MatraSport Forum

Decided to use my few days off to swap the gearbox  as second gear synchro has gone.  To start off with, all the trailing arm bolts were rusted solid.  Not to worry, Santa Claus brought me a nice new air hacksaw.  It has only taken me a day and two blades to cut through them all.  Those bolts must be made from good steel!  Now I can't get the left hand driveshaft out of the gearbox  :(  The bushes look as if they won't come out of the trailing arm without a fight and they need to be replaced.  And it's 2 deg.C in my workshop.  I hope after all this the spare 'box is a good one.  It came as part of the shedload of spares with the car, so I've no idea what it's like.

Its a common fault that the Drive shafts get stuck in the gearbox. And sadly if they cannot be removed by a quick pull.. you'll need to disassemble the differential to release them from the inside.

The gearbox i am rebuilding has the left hand drive shaft stuck in it as well

There's a tool described in the workshop manual to take the driveshafts out. Have you tried that (both of you)? I remember having seen a sketch of it at www.espace-murena.com... yes, here it is: http://www.espace-murena.com/articles.html (http://www.espace-murena.com/articles.html), click the link "Extraction Transmission" on the left. Seems to be an improved version of the tool.

I know the feeling, Pete, about starting jobs you fear you'll regret. I'm sure the suffering will pay out in the end in the end! Hang on and take it easy.

Cheers,
Anders

Yes.. I tried fashioning such a tool but to no avail. And Im quite certain that Hans did the same.

I feel sorry for you. Im planning on doing the same couse I have a crack in the gearbox, otherwise its very tight and no synchroerrors.
but now I dont know if its worth it or maybe try to weld it at place

damnit  >:( ::) :)

Thanks for the sympathy :D.  I'll think of you doing the same, you'll have to take the 'box off whether you weld it or replace it.  Personally, I'd replace it, or at least the casing, alloy welding is never that successful in my experience and it has to take a lot of load from the starter.  I noticed my starter has an additional  support at the back, as well as three bolts at the front, so there may be a problem with starter loading.  I've been at it for three days now and haven't even got the gearbox back on, there seem to be loads of pipes and anti-roll bars in the way.

It can be done no problem. But you need to have it TIG welded, and of cause done by someone who know what he is doing as this is very difficult to do properly. And the optimal solution would be to have a bit of extra material (from a broken gearbox casting) to use as "filler".
A mate of mine is educated as an alu smith, and after he welded my water pump housing shut (for my EWP build ). He told after wards , that "old" cast alloy is of much better quality (with regards to welding) then newer ones.

The last few days have not gone well.  The gearbox is now on and everything is connected up, but I've dismantled the diff on the old box and still can't get the shaft out.  I've removed the core plug and soaked everything in penetrating oil, I've tried the "two pins" trick suggested by Roy, I've tried a three-legged puller on the drive flange but it won't budge :'(  On top of that, when I was struggling to change the silentblocs, I noticed a rust hole in the trailing arm.  Still, the good news is that there is a serviceable trailing arm and a drive shaft in the hoard of spares, although it needs a new inner boot.  I'll put it all back together with the spares while I ponder what to do about the other parts.  Any suggestions welcome.  I'm having a few days break now, to give the parts time to arrive and the scars time to heal :)

I'm sorry to hear that.


How very annoying! It sounds like you have tried everything.


You are lucky to have a good bin of spares for your car - you should be able to get it back in running order then.


Time is sometimes what it takes to get rusty parts apart. Your best bet is to give it regular sprays of WD40 or similar, and to try again and again to get the parts apart using gentle persuasion...

Good luck with it!

- Anders

I'll take my differential apart next week.. maybe I can come up with something.

can youplease take some pictures of the diff etc where the stuff is jamed?
aint it possible to heat it up?

good luck  :)

I'll do my best.  I've tried heat but it didn't work.

Only seems to have attached one picture, here's the other.

Excellent photos, especially the latter. I'm impressed that you haven't managed to get it out yet! This must be very powerful rust  :o

Hopefully it isn't gust but rust contaminated grease!!
You SHOULD be able to use a couple of small screwdrivers and press the locking ring on the shaft enough to release it.

The problem is that you can't reach the locking ring down the splines.  If you manage it with yours, please send full details with a photo ;)

Well, it's running again.  Just had a quick test drive round the block and the new gearbox seems to have good synchro all round, although the constant mesh gears seem a bit noisy when it's idling.  I'll give it a few runs to work over the next few days to make sure it's ok before I risk driving it to Yorkshire for next month's club meeting.  I'm still left with this big chunk of partly dismantled gearbox with a drive shaft stuck in it.....
Any luck with yours Krede?

good to hear the car i back on its wheel

have you tried to put the driveshaft in acid and electrolyt so the rust vanish?
I think it would help

Interesting idea, Oskar, and one I hadn't thought of.  Not sure that acid is the best electrolyte though.  I saw an article in Practical Classics magazine recently in which sodium bicarbonate was used.  Might give that a try.

Pete, it's really good to hear that your 'new' gearbox is running well! That's very good news indeed. About the noise in idle, I think we all know it. The Murena is a noisy car with its stiff chassis and rather stiff engine mounts (at least compared to modern equivalents). My car has new main bearings in the gearbox, and I can still hear them when the engine is idling - and my engine is quite noisy.

I think we all know the feeling about wanting to gain confidence in the car before giving it a long trip!

- Anders 8)

use kausticsoda, very good results after 24h and a battery charger :)

Still looks pretty rusty to me Oskar..... sure you didn upp the "before" picture??? ;)

forgot the "after"  ;D

Now that's more like it!!  :)

I have done this a couple of times.  You need two tiny but long steel pin punches.  As soon as you tap them down between the splines to the lock ring, it moves and the shaft drops out.

Roy

Yes, I read this in your FAQs.  I obviously don't possess your sleight of hand.  Sounds like a job for the maintenance meeting in April ;)  I would appreciate a practical demonstration.