Brumby gearbox knocking EA81 D/R

David D · Post by **David D** » Sat Jul 30, 2011 9:51 pm

Hi Guys

Bad news today. I have a safety cert booked for next week but this afternoon I took the Brumby up the street and my gearbox has started knocking.
It's not a really heavy knock and it only occurs in forward gears. It's almost like a worn CV joint sound but not as metallic. If I put the car in gear and grab the front wheel (either one) I can feel the roughness as I move the car - it's a bit notchy.
The car is still driveable but I have no idea what's causing the noise. It shifts into all gears fine and goes into 4wd. The only things I've done since last time I drove it is to fit a carpet and the centre console etc and I've degreased the engine a bit. I did move the 4wd selector a few times when trial fitting the carpet but surely this won't have done anything?
I tried to record the noise on my phone but you could barely hear the knocking.
I changed the gearbox oil this afternoon hoping it might help but it made no difference.

Not sure what to do now. Not too confident removing and dismantling a gearbox but I can't see what else to try at the moment. I'm too disappointed to think rationally!

Any suggestions?

David

RSR 555 · Post by **RSR 555** » Sat Jul 30, 2011 9:58 pm

Might be an idea to check your gearbox mounts

If not that then I'd be draining the fluid into a clean container and check for any shiny bits

edit: ops.. just read your other post.. cancel last line. I'd also look at all the linkage rods and I wouldn't rule out CV joints

David D · Post by **David D** » Sat Jul 30, 2011 10:32 pm

Thanks for that. Sorry if it's a silly question but what would I be checking for with the linkage rods? Free play?
And would I still hear CV joints in neutral?
Good to know there are other things I can rule out before removing the gearbox.

David

steptoe · Post by **steptoe** » Sun Jul 31, 2011 8:20 am

exhaust mounts?

steptoe · Post by **steptoe** » Sun Jul 31, 2011 8:21 am

dry uni joints in tail shaft?

YouTube · Post by **El_Freddo** » Sun Jul 31, 2011 1:08 pm

David D wrote: And would I still hear CV joints in neutral?

I'm guessing you can still hear it when in neutral then? This would rule out CV's as their not in motion when sitting at a stand still - unless you mean in neutral when coasting, then CV's could be the issue.

When exactly do you hear this noise??

Make sure that the carpet install or the console isn't hitting anything on the gearbox as the floor pan could amplify it.

You could source a known good box and drop that in - or do as my post in your build thread suggests and drop an L series 5 spd in

Cheers

Bennie

David D · Post by **David D** » Sun Jul 31, 2011 5:21 pm

Thanks for the replies so far.

Just to clarify my original messy post:

I can only hear the noise when the car is in a forward gear and moving.

Bennie, I'll definitely check the console etc when I get the chance as there's not much else changed since it last drove OK. I did clean it underneath and I had it jacked up while I put some underbody protection on but that shouldn't have done anything.

I'm gonna have a look at it on Tuesday when I'm off work and see what I can find. I'm really hoping it's something I can fix. It will be such a shame to come this close to getting it on the road and be set back by a big problem.

Cheers

David

littlewhiteute · Post by **littlewhiteute** » Sun Jul 31, 2011 6:41 pm

In a forward gear moving.

Ok, under load or coasting?
If under load going forwards does it make the noise coasting in reverse or vice versa?

David D · Post by **David D** » Sun Jul 31, 2011 7:14 pm

It definitely happened under load but I'm not sure if it was when coasting. I'd have to drive it again to check.
Sorry I don't have more definite details - it caught me off guard yesterday and I didn't really get much chance to mess about with it.

Cheers

David

RSR 555 · Post by **RSR 555** » Mon Aug 01, 2011 8:52 am

David D wrote:Thanks for that. Sorry if it's a silly question but what would I be checking for with the linkage rods? Free play?
And would I still hear CV joints in neutral?
Good to know there are other things I can rule out before removing the gearbox.

David

Yeah David, just have a look underneath and look for anything loose or missing around the linkages.

steptoe wrote:dry uni joints in tail shaft?

This is a good point to check.. pretty common issue.

David D wrote:It definitely happened under load but I'm not sure if it was when coasting. I'd have to drive it again to check.
Sorry I don't have more definite details - it caught me off guard yesterday and I didn't really get much chance to mess about with it.

