E39 keeps jumping out of 3rd gear

The E39 520 seems to have suddenly started disliking the 3rd gear. When driving, and shift to 3rd, half the time after driving for a random amount of time, the gear will simply drop back to manual. This
seems to happen especially when slow driving. It doesn't happen in any other gear position. Also resting my hand on the gear stick in 3rd means it will randomly drop out of 3rd and I find that I can easily get it out of 3rd without depressing the cluth by just gently pulling on the lever. Again this doesn't happen in any other gear position.
Anyone know of this problem, how to fix it and what i'm looking to lay out to fix it
Thanks
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Forgot to mention, its a Manual Tranny. Also I meant it keeps dropping down to Neutral randomly sometimes.
ChrisJ wrote:

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It could be because the gear is not not engaging fully. Either because the g/lever, or the selector fork is not moving enough. You don't give the mileage, but a 3rd alternative is that the dog clutch for 3rd gear is worn. The last 2 possibilities would involve removing the g/box to fix. The first might be finding and fixing something that is restricting the movement of the g/lever itself. Mike.
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Jumping out of gear can be a sign of a worn (broken) motor or transmission mount, or it can be a fried transmission. I suppose there _could_ be an issue with the linkage, but searching for the transmission mount should discover such a malady. I suspect linkage problems would be noticable in other ways too, and since you did not discuss any other symptoms, I tend to discount linkage related problems.

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Got 102K on the clock.
I'm not sure what other problems should be noticeable, as of now all I see is sometimes in 3rd and moving and it justs shunts back to neutral by itsef.
It seems to happen sometimes, my guess is it would need for the gearbox dropped out before I can know for sure. I'm not exactly sure what would cause a worn or broken transmission mount, maybe cos I work my way down the gears when braking??
I'm not sure whats involved, any ideas on how long/how much to fix the problems you've suggested??
Thanks
Jeff Strickland wrote:

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ChrisJ wrote:

Does it happen when you brake hard?
Usually if it's not going into gear fully because of the linkage you'll get grinding on power, similarly if it's slipping out of gear you'll get a grinding or a bang. Incidentally most gearboxes when you're coasting you can take out of gear without using the clutch with no trouble at all and on some you can put them in gear ok too if you time the revs right.
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Usually, if the engine mounts are good and the engine does not move about under braking then the likely cause is work synchromesh blocker rings and synchro hubs or maybe just the springs and balls but more often a case of synchro hubs and brass rings.
Definitely a gearbox out job or a used box from a crashed car.
Hugh

Bognor Regis, W.Sussex, England, UK
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IMHO, a worn baulk ring won't cause it to jump out of gear as the hub goes onto the dog clutch after it's 'finished' with it - unless it's stopping the clutch engaging fully in some way.
More likely is excessive end float in the hub assembly.
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On Mon, 06 Nov 2006 22:57:05 +0000 (GMT), "Dave Plowman (News)"

Dave - I used to race the Hillman Imp - Remember those?
The bloody things were always jumping out of gear due to the synchro hub springs, plates and baulk rings - replace the springs, balls, locating plates and baulk rings and all was well again. The Jag GB had similar problem, especially the 2.8 XJ6.
Sir Hugh of Bognor
The difference between men and boys is the price of their toys. Intelligence is not knowing the answer but knowing where and how to find it!
Hugh Gundersen snipped-for-privacy@h-gee.co.uk Bognor Regis, W.Sussex, England, UK
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Well yes, but which one? Replacing the gearbox would have cured it too. ;-)
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Dave Plowman snipped-for-privacy@davenoise.co.uk London SW
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don't know about engine moving about, My mate thinks I might have done the linkage or the clutch. After thinking more about it, I think I can pin it down to human error (lol), the problem only began after I used engine braking on the motorway after some C*** pulled out infront of me on an exit. At first I thought the car was sluggish in 3rd or 4th but I then got this jump problem a few days later. I still think 3 & 4 gears are just slightly sluggish sometimes when compared to 1,2,5. The 3 & 4 are connected somehow me thinks. There is no popping, and the drop out to neutral from 3rd seems almost effortless and annonyingly quiet so I only realize when it happens if I rev and am going nowhere fast. It doesn't happen if I'm pushing above 35 I think so slowly cruising is when it happens. Better tip out the piggy bank.
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