1999 range rover gearbox box no selection

I bought a range rover 2.4 diesal 2 weeks ago and it has had a manual gearbox put in before I got it. When driving it was not going in first or 2 nd gear easily put goes in the others fine. Today went I set of i got half a mile down the road and when I got to a roundabout I put into 2 nd and then when I went to change to 3rd gear the gear box went loose. I have tried looking under the gear stick and everything looks okay so I'm thinking it's inside the gearbox. Can any one give me any clues water it might be?

youd have to take the selector housing off and see could be selector shaft pin ,or loose yoke,box needs dropping down a bit to do that ,you remove crossmember and box mount and lower down with a jack under box

Yes thankyou it was the selector pin. Got one of ebay for 20 quid so glad it weren't. A expensive job

Also sometimes it juggers abit once started and traction failure. Light comes on. Do u think I should get a new battery