Gearbox Issues

[JayW]

Having issues with the gearbox on the Athena, a bit of stick wobble in most gears but most significantly 4th.

No road or wheel vibrations as yet and no audible noise/whines.

Going to change the oil at the weekend and check for swarf but suggestions as to cause appreciated!

[MULLEY]

gearbox mount?

[Tinkley]

More likely the gear linkage ball joints starting to let go. Check the one that goes from the gearbox parallel to the engine about 230-250mm long ie the long narrow one. I had this come off once, at a set of traffic lights - fun. Worth knowing where they locate so you can pop it back to get you home!.. They were still available 2 years ago. It's the nylon cup which tends to wear and 'give' over time. Might not be this but worth a check.
BTW the new replacement was the correct length according to the Haynes and went straight on, no problems since and less sloppy. Same gearbox as you BE3 as on my Athena.

[JayW]

Not the linkages, definitely an internal mechanical issue

[Tinkley]

Might be the clutch though. When mine slowly deteriorated, never ever slipped mind, the gears became harder to select and you could feel it 'throbbing' if you held the gear lever when in gear. If there is any stiffness at all with clutch release or selection I would be tempted to change the clutch/release bearing. You will have to have it out to change the box anyway so worth an inspection? Cheaper than recon box
The clutch that went was a replacement put in at 90k and by 157k it was finished. That's not a lot of miles and I know I'm not a brute with clutches. I actually supect the bearing has worn through the diaghram fingers rather than lack of friction plate thickness, and the bearing eventually started whining but only in the v late stages.

[BX Bandit]

All selectors are held nicely in 'gear' via detent balls and I've not seen any significant wear on the shafts, even on my 200K TGDt.
It's also unlikely the gear selector pivot bushes are worn although not impossible. They are phosphor bronze and do not use the gearbox oil for lube. If it was one of the two bushes I'd expect a very gradual decline of 'gear change quality' if you get my drift.

BE3 boxes are virtually indestructable mate.

Where is the clutch bite point?
My guess here would be mountings too, not neccesarily the gearbox mount, but the lower bush mount (mounted in ally housing with driveshafyt through it) and the forked component that bolts through said bush at one end and onto subframe at other. There is a bush in that forked component at the sub frame end.

[rutter123]

could be a bent driveshaft causing the gearbox to wobble check the lower engine mount and stabiliser bar/bush and that the intermediate driveshaft bearing is still in the housing.

[Tinkley]

My intermediate bearing (6006RS BTW) was OK when I changed the clutch. I did renew it though. Could be that or like I have now, bent subframe!. Still reckon on the clutch though as the most likely candidate rather than gearbox itself. When I mentioned throbbing, I mean you could watch the lever shaking like crazy. Nothing wrong with steering geometry at the time...

[JayW]

Haven't had chance to drain the oil yet, but i very much doubt it's anything to do with the mounts. Worn mounts would increase driveline shunt but doubtful it would cause stick-wobble as under constant load the mounts would be pinned forwards and the engine/box wouldn't wobble back and forth.

Likewise, there'd be nothing to induce wobble through worn linkages.

Equally, from an engineering point of view, a clutch fault would be felt as vibration, either directly through the bellhousing or through the pedal i'd have thought.

This is definitely either internal or driveshaft related but i'm still leaning towards internals as most other possibilities would be felt as vibration through the wheels.

The only time i've experienced this on another car was a chevette many years ago, the fault was with the crownwheel in the axle, but being old and forgetful now i can't remember the exact cause.

Checking for swarf would be an excellent place to start, if only i could find the time!

Cheers!

[citsncycles]

I have heard if final drive issues on the BE3 boxes - I have Electrokid's old box from his TGD with a nice big hole in the casing where one of the teeth broke off and made a bid for freedom.

I've also have a BE1 box's final drive chew its way through the casing due to worn bearings, but don't know if it's common on the later boxes.

[JayW]

The first 'box on my 16V spat out various chunks of the Diff, can't remember what preceeded it though

[Tinkley]

Have to say the clutch problem I had, you could definitely feel through the gear lever. I know it does not seem to make much sense but there was increasing vibration on the lever as the problem got worse.
If I gently touched the vertical metal part of the lever you could feel it, not the gear plastic knob part so much. Part of an early warning system, obviously and it was worst in one particular gear too. Just can't remember if itwas 4th or 5th. I do hope it is not an internal issue for you. There was nothing out of normal on the pedal except having to press it harder down, no vibration though. The cable and end damper piece (large lump over bellhousing) probably takes it out.

On a m/c I had to replace the gear selector forks because of 0.15mm wear on one. 1st and 2nd gear only on the 70mph A3 coming out of London was er interesting. Car 'boxes are different though with synchro and shaft drive.

Be worth the oil change and filter the old stuff. What's the change like without the engine running? If that is hard maybe, it's the box. Try without clutch as well? I do know that on my old 14, 5th gear nearly went walkabout as some retaining part (circlip?) had come off, fortunately it was rebuilt for other resaons and the guy noticed it. If there are good drawings of the BE3 box it might be possible to further diagnose a possible cause?

[electrokid]

I have Electrokid's old box from his TGD with a nice big hole in the casing where one of the teeth broke off and made a bid for freedom.

And there's a crack in the diff housing as well where the GB oil pees out - poss worth mentioning that there were no symptoms other than increasing gear whine as the GB ran out of oil.

[BX Bandit]

What's the news on the box Jay? You may find a pug box with (very) similar ratios if a bx one isn't available.

[JayW]

Work was against me yesterday and the weather today!