Diesel Felicia Gearbox whine... the culprit!

[Ghia]

Having driven the Felicia around for almost a year, I've gotten fairly used to what is normal.

This means that when my gearbox suddenly got very noisy - i.e. a loud whine that was speed relation in 5th gear only, I realised that there was something wrong.

Also having rebuild many of my own gearboxes, I know that this kind of noise (audible above everything else) means 'get it sorted now!'

So, after doing as few miles as possible and only using 5th gear if I really had to, I looked up about Skoda Felicia gearboxes and found out that they have a habbit of 5th gear falling off.

I got the Felicia onto ramps and set about fixing it.

Starting point...

Support the gearbox underneath...

What we're aiming to do here is remove the end casing.

As you can see, the top gearbox mount is part of it, so you need to release this.

Then use a 16mm socket etc to loosen the bolt.

One bolt out - the nut at the other end is captive so you don't need to worry about it.

Gearbox mount bolt out and remove the casing perimeter bolts.

Now get your catch can underneath to collect the oil. It'll poor out!

Wiggle it out and you can see 5th gear fixed and non fixed gears along with the selector ring and synchronizer setup.

Now the culprit becomes obvious...

That there nut is supposed to be tight up against the gear!

In the next photo, I've pulled the gear out against the nut and you can see that it's very close to the dog teeth of the non fixed 5th gear. This was causing the noise. When under load, these will just have been making contact.

The nut has obviously been working it's way off slowly and it only becomes obvious when things get noisy.

The nut originally is only held on by the edges of the collar (part of the nut) being peened into the cut outs of the shaft.

Clean it all up with brake cleaner - to degrease. Add thread lock...

Put back on and tighten up as much as you can. I used an impact gun to tighten it up as you can't really get purchase on it as the gearbox just revolves when you tighten it up, even in 1st gear!

Clean up the faces again with brake cleaner, sealant and back on.

The fun job of re-filling the oil is carried out through the speedo drive hole.

Remove the 9mm headed bolt and retainer.

Be really careful removing it. The plastic drive will very easily drop off the end of the cable into the gearbox and you've no chance of getting it back.

Mine came out with the cable thankfully.

Refill the oil...

When refitting the speedo cable, pull the speedo gear off the cable, cover it in grease and pull it back in. The grease will hold the gear in place and not be a problem inside the gearbox.

One gearbox, ready for action and quiet once more

MG

[uma1998]

Thanks for these pics looks like i can do mine on my 1.6 box

[adurer]

Thank you very much for these rare photos. Do you have more?

It is for the first time (to my knowledge) that somebody took photos while working on a Felicia gearbox and, most importantly, posted them on a forum. If you have more photos taken, I am very interested seeing them. I postponed my gearbox overhaul (see http://www.briskoda.net/forums/topic/247026-very-strange-gearbox-noise/) and any photo, movie, document or knowledge about it are very important to me.

Edited 22 October, 2012 by adurer

[Ghia]

Sorry, there wasn't really anything else to take photos of. They're not that complicated.

What are the symptoms of your gearbox faults?

MG

[uma1998]

mine has a quite whine in 5th gear but missis whines and covers the sound lol

[Ghia]

Lol sounds familiar

I had to do mine quick on the drive last night so I could drive to work this morning so was taking as little off as possible.

It was a little awkward getting the housing back on without removing the top gearbox mount completely so if you want an easier time of it, I'd support the engine/gearbox at the front in the middle, take the gearbox mount off completely and just take your time.

I don't have the specs as to what the mainshaft nut should be tightened up to- maybe someone around here can come up with that info?

The end casing perimeter bolts should be tightened up to 18 ftlbs / 25 NM in an even fashion, similar to how you would tighten a cylinder head to spread the load etc.

MG

[Phil-E]

Did you check and tighten both of the retaining nuts?

Also it is recomended to use new nuts (a few £'s from the dealer) and the nut should have the corner peened into the key way again.

The torque should be either 60nm or 100nm depending on the box. Think the boxes on 1.3's is 60 and all others 100 but can't be sure.

I don't think it's vital to get it spot on. Just around those figures. The main thing is that they don't start to rotate again.

Phil

[adurer]

Sorry, there wasn't really anything else to take photos of. They're not that complicated.

What are the symptoms of your gearbox faults?

I believe the question was addressed to me.

Symptom: strange noise coming from inside the gearbox.

DETAILS ABOUT NOISE

1. it sounds like marbles moving randomly inside gearbox
   
2. it is located on the wheel side, not on the clutch side of the gearbox (I used a stethoscope)
   
3. it can be heard very clearly only when the gearbox is cold (first start in the morning). The noise disappears when the gearbox gets warm
   
4. if I depress the clutch pedal, the noise will go away
   
5. all local Felicia cars over 60K miles developed that noise to various degrees
   

Other than that, the gearbox works nicely, smooth shifting, no other noises whatsoever.

My guess (djaychela confirmed) is main shaft bearings. To me it's not easy to do. It's a first. That's why step by step inside photos would be gold.

[Uncorruptable]

Coincidentally i had just had a gargae complete this job for me monday gone, the day you posted this, was searching for a post like this, well done & hope it helps someone else out from head scratching, mind you the folks on here were very quick to diagnose accuratley what was wrong & how to fix.

Great site, i feel i will have my felicia for a good while yet.