buff68

Hi all, Have just bought a 1998 Ultima, 2.8 petrol Automatic. Noticed on the M5 on the way home that the speedo works in reverse ( managed to get down to 120mph at one point!). Whilst this was amusing for a while I really need to fix it.... I have discovered that the engine is the big dirty bit at the pointy end by myself; bearing in mind this level of technical skill, is there anything I can ook at re the speedo, or should I take it to a garage? Cheers