Crb or just noisy 5 speed?

[Burnside]

Hi all, 

it all started after a spirited drive on Sunday! My 5 speed is a noisy so and so most of the time but pulling back onto the drive after a blat it was noisier than usual. I pressed the clutch pedal down & the noise wentl. Having a minor moment thinking it's the crb I started the car this evening & no noise other than the usual?!?! Having read all sorts I'm starting to think it's not the crb....just not sure what it could be? 

Any suggestions as to what it could be or what I should do? I have driven the car tonight up and down the road but no noise other than the usual gearbox chatter. 

I plan on changing the oil this weekend in both the gearbox & the diff. 

Thanks

Paul 

[revilla]

Probably not CRB, you would more likely get noise when pressing the clutch rather than the other way around. Does sound like gearbox chatter. Check the gearbox oil level. Could it just be that you got the gearbox oil a bit hotter than you usually do?

[Paul Deslandes]

Dipping the clutch will have disconnected the gearbox from the engine so, if it went quiet, it's unlikely to be the CRB.

Assuming that gear changes weren't affected and they all engage ok, both when stationary and on the move, then the syncro rings, blocker bars and springs are probably ok.

Is it noisier in any one gear more than the others?  4th should be dead quiet (relatively speaking) as the shafts are locked and no intergear action is involved.

Might also be worth checking the gearbox mount to the chassis to see that it hasn't gone or is loose enough to move and allow the box to touch the chassis somewhere.

As Andrew says, check the oil level, and around the output shaft and speedo drive seals and the bellhousing drain hole if the level has dropped.

Paul

[Burnside]

Hi Revilla,

I am hoping that's what it'll be - post oil change this weekend I'll know for sure but having read conversations on here I've kinda decided it's not an issue, it just get's a little confusing reading so many differenet comments on what when why form various people. 

Noise hasn't appeared since. 

It was warm out and I was pushing it quite hard so being hot does make perfect sense - however I will change the oils regardless as I've just undertaken a full service of cam belt, oil, filters etc - pretty much anything that should and could be replaced - apart from the gearbox and diff oil of course, but that's next! :-) 

Thanks

Paul 

[Kevsta]

Paul,

 

Mine has been doing the same (was last year at least). I noticed it at the end of a track day. Exactly the same as yours. I too was worried about CRB but it didn't all stack up. 

 

Let me know how you get on with oil change - clearly you will need to get it all hot again to ensure you know it has gone away with oil change. I will be doing the same (when I get the rest of the car back together that is!)

 

Kev

[Burnside]

Hi Paul - thanks for the input....I'll be checking that gearbox mount when I do the oil change! Tonneau is going great by the way! :-) 

 

Hey Kev, I shall report my findings my good man - I'm hoping it'll be a simple case of oil change, worst case gearbox mount replacement as Paul's says above. 

 

 

[Jonathan Kay]

Dear Experts

I'll show my ignorance.

I thought there was a characteristic chatter from unhappy CRBs that went away when you pressed the pedal lightly without disengaging the clutch. Is that just wrong?

Thanks

Jonathan

[Burnside]

Update - so I've changed the diff oil, easy job & no difference other than new oil so that job is off of the list.

gearbox - not changed the oil - what a total nightmare of a job that is going to be! I'm no mechanic but I'm not stupid when it comes to servicing jobs. I can't see how this can be done without dropping the gearbox to clear the passenger footwell? Drilling a hole in the footwell seems the only way BUT I can see the chassis rail is inline with the filler plug. Alcester racing's maintenance page suggested just this but I'm reluctant to do this as there must be a way without it.

So ive had the car out on a long gentle run - all fine. Took it out for a thrash and again all fine.

whilst I've had a full major service with cam belt, tensioner etc I'm only needing to do the gearbox oil - is it really worth it? We'll see how my ocd lets me sleep and go from there :-) 

thanks for the comments & input, always helpful. 

Paul 

[CharlesElliott]

You use a cut down allen key to undo the filler on the side of the gearbox in situ, then suck the oil out.

[Paul Deslandes]

...or remove the gear box top plate (not as hard as it sounds) and suck the oil out.  Just be very careful not to drop anything into the box while the lid's off.

Another way of removing the filler plug is to get the right sized Alan key (can't remember size off the top of my head) and cut off a short length with an angle grinder, then use a ratchet ring spanner from Halfords on the Alan key stub.  Works a treat and you can do it from underneath.  Or, if you can wait for a couple of weeks when we're back from hols, you can bring it round here and do it over my pit.  I've got the tools and oil sucker too.

Paul

[John Vine]

gearbox - not changed the oil

There are many (me included) who claim that Henry Ford, in his wisdom, felt that his Type 9 box didn't require oil changes, which is why there's no drain plug.  But if you'd feel happier refreshing the oil (or want to be certain of what's in there), the only hit will be the cost of the oil (notwithstanding the pain in getting at the filler plug).

 

JK:  The usual symptom of a failing CRB in a K (or any set-up that has inadequate pre-load) is a squealing noise when you depress the clutch.  Persistent pumping of the pedal can reduce or stop this altogether temporarily.  The original CRB manufacturer (INA Bearings) told me some while ago:

....that the squealing when the pedal was pressed was definitely an indicator of pending CRB failure, and was most likely due to the metal bearing housing rotating against the plastic carrier.....and that pumping the pedal helped to "stick" the metal and plastic surfaces together more firmly.

I think the chatter you refer to is more likely to be a rattling layshaft.  Depressing the clutch will stop this straightaway.

JV

[Burnside]

Thanks for the input gents, after a hearty blat just now all seems happy & well, well enough for me to "let it go" & move on from wanting to change the oil. :-) 

i didn't realise the top plate was removeable Paul, but I'm sure under the tunnel cover the plates are riveted onto the tunnel? Certainly makes more sense as seems quicker to do the change this way. Maybe I WILL change that oil! Having done everything else it would seem a shame not too. 

But ive got an itch to upgrade....I want more power - is this normal?!?!?! ;-) 

[John Vine]

But ive got an itch to upgrade....I want more power - is this normal?!?!?

No, not normal at all.  In fact, you're probably the first one I've come across proposing such a thing.  Everyone else is entirely happy with their handling, power, braking, silencing, suspension, weather gear, screen, paintwork, seatbelts, seats, mirrors, steering wheel, 12v sockets and the rest.  There does seem to be very little interest in modifying the standard set-up.

JV

[Burnside]

So Mr Vine, you're suggesting there is a massive problem across the realm of 7 owners ;-)  

maybe there's a gap for counseling  - I'm sure it would be lucrative! 

[Jonathan Kay]

Thanks, John.

Jonathan

[John Vine]

JV

[Burnside]

So when do you chaps need an appointment?! ;-) 

[7 wonders of the world]

If you take the top cover off DO NOT change gear with this cover removed as it is possible to jam the box as the detent is not longer restrained.

Cut down allen key is still a pain, better use a short M6 nut and bolt nipped together or short off cut of allen key in a ratchet ring spanner.

Draining is easy enough, with the oil warm pop the level plug and insert a length of washer tube to the bottom of the box, pull a syphon with a syringe and leave to drain overnight into a tray, jack the car slightly so it picks up as much a possible.

[Jonathan Kay]

... or short off cut of allen key in a ratchet ring spanner.

Reminder from painful experience with an overfilled gearbox: make sure its the sort of ratchet spanner that you can reverse with a switch rather than the sort you have to turn over...

Jonathan