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Author Topic: Mechanical challenges  (Read 9219 times)
Jon Weywadt
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« on: March 24, 2009, 09:56:22 pm »

Restoring the gear shift function is turning out to have some interesting challenges. I originally thought that the problem with 1./2. gear might a problem of wear in the bushing connecting the shifter to the shaft running back to the gear box. Well, perhaps the former owner's "fix" should have been a hint. He had placed a metal strap around the shaft and fastened it to the left rear swinger. This would prevent any flex in the shaft when trying to engage 1./2. gears, thus providing a firmer push to lift the shifter out of the gear box. The shifter rod coming out of the gear box easily pushes in for 5. and reverse gears. However it is very hard to pull out for shifting into 1. or 2. gear.

Looking at a spare gear box, on which the rod moves smoothly, both in and out, I unscrewed the large bushing on top of the box. Underneath was the spring that keeps the rod centered on 3./4. gear. On this box it is in fine condition. Amazing considering that the gasket supposed to be under the bushing was missing and the rubber bellows, supposed to keep dirt and moisture away from the rod, was cracked in two.

I am guessing that I may have a broken spring that jams the shifter rod when trying to pull it out to 1./2. gear position. This should be revealed on saturday, when I tackle the problem. If all else fails I may have to mount the spare gear box while I rebuild the other one.

Helpful suggestions or experiences are welcome. Wish me luck.

PS. I am taking photos and plan to open a web page with the restoration progress, challenges and solutions.
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Anders Dinsen
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« Reply #1 on: March 24, 2009, 10:27:00 pm »

Hi Jon, I'm going to wish you luck removing the bush in the top of the gearbox. I have tried - and failed Wink I'm going to try again when I take the engine out one day and can apply heat on it.

I presume you've read my page on this, otherwise you may find something useful there:
http://dinsen.net/murena/gearshift/

/Anders
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'01 Grand Espace 24v
'08 Smart Fortwo 0,8 cdi
suffolkpete
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« Reply #2 on: March 25, 2009, 08:38:13 am »

The gear linkage is always a problem on these cars.  I bought mine as a non-runner because no gears could be selected.  The other places I would check before doing anything drastic with the gearbox are the L-shaped repeater on the gearbox and the ball and socket at the base of the gear lever.  The repeater is rather exposed and often seizes.  The gear lever base wears but can be fixed by taking it apart and shaving some material off the cup.  I think Roy has published an article on how to do this.  This was actually the problem with my car.  A quick test is to try and pull the gear lever up.  There should be no up and down play.  If you search this forum you will find an excellent drawing of the gear linkage produced, I think, by Lennart.  These 'boxes are quite strong, apart from 2nd gear synchro, and your problem could well be external.
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suffolkpete
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« Reply #3 on: March 25, 2009, 10:11:42 am »

Quote
If you search this forum you will find an excellent drawing of the gear linkage produced, I think, by Lennart. 
  Oops, just looked at the link in the previous post.  Sorry Anders Embarrassed  Advancing age means the memory is not what it was.  Excellent drawing though, helped me to sort my problem out.
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Jon Weywadt
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« Reply #4 on: March 25, 2009, 01:19:18 pm »

Hi Jon, I'm going to wish you luck removing the bush in the top of the gearbox. I have tried - and failed Wink I'm going to try again when I take the engine out one day and can apply heat on it.

I presume you've read my page on this, otherwise you may find something useful there:
http://dinsen.net/murena/gearshift/

/Anders

Hi Anders. Thanks for your wishes and the link. I have studied it and find it very helpful.

The top bushing, as you will have found, only has 2 flat surfaces on which you can grab on to it. On the spare gear box I examined, I used a 15" Bacho adjustable wrench, applied a bit of counter clockwize pressure and then hit the end of the wrench with a 5 pound hammer. Two good hits and the bushing came loose. I think it should be possible to repeat this process on the one in the car.
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Jon Weywadt
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« Reply #5 on: March 25, 2009, 01:33:31 pm »

The other places I would check before doing anything drastic with the gearbox are the L-shaped repeater on the gearbox and the ball and socket at the base of the gear lever. 

Hi Pete. Thanks, I have inspected the links and found that the previous owner replaced several ball joints and also the L-shaped link that converts the sidewards movement of the shifter to an up/down movement of the shifting rod in the gear box. The links appear to be in good shape. But if I pull off the lift link from the selector rod, then the rod cannot be pulled up as easy, or as far, as it can be pushed down. I conclude, but it is only a guess so far, that something is jamming the rod and I hope it is just a broken spring and that the pieeces can be pulled out.

