Piston Slap: A Triumph Over A Sticky Clutch?

Sajeev Mehta
by Sajeev Mehta

TTAC commentator krhodes1 writes:

Hi Sajeev,

Here is one for you and the B&B: ’74 (more or less) Triumph Spitfire with a clutch issue. The clutch feels “sticky”, doesn’t release smoothly, and makes starting off in first a little challenging. Otherwise, the clutch works fine once you are moving.

A bit of background: the clutch and throwout bearing have about 20,000 miles on them. Clutch hydraulics were done 15+ years ago, maybe 25,000 miles. No leaks. Last year, the pivot pin for the clutch release fork fell out, I drove the car maybe 100 miles before figuring out what the problem was and fixing it. There didn’t seem to be any damage when I had it apart, so I just put it all back together with the pin replaced (by a bolt) and it was perfectly fine — for a while. Then the “sticky” started. It gets worse when things get hot, but pretty much normal when the car is cold or been driven at highway speed for a while. It gets much worse in in-town traffic.

Would a failing throwout bearing cause this? It’s not making any noise that I can hear.

And before the Prince of Darkness jokes start, this car is usually bulletproof. I have owned it for 19 years and it is as faithful as an old dog driven as a toy for a couple thousand miles a summer. I think the last actual issue was 5+ years ago when the 35-year-old starter solenoid gave up the ghost. Replacement was less than $25.

By the way, the infamous “328!” is still going strong. It just passed 36,000 miles and warranty ends in seven days. I’m not worried about it in the slightest — though I did have an inspection done by our best local Indy BMW shop, who sadly did not find a thing I could get BMW to fix!

Sajeev answers:

ZOMG, I occasionally see a 328i and my mind wanders to your 328! So much excitement, such easy laughs.

On to the Spitfire: I suspect the clutch lever is slightly bent and it gets worse as the parts heat up as tolerances get tighter. That forum thread suggests eyeballing the lever may not raise red flags and only replacement with a new one shows the problem. Or perhaps removing the lever, rolling the rod portion on a smooth countertop and keeping an eye out for wobble?

The replacement looks pretty cheap, and the other clutch components are too new/low mileage to raise an eyebrow. Especially if nothing’s leaking.

What say you, Best and Brightest?

[Image: Shutterstock user Somchai_Stock]

Send your queries to sajeev@thetruthaboutcars.com. Spare no details and ask for a speedy resolution if you’re in a hurry…but be realistic, and use your make/model specific forums instead of TTAC for more timely advice.

Sajeev Mehta
Sajeev Mehta

More by Sajeev Mehta

Comments
Join the conversation
2 of 18 comments
  • MBella MBella on Dec 03, 2015

    The lever being bent could be an issue. I would also check the rest of the clutch assembly, and make sure nothing is binding upp anywhere. Corrosion on the input shaft can cause the disc to stick a bit.

  • Krhodes1 Krhodes1 on Dec 05, 2015

    Thanks Sajeev! Interesting forum thread, but not the problem I am having. Looking at the pictures in the thread, he used WAY too small a bolt, and he was missing the sleeves - I'm not. I could see where that much slop would easily cause issues. Mine engages and disengages where it should, and doesn't rattle, it just doesn't engage smoothly. I'm really leaning toward it being a slave cylinder issue, so I am going to replace that first - I have a spare on the shelf, just need a rebuild kit. Of course, being a Little British Car, correlation does not imply causation - it could be a failed master cylinder! But if that doesn't fix it, I'm just going to replace the lot. It's all dirt cheap, and I can have the motor out and on the floor in an hour. Try that in a Miata! You will be happy to know that BMW managed to get the i right way around on my M235i! I put 3600 miles on it in Europe, just got it re-delivered a couple weeks ago. Makes a nice pair with the wagon, I think, but I might be a tad biased. So two Brits and two Germans in the garage these days.

Next