{wend, went, went} changed into {go, went, gone}

Solution 1:

FreeDictionary seems to support this, see here. Yet wend (Old English wendan) still is a word in modern English, meaning to proceed, go one's way, move, travel. It is related to German wenden: turn around, sich wenden an jemand: go to somebody for help.

Wikipedia shows that went comes from wendan, while go and gone are based on gon. They became synonyms in the 15th century and merged:

Development of a new preterite In Middle English, ēode evolved into ȝede, yede, and yode. By the 15th century in southern England, wende (wend) had become synonymous with go, but its infinitive and present tense forms had ceased to be in frequent use. This was also true of the various ēode-derived preterites of go, thus a variant preterite of wend absorbed the function. After went became established as the preterite of go, wend took on a new preterite, wended. In Scotland and northern England, yede was gaed, regularly formed by suffixing -ed to a variant of go. Due to the influence of the region, southern English forms constitute the standard language of England, and so went is the standard English preterite. Spencer used yede to mean go with yode as its preterite form but as dialect.

See here.

Solution 2:

According to Etymonline.com (entry for go),

The Old English past tense [for go] was eode, of uncertain origin but evidently once a different word (perhaps connected to Goth. iddja); it was replaced 1400s by went, formely past tense of wenden "to direct one's way".

Note that wend is still a verb. Definition from the Oxford dictionary:

go in a specific direction, typically slowly or by an indirect route.