An additional challenge has appearred. At one point the engine stalled on me. I stepped on the clutch and turned the ignition key. The car moved forward.  Huh Not a good sign. It seems that If I hold the clutch pedal pressed for a while, the clutch slowly engages. That sounds like a problem with the seal in the slave cylinder, or perhaps in the clutch master cylinder. Oh, well. I knew it was a project and it wouldn't be done on a weekend.  Cool
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valross
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Bagheera X 1980 + 7 CitroŽn


« Reply #6 on: March 25, 2009, 02:30:47 pm »


I presume you've read my page on this, otherwise you may find something useful there:
http://dinsen.net/murena/gearshift/

/Anders

Is there a similar description of the late Bagheera gear linkage somewhere?

Lasse
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Anders Dinsen
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« Reply #7 on: March 25, 2009, 11:00:04 pm »

The top bushing, as you will have found, only has 2 flat surfaces on which you can grab on to it. On the spare gear box I examined, I used a 15" Bacho adjustable wrench, applied a bit of counter clockwize pressure and then hit the end of the wrench with a 5 pound hammer. Two good hits and the bushing came loose. I think it should be possible to repeat this process on the one in the car.

Well, I used a correctly sized fixed spanner, plenty of WD40, a large hammer, but to no avail: It never moved a hundredth of a degree! Fortunately, the linkage works pretty well on my car despite the 1-2 mm play of the shaft in the bush.

Is there a similar description of the late Bagheera gear linkage somewhere?

I haven't seen it anywhere...

/Anders
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roy4matra
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« Reply #8 on: March 29, 2009, 05:15:50 pm »

Restoring the gear shift function is turning out to have some interesting challenges. I originally thought that the problem with 1./2. gear might a problem of wear in the bushing connecting the shifter to the shaft running back to the gear box...

Helpful suggestions or experiences are welcome. Wish me luck.

The most common problem with the gear selection is the 'L' shaped lever seizing up on the 'front' of the gearbox (sort of just behind the driver).  There is a pin fitted to the box, pointing up at the back of the driver, and the lever is fitted to this with two plastic top hat bushes and a circlip holding it in place.  This lever must rotate freely.  When it seizes up, it restricts the gear lever movement across the gate, so you often cannot get it far enough to the left or right to get either 1st/2nd or 5th/Rev.

Strip it, clean it, lubricate it, and if necessary you may have to replace the bushes.  Once free the gear change will be fine, as long as no-one has tried to adjust the linkage to compensate for the seized lever and messed up the setting!

If the problem is the movement backwards and forwards on the gear lever, actually selecting the gears, the problem could be external linkage or inside the box.  The easiest way to determine this, is to disconnect the long rod at the ball/socket at the back and use the large lever on top of the box to select the gears.  If you can do it easily here, the problem is in the linkage, if not, it is probably inside the box.

Finally, the gear lever and the nylon ball at its base is the same as some CitroŽn CX apparently as I remember one club member getting one from a scrap yard and fitting that.  It was a straight swap although the lever was longer and had to be cut to shorten it to the same as the Murena one.

Roy
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Jon Weywadt
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« Reply #9 on: March 29, 2009, 09:44:24 pm »

The most common problem with the gear selection is the 'L' shaped lever seizing up on the 'front' of the gearbox

Hi Roy. Thanks for your suggestions. A previous owner has already replaced the "L" bracket. It is virtually new and moves freely with no slack.

I spent the whole day, today, working various challenges. Primarily the gear problem. I disconnected the links and took the arm off the selector rod on thegear box. It took a good amount of work, as it had corroded and stuck to the rod. Some WD40 and putting it in gear and then applying pressure until it twisted on the rod. The screw had been removed of course  Wink Then twisting it back the other way and so on until it was loose enough to pull off the rod. That broke sweat.

This done I managed to unscrew the bushing on top of the shifter rod, A large wrench, and an other one as a prybar against the frame, broke it free. Once free it could be unscrewed by hand. On the picture below you can see the rust on the rod.

The other picture shows what a previous owner has tried in order to fix the problem that I now work on. The short bushing is from my gear box. You can see that it has been cut down with a hack saw. That obviously has not fixed the problem.

