MatraSport Forum

Each model => Murena => Topic started by: Colin on July 29, 2017, 06:54:10 pm



Title: Gear linkage set up 2.2
Post by: Colin on July 29, 2017, 06:54:10 pm
I have read a lot on here about the various problems people have had with sloppy gear linkages. I have a few issues with mine, so far I have changed all the ball joints (with the kit from Matra Magic), the top hat washer and the nylon bushes on the fulcrum on the gearbox (with bronze ones from Simon). 
However I am still having difficulties with setting the linkage up properly. I can now get all the gears, but it is far from precise. when trying to select 5th I frequently get 3rd, and the same for reverse and 4th.  I can adjust it to make it more precise, but in doing so I lose 2 gears, either 1st and 2nd, or 5th and reverse.
I am wondering if there is any kind of datum I can find to work form, or if there is a standard length to set the 2 front rods to. The issue is with the left/right movement of the gear leaver, not the forwards/backwards.


Title: Re: Gear linkage set up 2.2
Post by: GP on July 30, 2017, 05:58:49 am
Q: What is the condition of the gear lever assembly? If this is worn out and loose you will not achieve the sideways deflections you are after.

Starting with the gear lever in the neutral central position so that deflections can be achieved equally. I have then just made logical adjustments to the linkage whilst lying under the car and having someone (patient) move the gear lever for me.

F.Y.I.

1st. quick shift modification picture with the top of the gearbox lever nipple moved forward will reduce the forward and back throw of the gear lever.

2nd. modification picture with the split nylon pipe clamp assembly over the main gear change tube improves the precision of the all the movements. (although technically not how the system is designed to work).

Good luck.



Title: Re: Gear linkage set up 2.2
Post by: Anders Dinsen on July 30, 2017, 09:47:49 am
I prepared this little guide many years ago, but the system and the troubles it cause are still the same, it seems :)

http://dinsen.net/murena/gearshift/

My guess is that you have a worn bush at the end of the gear lever rod which gives you trouble pivoting the long rod under the car enough to engage fifth gear reliably.

(http://dinsen.net/murena/gearshift/murenalinkage.jpg)

Good luck!

/Anders


Title: Re: Gear linkage set up 2.2
Post by: Jon Weywadt on July 30, 2017, 12:17:21 pm
@GP
where did you get the nylon clamp assembly? Homemade?
I made a similar support but not as elegant :-[
One major problem on mine was that the "L" bracket on the gearbox (item E on Anders drawing) was 'frozen' so it pivoted by moving the bolt rather than pivoting on the bolt.
Fixing that, replacing the bronce bearing on the end of the gear shifter, and adding the support around the shifter pipe, solved most of the problem.
The support makes the shift a bit 'stiff' from side to side, so I have a plan to instal a universal joint in the shifter tube about 6" in front of the support.


Title: Re: Gear linkage set up 2.2
Post by: Colin on July 30, 2017, 06:26:00 pm
Thanks for the advice so far...

I have only ever driven this Murena, and a Peugeot 1.9 engined one I had last year, so I may be being too fussy, and expecting a very precise gear change.

further investigation has revealed that the gear lever has no slop in it at all, and has a metal ball on it, not a nylon one. A long ish run today had proved that it is ok as it is, but I think there is still room for improvement.
The play is very visible, when operating the linkage from underneath. The longitudinal rod moves a long way (around 2 inches at the top end of the gear lever) before it begins to move the front horizontal link (D on the above diagram), but there is no play anywhere else in the system.  When the car is put into 5th, the lever springs back to where you would expect to find 3rd.

Has anyone attempted to make a Ferrari-esque gated gear lever base? This may stop it springing around, as mine seems to do.

It is my understanding, from what I have read on here, that the lever needs to swing, rather than just rotate. How do you get on with the extra support bush? it seems to work against the geometry of everything else.

To summarise; the top hat washer in the end of B is new, as is the ball joint at the other end. D, F & K are all new, and there is no slop in the ball on the lever...


Title: Re: Gear linkage set up 2.2
Post by: GP on July 30, 2017, 06:53:55 pm
@GP
where did you get the nylon clamp assembly? Homemade?
I made a similar support but not as elegant :-[
One major problem on mine was that the "L" bracket on the gearbox (item E on Anders drawing) was 'frozen' so it pivoted by moving the bolt rather than pivoting on the bolt.
Fixing that, replacing the bronce bearing on the end of the gear shifter, and adding the support around the shifter pipe, solved most of the problem.
The support makes the shift a bit 'stiff' from side to side, so I have a plan to instal a universal joint in the shifter tube about 6" in front of the support.

Hello Jon,

The split nylon hydraulic pipe clamp assembly came from a ship yard in Norway and I drilled it to suit. I do have a spare one if you p.m. me your address I will post F.O.C.

The universal joint in the shifter tube is a good idea to try.

Cheers,

Graham




Title: Re: Gear linkage set up 2.2
Post by: Jon Weywadt on July 31, 2017, 12:26:26 pm

------

The universal joint in the shifter tube is a good idea to try.

