work as a Field service Tech, Have recently had our vehicles taken from us, are suppose to work our scheduled time and drive back to office and clock out. we were told that the drive back to the office in our company vehicle to clock out will be taken off and put back to the time we were scheduled to get off. Is this allowed

Probably not, although your wording makes your situation a little difficult to follow.
- You are legally either Exempt or Non-Exempt. If you are Non-Exempt, then you are legally paid based on actual hours worked. The key is determining legal hours worked, not talking about moving clocks back or forward, which really does not mean anything. If your employer is paying you for hours worked, they are following the law. If your employer is not paying you for hours worked, then they are not following the law. Clock times per se do not really enter to this.
- Just to be clear, Exempt Salaried employees are paid their salaries, which does not change no matter what travel time is. Travel time is mostly of legal interest to Non-Exempt employees only. (Also Exempt Hourly, but those types of employees are fairly rare).
- Assuming that you are Non-Exempt, then the drive to and from your house to the office is not hours worked. All drives after that probably are hours worked. The related federal rules are regulations 29 CFR 785.33 (http://www.dol.gov/dol/allcfr/ESA/Title_29/Part_785/29CFR785.33.htm) - 785.41.