Das MB-trac Forum

Hi, I am new to this forum and thank you for letting me join, I am currently in negotiation over the purchase of a MB Trac 900 turbo which is a 440.169 and has an issue with the gearbox. I understand that the the high and low ratio lever was initially held in high ratio with a bundgy strap, but eventually this would not hold the drive in gear. My question is, what might be the issue, causing the MB Trac to only now drive in the low ratio. I apologise if this issue has been discussed previously but I need to be sure of the issue prior to concluding the deal.
Your thoiughts would be very much appreciated.