Cable change ends

Took my car on the longest ever drive since I've had it today, a 200 mile round trip (only do-able with the use of earplugs!)
However, within 5 miles of home, my gearchange linkage snapped and I was stranded on a roundabout! Luckily I managed to gain access to the gearchange mechanism (gear lever end) and was able to get the car into 4th gear and with a bit of clutch slipping, was able to limp home. When I bought the car the previous owner told me that he thought these parts (see picture, broken joint on left) were a weak link in the gearchange mechanism and had bought some spares. I fitted one and was away again (although being MUCH more careful with the gearchange!.
I presume it would be quite straightforward to change these ends for rose joints (rod ends) which would make it a better and more secure joint.
Simon
 

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David Morton

Lifetime Supporter
Simon,
Put the gearchange cables into the nearest bin and go for a
much more solid rod change. Sure, it costs to do it and you'll have to take the sill and fuel tank off as well but it's provident in the long run.
Dave M
 

Robert Logan

Defunct Manufactuer - Old RF Company
Simon,

I agree with Dave regarding the rod change being the most rigid, but we use a cable central gearchange and it is posible to get them to work correctly (remember that the McLaren F1 uses cable gearchange).

The rod ends in the picture above are ONLY fit for throttle linkage on our cars. The standard rod end 8mm. or there abouts is what is needed on a gearchange. Use good quality morse cables and make sure that the mounting points are RIDGID and all should be good.

Best wishes,

Robert
 
The rod change method is fundamentally flawed. A rod change will never work accurately as long as the engine is mounted on flexible rubber mounts and the rod system is attached to the chasis. The slightest movement of the engine will be multiplied by the lever ratios of the linkage and inevitably give rise to innacuracy in the gear change. Only racecars with solid chassis mounted engines can be expected to benefit from a rod change. I had a cable system in my car which after meticulous setting up worked fine. I was persuaded by Frank Catt to have one of his rod change systems. From then on I had constant missed shifts and over revving incidents. I now have a cable operated Quaife six speed sequential box, which after some time getting the set up right is just a dream.
Little rose joints on the cables instead of the horrible ball joints, and careful setting up will give you an excellent change system.

Mike
 

David Morton

Lifetime Supporter
Robert,
I guess you are talking about the F1 GTR from McLaren Cars Ltd. rather than McLaren F1 (McLaren International Ltd) which uses hydraulic actuators controlled by two dc paddle microswitches. /ubbthreads/images/graemlins/wink.gif /ubbthreads/images/graemlins/wink.gif
Jasper,
What did the quaife sequential cost to buy and install? Really curious to know. Does quaife offer electrical operation as well?
Dave
 
Dave, I am afraid that I don't discuss costs relating to my hobbies. If I remind myself how much these things cost I would probably never do them! You are welcome to come and have a look and chat anytime.

Mike
 
Hello -

ALthough no owner, I have had the pleasure of driving (some in anger) quite a few GTD 40s. These have had a mix of gearchanges, both cable and Rod.

Roys initially had cables (GTD) and when set up correctly was as sweet as a nut and gave as fast a shift as any Rod I have tried. (might even have been a 10th faster if I recall).

Dave's R42 retains a fully cabled system (GTD) to NS rear of Renault box and when driving that, I have never missed a gear - very smooth - a bit of a long throw 1-2 3-4 but Dave's arms are longer than mine! (and hey - its his car)

Andrew Fordyces superb 40 has a Rod change (FrankCatt) that is also very good and never gave me any problems - no missed shifts and very smooth action with a narrow gate pattern.

Whilst I have not driven Robin's car - I am reliably informed that it also has a super smooth acting rod shift (FrankCatt) and I can certainly NEVER recall him missing a shift, something especially annoying when competes against me - doh!

Roy now has his own designed Rod (STP) change and it too is very good - took a while to get it right and as Mike states, engine movement in relation to chassis was a bit of a problem but as Roys engine is now braced against excessive movement fore/aft and also across the car, there don't seem to be too many problems. Details of his have been recently included in the club mag if anyone is interested.

Bottom line as I see it - BOTH systems work - some better than others but the real crux to the problem is getting the system correctly adjusted, keeping it clean and lubricated.

Follow the last three pointers and all should be fine.

Now if I could only finish that paddle air shifter........ /ubbthreads/images/graemlins/smirk.gif
 

MWGT40

Supporter
"You pays your money and takes your choice" so the saying goes. I am one of the few people who have been lucky enough to drive the yellow peril which has Frank's rod change mechanism in it and can also confirm that it is beautifully smooth. I wasn't happy with the cable gear change in my car and so had it switched out to a rod gear change after 6 months or so with the car, and I have had no problem with it despite regularly driving the car in anger at the various hillclimbs and sprints that I compete in.
 
