Won't change gear

Defender 1997 tdi 300

With the engine running I can't select a gear, can't select low or high range either. With engine off I can select all gears and high / low.

Been standing about a week, no problems like this before. Any ideas what to check?

Clutch plate stuck?
Does the clutch feel like it’s working when you push the pedal?

I take it all was fine when you last drove it?

If it feels ok, try starting in gear with clutch pushed. Careful not to drive into something though

J

Clutch feels normal, checked fluid, level OK, looks a bit dark coloured, had a new clutch about 15k miles, no problems with clutch in the last three years. I can drive it both forward and reverse but can't change gear when engine running.

Hydraulic clutch? Does it pump up? Could be air in the system, or a leak

Fluid level is OK. Puzzle that the clutch works fine when engine is off, no sign of a leak.

Silly question, how do you know it works when the engine is off? Have you tried rolling it while in gear with the clutch pressed?

With the engine off I can select every gear easily, clutch works fine. Engage gear switch engine on, car moves but can't change gear, can't engage neutral either.

When the engine is running and it's in gear, pressing the clutch down does not disengage the gear. In summary, it's stuck out of gear or in gear when the engine is running. Looks like a clutch problem not a hydraulic one.

I found a YouTube video which suggests it might be the return valve in the clutch master cylinder but there's no description of the fault so it's hard to decide if this is the cause, anybody got advice ?
It had a heavy duty clutch fitted 20k miles ago and has had an easy life since then, no towing.

Your clutch ain't working fine pal otherwise it'd disengage with the engine running.

Check the flexy pipe to the slave cylinder and hope it isn't the clutch fork flexing

Fluid bypass or rod working through fork. I had exact symptoms getting rev with engine running but general consensus seems to think as brand new clutch , the clutch plate is slightly being turned by fly wheel with engine running stopping me selecting rev as no synchro. Engine off, no problems . As yours was ok for a while suggests hydraulic issue.

Just checked the flexi pipe and slave, no signs of a leak or damage to pipework from master. A new heavy duty fork was fitted with the new clutch. Clutch fluid reservoir is full, breather hole clear. Workshop manual suggests hydraulic problem but if that is the case why can I select gears when the engine is off?

Sofasurfer said:

Just checked the flexi pipe and slave, no signs of a leak or damage to pipework from master. A new heavy duty fork was fitted with the new clutch. Clutch fluid reservoir is full, breather hole clear. Workshop manual suggests hydraulic problem but if that is the case why can I select gears when the engine is off?

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Because everything is aligned cos it's not turning over....

If fluid was not returning to reservoir you would have no drive at any time.

Sofasurfer said:

I found a YouTube video which suggests it might be the return valve in the clutch master cylinder but there's no description of the fault so it's hard to decide if this is the cause, anybody got advice ?
It had a heavy duty clutch fitted 20k miles ago and has had an easy life since then, no towing.

Click to expand...

Have you tried starting it up in gear with the clutch depressed? (I see that you have)
Warm the engine up a bit first and when it at arts moving, stamp on the brake.
This should free it if the plate is stuck.

When I start it in gear it moves and I can't change gear or put it in neutral. It's on the drive, house in front, road behind. Got a recovery organised, chatted to guy who fitted the clutch, he thinks it's a hydraulic problem. I think the seals in the master cylinder are perished. We will see. Thanks everyone for the advice

Turns out the hydraulics were fine, the clutch (only 20k miles old) had deformed for no apparent reason. New heavy duty clutch fitted.