Clunky Series 3 Aero 8 Gearbox

[mdrc]

There must be some comments somewhere on this, so apols if it's a recurring thread, but when I test drove a Series 3 recently, the only niggle was a clunky transmission in low gears. The response I received at the time was one of those 'they all do that sir'. Having owned several TVRs, I am used to the expression, but wondered whether they did all do that?? If they do, does it disappear with running in and use??

[cerealsurfer]

Both mine and my fathers and all the ones I test drove did it... you'll soon learn a clutch style that minimises it happening.

The shift can also be clunky but this can be solved by installing a quick shift.

[mr_tony]

As the man says - quickshift gearstick seems to make a difference, but they do all do it.

[boshly]

Am I missing something here?
I have no clunks in my series 2 (mechniclly similar to series 3). I m sure I would sense such an obvious symptom.

BTW did you drive the green factory demonstrator?

Andy

[Aeroman]

Are we talking a clunky gearbox, or something else? Personally, I agree with Boshly and would not call the ZF gearbox in the Series II/III clunky, nor the Getrag in the Series I come to that!

However, there is some driveline shunt in all models so far and whilst this has been reduced in the Series II/III due to a different mounting system for the rear diff, it is still there but you quickly learn to drive round it and after a short while you don't notice it at all. As to whether they all do that the following verbatim from the owners handbook (Series II) could be relevant:

Quote
Transmission
To provide the positive and responsive performance the drive train is very direct. Due to this there is a tendency for a small amount of transmission shunt. This is not a fault and will not cause any damage. Smooth operation of the controls will minimize this and improve the driving experience. Unquote.

Seems that they 'all do it', sir.

Cheers
Brian

[mdrc]

This would appear to answer my question - thanks to all - if I'd known what I was talking about I would have referred to it as drivetrain shunt and not clunkiness!!

[Michael997]

As I hope to have my own Aero 8 very soon I thought I would ask if any engineers among the owners here has tried to work out why the car has this unwelcome feature and how perhaps it could be modified out.

I am sure the Aero experience would be all the more enjoyable with the shunt/clunk taken out.

Michael997

[cerealsurfer]

Michael997 said:

As I hope to have my own Aero 8 very soon I thought I would ask if any engineers among the owners here has tried to work out why the car has this unwelcome feature and how perhaps it could be modified out.

I am sure the Aero experience would be all the more enjoyable with the shunt/clunk taken out.

Michael997

Michael... I took some pictures of the problem area exactly for this type of question.

http://rides.webshots.com/album/55532

If you look at pics 8 - 11 you can see that the rear diff is bolted directly to the rear chassis both from the front and the rear. Usually you would not do this. The TVR Cerbera has the same Hydratrack setup but on my old 4.5 Cerb the diff is esentially floating with a number of rubber bushes to take up the snath... on older Morgans this is characterised by the diff pitching upwards onto a rubber bush mounted above UJ where the prop attaches when the clutch is engaged swiftly.

If you wanted to change this characteristic you would need to create a new diff hanging system that would not be torn apart by the torque from the engine. TBH... it's actually a benefit from a performance perspective as the suspension geometry and power take-up is fixed. The parts are so over engineered the shunt you are feeling (the totalised grear system play) will not damage any of the parts....

Don't worry about attempting to fix the engineering... I'd concentrate on getting your clutch changes right... the shunt is only really felt if you don't heel and toe especially when changing into a too-lower gear or too higher gear when bieng in-decicive on the throttle.

Trust me... after a few sessions driving it won't be a problem.....

Not a reason not to get one... just go for it.
(just in case you were going to use it as an excuse not to join us....)

[Michael997]

Well my friend your photo's answer a lot of questions on this subject, there seems to be a lot of metal to metal contact which will transmit transmission chatter.

I will be interested to see if in the future some clever chap comes up with a mounting mod kit, who knows.

I am very grateful for your reply and your pics, hope to meet some Aero day.

michael

Edited by Michael997 on Saturday 11th November 07:55