Hi Simon

I had two of those joints break on my car whist building it! They are just not up to the duty.
You are right, they are easy to replace with rose joints. Working from memory (so please check and in any case, your cable end threads might be different) the threads are 3/8BSF and a 6mm stainless bolt fits nicely in the rosejoint hole to bolt on to the gearchange plate. The only thing I had to do was to file the underside of the hex heads on the bolts as when the cables are at full push or pull, the angle of the plate to the cables is such that the underside of the hex head was fouling the rosejoint body. Maybe setscrews would get round this, but you can't get them with a shank so the fit in the rosejoint hole isn't as good.
Don't forget to replace the two under the gearstick either.
Hope this is of some help.

Regards

Dave Tickle
 

Malcolm

Supporter
I have had both cable and rod systems fitted to my car.

For the first 9 or so years I ran the cable system that GTD set up for me in year one. I never needed to adjust it, even when I changed the ball joints ends to rose joints. It needed good setting up to become light in use, something that many owners I feel do not always get right from other cars I have tried. Their cars have very stiff cable systems that are quickly blamed as bad, which I think a little unjust.

I have some data on the gear change speed that showed it comparable in shift time to the rod system. However all systems are governed by the fact that the Renault box can only change gears so fast. A well set up system can out do the gearbox easily be it cable or rod linkage. I didn't miss gears with the cable system but have done so with Frank Catts system. I hope to forget the first Isle of Man trip after Frank fitted the system as I seemed to remember a lot of swearing as I had to keep adjusting the system to get the ability to change down sorted to my liking. The problem there was use of cheap rose joints that wore out too quickly and not having the rods fixed in the helicopter joints properly, items now corrected and the system does work much much better, although requires regular maintenance. I do not plan to go back to cables or to change away from Frank's system yet.

However from where Simon is, my advice would be to fit the rose joints mentioned above, adjust the system correctly so that it operates smoothly and lightly (this may take a little time to acheive)and then mark the lock nuts so that you can see they do not move.

You do need to heat sheild the gearbox end of the system quite heavily as the morse cables can otherwise melt and that often causes tightness in the system. I folded an ali plate and used heat sleeving from the cable ends right into the side panel.

If I were doing the gear change again, with my current knowledge and tool kit, I would stay with a rod change and most likely utilise the design at the front end as used on some of Mike's race cars in his toy shop, his Lola being an very good simple example. I will try and attach a drawing to this post with a sketch I did for someone a while back. No gauarantee of success! The design at the rear I would try and improve by making it much tighter to the gearbox casing as the further out it gets the more amplified the movement of the gearbox/engine is. I also thinks it needs dirt protection as it is rather exposed. One grain of dirt in any rose joint and it can lock up solid requiring a big effort to free up. So far I have been lucky not to have this happen to me but others haven't been as lucky.

Hope this helps

Malcolm
 

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Rick Merz

Lifetime Supporter
I feel like the cable change is getting a bad rap. I had the GTD cable system as supplied and after about a half hour of adjustment found that it worked great. I will agree with the heat shield as added insurance against heat. As many of you know I have a Porsche gearbox now and I use a Kennedy cable shift that works very well. The Kennedy system uses larger diameter cables and the Porsche box does not need a translator which may make this a more robust and accurate gear change system. Kennedy will make the cables to any length that you specify.
 

Malcolm

Supporter
Well said Rick, that was meant to be the gist of my post! I like the idea of perhaps upping the diameter of the morse cables as it should make them more durable. It is only the fittings then that would require a little alteration to suit.

Malcolm
 

Dave Bilyk

Dave Bilyk
Supporter
Malcolm,
I note that my car has rubber boots on all the suspension rose joints. Maybe these can be obtained independantly, and would be worthwile precaution for the gear linkage rose joints too.
regards
Dave
 
Just a thought. Could heat shrink tubing be used for such things? Joe /ubbthreads/images/graemlins/confused.gif /ubbthreads/images/graemlins/grin.gif
 

Howard Jones

Supporter
I was wondering if anyone has done a center shift(USA) rod system? This seams like it would require quit a lot of monkey motion. It might be better to do a left hand rod shift in a left hand driver(USA) location car. Heat srink would seal thing fairly well but isn't really very flexible or ment to be a heat shield.
 
ERA does a center shift rod for the ZF.
DRB does a center shift rod/cable combo for the G50.
Every 016 trans I've seen is cable shift.

MikeD
 
My car has an 016 with rod shift. The car is RHD with right hand shift. Since an 016 selects on the left side of the box, the shift linkage has a "swing arm" that crosses over the top of the box from right to left. Works great with very minimal play.
 
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