What do you reckon…. I’ve got problems with the Type 9 gearbox in my x-flow locost. It’s always been quiet and had a nice smooth gear change. However that all changed when I took it out last week, briefly… I can use 1st 2nd 3rd and 4th for as long as I like without any undue noise or selection problems. It goes into 5th nicely, but if it’s left in that gear for any length of time (30+ seconds’ish) it causes a gear selection problem. From 5th it comes back to neutral nicely, but then the gear lever ‘locks solid’. It eases (after 20 seconds or so) and I can get it into 3rd and 4th, and after another few seconds it eases further to give me all the gears again. And then it’s ‘back to normal’… I can use 1st – 4th without a hint of a problem for as long as I want, but if I go back into 5th it locks-up again. I’ve checked that the clutch is releasing properly, and that the gearbox if full of the right oil. I’ve bypassed the gadget bolted to the top of the gearbox (…the ‘auxiliary remote’ that moves the gear stick back a few inches) and the problem still exists. It really looks like it might be caused by something deep in the bowels of the gearbox. Aside from this ‘5th gear thing’ it runs really well and I’m reluctant to just ditch the gearbox and change it for an ‘unknown quantity’ replacement. Has anyone heard of this sort of thing before, or has any ideas? Any comments or advice would be very greatly appreciated. Many thanks.

sounds like synchromesh baulk rings, usualy a problem in 3rd and 4th, difficulty in disengauging, worst case is the box jammed in gear, sounds like you are close to complete failer, worth taking the top cover off, it could be as simple as the gear selector roll pin dropping half way out locking the gear lever.

Thanks. I was afraid of that. I guess there's nothing else for it but to take the car off-the-road for a while, get the gearbox out and have a look (...never happens when it's raining does-it... I'm going to miss all this luvverly weather). Thanks again.

BGH do HD baulk rings for 3rd & 4th in there top spec boxes to avoid this problem: linky

[Edited on 28/6/2010 by mcerd1]

Many thanks. The engine is tuned to give around 135bhp at 7000rpm so perhaps I should think about beefing-up the gearbox. Next job... as soon as I get a moment... will be to open her up and have a look (I will post some pics when I have found the problem). Thanks again.

well even BGH say the standard box is good for 145bhp / 145ft.lb - so maybe it just needs to be a good standard one....

Find a s/hand box and have a good summer

Thanks guys... I'm going to go for a second-hand replacement to keep me on the road while I have a go at the 'dodgy one'. So, ebay here I come!

One of the best mods that I have done to my car was a BGH box with the higher first gear, well worth the money it cost. My car has a similar spec to yours

Just a quick update. I've replaced the gearbox with a really good 2nd hand unit and all's fine. As for the dodgy 'box' I have stripped it, and cannot find anything wrong. Nothing's 'broke' and it's not badly worn. However, with a bit of fiddling-about I can sort of replicate the problem. There’s a 5th gear selector locking plate on the RHS of the rear casing. This has some adjustment, and if it's not 'just right' it allows the gear stick to move front to back, but not left to right. I guess that this might have been the source of my problem. Anyway, I'm going to rebuild the box and keep it a spare. If anyone gets the same problem, it's probably worth having a go at adjusting this lock-plate (…can be done with the box in the car)... before stripping it out.