Input shaft bearing failing - temporarily replace 75W80 oil with something like 75W85?

[giochel]

My BE4 (C5 X7 with EW10A engine) gearbox seems to be failing, making a „rattle” noise when the clutch pedal is not pressed. It is louder as the weeks pass, faint when the engine is just started, much louder after it warms up. I can hear it in neutral from the outside of the car. The diagnostic without having the clutch/gearbox open has been that the input shaft bearing is failing (or, less likely, the flywheel). I will replace the gearbox and clutch this year, but I want to know if I can use it a couple more months by running a „thicker” oil, as someone has recommended. The alternative suggestion was some additive, but we're not very clear about it.

Questions:
1. If this theory with more viscous oil is correct, which oil or additive should I use?
2. What do I risk continuing to run like this? Will it be obvious it is going to fail soon or do I risk to get unexpectedly stranded?

[Hell Razor5543]

Please don't use a different oil than that specified. The gearbox was designed to use that oil, and using a different one could very easily destroy it. It is not unknown for the wrong oil to wreck the synchromesh gears, and then end up with the viscosity of a thick treacle.

[white exec]

Stick with the standard 75W80 GL4 gear oil. Don't use GL4/5 or GL5 oils.
What you describe sounds like the early signs of the DMF (dual mass flywheel) breaking up.
Replace a.s.a.p., or be prepared to lose all drive without warning at some point.
Drive very gently meanwhile.

[citroenguy]

There is no DMF on this engine.
To me this sounds more like the throwoutbearing/clutch release bearing has gone bad.
Very common on BE4 gearboxes after 150kkm, i'd start by checking that first. Probably put a clutch kit when i'm there.
Never heard of internal bearing failure on PSA gearboxes, mostly clutch problems or loosing 5th gear.

[RichardW]

No DMF on these by the look of it. These boxes are near indestructible unless you run them without oil. My guess is that the release bearing is starting to complain - they are the weak link, being about a 50p plastic part....

Edit: Snap

[white exec]

There is no DMF on this engine.

What a relief! Form an orderly queue, please.

If applying really light pressure to the clutch stops the noise, that would point to a bad release bearing.

[giochel]

To better describe it: when pressing the clutch pedal the rattle disappears at around half the travel distance of the pedal. There's a quite clear point at which the noise stops, full rattle in the upper half of the pedal travel, press one centimetre deeper and the noise stops. I didn't try to listen the noise while moving, as it requires more attention.

What is the procedure of changing the clutch and gearbox? My most trustworthy mechanic is not a PSA specialist unfortunately.

I really wanted to postpone this work until I prepare for the EW10A with 6 speed gearbox project: viewtopic.php?t=64337 but the replies here have me worried.

[doctle]

Any reasonably competent mechanic can change a clutch kit. My wife says I'm a useless lazy pathetic git and I can change a clutch as can many DIY'ers its not big job for a mechanic

[giochel]

An update and a question:
I had the clutch replaced, and the gearbox opened and serviced. The rattle happens less often and is much diminished, but did not completely disappear. The gearbox people replicated the noise but were not able to precisely identify it (gave me a warranty instead).

Also the 5th gear cog set was replaced, 47x35 --> 50x33, for a big engine noise reduction at high speed.

The question: which ECU changes need to be done for this new 5th gear ratio? The gearbox people don't do electronic stuff. One obvious problem is cruise control, which refuses to work in 5th gear.

[GiveMeABreak]

You can't just replace a different cog set and programme it. The settings are specific for the gearbox / engine as fitted to the vehicle.