Klanking noise from BW35, which had little fluid in it...

mrtask

Well-Known Member
Mr Misdiagnosis swapped his propshaft, only to discover he hadn't thereby managed to banish the klanking noises. :( He then checked the fluid level in the autobox as per the instructions elsewhere on this forum, i.e. on level ground, with the engine running, fluid warm, and after pausing through each gear beforehand.
Bubbles on the dipstick, and not much fluid! Topped up with TopTec 1300, half a bottle, hasn't banished the klanking. Nor the bubbling transmission fluid on the dipstick.
Billion dollar question is, have I b*ggered the box? Still goes, forwards and backwards, but the klanking is still there now and then, most noticeably at low speeds.
I was hoping to drive from Berlin to London this weekend... Not too confident about a long motorway journey with these occasional noises though!
 
Bubbles on the dipstick, and not much fluid! Topped up with TopTec 1300, half a bottle, hasn't banished the klanking. Nor the bubbling transmission fluid on the dipstick.
Billion dollar question is, have I b*ggered the box? Still goes, forwards and backwards, but the klanking is still there now and then, most noticeably at low speeds.

These bubbles of which you speak, are there thousands of microbubbles that turn the fluid light pink and frothy?
If it still goes forwards and backwards, and the fluid doesn't look and smell burnt then that part of the box should be OK, but the noise is an unknown so you're not going to know what's going to happen with that.

I was hoping to drive from Berlin to London this weekend... Not too confident about a long motorway journey with these occasional noises though!

The only thing to do is set off, and if you run into problems providing you've put in place plans to get you and the car home then it's a disappointment not a disater. If the box fails you were planning an LT77 install anyway....
 
Hi Harvey. The bubbles are tiny, but the fluid doesn't have a pink tint to it because the LiquiMoly TopTec 1300 looks more like urine from the bottle, yellowish green. So frothy, yes, but pink, no. Does that help diagnosis from a distance?
Thoroughly agree with your sentiment regarding not wanting to pour more money into a box that I plan to get shot of during August anyway! Don't want to have to fly to Blighty though.
 
When the fluid turns frothy it can be that the O-ring on the fluid pickup pipe has failed, so the pump draws air in as well as fluid. Air in the fluid will reduce the clamping force on the clutches, same way as air in the braking system does. The air can be compressed whereas the fluid can't. If you could post a pic of the bubbly fluid on the bottom of the dipstick that might help. I can't see that accounting for a clanking noise though.
 
Hi, Check the torque converter bolts for security and the flex plate for cracks with regard to clanking noises.

Colin
 
Hi, Check the torque converter bolts for security and the flex plate for cracks with regard to clanking noises.

I've never had a V8 flexplate crack. I've had converter bolts loose and it sounds like a big end knock. Worth checking though.
 
If I take off the cover plate at the bottom of the bellhousing can I reach the bolts for the torque converter? The noise comes and goes, so I reckon one or two torque converter bolts are loose, but not all of them, if that makes any kind of sense, which it probably doesn't!!
Be nice if it were just a matter of tightening up a few loose nuts'n'bolts. Sounds like somebody is shaking a metal bucket with a spanner, or a Ducati dry clutch at a standstill. Not healthy, for sure!
I just admitted defeat to SWMBO, and let her book flights. Her patience with my old banger is worn thin. I'm too far gone, quite hopelessly addicted, no 'intervention' would help.
August is manual swap time, I've lost patience now, simply has to happen!
 
Removing the halfmoon cover plate will allow you to get at the converter bolts. If they work too far out they hit the back of the block, but in that case I would expect the noise to be loud, and permanent!
 
Can't get my head around the way the noise comes and goes. If a bolt on a rotating component is loose, and is knocking against something immobile, it won't go away at higher speed. If I make it as far as my lock-up tomorrow I'll poke about a bit deeper...
 
Made it as far as my lockup, pulled up, put it in neutral and suddenly the gear selector lever dropped two inches into the tunnel! Guess I found the source of the clanking noises! Cup of tea and let it cool off before I lift it up and start fiddling... methinks this will require prop removal for access... commencing cursing now!
 
Spherical plastic bush must be knackered. Ball on bottom of gear lever drops right through. Pin that should go through the ball is missing.
One more journey across town, holding the gear lever up! Fingers crossed!
A clear signal that it is high time to install my manual box next month...
 
If I manage to unearth a spare spherical seat amongst my spares, perhaps I'll fit it as a stop-gap. I don't remember if I sold it with the other BW35 from the car I broke. I'm tending rather towards ripping it all out after my return from the UK in a few weeks time...
That was a fun drive back across town just now, holding the gear stick up the whole way to prevent it fouling on the prop! Very difficult to select gears with the stick flapping about!
 
Back after a brief vacation, time to fix my daily whip. I'll have to replace the knackered spherical bush in the short term, 'cos I can't do my planned manual install at my mates workshop before the last week of August. Bush seems to be readily available on fleabay, what about 540959? Parts Manual helpfully states "Locating pin for spherical seat". No info as to length or OD. Can anybody help me out with that info? ....Harvey!?
Auto gear lever spherical bush and locating pin
 
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You should be able to use your old one. If it wasn't there the lever would twist around all over the place so I'd be surprised if it's gone missing.

It's a roll (mills) pin, and if I had to guess I'd guess at about 1" long and 3/16" diameter, but it's only a guess.
 
Thanks Harvey. Old pin seems to have fallen out on the road somewhere, lever certainly twists about all over the place, as you describe!
 
That's unlucky! It's possible I have a pin here somewhere, as one of the last remnants of a couple of lever assemblies I've sold in individual parts. I will look, but it's going to be a bit of an ask so don't hold your breath.
 
Could just go through your drill index and find a drill that fits in the spherical bush and then cut a length off the shank, the length is not critical.
 
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Thanks Harvey, I think I can spare you the trouble.
Many moons ago I bought a manual gear lever assembly out of a 3500S, so as to use the top half of the 'correct' gear lever spliced to the bottom half of an SD1 LT77 lever, when I get around to doing the manual swap I've been gabbing on about forever! If the spherical bush is the same on the automatic 3500 and the 4 speed manual 'S', then I must have a spare roll pin in that 2nd hand manual gear lever assembly, right!? I'll have to go and have another poke about in my lock-up, while I wait for the replacement bush to come in the post...
Cobraboy, good tip. I did once buy a selection of drill bits for steel, but my colleagues in our four man garage share quickly 'borrowed' almost all of them, and IIRC only the largest ones are still extant!
 
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