Can't Select 3rd coming from 4th gear

[Ramsden15]

My girlfriends van, that she bought earlier this year, has had a whole host of problems that I am working my way through.

The latest being the gear change. When she got the van gear selection was vague and it would stick in 4th gear if you stopped the van with it in gear.

So my first job was to change all the linkage components, front to back and fit a short shift kit. This had the effect of tightening up the gear selection but introduced a lot more problems. It was sometimes very difficult to get in gear and still stuck in 4th if I stopped the van with it in gear.

So last night I replaced the gearbox oil. The first this was there wasn't much in and it was like black tar.

Following this, the gear change was considerably better and did not stick in 4th, but it refused to go into 3rd from 4th, I can go from 4th to 2nd then into 3rd, or just 2nd to 3rd.

My fear is its the 3/4th gear synchro but I am clinging on to the fact I could select 3rd from 4th, as far as I remember, before 'improving' the mechanism.

Can anybody offer any advice please, could it be the way I've set up the linkage (I did have it all apart) or anything else?

[Mr Bean]

Not wishing to put a damper on things:
My five speed gearbox failure many years ago started similarly to that and eventually failed altogether. Sadly the center section of the gearbox was damaged as the spring steel cage for the linear bearings for the selector shaft had collapsed and the shaft had worn through the gearbox casing. My repairer couldn't source a replacement center section and I eventually bored it out on my mill and fitted a steel liner. I also sourced the cage and balls from a firm called I believe Bear Racing in the Midlands who were building race cars using the WBX engine and five speed gearbox. I am not familiar with the four speed box but guess you need advice from someone like Aiden. Sadly I was not aware of Aiden at that time and so had to knife and fork the repair with a local chap.
CS

[Winchweight]

It sounds a lot like something is adrift inside and changing the oil moved it. I think you need to call Dr Talbot and get it booked in for repair.

http://www.aidantalbot.com" onclick="window.open(this.href);return false;

[Ramsden15]

It sounds a lot like something is adrift inside and changing the oil moved it. I think you need to call Dr Talbot and get it booked in for repair.

Yes that's possibly the case, I want to just check all other, if any, possibilities before looking at a bill for £1000+ when that's a third the value of the van