My control arm hit my oil pan!?!?

While making my way through a canyon near Lake Pleasant today, I had to cross a rock that required a good amount of articulation (relatively speaking) from my stock suspension 00 XJ.

When I got half way over the rock, I started hearing the starter motor spinning! I pulled off the rock the rest of the way and shut off the truck but the starter motor kept spinning (even after I pulled the starter fuse and relay), and in fact started to catch on fire after a minute or so. (Nothing a little sand thrown on the fire didn't fix)

Long story short, I had to get towed out of there by the guys with me, and my melted starter would no longer turn the engine over or even make any attempt to engage.

Upon getting back into town I discovered that the battery positive cable to the starter was completely worn away/smashed where it runs along the bottom of the oil pan area, and the starter ignition signal cable is in the same loom so they had shorted together providing constant B+ to the starter.

Closer examination showed me that my passenger upper control arm mount on the axle is making contact with that wiring and with the oil pan mounting flange right next to the motor mount. The wiring managed to get wedged between the two on that rock, I presume, which is what destroyed it and caused the short to B+.

So, long story long (sorry), does anyone have any idea why a completely stock XJ would see the upper control arm mount make contact with the oil pan? I'm talking stock tires, swaybars connected, etc. Completely stock.

Any advice on possible things wrong is appreciated. I'm a rookie at this whole thing.

Thanks!
Aaron

i had my upper control arm crush my auto-tranny cooler line against the oil pan...
it was on a beat-down xj i still have that was abused by its prior owner.
how are your bumpstops? they usually get worn down, and sinse you havent installed a lift you might not have noticed.

are your motor mounts in 1peice or two?
at least you broke down wheeling, i crushed mine coming off a slight curb out of an in-n-out drive-thru

To the best of my knowledge the motor mounts are in good shape. This was my brother's Jeep and the records he provided when I bought it from him say that he replaced the motor/tranny mounts a year ago.

The bump stops? I couldn't tell you. Certainly a viable option there. All I know about them is that they are there, because I can see them. But yeah, I suppose they could be collapsed or some such.

Thanks for the insight!
Aaron

if theyre gone, theyre gone, no ifs about it.
is there an impact mark on the oil pan?
maybe it pinched the cable somehow?
sorry man, thats all i can think of

Yeah, there is a definite impact mark on the oil pan flange in the perfect shape of the upper part of the control arm mount, and in fact, there is even some smashed-on red battery cable wiring insulation fused to the oil pan now.

Tomorrow I'll get under there and take a closer look at those bump stops.

Thanks for the input!

My upper control arm broke my trans cooler line at stock height. XJ's have too much articulation for their own good, lol.

ManBearPig said:

My upper control arm broke my trans cooler line at stock height. XJ's have too much articulation for their own good, lol.

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i should have mentioned, mine was at stock height when i busted mine as well... looking at lifted jeeps, i dont think it will happen as easily.

On my 1990 it looks like the control arm or the axle houseing hit the oil pan on pre lift

mine did that too. so i added a hockey puck bumpstop and now nothing hits or rubs. mine is stock too but i wheel with the sway bars disconnected.

Might be a dumb question, but which way does the bolt (upper control arm bushing at axle) face? If the head is on the outside, and the nut on the inside, the end of the bolt can contact the engine.

tbburg said:

Might be a dumb question, but which way does the bolt (upper control arm bushing at axle) face? If the head is on the outside, and the nut on the inside, the end of the bolt can contact the engine.

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The FSM shows nuts out at the axle and nuts in at the frame rail for both upper control arms.

mine did it too, smashed the tranny cooler line.

goodburbon said:

mine did it too, smashed the tranny cooler line.

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Yeah, it seems to happen alot on unlifted rigs. Happened to a buddy in town as well