Sometimes hard to shift gear

[aidenfward]

I've noticed that shifting gears (M90) is sometimes harder than it should be, with around 1 in 10 shifts needing a lot of force/grinding. Seems to mainly affect gears R,1-3 and maybe 4, and seems to occur randomly.

I also always have to press the clutch hard to the floor to get a smooth shift.
I recently put in ~10mm of soundproofing under the carpet, but surely should engage lower than this?

A new clutch was fitted a few months back, so its not worn out.

I understand the hydraulic clutch shouldn't need adjustment so it must be a worn component in the gearbox or clutch? Any ideas?

[360beast]

Was the gearbox oil changed at the same time and if so what oil was put in?

Is the oil level correct?

What year is your car? Pre 97 M90 gearboxes have a weaker 3rd gear synchromesh which could explain it for third gear.

Was the insulation fitted around the same time as this issue?

[tofufi]

Also, when was the hydraulic clutch last bled?

The clutch on my 740 was slowly getting closer and closer to the floor. The fluid was manky, but new fluid got it working great again

[loki_the_glt]

Another forum member suggested that the clutch release bearing might be the culprit after hearing my description of the Valdez's clutch problem: occasional inability to select 1st or 2nd gear or to disengage first gear. As I haven't rpelaced the car's clutch and I've done 110k miles on it, it is possible the car's on the original clutch.

Renewing the hydraulic fluid helped with the problem but it still appears occasionally.

[Laird Scooby]

Originally Posted by aidenfward

I've noticed that shifting gears (M90) is sometimes harder than it should be, with around 1 in 10 shifts needing a lot of force/grinding. Seems to mainly affect gears R,1-3 and maybe 4, and seems to occur randomly.

I also always have to press the clutch hard to the floor to get a smooth shift.
I recently put in ~10mm of soundproofing under the carpet, but surely should engage lower than this?

A new clutch was fitted a few months back, so its not worn out.

I understand the hydraulic clutch shouldn't need adjustment so it must be a worn component in the gearbox or clutch? Any ideas?

That's a serious amount of soundproofing! If your clutch adjustment wasn't perfect before adding that amount of wadding under the carpet then it might well be the cause. Surprised you were able to get the carpets, seats and trim back in after with that thickness of soundproofing! I used 6mm in the front of mine and that was tight!

Also worth checking the fulcrum pin the clutch pedal sits on isn't worn and that the pushrod between the pedal and clutch master cylinder is correctly adjusted. Should be a little clearance but not much, if there is too much clearance that will also cause problems.

[TonyS9]

2 possibilities come to mind.

1. Worn holes in clutch and master cycl (where the metal pins transfers the load). My car had this problem when I bought it (80K miles) and was prone to crunching because I had run out of clutch pedal travel. After seeing the pedal could be lifted significantly (maybe 1-2cm) when up I could see the problem. I fixed it eventually by replacing buth master and pedal. Its been ok since. There was evidence of it at 10K in the receipts, where they bleed the clutch. Simply lift the pedal with your toe, it shouldn't move much.

2. A sticky/tight clutch friction plate. I'd had this only in a 340 after a new clutch which was just not machined well. The friction plate wasn't sliding on the splines well. Lubrication fixed it.