So what is the problem? Well, from the center position (3/4 gear selection) the shifter rod can be pushed down appx. 1 cm. Here it can be twisted to select 5th or reverse gears. No problem. But when the rod is pulled out, it  can only be pulled appx. Ĺ a cm out. It is possible to select 1/2 gears, but only just. When in, say 1st. gear there is no play in the rod (up/down) at all. Comparing to the spare gear box that my friend has, that shifter rod can be moved 1 cm in both directions and when in 1st. gear there is about 4 mm play in the rod (up/down)  It seems that he rod in my gear box can not be pulled out sufficiently to switch cleanly into 1st. or 2nd. gears. The previous owner probably thought that cutting the bushing would allow more movement and cut the bushing. (He could have just unscrewed it Ĺ a cm to check)

My question is now, what on earth can prevent the rod from pulling out like it is supposed to? It does change the gears, but only just in 1./2.  Any ideas? I wish I had a fiber scope so I could look inside the box while changing gears.  Roll Eyes
« Last Edit: March 29, 2009, 10:32:34 pm by Jon Weywadt » Logged

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Jon Weywadt
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« Reply #10 on: March 29, 2009, 10:29:44 pm »

The problem I describe above, require you to put a lot of force on the gear shifter, pushing it hard to the left, in order to make sure the selector rod is pulled out as far as it will possibly go. In order to make sure that there is no "give" in the connecting shaft from the gear shifter to the linkages, the previous owner placed a strap around the connecting rod and the frame. See photo below. Any give in the shaft will nor push the rod out far enough to allow you to shift into 1. or 2. gear. So, jury rigged as it seems, it actually does help.

What do not help the situation is that the clutch slave cylinder is leaking and I ran out of fluid without realizing it. So today I refilled and bled the system. Now I just have to keep an eye on it unltil I can get hte slave cylinder rebuildt.

On my Murena a previous owner (yes him again  Cheesy) Fitted the clutch with its own fluid reservoir. Thus no low level indicator, as those of you, who have the brakes and clutch feed off the same reservoir, benefit from. The home made reservoir is made of a Tupperware cup (or urin specimen bottle, I can't tell  Wink ) It can be seen, in the photo below, between the sprinkler fluid tank and the master cylinder. It only holds 1 dl., so with a leaking slave cylinder I got to keep a close eye in the level.

Well besides all that fun, I managed to adjust the stop for the frog eyes so they would not pop up too far and jam on the frame. They would open fine, but jam and not go down again without a push. Also welded (plastic) the broken speeder pedal together again. But that may not hold for long. Ohh, and I got the second horn working. Two tone. Sweet. Smiley Before it was just a squeak. What else today.. Replaced the windshield washer fluid tank with a spare. The old one had sprung a leak because the mounting bracket had a sharp point. Also, fixed the right windshield wiper arm, which tended to get stuck under the edge of the hood. Positioned it right and gave it some blue Locktite before tightening the nut. I also cleaned the connectors on the fuse circuit board and fuse holders. Now I have stable (until next time) power to the instruments. I think the last thing I did was to tighten the nut on the fan selector switch in the instrument panel.

That was a busy day and my back is sore. But it was a pleasure driving it home again. Still got to figure out what is the problem with the gear box. Maybe I will take it apart during Easter.
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roy4matra
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« Reply #11 on: March 30, 2009, 10:50:38 pm »

The most common problem with the gear selection is the 'L' shaped lever seizing up on the 'front' of the gearbox

Hi Roy. Thanks for your suggestions. A previous owner has already replaced the "L" bracket. It is virtually new and moves freely with no slack.

I spent the whole day, today, working various challenges. Primarily the gear problem. I disconnected the links and took the arm off the selector rod on thegear box. It took a good amount of work, as it had corroded and stuck to the rod. Some WD40 and putting it in gear and then applying pressure until it twisted on the rod. The screw had been removed of course  Wink Then twisting it back the other way and so on until it was loose enough to pull off the rod. That broke sweat.

This done I managed to unscrew the bushing on top of the shifter rod, A large wrench, and an other one as a prybar against the frame, broke it free. Once free it could be unscrewed by hand. On the picture below you can see the rust on the rod.

The other picture shows what a previous owner has tried in order to fix the problem that I now work on. The short bushing is from my gear box. You can see that it has been cut down with a hack saw. That obviously has not fixed the problem...

My question is now, what on earth can prevent the rod from pulling out like it is supposed to? It does change the gears, but only just in 1./2.  Any ideas? I wish I had a fiber scope so I could look inside the box while changing gears.  Roll Eyes

Sounds like something is worn, bent or broken inside the box; so I'm afraid you're going to have to strip it.

Roy
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Jon Weywadt
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« Reply #12 on: April 06, 2009, 01:14:14 am »

OK, so this week I have not had time to work on the car. I have, however, been studying the repair manual for the workings of the gearbox. I hope some of you guys, who have had a gearbox disassembled, can help me out with a couple of questions.

