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Author Topic: Modifying gear shift  (Read 26204 times)
krede
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« Reply #30 on: October 09, 2009, 05:39:07 pm »

The reason that we (Hans is too) are thinking about replacing the linkage with wires is really more of a space issue, as the standard system gets in the way when dropping in a turbo engine.

However. As I have put my turbo project on hold for the moment (Cost , time, facilities) so is the wire linkage stuff.

Mr.Dinsens solution looks very sound to me though (I expected nothing less from him Wink ).
Cutting and Fixating the "B" rod is surely the way to go about it, and I think, that if done right it could make a HUGE difference at very low cost and effort.
I would fabricate the fixing point as a rod sliding inside a decent length of tube with just enough tolerance to allow lubrication by fitting the tube with a couple of grease nipples, and then fit each end of the tube with a small gaiter to keep any excess grease from going everywhere. Smiley
  
« Last Edit: October 09, 2009, 05:42:27 pm by krede » Logged
GP
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« Reply #31 on: October 20, 2009, 02:24:17 am »

Hi all,

Before I start modifying my existing "torsion bar" gear linkage, I thought I would try out Richards modification (see previous picture from Titus) to reduce the throw of the gear lever by shortening the pivot point on arm "G" and actually take some measurements at the gear lever throw, using a calibrated piece of 4" x 2" timber!  Smiley

I found a suitable Ball and Socket Joint to bolt onto the arm "G" at a firm in Dorking U.K. called Automotive Components, at the grand cost of £1.54 each. See attachment. However I decided as arm "K" is not actually horizontal, I would make up an assembly using a female M8 balljoint from Car Builder Solutions and an assembly of track rod Go-Kart components utilising a 55mm high tensile bolt to bring rod "K" into the horizontal plane, thus increasing the applied force on arm "G" as much as possible.

I had an educated guess of where to drill the hole in arm "G" and decided on 60mm from the existing socket. The water reservoir was moved to one side and the drilling of the hole was possible to do in situ. Just make sure to cover up the drive shaft and gearbox vent below first though.

The assembly was bolted on and road tested out O.K. The extra force required is noticeable, but with a firm action which is quite acceptable to me.

The actual distance of measured gear lever throw before modification was 140mm. The resultant measured distance of gear lever throw after modification was 100mm.  Which is approximately a 30% reduction of gear lever movement for very little effort and expense.  Well done Richard!
 
See attached images for further clarity and general interest to all I hope.

Cheers,

Graham
« Last Edit: October 20, 2009, 02:29:49 am by GP » Logged
krede
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« Reply #32 on: October 20, 2009, 06:56:07 am »

NICE!.... I bet quite a few people will be doing this modification soon.
And Good work on the "special" calibration tool! Cheesy ...
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Oetker
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« Reply #33 on: October 20, 2009, 10:24:02 am »

Good solution.
This will make it almost quickshift Tongue
Now a few new synchromesh,  and I wil be undefeatable at a trafficlight Grin
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I feel like Jonah, only my fish looks different.
Murena 2.2 Red 1982. Murena 1.6 black on places.
Jon Weywadt
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« Reply #34 on: October 20, 2009, 09:54:30 pm »

Hi all,

Before I start modifying my existing "torsion bar" gear linkage, I thought I would try out Richards modification ---

Cheers,

Graham
I may try this mod myself. But while I am waiting for my new cooling pipes to come back from electro polishing, I thought I would put the time to good use by trying to fix the play in the ball on the shifter arm. On mine you could pull the shifter up/down about 1mm due to wear of the ball. The nylon housing pieces were pressed fully together so there was no adjustment possible.

After thinking of how to replace the ball I decided that it was not practical and, save from making a whole new assembly in metal, I had no really good solution. (I'm too cheap to by a new one  Cool)

That is when I remembered a teflon sheet that Jan had given me years ago for some project. It was 1/10th of a mm thick and there was enough left to wrap the ball. Worth a try. I cut a piece big enough to wrap the ball and extend through the nylon housing parts. (photos) This proved to be exactly enough to remove the slack and make the ball rotate nice and firm in the housing, with no sticking. The housing squeezes a small fold on the sheet on two sides, so it should stay in place.

The metal plates were cleaned in phosphoric acid and painted with Hammerite. The whole assembly feels like there will be no play and the teflon is nice and smooth, so it should hold up nicely. If not, hopefully it will last long enough to be worth replacing every so often.

