Stiff gear change, any ideas?

[tcw]

Hey everyone, sorry to ask such a vague question. I've got a reasonably stiff gear change on my 1999 996 (C4).

I've had the clutch / flywheel changed, whilst the box was out I got the box oil changed for Millers Nanodrive 75w90. It is worth noting I gave the place a 5L bottle and only about 1.5L remains, which implies they've managed to fill it with ~3.5L of oil (and I know the box needs ~2.7L).

Anyway, the gearchange is quite stiff. It doesn't show any signs of crunching, it doesn't seem to get _that_ much better when it's hot.

I've greased the cups on both ends of the gear cables, the cables themselves don't appear to have huge amounts of resistance.

I've noticed if I double declutch it can be slightly better.

My current plan of attack is:
- empty the box of oil and refill with exactly 2.7L.
- check the end of the slave isn't worn excessively, I've got a new slave cylinder on order given how cheap it is I figured it was worth a shot.

Has anyone had issues like this, how did you resolve it?

 

[deMort]

If the gear change is stiff with engine NOT running then it's probably the gear cables .

With running then are the cables set correctly .. possible syncro but that never affects every gear so is it all gears ?

 

[tcw]

If the gear change is stiff with engine NOT running then it's probably the gear cables .

With running then are the cables set correctly .. possible syncro but that never affects every gear so is it all gears ?

It's not very stiff at all with the engine not running, but I'll check again just to be sure, to be honest I am kind of considering buying some new cables at some stage anyway so maybe I'll bite the bullet.

It's pretty much every gear, really. I am wondering if it could be as simple as being overfilled? I know some boxes can be a bit weird with some oils too, but I find it hard to believe it's that tbh.

 

[deMort]

overfilled can cause this but it has to be a fair amount which considering its fill to the lvl and oil will come out of the fill hole when correct then it's not that easy to do .

Syncros govern the gear change but as this seems to be all gears it just can't be this .

usual cable check is disconnect it at the box then feel for any resistance on the gear lever .

cable alignment .. i use the green factory tool to set the position but you can adjust by feel of gear change engine not running without one of these .

I would ask .. was the gear change difficult before the clutch / flywheel were replaced ?

If not then there is a possible issue with the clutch dragging ... why i can't say .. correct clutch etc etc .

 

[Alex]

When I had a CLK, Merc put out a service bulletin to drop the oil from 1l to 900ml due to the gear changes being stiff. When I changed my gearbox oil I filled it with 1l. I noticed it did seem stiff so dropped it to the revised level - the difference on gearchanges was night and day.

Also - this time of year the 996 gearbox is much stiffer for the first 10 minutes of running due to the cold affecting the viscosity. Once up to temp it should be much easier to change gear.

 

[Stewpot67]

Mine also became stiff, I replaced the cables and the gearbox oil now fine..Buying the cables directly from Porsche were the cheapest by a mile!!