Metro Inner CV Popping

[shambolic]

Very similar to Minis, and years ago I had a Mini that lost all drive in a similar manner, and I never did work out what it was I'd replaced that made it work again..

Going over bumps, and now seemingly just trying to accelerate with any gusto, my Metro inner left CV joint is popping out - The cage and Ping Pong slide too far from the pot joint, and there's hellish vibration till I back off and it settles back in. At rest the Ping Pong feel a little too close to the edge of the pot, too.

It's been a problem since replacing the engine, and is steadily worsening, but the engine went in straight, no twisted mounts or suchlike. It's as though the hub is 1/2" or so further away from the diff than it should be.. Or is that the diff is 1/2" too far from the hub..? Sigh

There might - And I've not had chance to investigate further, but *night* be some weakening on the front right engine mount. The engine rocks notably more when loading it in first against the handbrake, than in reverse. But it doesn't seem torn.

Anyone any ideas? Been suffering this for a while, have ploybushed the lower arm, replaced the outer CV, now replaced the whole chuffing driveshaft, and still no luck. The subframe doesn't look split or cracked, and I've replaced the sub mount too.

[notamini]

Not that familiar with the inner pots but it almost sounds as if there is a retaining ring missing like the one in the outer CV.

Does the drive shaft have a splined slip joint just out from the inner pot? Maybe it is not loose enough.

Maybe the splines are worn on the pot.
Just some thoughts. I have a full Metro 1275 engine/trans in my carport I'll try to get some time to look at it.

[shambolic]

I've not had chance to log in for a couple of days, but I replaced the front engine mount (later typed Metro system, two large mounts at the bellhousing end, then two small ones on a y piece at the pulley end). So far, not had the issue again - Also made sure to slacken all mounts and make sure the engine was located properly - Couldn't feel the Ping Pong quite so close to popping out the pot joint after that. However, the old mount.. Looked fine when fitted. Felt fine. Couldn't rock the engine much by hand. *But*, when I took it off, there's a bit of a small split in the rubber, and more important the metal plate (about 4" round I'd say, one each end of the mount.. Think of a very wide exhaust bobbin) had fractured, so I guess the mount was flapping quite a lot under load.

The problem I'd had was the inner part of the inner CV was slipping out of the outer part - Which you'd think just couldn't happen, unless there was something miles out (like half an inch or more). But possibly this mount has been failing over time, till finally giving way, allowing the engine to rock and rotate enough to pull the joint under certain conditions. I'm still driving it like there's a baby mouse under the throttle pedal, for fear of it popping again, but.. So far so good. Touch laminated Argos desk wood..

[notamini]

Love the wood reference! You reminded me of a situ in 1976. My wife and I drove from here to Toronto, ON. (abt. 50mi.) on a 60 mph highway. We parked and went shopping all day. Upon returning, I started the car, shifted to D and felt nothing engaging. Tried the throttle and it was like It was in N. Looked under the car as Wify held the brakes.
I found the left side drive shaft turning. Naturally, I thought it was major and shut her down. Called the tow truck back home and went back in tow. When I finally inspected the shaft, with boot off the CV, I saw that the end had popped from the outer CV due to a faulty retainer ring. I rammed it back in place by hand. End of problem!

[mra-minis]

The outer joint on all minis is a Birfield joint, the inner on later Minis and all metros is a sliding Birfield joint or more commonly a "pot" joint, the assembly is designed so that they cannot come out fully, this would create a potential life threatening situation..... therefore something must be wrong somewhere, ie engine mounts or damaged subframe or suspension..