I have had my rear subframe off to paint and renew, now it all is refitted, I have a kind of bang type noise.

 

It happens when letting the clutch out the first time going forwards or reversing, there appears to be play in the diff, when I let the clutch out, the prop and diff seem to rotate about a Cm before becoming solid, or engaged, and when it becomes solid, it makes a bit of a knock, or slight bang, is it normal for the input of the diff to have play in it? I noticed it when I had the diff off, presumed it was normal. If I put her in reverse with the handbrake on and let the clutch bite repeatedly, it is knock, knock, knock etc. each time I let the clutch bite... Any ideas? (I haven't changed the diff fluid, but I will be doing very soon)

 

Cheers, Tudor...

It's a 92' JDM TT by the way, HICAS still in place, I haven't bled the HICAS yet either, waiting to use a lifter...

Silly question but you have put then spacers in bewteen the chasis and the prop bearing eg so the prop is straight?? only reason I ask is this idiot didnt at first and i had the same prob.

 

Also is the prop in the right way eg did you mark it and its correctly lined up not 180 degrees out???

Yes, and yes, it isn't the prop, it is attached to the diff lovely and solid, no play in the prop, it's the diff, as the gearbox turns the prop and diff, the diff turns about a Cm (play) before the wheels want to move, and after that Cm, it engages the wheels, that's when I get the knock/slight bang, I can easily watch what is happening just by sticking my head under the car whilst someone else lets the clutch out...

And, also, from around 30 MPH, (haven't been faster than 40 really, as I am only test driving on a private road), I get a noise in the cabin, very similar to having one window open slightly on the motorway, you know the kind of low frequency 'b b b b b b b b b' noise? I have two different halves of propshaft as I did a manual conversion, could the prop need balancing?...

bump :)

sure it is not you prop centre bearing?

Thanks for the reply mate... The centre bearing appears fine, no play, I checked it when I had the prop off, I will check again, that could explain the noise whilst driving, but not the diff play, is it normal for the diff to have a bit of play in it from the input side of it?...

After market rear diff? Might be the backlash between the crown and pinion gear has not been set correctly?

yes there should be some play in the diff but im not 100% sure how much. as said above it is known as backlash

Hi mate cant say if its normal, but i done a clutch change on mine couple weeks ago and noticed the same thing, if you twist prop i get about half inch ever way before it goes solid diff end,

 

get clonk if i come off and on throttle hard, originally thought gearbox mount or something but seems to be the slack in the diff,

 

Also got an helicoptor type noise at speed,

 

be interested to know if its normal diff end too,

 

goodluck mate.

Hi mate cant say if its normal, but i done a clutch change on mine couple weeks ago and noticed the same thing, if you twist prop i get about half inch ever way before it goes solid diff end,

 

get clonk if i come off and on throttle hard, originally thought gearbox mount or something but seems to be the slack in the diff,

 

Also got an helicoptor type noise at speed,

 

be interested to know if its normal diff end too,

 

goodluck mate.

 

Sounds exactly like mine mate! I'll let you know when I get to the bottom of it, been meaning to get her on the lifter all week, just too frickin' busy...

First thing to do would be to change the diff oil in my opinion....might find it's got hardly any in it!

I will be doing as soon as i can get it on the lifter, it isn't being driven at the mo, infact, it has hardly been driven for a long time as i have been working on it, diff showed no signs of leaking at all, but that could just mean there's no oil in it!

That was more a tip for terry I guess with his 'helicopter' noise! lol

That was more a tip for terry I guess with his 'helicopter' noise! lol

 

I will Check my oil level too, filled it to the level not long ago, but you never know with a zed - my zed anyway,

 

Cheers 4 reply.