is that wrongfull termination ?

Are you not able to lift over 40lbs? Is it because of a physical impairment (ie, substantial limitation of one or more of your major life activities)? If so, it is possible you may be an individual covered by the Americans with Disabilities Act (as amended), which prohibits employment discrimination based on a covered person's disability. If you are covered by the Americans with Disabilities Act, then the next question is whether the 40lb lifting requirement is an essential job function. Because your job application stated you need to be able to lift up to 40lbs and the pallets are over 40lbs, there could be an issue as to whether lifting over 40lbs is really an essential job function. If it is not an essential job function and you were discharged because you could not lift over 40lbs due to a disability covered by the Act, then you may have a legal claim. If you believe this is the situation, then you should file a charge of discrimination with the EEOC. In Texas, you have 300 days from the date of the discriminatory act to file a charge of discrimination based on disability, otherwise such a claim may be barred.