Not Too Happy

Yesterday our club did a run up to Watson Peak for a scenic lunch overlooking Tahoe. Almost to the top of the trial I noticed my fan was tapping against something. Never a good sign. I couldn't see anything major wrong, but the fan was tapping against the front brake line where it crosses at the radiator crossmember. Today I jacked up the engine to check it out and found this.






Broken motor mount. This is the second set of Novak motor mounts I have had a problem with. In fairness, the first set failed because I launched the Jeep (not intentionally) over a 3' dropoff. Not the case with this set. I've been through the Rubicon 3 times with these mounts and a bunch of local trails, but I haven't abused the Jeep at all. I kinda drive like an ol' lady mostly.

Anyway tomorrow I am heading up a work party on the Rubicon trail so I needed this fixed today. I cleaned all the paint off and left it with a welder friend of mine to burn it back together. Wish I had kept my original stock mounts now, but I'm going to make some this Winter that will incorporate the original style rubber mount to the block.
Here's some pics of the mount ready to go to the welder. I used Jasco Paint Epoxy Remover to get the metal clean.





I'm sure the Novak mounts would be OK for a light duty trail rig or daily driver, but not for a rig that see's more difficult trails.

Our project tomorrow is to remove a 20' x 2' dia steel culvert that was washed out several years ago. We will be winching it out of its present location, cutting it in 2 or 3 pieces and hauling it out on a trailer. I'll post some pics after we're done.

 

That sucks John,
Seems like that steel should not break there but there is a ton of torque on motor mounts. Good luck with the fix and the work project.

 

Back from the welder. I had already made a re-inforcement piece for the mounts when I put this set in. My buddy welded that piece in to bridge the break and tie it all in together. He also filled in a rather large void with a piece of steel rod and a lot of weld material. I may take the other one out next week and have him do that one before it cracks as well.

 

Looks like it broke right at the point where the plate was bent on a press brake, that area would be weak once the metal was bent and stretched ...........the bottom plate should have been designed a little differently to incorporate a gusset which should have extended up into the right angle where the plate was bent.........never would have broken then.......was there not a rubber donut at the big hole? Eric at Novak is a smart guy and would like to see that.........PM me and I'll give you his e-mail.

 

Yes, there is a donut on top and bottom of the mount. You could probably skip the gusset if the plate was 5/16 or 3/8". I sent you a PM, Terry.

 

Glad you got out without further trama.
I would never skip a chance to have a gusset, or two. That is why my stuff is always too heavy.

 

I agree. I always build to maximum not minimum. When in doubt, make it bigger.

 

A lot of twisting going on there by the looks of it. I understand the "build a stronger mount idea" but you might want to look at the rest of your frame for more damage. You might have some weld joints starting to fail also allowing a little more twist than normal.

 

Not a problem with this frame. I fully boxed it and it's as rigid as you can make one. I had one of those floppy frames for a lot of years and it caused nothing but problems with the tub and cracking of the frame. I started with a pristine M38A1 frame and boxed it end to end and welded bumper/crossmembers at both ends. I'd be more inclined to think that engine vibration as much as anything else caused the crack to form in the motor mount. With an oddfire you'll never get rid of that. I just don't think that those mounts are very well engineered for the thickness of the backing metal.

 

Hey Chuck,
The mount that I had the problem with is a newer version of Novak's mount. It has a cutout (see pic) on the arm where it joins the plate that bolts to the engine. Obviously that doesn't add any strength to the mount at a critical point. The only thing even approaching a gusset is the two ends that are welded to the plate. One had pretty good penetration the other had none.

 

Yes when in doubt, over engineer.

The metal cracking at the bend, dose not concern me as much as the weld it self just popped off, indicating a cold weld with no penetration.

 

I also would have laid a stringer bead, at the bend for strength .

If that weld that popped, didnt pop, it may not have split

 

I guess I should clarify Across the bend, like a gusset .

perpendicular to the bend, to tie the two , maybe lay two but one centered to make a gusset that looks like a cross, across the bend