I have 2002 Accent 4 door with 48,000 miles (1/2 LA freeways - 1/2 city streets). About 15,000 miles ago, I hit a pothole which I could not avoid (front end) & the underframe was damaged. Insurance paid for the repair & it was done by the dealer. The underframe was replaced & is still squeaky new in appearance. They also replaced the automatic transmission on warranty at the same time because it showed a failure code (it had been deteriorating over the last few months before the bottoming out). All was well & good with the frame except that there is a periodic frame creak which I will get & have been getting periodically for over 6 months. A body shop inspected it & replaced a bolt which the dealer paid for. The dealer has lubed the frame which takes away the creak until (I assume) the lube is dissipated & then the creak returns. It sounds like an old screen door and happens only on acceleration or deceleration in light traffic at low speeds. What do I do? Is there a body or frame filler that can be used or something else that I can research or suggest? Any relation between the transmission replacement & the creak? I'd like any ideas.

Is it possible that you could ask the dealer where they are applying the lubricant.
This will give you an idea as to where your problem is at.

Do you know whether they replaced your engine mounts. Ideally the three that are attached to the transmission??? :)

I was actually thinking about asking where they are lubricating. As to the engine mounts, I don't know. I've had a suspicion they did not replace them & that the creak could be from a bad engine mount. Could that account for the problem?

If you clobbered the sub-frame as hard as you say, which also finished off your auto, then yes it is quite possible that you have damaged an engine mount which is causing a groan or a knock.
You can see these mounts quite easily.

It may pay to get some one to help you and carry out the following procedure:

- With engine running, watch the front and rear engine mounts, which are attached to your auto trans.
- Now whilst you are watching them, get the person in the drievrs seat to select drive and inspect the action of the engine mounts.
- Whilst still watching, get the person to select reverse and inspect the action of the mounts.
In theory they shouldn't move more than about an inch in either direction, and should be firm. In other words they should hold the engine fast without the mount wobbling around.

If you can see no abnormalities here, then carry out the same procedure as above, but this time watch the OS and NS engine mounts (left and right).

Let us know how you go! :)