Shuddering (mainly in reverse..)

[KillerJim]

Hi,

Took the Sagaris for a run as the road's where dry and noticed a significant shuddering whilst reversing out. It goes through the entire vehicle but is most noticeable on the pedals. I also notice it when the engine is fired up and turning it off - thumping sound.

It only occurs when in gear, if I go backwards with the clutch depressed - no shudder. If I keep my foot on the brake and let out the clutch you can feel the shudder.

The car was 12k serviced about 700 miles ago with new engine mounts, and the clutch has had about 1000 miles on it..

Its off to get looked at this week but does anyone have any ideas on the problem? Hopefully something has just loosened!

James

[Zippee]

I had this on my T350 when I had my clutch and slave changed. After about 1500 miles it has now gone away, I was told it takes a while for the clutch to bed in though how true that is I don't know.

[softtop]

Zippee said:

I had this on my T350 when I had my clutch and slave changed. After about 1500 miles it has now gone away, I was told it takes a while for the clutch to bed in though how true that is I don't know.

if they are set up right you should not know you have a new clutch(apart from being able to change gear)

[sidewayz]

Could be engine mounts.I had two go at once and the symptoms sound similar.

[VARLEYHYD]

Could just be a glazed flywheel/clutch plate?

James, Try a slipping clutch take off!

That bedded mine back in; after a bit of city driving


G

[s6boy]

KillerJim said:

The car was 12k serviced about 700 miles ago with new engine mounts, and the clutch has had about 1000 miles on it..

James

That is interesting as when mine came back with new harder compound engine mounts I've got exactly the same symptoms when pulling away. I wonder if the engine location is altered sufficiently to cause a drag....

Do you also notice a fair degree of extra harshness from the mounts? I'm beginning to think replacing the original RV8 mounts every 2 years would be better.

[OatSy]

I had this on another (non TVR) car, was found to be the diff?? fine in forward motion only in reverse when the stearing wheel wasn't centralised did it happen.

[KillerJim]

s6boy said:

Do you also notice a fair degree of extra harshness from the mounts? I'm beginning to think replacing the original RV8 mounts every 2 years would be better.

I was offered the new 'hard' mounts but decided against it, I was more interested in comfort driving and didn`t mind changing the mounts every few years.. maybe the hard ones went in, must check my receipts..

I`ll try your clutch method Graham, hopefully the weather holds until tonight!

The shuddering is definitely worse when turning in reverse (as I always have to turn out of the space, rather than drive back..) - Hope its not the diff as I`m far from a harsh driver

J

[Druid]

KillerJim said:

I also notice it when the engine is fired up and turning it off - thumping sound.

Really does sound like engine mounts, get them checked and let us know.

[KillerJim]

Druid said:

KillerJim said:

I also notice it when the engine is fired up and turning it off - thumping sound.

Really does sound like engine mounts, get them checked and let us know.

I`m dropping her down in the next few days to get looked at, I`ll grab the torch tonight to see if I can see any damage to them...

I`m pretty concerned if they have failed after so few miles!!

[KillerJim]

It is the engine mounts...

They failed after 577 miles (!!!!)

There were the "normal" engine mounts (not the hardened ones) and would be fitted to most cars (there is only one source for them, the original TVR items were slightly different). The problem is that in Speed 6 car's the stress on the mounts is different and is causing failure.

[s6boy]

KillerJim said:

It is the engine mounts...

They failed after 577 miles (!!!!)

There were the "normal" engine mounts (not the hardened ones) and would be fitted to most cars (there is only one source for them, the original TVR items were slightly different). The problem is that in Speed 6 car's the stress on the mounts is different and is causing failure.

It's the heat from the exhaust that does it, that and the fact most of the weight is supported on the nearside mount. My 2nd set went after a similar mileage but that was down to idling in a 2 hour stop start traffic jam in 35 degree heat. I was hoping the harder compound would last longer but don't think the side effects are worth it unfortunately.

[KillerJim]

s6boy said:

..but don't think the side effects are worth it unfortunately.

What are the 'side effects' of this harder mounts?

I don`t think i've any option but to fit them..

[Druid]

Failure in so few miles must be unusual. I had something done with the heat shielding in an attempt to prevent it....time will tell!

[s6boy]

If you're not happy with how long they've lasted take them back, if not in exceptional heat that is a very short life and you may have got a duff batch.

Side effects are much increased harshness through the chassis resulting in a high frequency vibration from behind the dash that wasn't there before, also a fair bit louder. Also the perceived clutch judder which started as soon as they were fitted (although it is over 40,000 miles old now), as I said earlier that could be down to an alignment issue- not sure on this, but know they will have been installed correctly.
I'm going to give them a chance this weekend and get them as warm as possible and see if that 'softens' them at all. I drove into London a few weeks ago in the freezing cold but after an hour or so I think there had been enough heat transfer so that they were a little more forgiving.

[KillerJim]

Thanks, just collected her and you can certainly notice the difference when cold - plenty of excess vibrations around idle and up-to 1500rpm but nothing I can`t live with..

Its a little quieter when warmed up..