Help Diagnosing Drive Issue 240D 4 Speed Man

[hazzac181]

Hi all,
I would like some help from the brains trust on a issue I've just had with my newly acquired '81 Sahara Yellow 240D 4 speed manual. The car has been in storage for many years, I've just got it back on the road.

I was driving on the freeway at 100km/h, and had been doing so for a number of hours. I suddenly lost 4th gear - it was as if the car had popped into neutral. The engine would rev freely, but I had no drive. I pulled over into the emergency lane. I could grab first, but it felt like the clutch was slipping a little. Shifted into second, and I lost drive again. The car was towed to my mechanic this morning, he drove it for around 8km and said it was fine - no slipping, no loss of drive.

My first thought (naturally) is the clutch, but it just seems odd that it would completely disengage without warning on me, and then behave fine when relatively cold. What are everyone's thoughts? Is there some other component that I'm missing? that could result in the above symptoms. Clutch will be replaced anyway, but I just thought I'd check in case I'd missed something.

Any insight appreciated!

[tsharkey]

Shifter linkages ?

[Bartman4800]

Just a thought:

the clutch is hydraulically operated, using brake fluid

If there is too much fluid in the reservoir, it can start operating the clutch when it gets hot. The same happens with brakes.


my 0.02, Bart

[hazzac181]

Shifter linkages ?

Shifter linkages were replaced by my mechanic I was told, but there is definite play (up-down) even when in gear on the shifter. I tried going back into 4th while coasting to no avail, so not sure that's it. I will persue though

[hazzac181]

Just a thought:

the clutch is hydraulically operated, using brake fluid

If there is too much fluid in the reservoir, it can start operating the clutch when it gets hot. The same happens with brakes.


my 0.02, Bart

Interesting, definitely something to be aware of. Mine doesn't appear to be overfull. It's below the "max" line and sits about where the seam between the two halves of the reservior are (i.e., just below max).

[Bartman4800]

That is an image of the brake fluid reservoir. Are they shared in your car?

[tsharkey]

W123's share the fluid reservoir

[Bartman4800]

W123's share the fluid reservoir

OK, so that's not the issue.

Another possibility is a collapsed hose to the clutch slave.
Look for dry rot on the hose and replace if needed

Regards, Bart

[hazzac181]

W123's share the fluid reservoir

OK, so that's not the issue.

Another possibility is a collapsed hose to the clutch slave.
Look for dry rot on the hose and replace if needed

Regards, Bart

I'll put the car on ramps once I get back from Sydney and report back. Thanks for your assistance insofar

[CraigB]

My favourite is the collapsed internally flex line. Years ago(like more than 40!) I had one on a brake, that acted like a valve, so fluid pushed past under pedal pressure to lock it on and then very slowly returned. It could fit your description. Perhaps when cold, pump the clutch pedal many times first, then try and drive and see if normal or lacking drive. They are cheap and probably never been replaced!

[Bartman4800]

My favourite is the collapsed internally flex line. Years ago(like more than 40!) I had one on a brake, that acted like a valve, so fluid pushed past under pedal pressure to lock it on and then very slowly returned. It could fit your description. Perhaps when cold, pump the clutch pedal many times first, then try and drive and see if normal or lacking drive. They are cheap and probably never been replaced!

I had one hose on my finny that was so blocked that it resisted full pressure (never pushed that hard on a brake pedal before) until it went pop and the side wall of my shed had an oily spot. The steel tube to the rear brake slave was disconnected to figure out why that wheel was not braking...