UCA crushed my trans cooling lines….

The other day, while wheeling, I crushed my trans cooling lines. Apparently, my front axle flexed in a strange way where the front passenger side UCA hit the cooling lines, resulting in the trans oil leaking out.

I’ve done some searching here and found that this has happened to others and there were some good ideas on how to fix this, simply cutting the crushed sections and replacing them with trans rubber hose.

What I’m interested in is HOW COULD THIS HAPPEN? I have a 2” lift (BB) (Using 2” coil spacers in front + one additional stock coil spacer (0.25”)). I also have 1” bump-stops installed at the bottom of my coil springs. The stock top bump-stops are there as well.

I took a look at another xj that had no lift (Everything was stock), I noticed that the trans cooling lines were out of the travel path of the UCA, assuming the axle travels upward in an even manner. But, even if it flexes, it would really have to flex in such a bazaar way to hit the lines or something has to be broken for the UCA to hit the lines. And this is what I suspect. Even though my track-bar and UCAs, LCAs look O.K. I think something is wrong. I say this because I have been having some vibrations at 40 – 50 MPH speed for awhile now, even after alignment, the problem is still there.

Could it be the track bar is loose? Could it be the sway-bar bushings are worn out (They do look like they are). Or maybe the bushings of the Control Arms are also worn out?

Any ideas ???:helpme:

My XJ Specs:
2000 4x4, 4-dr, 4.0 XJ, Auto Trans. 2.25” lift (Coil spacers front + Add-A-leaf rear). 30x9.5 tires on stock rims.

This happened to a friend of mine a couple years ago. It happened on a trail, so we fixed it using rubber line and hose clamps. It it still holding today. Remember there is a good amount of pressure here, so make sure the hose fits a good 2" or so onto the line. We used 2 hose clamps on each end of the lines too (total of 8), just in case.

What caused it on his was the lines weren't mounted correctly. There are clamps that mount them up near the oil pan, high and out of the way. His didn't have the clamps and the line was hanging down too low and got smashed by the UCA.

Trac Bar

If your Trac Bar is out of alignment it can crush it between the oil pan and control Arm. The same thing happened to my sons after clipping a stump out wheelin it bent his trac bar and that happened. We replaced the crush part just like your post says and it hasn't leaked since. I broke one in a wreck a few years ago and did the same repair and it hasn't ever leaked either. Just make sure that after the fix you route the lines so they don't get pinched again.

If you use hose make sure its the correct type or it will get soft and leak. Dont use regular fuel line. It may last a while but it will end up mushy. You may try to use a flare tool to put a small lip at the end of the tubes so it wont come off easily. Make it enough of a lip to help the hose stay on but not so big you have trouble putting the hose on. But more importantly it should also be smooth at the end if you flare it or not. Imagine the hose sort of drooping down at the end of the tube. If the end is sharp it will want to eat into the inner wall of the hose after some time. If you flare or not kind of smooth out the end of the tube before you assemble it. I watched the Two roads to Baja movie again. One guys battery box came loose and cut the trans cooler line. Its the little things that can kick your butt. Try to secure everything. Lay under it and look at everything slowly and meticulosly. Look at everything that could rub or get pinched. A lot of the time the original clips, clamps, and brackets are missing after someone has worked on it. ONE OTHER thing about HOSE.........especially fuel system hose is that some fuel systems run 50 to 60 psi and the WRONG hose can result in toasted veeeeeeeeeehicle.

Definitely make sure you use the right hose. We used some transmission line off my old parts XJ that was still in good shape.
I usually carry smaller lengths of various hoses and vacuum lines just in case. A good assortment of clamps and some coupler fittings comes in handy too.

And don't forget fluids!

Thanks guys for the tips. I will definetly follow your advise as far using the right type of hose and doubling the clams at each end.

I would just like to shift the attention to the cause of this. My cooling lines were actually in the right place (Near the engine oil pan and far from the UCA). I think the UCA has hit the lines so hard that there is now a little scratch on the side of the engine oil pan.

Is there a simple way of knowing if my track bar is loose?

If your lifted, and still running the stock TB, this could easily be the problem. The axle will be pulled towards the drivers side, and that would make sense.

Either get an adjustable Trac bar, or re-drill the hole on the axle mount to position it properly.

hmdxj said:

Thanks guys for the tips. I will definetly follow your advise as far using the right type of hose and doubling the clams at each end.

I would just like to shift the attention to the cause of this. My cooling lines were actually in the right place (Near the engine oil pan and far from the UCA).

Click to expand...

i had this happen, 2 months ago... on a 90xj.... it actually crushed my line exactly where it was mounted to the oil pan, so it has nothing to do with tranny line movement....

my line of thinking has led me to beleive the suspension on this jeep is way sagged... its stock, with 31s.... its the way i bought it, and it hasnt gotten a lift yet...

comparing the distance between the UCA, and tranny line hose, on said vehicle, and another 90xj, with a 3" lift... there is plenty of clearance on the lifted jeep... and NONE on the sagging one...(this is parked)
are you lifted?
bumpstops.... i gotta get underneath mine and replace the bypass, i was trying to lift it first though

That's just what they do. That much flex @ that ride height apparently wasn't considered as an option by the Jeep engineers. The same problem sent me door to door looking for tools in a hippie mountain town years ago.