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Jumping out of gear
Chris.B - 10/9/07 at 10:07 AM

Westfield 2.0L Zetec 221bhp, BGH close ratio (type 9) gearbox.
Went to the Combe Euro Action day on Saturday with the Bath /Bristol + Chelt / Glos WSCC areas. During several track sessions this problem reared its ugly head - and it is completely reproducible. When braking hard then changing down from 4th to 3rd (i.e. the most common downshift at Combe) it goes smoothly into 3rd gear, but on the overrun jumps out of gear. This happened several times. I had to hold it in 3rd with my left hand & steer one handed until back on the throttle & it then stayed in. There was a little bit of free play in the clutch pedal which I adjusted out on the cable - however the problem remained. It only occurs on the overrun following a downshift from 4th to 3rd. I re-adjusted the cable on Sunday & went out for a spirited drive & it is there on the 4th - 3rd downshift.
I feel a gearbox removal & shipping it back to BGH is on the cards but would appreciate any ideas first. Oil maybe? Clutching at straws.
Chris


tks - 10/9/07 at 10:33 AM

if you are sure that the movement of the engine / box isn't pulling the gear out themselfes...

untherstand??? i don't know the setup (cables or rigid etc. etc.) but i can imagine a scenario where movement of the box could pull the gear out by them selfes...


Peteff - 10/9/07 at 10:51 AM

The clutch won't affect the gearbox jumping out of third gear. It sounds like a synchro problem.


David Jenkins - 10/9/07 at 11:10 AM

I happen to have the Haynes gearbox manual next to me... to quote:

Transmission jumps out of gear

- Worn synchroniser units
- Worn selector shaft detent plungers or springs
- Worn selector forks
- Selector linkage damaged or adjustment incorrect

Which gives you plenty of options!

It's probably worth taking the lid off the box and having a good look at the synchro bits for wear or breakage (they're quite easy to see). At the same time you can look at the selector shaft and forks, especially the roll pin that holds the striker block on the shaft.

It's certainly gearbox out time though...


DarrenW - 10/9/07 at 11:35 AM

Was the gearbox new when you fitted it? How many miles has it done since? Just trying to get an idea if its been Ok for ages and just started to do it.


David Jenkins - 10/9/07 at 11:39 AM

One thing you might like to consider - BGH have said in a magazine article that the Type 9 box does not like gearchanges that are too fast; repeated fast changes can break the synchro bits. In fact, he didn't recommend quick-change devices at all.

Just something to consider when taking your gearbox back... "Quick changes? Me? No - I always go VERY slowly between gears!"


Chris.B - 10/9/07 at 12:16 PM

quote:
Originally posted by DarrenW
Was the gearbox new when you fitted it? How many miles has it done since? Just trying to get an idea if its been Ok for ages and just started to do it.


No it wasn't new - had been fitted to a sprint car previously with 3000 miles on it. I've added another 3k ish all on track and assorted competitions. So it's not had an easy life. Wouldn't surprise me if bits are worn out. Never had the problem before - it has only just started jumping out of gear.

[Edited on 10/9/07 by Chris.B]


02GF74 - 10/9/07 at 01:18 PM

from what has been discussed on LR forums, any jumping out of gear problem is usually due to something wriong within the gear box itself.

I cannot see how it could be the clutch or gearbox/engine movement but then I am not g/box expert.


tks - 10/9/07 at 04:15 PM

guys wiuth movement i mean movement of the gear lever..

sow imagine the gear lever being static and the engine moveing, sure that with enough movement it could be pulled out!

Regards,


Chris.B - 10/9/07 at 04:54 PM

quote:
Originally posted by tks
guys wiuth movement i mean movement of the gear lever..
sow imagine the gear lever being static and the engine moveing, sure that with enough movement it could be pulled out!
Regards,

Good idea - That's one of the things BGH siad I sould check when I spoke to them this afternoon. Since it's happening under heavy braking / on track etc it's possible that the engine / gearbox is flexing & knocking the gear lever on the tunnel. I'll look when I next get to the car.