Diff mounts shot???

[vipergts]

Hi
I'm getting a knocking sound up back, quite a heavy one. Nothing obvious and can't replicate it on a ramp

Do these diff mount bushes look shot and if so is this likely to cause the noise?

 

[toopy]

FUBAR!

 

[jonbills]

They certainly don’t look good. When do you get the noise? On acceleration or deceleration?
The play in the final drive itself can be quite large and give a clunk on taking up the drive too.

 

[Rob Gaskin]

I would have suspected the front of the diff lifting under acceleration. Have you got a strap over the top of the diff nose?

http://www.thezstore.com/page/TZS/PROD/10-2252

 

[Rob Gaskin]

FUBAR!

I'm not sure about that - they do have that wavy shape.

https://www.ebay.com/itm/Datsun-240...-Mount-Bushings-Upper-Lower-NOS-/282099223385

 

[jonbills]

I'm not sure about that - they do have that wavy shape.

Crumbled away in parts!

 

[tjrvp]

Hi
I'm getting a knocking sound up back, quite a heavy one. Nothing obvious and can't replicate it on a ramp

Do these diff mount bushes look shot and if so is this likely to cause the noise?

 

[tjrvp]

I had my diff mount bush replaced as it looked a lot like yours and i had a knocking. knock went away

 

[Rob Gaskin]

Crumbled away in parts!

Yeh they aren't new but the bushes that do most of the work to limit twisting are inside the 'rolled end' of the bar. I think those wavy ones are there to allow a bit of twisting when the bolt is tight if you follow me?

 

[Rob Gaskin]

I had my diff mount bush replaced as it looked a lot like yours and i had a knocking. knock went away

But was that the front bush/mounting?

My main point is to check the front of the diff for vertical movement as a priority. If that's ok then focus on the ones you have highlighted.

 

[vipergts]

Thanks Fellas

It's knocking on general bumps, quite a heavy sounding knock

Not sure re the nose strap, will check

Rob, as per your link, they are wavey. Gordon Bennett, they are trumpy

 

[AliK]

My bushes are in a worst state than that I.e one of the serrated washers / bushes that Rob posted has completely disintegrated.

I seldom get knocking from it if on the power and I go over a bump or pot hole type surface on that side. But this is rare - as rob said, the main bit inside the rolled part of the moustache bar is doing most of the heavy lifting, those serrated bushes are really behaving like bump stops.

I also get knocking when suddenly decelerating or changing down on engine braking, where the nose of the diff is coming down hard and something in that region is making contact - my diff mount insulator has seen far better days and the rubber compresses too much. I have on two occasions heard it say hello to the anti-roll bar which is a heart in mouth type sound!!!

Two different knocks two different bushes involved.

 

[jonbills]

Knocking on bumps sounds more like suspension/anti roll bar to me- the diff would have to be really loose to be the problem, and I think you test on the ramp might have already covered that.

 

[vipergts]

Thanks guys...Really annoying. been out in it today, been under it twice too. So irritating

Will start at the Moustash jobbies first

Anyone know if Mike MJP is in or out atm?

Mike, I've emailed you

 

[AliK]

You will struggle to find the OEM ones at a reasonable price. You will likely need to consider the poly bushes from MSA which are a bit of a faff as you have to try to recover the metal case of the original ones.

http://www.thezstore.com/page/TZS/PROD/classic22d06/23-4139

Edit: I will eat my word, look at this:

 

[Alphabettispaghetti]

is it on acceleration or deceleration?

 

[jonbills]

is it on acceleration or deceleration?

Bumps