Can you run a 4.0 without a....

Can, or should, you run a 4.0 without a harmonic balancer. Im working on a buddy's 88 XJ to fix a rear main and a front main seal. While we had it apart we noticed the timing chain was worn and needed replacement. We also replaced the oil pump and water pump ( the harmonic balancer is weak and needs replaced but it had to be ordered. He wants to start the Jeep to make sure the timing is correct but the balancer is not in yet and it wont be till next week. I say we should wait but he really wants to make sure everything is correct and when the balancer comes in all we have to do is throw it on and we are done. What do Y'ALL think?

i would just wait

DO NOT START IT WITH OUT THE BALANCER!

Thats my thought as well. What kinda damage will that cause? Im thinking exessive wear on the Crank and the new front seal we just put in.

you can run her without a damper, and cause no damage for a second, but only just. the engine will shake the shit of itself. it might run smoother as the revs increase, but so will the possiblity of main and journal damage.

take just enough time to check that it fires, and shut er down! 2 seconds or less.

Just wait, why chance making more work for yourself.

Thanks to all for the help. I felt the same way but he stated that for a inline six and especialy one with 7 main bearins it wouldnt hurt it. I knew better but this help solidify my opinion. THANK YOU !!!



arty:

My worry would be that the time chain sprocket would come off and cause really big problem when the cam was holding up some valve and the piston bent them or even broke the piston!

put the old on back on temporarily if he is determined to start it!!!!

In theory an inline 6 (and v12) don't need any kind of balancer because they are the perfect configurations as far as recipricating engines are concerned.

If it were me I wouldn't start the engine without all the parts just for safety's sake. The balancer was put there for a reason. But I doubt you would blow the engine up if it didn't have one, it just wouldn't be as smooth (or last as long).