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Gearbox shutter problem
zeuspig - May 10th, 2013 at 09:24 AM

Hi all,

Got my split bus registered yesterday but the teething problems have started.

I have done the Subaru Ej25 conversion, creative IRS and L plate beetle box with shirwin heavy duty clutch etc.

Every gear works fine except first, you can start off in first with out it shuttering the while car and it pushes it out of first.. You can't even hold it in first.

If you start in 2nd all is sweet.. Any suggestions?

Mr Muppet - May 10th, 2013 at 10:09 AM

Hey mate, sounds like the Bowden tube doesn't have the right amount
Of 'sag' in it. I believe there should be 25-45 mm Sag in the tube , although
this is for a beetle and I don't know much about Bus's. The Bowden tube is
the hard rubber tube that is between the body and the gearbox in which the clutch
cable runs through. This is coming from my own personal experience so I maybe
wrong, but it's something to consider anyway.

Cheers
Michael

donn - May 10th, 2013 at 11:06 AM

Hmm, yeah I've had that problem Mr Muppet, but that's clutch shudder, I think zeuspig has a different problem, the gear wont stay in, though it's a bit hard to understand what he's writen, maybe a better / clearer explanation would help zeuspig

matberry - May 10th, 2013 at 02:08 PM

Yep, bowden without enuf pre-bend and/or engine mounts loose

ragged - May 10th, 2013 at 04:04 PM

Is it a new or secondhand gearbox?
It sounds to me like the 1st/2nd gear fork adjustment is incorrect or the 1st gear/selector hub no good.
Has it been rebuilt?
Dave

zeuspig - May 10th, 2013 at 05:15 PM

No I bought the box secondhand.

Seems to only do it from a complete stop when in first and you go to take off it shutters real bad and jumps out.

I've been starting off in second. But I don't want to keep driving it like that

mactaylor - May 10th, 2013 at 05:34 PM

Quote:
Originally posted by matberry
Yep, bowden without enuf pre-bend and/or engine mounts loose

yep X 2

bajachris88 - May 10th, 2013 at 06:41 PM

Quote:
Originally posted by zeuspig
No I bought the box secondhand.

Seems to only do it from a complete stop when in first and you go to take off it shutters real bad and jumps out.

I've been starting off in second. But I don't want to keep driving it like that


Motor rotates about its mounts most on lift off. As engine and gearbox are hard mounted, the gearbox moves around to. If not enough bend in bowden tube, this engine/tranny movement retracts the clutch cable ever so slightly enough to disengage-engage-disengage repeat as it bounces back and fourth in the mounts.

If the engine mounts are shot, they allow this excess movement as well, which means they could also be a problem.

zeuspig - May 11th, 2013 at 08:08 AM

Great thanks all, I will suss it all out this week and let you know how I go

zeuspig - May 17th, 2013 at 04:27 PM

Yep Bowden tube.. Thanks heaps for the heads up

grogy - May 17th, 2013 at 05:40 PM

does it have a bar under the rear of the motor, as it twists it will go down at the back and shudder. a bar under the back of motor cures the shudder caused by that