A couple of weeks ago I installed my rebuilt motor. I bought motor mounts from Ames, these were the mity mounts. I tightened them down to around what I thought was snug. I sent an email to the tech-support at the engine mount company, and they said 40 to 50 pounds was sufficient torque. Today I went back to snug them up, and the passenger side spun. I removed the bolt and saw that the threads were a little messed up. I do remember hand threading it in but the butchering of the threads was more than a couple turns up, and this I missed during assembly. I’m not sure if I should run a tap over the bolt and insert a tap into the mount to clean up the threads on each, or just tap it to a bigger bolt. The original bolt was 1/2†x 1 1/8-20. I know I can change the mount, but this would involve me getting an engine hoist back after I returned it. Is it recommended to change The entire bolt, or re-tap with old bolt and threads in mount, or order a new mount? I’m not sure how much stress these bolts that connect the frame and the mount receive.
Did you use the proper grade bolt? If to soft a grade was put in that can cause pulled threads. As far as the bolt I would just use a new one but if the threads aren't to bad you could chase them. Without seeing the threads in person it is hard to judge how bad they are and if they can be fixed/chased good enough to hold 50 ft. lb. of torque. You could easily retap to the next size though. By the way you don't have to have a hoist to change a mount I have done it in the past with a floor jack and a block of wood.
Thanks Barnbird. Again and again you have bailed me out. I used the bolt that I had from before the rebuild. Just tried tapping at 1/2" to clean up the threads and it's stripped. I'm going to try another 1/2 bolt just for kicks. I'll need to tap either to a metric (yuch, but maybe necessary) or go one size up 9/16. Either way it 's off to the hardware store. Grade 5 or grade 8 for this?
If not where do I mount the wood under? I could make a u channel to ride under the Oil pan bolts My oil pan looks really nice, so I don't want to muck it up.
On the grade without researching I don't remember but you are always better off being a little harder than softer, the only thing it will hurt is your wallet. On supporting your engine if it's a factory pan and not a cheap aftermarket/Chinese one I have never bent one supporting it correctly with the right size/piece of wood on the lower part of the sump in fact I have had many Pontiac motors setting on a cement floor on their pans without problems. This is it's strongest point where it goes straight up to the block forming right angles just watch out for the drain plug divot. Make sure you unbolt both motor mounts and if your fan is mounted be careful of your shroud. Because there is a bolt and not a stud you don't have to go very far to sneak it out just go a little and try and go a little more if it won't come. As far as scratches just use a little cardboard between your wood and pan. And don't sweat it, crap like this always goes wrong when doing mechanics just remember to fight one battle at a time and you will win the war. One last thing if you have Hei with the big cap take it off first or you will break it.
