OBXT Hitch Install Problems

[AWDFan]

Yesterday I tried to install the Subaru factory hitch on my '09 OBXT. It took way longer than it should have, but some of that was getting the mufflers off and then getting one of the heat shields off before I figured out that I didn't need to remove the heat shields after all (the directions that came with the hitch must be old). Some tips from past threads were helpful (like using a jack to hold up the hitch). Generally things went ok up to the point where you torque down the M14 bolts for the hitch.

 

I had borrowed a torque wrench from a co-worker since I don't own one. It's the kind that supposed to slip when you hit the desired torque, but it *never* slipped! I set it for the specified 69 lb-ft and started tightening the first bolt. When it didn't slip, I thought "gee, 69 lb-ft must be pretty tight" and I lowered to 30 lb-ft just to see it slip. And it didn't. Either the wrench doesn't work right or 30+ lb-ft of torque is a hell of a lot tighter than I'd guess.

 

So, to get the car back in operation for work today I just tightened all the hitch bolts down pretty tight and then tried to tighten the muffler bolts about to where they seemed to be when I took them off.

 

Now I'm not sure what the status of all this is. Today I think I'll go by the local Sears and pick up a torque wrench. I'm hoping I can at least check the current torque on the bolts without dropping the mufflers again.

 

How crucial is getting the right torque setting on the hitch and mufflers?

 

How bad is it if I over-torqued them already?

 

If I do drop the mufflers again, do I really need a new set of gaskets and lock nuts?

 

I would have just had the dealer install this if I'd known it was going to be such a pain.

[jedraz]

As long as you take off the muffler cans it's easy. i did it on my 07 and on my 09. i did not go nuts with the exact torque amount, as long as you have a long ratchet you will be fine. The hardest part was aligning the exaust cans when you reinstall them.

[mwiener2]

The torque spec isn't all that important. You want it tight enough that nothing will move and that it won't vibrate itself loose. Lying on your back, under the car, 70ftlbs is going to feel like ALOT. Basically, get those things damn tight without crushing anything or breaking the bolt.

[AWDFan]

Ok, that's about what I thought. Like you say, 70 ft-lbs is a lot when you're working in a tight space under a car. I was so tired by the end of the job on Sunday that I was having trouble holding up the mufflers to get them back on the hangers.

 

What's the point in replacing the lock nuts on the muffler flange? Is it that they won't necessarily stay tight after having been removed and reinstalled?

 

I borrowed a beam-style torque wrench from a co-worker yesterday. If I get home early enough tomorrow I'll get back under the car and see if I can verify the torque settings on the bolts.

[AWDFan]

Ok, I borrowed another torque wrench and took another shot at it this past weekend.

 

This time I just unbolted each muffler and popped off just the rear hanger. With it still attached to the other hanger I propped up the muffler to take the strain off the hanger and torqued down the bolts where the hitch was attached the previous weekend.

 

It's a good thing I decided to recheck the bolts, because some of the M14 hitch bolts were clearly loose. Things went pretty well this time, except 2 or 3 of the bolts just kept spinning. I guess they're stripped.

 

I pretty sure I couldn't have over-torqued them (I had to pull awfully hard to hit the 69 ft-lb mark on the rest). I am hoping that just the bolts are stripped and the chassis bolt holes are ok. If so, I can replace the bolts at some future point. I guess I'm screwed if the bolt holes are stripped.

 

So at this point, with some loose bolts, I don't know if the hitch is really good enough to tow a trailer. I really just wanted it for a bike rack, and I figure it's good enough for that. I didn't bother installing the wiring harness since I don't know if I could safely tow with the hitch anyway.