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Transmission Noise
ttalps2000 - 14/5/18 at 08:13 PM

I seem to be getting a lot of transmission noise, mostly on overrun with the throttle closed.

It is a MK1 escort rear axle with a standard diff. Diff was re-built by myself (engineer) and is very quiet when running etc (no whine or nasty noises)

Gearbox is a standard T9 box and was not noisy etc when removed from the Sierra many years ago now!!

The noise sounds as though somthing is loose and rattling. All has been checked and appears to be ok. Is this quite normal for a live axle setup and T9 box and is usual?

Thanks


Mr Whippy - 15/5/18 at 05:31 AM

why would it not be noisy?

is the car sound insulated? to expect it to be as quiet as a Sierra is a bit unrealistic unless a lot of work has been done to insulate the cabin from transmission noise, even then it depends greatly on what kind of mountings have been used for the engine & gearbox, some do very little sound insulation wise, also depends on what kind of rear mount you went with on the T9, the OEM one being quite good but bulky. Some like Transit diesels and genuine Landrover diesel engine mounts do a very good job of keeping things quiet.


Tazzzzman1 - 15/5/18 at 10:00 AM

Are you sure its not the clutch release bearing/ Pawl thats not rattling in the bell housing? Had this before where the clutch cable is not holding the Lever under enough tension. May just need adjusting


JAG - 15/5/18 at 10:57 AM

I'm with Mr Whippy....

You are sitting very close to the gearbox and the whole drivetrain. I'd expect you to hear every clunk/click and whir as you drive along and I think it's part of what makes these cars great fun.

The car will have no noise-dampening technology in the body panels, firm suspension and less than ideal engine/gearbox mounts. Noise is inevitable.

Tazzzzzzman; sort out your Avatar

[Edited on 15/5/18 by JAG]


ttalps2000 - 15/5/18 at 12:31 PM

The gearbox mount is quite small to be honest, but there is not a lot of room to get one in as it is!

When running, on the motorway etc and even at lower speeds, 30mph etc, all is silent, its when you let off, mainly at lower speeds that all the clunking etc begins!


nick205 - 15/5/18 at 01:18 PM

As others have said you have to allow for the fact the diff is usually bolted straight to the chassis right next to your left bum cheek. Although I used rubber engine/gearbox mounts in my MK Indy they were pretty stiff. It whined and clunked a bit, but never bothered me really.


Having said that I did wear a full face crash helmet (no windscreen) so maybe I didn't hear it.

[Edited on 15/5/18 by nick205]

[Edited on 15/5/18 by nick205]


leon51274 - 15/5/18 at 02:09 PM

I use earplugs, sorts all the clunking etc beautifully!


On a serious note, are you sure its not the backlash on the prop you can hear when changing gear?


ttalps2000 - 15/5/18 at 03:56 PM

looks like im being fussy and need to be quiet

Thanks for the reply's!