95XJ-PA

Its been said on here before but after a recent experience, it bears repeating, "Check your motor mount bolt tightness, particularly the ones that mount the bracket to the engine."

I was returning from picking up my daughter and just driving along, road was fairly smooth when I heard a loud bang, then a grinding noise. I pulled over and looked for leaks and anything obvious...nothing. Restarted engine, heard grinding noises and since I wasnt far from home, drove it there. Once there I looked at the engine a little harder and saw that my fan was contacting the shroud making the grinding noise. After thinking about it, I looked at the motor mount...sure enough, the three engine side bolts had sheared completely and my mount was tucked up underneath the distributor. Long story short, picked up some brown dog mounts and got her up and running. The remaining bolts in the engine bosses were a ***** to chase out (about 3 hours worth). Check the tightness of your engine mount bolts especially if your mileage is high (mines at 180k)

hankthetank

Or not too tight either? Is there a torque spec? Do the brown dogs have a different spec or better grade fasteners with them?

OverlandZJ

Same thing happened to my son this past summer in his YJ, i said screw it with 250K miles.. i dropped my XJ's engine in.

Lots of guys have issues getting the bolts from the block, usually breaking off the extractor. Which is one of the reasons i wasnt looking to waste time trying. How about describing the correct way to do this?

xj_maniac_newb

So what that means... is its gonna be a ***** replacing both my engine mounts?

OverlandZJ

I'm sorry, it should have read "Guys have problems getting the BROKEN bolts from the block"...

xj_maniac_newb

ok good cause both my mounts are shot, as in there is no rubber left in either of mine lol

Gee oh Dee

Moved to OEM Tech.

gpeade

Just bought an XJ with the same issue. When the motor dropped the fan ripped one of the tranny cooler lines. Guy sold it to me said the tranny was blown. His loss I guess.
It wasn't too bad to fix. I removed the entire engine mount from the frame which gave me alot more room. took a right angle drill and drilled a hole in each screw. Started with a tiny bit and worked my way up to a 3/16. Took a hammer and tapped the easy-out in the hole and want real slow and they came right out. I soaked them with kroil for about an hr or so before I started. The first one came out real easy but the other didn't want to turn so quickly so instead of steady pressure and spinning or breaking the easy-out I just got a torch and put a tad of heat and they backed right out. While I was under there I relpaced the three on the other side as well. 6 new grade 8 bolts and a little thread locker.

idahomurf

Where did you get the bolts and what size?

ultimatewarrior

X2 I'm about to do the exhaust manifold, transmission mount, and engine mounts this weekend. I would love to upgrade the bolts and knock this out in one shot.

5-90

I cover this, somewhere, probably once a month.

1) It's not that the screws are loose - it's that the holes are sometimes not drilled/tapped deeply enough. The screws will feel like they've been torqued properly, but they're tightened against the bottom of the hole (instead of the underside of the head.)

2) The fix is to replace the screws outright (3/8"-16 by 1" or 1.25", I think) and to put two flat washers under the head before they go through the bracket! This keeps the tip of the screw from hitting the bottom of the hole, allowing them to be torqued properly.

3) Why replace the screws outright? They'll be weakened by having been loose and shaken about. Use a quality replacement (read: not "Made in China") for the screws and flat washers.

4) Using LocTite #242 (or equivalent) is highly recommended.

To test to see if the holes aren't deep enough? Take a thin (.003"-.005") leaf gage and try to slip it under the screw head. If it goes, go buy some good SAE8 screws and flat washers. If it doesn't, you should be fine.

Even with the Brown Dog mounts, you may need flat washers - do the leaf gage test after you torque the screws. If it goes, remove the screws immediately and install flat washers under the heads. If you have to run the screws, plan on replacing them outright. The fault isn't with the mounts - it with the holes that the screws go into, and while installing the Brown Dog mounts are a good idea, they're not necessarily going to correct the basic problem.

Screws that don't get properly preloaded in tension (indirectly measured through applied torque) are subject to premature failure. This is a Bad Thing (tm)

gpeade

While I'm not discounted 5-90's advise above I simply pulled one out the other side mount and went to the hardware store and bought 6 grade 8 bolts the same size. Added a little thread locker and replaced all of them on both sides just to be safe.