How do I fix the transmission issue on my Vauxhall Vivaro?

I have been experiencing some grinding noises and difficulty shifting gears on my Vauxhall Vivaro. What could be causing this issue and how can I fix it?

It could also be caused by low transmission fluid levels. Check your transmission fluid and top it off if needed.

If all else fails, it may be necessary to replace the entire transmission. This can be a costly repair, so make sure to get multiple quotes from different mechanics.