amc 258 rod nuts

[jsohn]

Hey all,

I have a 1985 AMC 258 i6 / 4.2l that I am in the process of rebuilding. I have built several engines in the past but never a AMC 258 i6 / 4.2l . I am just doing a re ring, reusing pistons and rods. I am very very confused and getting more and more worried about my rod studs. I installed the pistons and when I went to put the end caps on the rods, all went well until I went to put the final torque on the nuts. The end caps drew in the pistons just fine but there are several nuts that wont hold running torque. They just spin and spin, they dont feel stripped or anything but it is blowing my mind. The stud is not spinning when I try to tighten it with a combonation wrench and there is no evidence of metal shavings or thread damage. The really bad part is that I cant get the nuts off the studs, I try putting upward pressure on the nut but it doesn't do anything. Since it is an engine setup to specification I am very leary of prying to hard or using certain tools. Any one have any input?

 

[Torxhead]

Sure sounds like they are stripped. I would try to grab the wrench flats with vise grips and unscrew them, pulling out as you do so. From there a close inspection is needed.

 

[rlitavecz]

You may need to cut the nuts off. Try using a cut-off wheel on a die grinder.

 

[Hedgehog]

How long is your socket? I've never done what your doing, but on occasion, when confronted with this sort of thing the answer was as simple as the socket not being deep enough to catch the nut.

 

[jsohn]

Socket is for sure long enough and the vice grips were one of the first thing i tried but even with me lifting with enough force to take the weight of the engine, the nut still just spun. I am running out of ideas and I really dont want to have to cut in that area.