Cheers,

Graham

I got mine, and a boot to match, at Car Builder Solutions here:
https://www.carbuildersolutions.com/uk/filterSearch?adv=true&cid=0&q=universal+joint&sid=true&isc=true#/pageSize=8&viewMode=grid&orderBy=0 (https://www.carbuildersolutions.com/uk/filterSearch?adv=true&cid=0&q=universal+joint&sid=true&isc=true#/pageSize=8&viewMode=grid&orderBy=0)

As with my zillion other ideas, this one has not been implemented yet.  :(

Jon.


Title: Re: Gear linkage set up 2.2
Post by: suffolkpete on July 31, 2017, 04:31:37 pm
Colin,
Is your gear lever the type where you have to press the lever down to select reverse.  If so, there is a metal detent at the base of the lever and this will prevent the lever moving far enough to select all the gears.  The cure is to remove it altogether and weld up the sliding section on the lever.  This detent is not fitted to later cars anyway.  The Ferrari arrangement is not the way to go as the restriction in movement will stop you selecting all the gears as the linkage wears, and it will wear.  If there is play in the nylon cup at the end of the lever it can be split apart and the faces filed to make it tighter.


Title: Re: Gear linkage set up 2.2
Post by: Colin on July 31, 2017, 04:50:20 pm
It is a 1983 car, so does not have that arrangement. I will take a video of what is happening, next time I jack it up.


Title: Re: Gear linkage set up 2.2
Post by: Oetker on July 31, 2017, 05:13:26 pm
Some points to look at.
The play on this point.
(https://lh3.googleusercontent.com/bKoR-WJ-8NlmzlE-AGDAVQWmrMKIOY2Mr1-rdmNJ-IBWGMYqihkHPCkbHX4GXYxcVtFpbNDq8OrE5DwOJw=w800-h600-rw)
I made a bush in it.
(https://lh3.googleusercontent.com/RebBjze1gaoMO6SVZhfaxpWyXa_IigfyxaAzfebyCoAczXYWxuHTJotNoFMi3Y7FdfPARz8IeKYmrouYmA=w1024-h768-rw)

The play on this point.
(https://lh3.googleusercontent.com/zxzNM8Ebk0AauH31flUSG68cBFYTc17-qtPB8JQuuD-Sq-k2kUh5QBhGNcwtCSCEvhRvxxH41qTQJyBhuA=w800-h600-rw)

Shorter shift for/backwards like Graham.
(https://lh3.googleusercontent.com/6Nntvn1f399bgVSZf7bcjExpvmAwGNQOFPUvB_wQSHLXLkcx8Unyr8C_V-R0WTW0l-gFnW_XVe2ddafJ-w=w800-h600-rw)


Also new bushes (Simon)
(https://lh3.googleusercontent.com/OmOA9W4X7vQ9ACCa01DhoSb3tcuzZlnLglX4AaOknSr0TdF3r1DdbTQjosYiNoUSuINkkrBppwijecnu5Q=w800-h600-rw)


To keep the swing and make a shorter shift.
(https://lh3.googleusercontent.com/TwPrFh1wMi9TYszENn2Cm6QPhMYW1KJKWCOD-hCOQf26YdAFCQhPnJhaAOg3OswBixdKPBL3lPJOPCrMxQ=w800-h600-rw)

Herman



Title: Re: Gear linkage set up 2.2
Post by: Jon Weywadt on July 31, 2017, 10:10:19 pm
Some points to look at.
The play on this point.

-

Herman


Hi Herman.

Sorry, but no photos show up, just question mark logos.  ???


Title: Re: Gear linkage set up 2.2
Post by: Oetker on July 31, 2017, 10:46:23 pm
I see no probem but I just resized the pics to standard resolutiion.
It should be visible.

Herman


Title: Re: Gear linkage set up 2.2
Post by: Anders Dinsen on August 01, 2017, 08:39:12 pm
It is a 1983 car, so does not have that arrangement. I will take a video of what is happening, next time I jack it up.

Thanks for the advice so far...

I have only ever driven this Murena, and a Peugeot 1.9 engined one I had last year, so I may be being too fussy, and expecting a very precise gear change.

further investigation has revealed that the gear lever has no slop in it at all, and has a metal ball on it, not a nylon one. A long ish run today had proved that it is ok as it is, but I think there is still room for improvement.
The play is very visible, when operating the linkage from underneath. The longitudinal rod moves a long way (around 2 inches at the top end of the gear lever) before it begins to move the front horizontal link (D on the above diagram), but there is no play anywhere else in the system.  When the car is put into 5th, the lever springs back to where you would expect to find 3rd.

Has anyone attempted to make a Ferrari-esque gated gear lever base? This may stop it springing around, as mine seems to do.

It is my understanding, from what I have read on here, that the lever needs to swing, rather than just rotate. How do you get on with the extra support bush? it seems to work against the geometry of everything else.

To summarise; the top hat washer in the end of B is new, as is the ball joint at the other end. D, F & K are all new, and there is no slop in the ball on the lever...

It sounds like it's just the way it should be. I agree with you that the support bush would work against the geometries, I would not recommend it.

/Anders