get these?

jeepxj3
07-01-2009, 10:50 AM
there are a couple bolts that hold the head to the block that I would use to pull a motor. They have threads that continue beyond the nut.

mxg342
07-01-2009, 12:17 PM
I think the front drivers side head bolt is very weak. There is not a completely threaded hole in the block where it threads into. I wouldn't use that one.

jeepxj3
07-01-2009, 02:04 PM
I think the front drivers side head bolt is very weak. There is not a completely threaded hole in the block where it threads into. I wouldn't use that one.

it passes through the water jacket, and gets a different torque setting thats all.

mxg342
07-01-2009, 02:57 PM
it passes through the water jacket, and gets a different torque setting thats all.


hmmm.. wonder why a different torque setting? Maybe because it doesn't have full thread engagement, therefore it can support the full clamping force on the head. I still wouldn't pick half of the weight of a 4.0L from it.

mxracer513
07-01-2009, 10:42 PM
i get about 8 seat belts and rachet straps and attach them to different points. Works for me pretty well

notmYJ
07-02-2009, 03:51 AM
hmmm.. wonder why a different torque setting? Maybe because it doesn't have full thread engagement, therefore it can support the full clamping force on the head. I still wouldn't pick half of the weight of a 4.0L from it.

If its a 1/2" bolt, and the threads are engaged 1/2", then you have full engagement. There is virtually no way the threads will pull out unless the threads are damaged. This is why the NHRA requires, for cars running 7.50 1/4mile and slower, "Wheel studs must be threaded into hex portion of lug nut a distance at least equal to the diameter of the stud."

Mainly because if it goes further you gain no additional strength, as the stud will yield before the nut pulls off.

For lifting an engine, the bolt or stud is in tension, and a 1/2x20 grade 5 (which is weaker than most head bolts) will fail at minimum of 18,139 lbs. In single shear it will fail at 14,730 lbs. The same bolt in grade 8 which is closer to what head bolts are fail at 22,674 lbs and 17.870, respectively.

So, the bolt or stud is not the issue, so maybe its the parent metal. ASTM A-48 Cast Iron has an ultimate strength of 30,000 PSI. So lets figure there is one square inch of parent material around the bolt or stud, and say its 1/2" thick. That still puts you at 15,000 PSI. Sure, there are other factors, but you should be able to see where I'm going with this.

Bottom line, yes, any head bolt or stud, with proper engagement will support the drivetrain. Personally, I have hoisted fully dressed big blocks and small block v-8's from the intake bolt holes. I just used longer grade 5 bolts to get the proper thread engagement. Not once did the bolt or threads ever show signs of yielding to the forces applied to it.

My final answer, yes, it is perfectly safe to hoist the entire driveline from the head bolts. just about any bolt on the engine will do it.

Your lifting maybe 1000 lbs, not the whole damn jeep.

If any of my math or engineering is off, please feel free to correct me.

Krod
07-02-2009, 11:56 AM
This is one time where I really don't think any engineering needs to come into play. The motor/trans combo is going to come in at < 1000 lbs combined. Don't load the bolts in shear, dont use small garbage chain/hooks, and dont keep pulling on it if you get it stuck....

Thread two bolts into the appropriate holes through the head, connect to chain, make sure that nothing is still hooked up to the engine or in its way, and pull it out. Done.

You should have no problems pulling the engine if you apply common sense and proper lifting equipment. Both of which I know you have.

gonecheenin
07-02-2009, 12:16 PM
Single 1" HD ratchet strap from the rear header tube to the front A/C bracket. Never had a problem & have pulled many this way. (Even used El-Cheapo 1" ratchet straps before, didn't stand under or near those ones though!)

Would never try to pull it tranny connected since its already such a long item.