Looking forward to feeling if it makes a lot of difference. Grin

PS. I am sure you notice the nice clean work bench.  Cheesy That is a coming project in itself. Grin
« Last Edit: October 20, 2009, 09:56:19 pm by Jon Weywadt » Logged

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Oetker
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« Reply #35 on: October 20, 2009, 10:01:41 pm »

That is a nice solution.
Hope it will last.
My murena has a steel ball in it, so I have no problem with this.
Somewhere in 1982 the plastic ball made place for a metal one.
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I feel like Jonah, only my fish looks different.
Murena 2.2 Red 1982. Murena 1.6 black on places.
Jon Weywadt
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« Reply #36 on: October 20, 2009, 10:08:29 pm »

That is a nice solution.
Hope it will last.
My murena has a steel ball in it, so I have no problem with this.
Somewhere in 1982 the plastic ball made place for a metal one.
Does your metal ball version aslo have the reverse lock-out pin seen in my bottom photo?
« Last Edit: October 20, 2009, 10:14:08 pm by Jon Weywadt » Logged

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Oetker
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« Reply #37 on: October 20, 2009, 10:23:07 pm »

Looking in my list of modifications I found a bulletin dated juli 1981.
I quote this translated.
Since chassisnumber 5491 the reverse locking is placed in the gearbox.
March 1982 when old stock was finnished they changed all gear levers to the metal ball without locking pin.
« Last Edit: October 20, 2009, 10:32:51 pm by Oetker » Logged

I feel like Jonah, only my fish looks different.
Murena 2.2 Red 1982. Murena 1.6 black on places.
Oetker
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« Reply #38 on: March 20, 2010, 09:41:40 am »


Part 1 of this modification I have now on my car to.
I used a holder for a telescope from a rifle .
Tapped for M10 and made the hole  wide enough to fit.



It is very short shifting and a bit more heavy to change gears, but I like it.

Movie.

http://www.youtube.com/watch?v=5Si49t-haeo

In a short while I will do the other part to.
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I feel like Jonah, only my fish looks different.
Murena 2.2 Red 1982. Murena 1.6 black on places.
Bart_Maztra
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« Reply #39 on: March 20, 2010, 10:20:08 pm »

It is very short shifting and a bit more heavy to change gears

Is this the right way to go?

The front end of the rod is moving sideways, because that's what the stick makes it do.  To operate the levers on the gearbox, the rod only have to rotate and move forward/backwards. When the stick rotate the rod, the stick also move the rod sideways. That's the way it is. If this sideways move is not wanted, the rod have to be attached to the stick in the center of the ball!

So fixing the rod in the middle..... and the stick moving it sideways.... Stress!  The stress will try to bend the rod, and put tension on the gearbox levers, causing excess wear.


I think the only right way to go is taking the slack out on every joint, especially the ball of the stick.

Disclaimer..... personal opinion

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Oetker
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« Reply #40 on: March 21, 2010, 12:03:51 am »

I think you made a point, but 1 mm play in the middle will give it cm's on the downside of the stick because of the long distance.
Because of no play at all on my ball joints I am very short shifting now.
I am thinking about giving it a tiny bit more play.
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I feel like Jonah, only my fish looks different.
Murena 2.2 Red 1982. Murena 1.6 black on places.
GP
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« Reply #41 on: March 21, 2010, 10:48:01 am »

I think you made a point, but 1 mm play in the middle will give it cm's on the downside of the stick because of the long distance.

With the gear lever end of the main rod clamped in a vice I measured the deflection achievable at the point of the new bearing assembly 110 cm further down. Applying a small force with one finger at the furthest rear end of the rod produced easily 4 cm. of sideways deflection.
« Last Edit: March 21, 2010, 11:21:29 am by GP » Logged
GP
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« Reply #42 on: March 21, 2010, 11:30:26 am »


In a short while I will do the other part to.

These are the bits I used to do the other part.
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Bart_Maztra
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« Reply #43 on: March 21, 2010, 11:43:39 am »

With the gear lever end of the main rod clamped in a vice I measured the deflection achievable at the point of the new bearing assembly 110 cm further down. Applying a small force with one finger at the furthest rear end of the rod produced easily 4 cm. of sideways deflection.

 Huh
Try this again, but now with the rod clamped in the vice at the point where the additional bearing will sit. (behind the upright lever) And try to bend the gear stick end of the rod.

Because that's what is happening. The additional bearing is fixing the middle of the rod, and the gear stick is moving the rod sideways.
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GP
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« Reply #44 on: March 21, 2010, 03:33:07 pm »

Hi Bart,

Your right. A few too many rum and cokes last night I think!

With the bearing area in the vice and a similar force applied 2 cm. of deflection was observed at the gear lever end.

Cheers,

Graham
« Last Edit: March 21, 2010, 08:19:17 pm by GP » Logged
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