Cheers

David

No rush, more info the better it is to diagnose.

David D · Post by **David D** » Tue Aug 02, 2011 2:07 pm

Ok guys

A mate came round this morning and we both had a look at what's going on.

The noise is only evident under load going forwards. Coasting, it seems to go away or at least go quieter than the engine. Still noisy in 4wd.

Definitely sounds like it's coming from the gearbox, possibly left hand side.

It did quieten down a bit second time we went out but I went out again later and it sounded the same again.

I had a look at the linkages and nothing appeared to be loose or missing.

The carpet doesn't seem to be causing any problems.

No noise in neutral.

One thing I did notice - when I put the car in gear in 2wd and move it, the tailshaft spins. Is this normal in 2wd?

My feeling is that it doesn't look good. It doesn't sound catastrophic yet but it does seem like it's not gonna be an easy fix.

Thanks for the help so far, if there's anything else anyone can think of let me know.

Cheers

David

subius · Post by **subius** » Tue Aug 02, 2011 7:34 pm

take a good close look at the uni joints. They do wear out and become loose but can still look ok at a glance.

see if you get any movement when you get under the car and twist/pull the tailshaft.

I have found that worn uni joints also create vibrations on acceleration/deceleration as they are out of balance when under load.

good luck.

David D · Post by **David D** » Tue Aug 02, 2011 8:13 pm

Would the uni joints still cause noise in front wheel drive?

subius · Post by **subius** » Tue Aug 02, 2011 9:10 pm

probably, depends on the extent of the wear. may not vibrate as much with no drive to the rear diff.

just something to consider

ashleyn · Post by **ashleyn** » Tue Aug 02, 2011 9:53 pm

David D wrote:It definitely happened under load but I'm not sure if it was when coasting. I'd have to drive it again to check.
Sorry I don't have more definite details - it caught me off guard yesterday and I didn't really get much chance to mess about with it.

Cheers

David

After I fitted lift, had a nasty knock. It turned out to be the air cond aluminum pipe rubbing on the compressor belt pulley. Went away under load as it moved. Probably unrelated but you never know.

David D · Post by **David D** » Sat Aug 06, 2011 12:37 pm

After closer inspections today, and some help from another mate, it looks like the noise could well be CVs after all. I'm obviously hoping it is. I'm not sure whether it's inner or outer but both sides are noisy when under load.
I reckon I'll need to remove the driveshafts and see if I can tell what's worn. Looks like a bit of work to get them removed so standby for some more questions;)

Cheers

David

steptoe · Post by **steptoe** » Sat Aug 06, 2011 1:37 pm

45 minutes out and in is my record on my Brumby.

Start looking for a 36mm socket 3/4" drive, a 600 mm long breaker in 3/4", water pipe to extend leverage on that front nut to undo and do up.

A pin punch for th pin on the inner joint - actually called double offset joint..

A flat blade screwdriver big is good to jam in the split when ball jont retain bolt has been removed - reduces the clamp on the ball jont so it almost drops out, bit of grease on it for next time.

14, 17 and 19mm sockets.

Some have suggested swap RHS with LHS as they turn opposite to wear after and may lose noise for a while

David D · Post by **David D** » Sun Aug 07, 2011 11:28 am

Cool, thanks for that. Not sure when I'll get it done but hopefully soonish.
Is there any good way to tell whether it's the double offset or outer CV that is worn? I can't tell at the moment but both sides are noisy. I understand that the double offset joint can be renewed but the outer CV is part of the driveshaft so a new driveshaft would be needed.

Thanks

David

David D · Post by **David D** » Fri Aug 12, 2011 10:26 pm

Hi everybody

Just to let you know, I got 2 new front driveshaft assemblies today and fitted them. The knocking has gone so that's great news. Thanks to everyone for their help.
It took a bit longer than I hoped, partly because I put the first one in and mis-routed the handbrake cable so I ended up taking it out again:oops:
The hub on one side was really stubborn coming off and going on and, for some reason, I had trouble getting the caliper back on and had to wind the piston back in.
Anyway, all done now.

David

RSR 555 · Post by **RSR 555** » Sat Aug 13, 2011 12:20 am

Glad to hear. Thanks for the update.

I've had easy and hard ones to take out and put back in

I put it down to just luck

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Brumby gearbox knocking EA81 D/R

Brumby gearbox knocking EA81 D/R

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