1. I see that there are two stop-screws, that are accessible from the clutch housing. The manual say they are for 3./4. gear and 5./R gear shifting rods. Can a wrong adjustment of these affect 1./2. gear?
I just found another stop-screw that is located next to the 5. gear on the end of the gear box. It say to adjust it with 4. gear engaged. Does this screw work together with one of the two other screws above, so that they are used to "center" the 3./4. shifter rod?

2. Does the fastening screw for the 1./2. gear shifter fork, lock into a grove on the shifting rod, or can it be adjusted?

If all three shifter forks are aligned properly, then the selector rod should move in and out freely and engage the shiftter forks cleanly. Since the problem is with 1./2. gear, I am guessing that perhaps the stop-screws above are out of adjustment, so that the  shifter forks for 3./4. and 5./R are not aligned with the shifter fork for 1./2. Thus, when you try to put it into 1. or 2. gear, the arm on the selector rod catches on the "claw" of the 1./2. shifter fork, preventing the selector rod from pulling up to the proper position.

It could of course also be the 1./2. gear shifter fork that is misaligned, depending on the answer to question 2.

After all the work I did last weekend, it shifts consistently (although difficult) into 1. gear. It is not possible to shift from 1. into 2., so I go straight to 3.  When down shifting it is possible to go into 2. but I have to apply careful pressure backwards and full force to the left on the gear shifter. I kind of have to "fish" for the gear to engage.

No matter what the answers are, unfortunately the gear box has to come off. Perhaps during Easter, as I have taken a couple of weeks off. We shall see. But I am curious if that "previous owner" forgot to set the stop screws when he had work done on the box.

I have also studied Anders' article at http://dinsen.net/murena/gearshift/ where there is a photo of the disassembled box. On the photo a red arrow points to the forks, that the selector rod engages to shift the gears. If the forks are not aligned, the selector rod may catch on one of the forks.

Anders.
Can you tell me if there are springs at the end of the selector rods, so that the stop screws are used to position the rods and align the forks? Can you tell if they are correctly adjusted with the gear box assembled?
« Last Edit: April 06, 2009, 02:38:16 pm by Jon Weywadt » Logged

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Jon Weywadt
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« Reply #13 on: July 20, 2009, 12:42:55 pm »

For the past two weeks My Murena has been sitting on jack stands in my carport. I have taken both rear trailing arms off and the challenges with those are in the post about Rear suspension problems.

I also took off and disassembled the gearbox. (Many thanks to Roy for the excellent online guide. Smiley ) As others have found, the lock nuts on the fifth gear wheels are a bi... to get off. Why on earth someone would tighten them so much I cannot understand. After "unlocking" the nuts by straightening the rim with a custom made punch, I had to use a 80 cm extension to my socket wrench, in order to get enough leverage to break them loose.

After finally getting the gear box housing off I inspected the claws on the shifter arms. They all looked ok and were close to perfectly aligned, eliminating alignment as the problem. (my first suspect) After then inspecting the how the selector arm that engage the shifter claws moved, I discovered that it had been repaired by someone who obviously was not very good at welding. The weld was thick and had left globlets on the shaft and, guess what, they prevented the arn from lifting up far enough to easily engage the 1./2. gear shifter claw.

I took the arm out and used ny bench grinder to smooth the shaft and shape the weld. Result, the arm now moves freely up and down and the gears can be selected without applying a lot of force. Smiley I fully expect the problem with 1./2. gear to be fixed, but won't know for sure until I get all the links back on. One note here. The rod of the arm was worn and the O-ring in the bushing, supposed to seal it from outside contaminants, did not seal tightly. I had ordered the rubber boot from Simons, that is supposed to sit on the rod over the bushing (photo 3). I found that with this boot in place the rod could not be pushed in far enough to engage 5./R. gears. So I cut 2 mm off the colar of the boot and ground 2 mm off the bottom of the outside selector arm. This solved the problem.

Speaking of links. The pivot point for the links, that is mounted on the gearbox itself (the one that transfers the sideways movement of the gear shifter, to the up/down movement of the selector arm on the box) turned out to be frozen (Roy was right about that  Grin). But the way that it worked at all, was by pivoting on the threads of the shaft in the gear box.  Angry That has now been fixed too and I found a plastic cap that will prevent moisture from entering the pivot assembly again. The threads will be secured with Locktite.  Grin (photo 4)
« Last Edit: July 20, 2009, 12:50:31 pm by Jon Weywadt » Logged

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Anders Dinsen
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« Reply #14 on: July 21, 2009, 07:34:19 am »

Hi Jon

Congratulations on finding that problem - and fixing it. Regarding the rubber boot, I had the same experience and took it off. It was never on the early gearboxes, but is a later upgrade for another car, I think.

/Anders
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'82 Murena 2.2 prep 142
'01 Grand Espace 24v
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