Deed of Variation Help…

Hi. 
I own a freehold house which is accessed  down a private drive with two other houses on it. Each house has its own parking area off the drive. The drive js approximately 100 metres long and is in good condition. 
I sold the house and explained to the buyers that my house which is the last one on the lane has the right of way written into the deeds. I do not have to contribute ( never been asked) to its repair or maintainence. I have a good relationship with my neighbours and have had no issues in the last 17 years.  I do my bit as required keeping the drive swept and cutting back bushes etc. I have even got some tarmac ready to fill the one small pot hole in the spring. Such as a good neighbour would do. 
My buyers solicitor is not happy and has insisted we get a deed of variation put on the deeds that states whose responsibility it is to repair and maintain the drive. I did not have any issues when I bought the house regarding the drive, it is what it is and I would have chipped in my fair share to repair it if it needed it. 
However the solicitor has recommended my buyers not to proceed with the purchase as my conveyancer has told them it’s not required. 
I have been to speak with my neighbours and asked them if they agree to add a deed to the title of I presume just my house which states that all properties on the shared drive agree to split any costs for repair and maintenance in thirds. 
They have no objection to that at all, as it takes some of the responsibility from them to keep the drive maintained. We all use it, so it’s only fair. I have agreed to do the deed of variation.  
is their solicitor correct in doing this. Are there any alternatives.. I fear that my buyers will pull out of the sale if it’s not done. 
do we have to change and add the variation to All the properties on the drive not just mine? 

Help appreciated.  A worried seller.  Thanks

Hi Andrew - it's not really something we can comment on as what advice the buyer's solicitor gives them is very much a matter for them and their client.
All I can add is that we do receive enquiries from people who own shared drives etc querying whose responsible for maintenance etc so it's often best to formalise such matters. What worked for two sets of neighbours over time may not work for a new neighbour who has a very different view to such things including additional expenses when on a budget for example.
So I don;t think it's a question of right  or wrong here as the solicitor is presumably simply advising the client based on own experience of where future issues may lie as it could work the other way and the existing neighbour refuses to do the works and the client is left with the decision to do so all on their own