755 engine mount torque and questions.

[rly]

Two of our 20hp 755 tractor's four vertical engine mount bolts are loose. That is, I presume they are loose because I can turn them by hand, and a ground (?) ring under one is loose. This may be contributing to the fact that the radiator cooling fan in not centered in it's housing and can hit either the radiator or the bottom of the housing/shroud. I can't pull the bolts out so I assume the underneath locknuts are still attached but have backed off such that the mounts aren't being properly compressed. I have all the shop manuals, but find no reference to the torque for these specific bolts. I don't know if the fact that they are for engine mounts with rubber components means the torque would be other than for a bolt in steel. 10mm I think.

Also, any tricks for getting to the locknuts to hold them while tightening the bolts. Today I'll get horizontal and see what I can from below, but I wasn't successful in seeing much with a mirror, and I'm afeared the access may be very poor. Pulling the engine is beyond my means--that's what one person said they did.

Thanks.

My first post. I live in Mt Shasta CA. I'm presently battling with three feet of wet snow.

 

[beenthere]

:welcome: to TBN

Sounds like you are zeroing in on the problem (mounts are shot), and I don't know the torque off-hand, but loose is not likely correct.
Here is a screen capture from jd parts that shows the engine mounts (isolator). Check it out, as the part numbers are shown and the position of the "isolator" that is riveted to the frame. Maybe a pic or two of the loose bolts would help add advice to help.
https://partscatalog.deere.com/jdrc/sidebyside/equipment/66727/referrer/search/pgId/14425708

 

[rly]

Thanks. That's the area exactly. It's those #7 lock nuts that are still on the bolts, but not applying pressure to anything. I suppose the problem is NOT that they have loosened, but that the rubber components have become tired, and effectively thinner. I've yet to see what I can access from below. If what needs to be done is tighten the bolts, and I can't access the nuts from below, it did occur to me that I could drill a small horizontal hole through the frame at exactly the right spot and insert a tapered punch (or something) to 'jam' the nut so that it couldn't turn and I could tighten the bolt enough to suck up the nut so that friction would then keep it from turning. There seems to be plenty of metal in the frame there so that a 1/4" hole shouldn't be an issue, I think. However, I'll first try tightening while pulling up on the bolts heads, in case that creates enought friction on the nuts below so that they don't spin when tightening. But the first thing is to confirn that I can or can't get a socket on the nuts from below.

 

[beenthere]

I think you can access these nuts from below. Shows a C-channel frame.

 

[rly]

We'll see. I think the reality of the situation may be less straightforward than the diagrams, but I'll assume the best and report back after I get down on the ground to take a look. Probably tomorrow--when I'm less sore from shoveling and tractor fixing.

 

[rly]

Only the front left one was hard to get to from below. With the front left I had to wedge the nut (underneath) with a long screwdriver, but it tightened well enough from above. It's 50/50 I could have used a crowfoot wrench successfully. but I didn't have the right size. This tractor/loader/backhoe seems to be a mix of metric and SAE.