HELP with annoying backlash noise

Help with annoying backlash…

Since changing my clutch I’m getting a really annoying backlash noise… Worst on De-cel from higher revs but can also be heard on acceleration aswell…

Tried the PPF in various different positions and it’s made no difference to the sound ( its now at factory spec), Even tried another clutch as thought the new one may have been faulty but no difference…

I’m convinced the noise is coming from the diff and it completely disappears as soon as you dump the clutch….

Oil has also been replaced in gearbox and diff…

Car is a 1991 1.6l 115bhp

Please help with what I can try next to get rid of this annoying backlash :sob::sob:

I had similar on a 1990 I had. It turned out to be the joint in the propshaft.

I’ve heard this a couple of time now, is the the U Joint you’re refuring too ???

yes. the needle rollers stick

Wouldn’t that still make a noise with the clutched engaged though… My noise completely disappears if I dump the clutch

Mine only did it on over-run, that I could hear. Took the prop off tapped it a few times and used spray grease on it. Noise stopped.

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Gotta be worth a try, Diff and Prop is certainly where I plan to look next tbh

Ill give the joint a tap and good soak with spray grease and see if it helps

What do you mean by dump the clutch?

To me it means the action of suddenly engaging the clutch i.e. instantly removing foot from clutch pedal.

If you are running along in gear and you get the lash as you go on and off the accelerator, that would be typical of worn UJ’s either on the prop shaft or drive shaft(s).

The prop shaft has obviously been off. Is it bolted up properly with the correct bolts and any bushings that came off the first time? Can you physically find any play at the UJ’s?

The mystery here is why it has started after the gearbox has been off. So what’s changed? Are all the gearbox and engine mounts good?

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Yea sorry poor terminology by me there… I mean the noise goes if I depress the clutch

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My noise was pretty much diminished, after doing the gearlevel boot change and adjusting the gearbox on the PPF. However yesterday driving home from the show it was definately back.

I have been told by a couple of people now to measure everthing before starting clutch the change and put everything back in the same place.

Like the OP this only occured after the clutch change. Will be watching with interest.

[NA Whining Gearbox]

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Have you fitted a genuine Mazda clutch (pressure plate and disc)?

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Yes buddy… full exceedy clutch kit…

Hello Robbie,

Like Dave the OP the only thing that changed on my car was the Exedy Clutch unit. I’m not sure who made the original clutch units.

I take it you mean the Genuine Mazda pressure plate and disc rather than OEM Exedy kit. Reading between the lines do you feel that getting the original parts might resolve this issue or am I reading too much into this?

Theo

Yes, my implication was towards a genuine Mazda clutch. It’s a big outlay though if it makes no difference.

I was under the impression the Exceedy was OEM ??

I know the question’s for Robbie and I’m really interested in hearing his answer as an expert (him, not me).

People certainly sell “Exedy OEM” clutch parts/kits. Sometimes referred to as “OEM replacement” which could just be to distinguish them from the so-called upgrade parts, rather than to say they are identical.

Article from Exedy UK website

All the same, I can’t immediately see why a replacement kit from the company that probably makes the original parts anyway and certainly is an OEM manufacturer should give rise to lash in the driveline. I’d have bought the Exedy kit at £160 vs. £250 for the Mazda boxed parts without qualm.

Mind, I’ve only ever replaced one clutch and I’ve never worn one out so I hope never to have this dilemma!

This sounds like an issue that should have an identifiable cause related to disassembly/reassembly for clutch replacement.

Apart from my banger-owning days, I’ve only had this on-off throttle clunking in one car - a one year old Ford Orion back in about 1988. The cause was a broken top engine mount. Is it by any chance necessary to loosen the engine mounts to get the gearbox off on the ND?

I should say my diagnostic record isn’t great, I’m just throwing stuff out.

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As I said, it’s an expensive test, but in the past I’ve known a genuine Mazda clutch to cure backlash noise. Maybe it was just a coincidence or maybe the extra cost for a genuine one gets a better balanced part.

All speculation on my part…