Tapping / Clunking under load from gearbox, propshaft area of Berly

[pyrovee]

Hello everyone, sorry if I am covering a subject which has already been gone over before. Drove my new berlinetta home this morning and noticed a tapping or clunking noise coming from the front of the car under load at around 3k rpm and 50+ mph - this got worse when pressing the accelerator. When the clutch is pressed in however, the noise stops. Similarly, when the engine is revved with the clutch in, there is no noise. This leads me to believe it is a propshaft or gearbox issue. It is intermittent and appears to be randomly worse at some times than other. Could it perhaps be some bushings or mounts? Thanks in advance.

[Dane_Rescueman]

Re: Tapping / Clunking under load from gearbox, propshaft area of Berly

Hi.
This was not uncommon with the Cortina based Berly. I have no experience of the Sierra based version.
The tunnel and chassis members don't leave a huge space for the rear or top of the gearbox. It can touch various parts under load. The rubber mount can rot a bit due to oil contamination. This can allow enough movement under load to allow parts of the box to contact the tunnel/chassis. A new mount is easy to fit and can cure this problem. This rubber mount can be adjusted with washers under or over the side mounting bolts as shims to lower it slightly too. Check the rubber engine mounts at the same time.
The prop shaft is short and not exactly in line. If the front UJ has a bit of play it is just possible for the shaft to touch the handbrake extension which can cause a noise too.
You say the noise doesn't materialise with the clutch in. How about in neutral with the clutch engaged?
Is the exhaust system touching anything? that can cause thumping if it touches anything under load.
The other thing that may be the cause is a big end starting to wear. In neutral, with the clutch disengaged, stamp on the throttle. If you get a couple of rhythmic rumbly clatters from the engine maybe the big ends are worn. Again, in the Cortina Berly if you can get under the car it is possible to replace the big ends with the engine in place.
I do suspect though that the noise is a contact between GB and chassis/tunnel.
Good luck with your ownership. The car is great fun to drive and easy to work on.

[chris_cussen]

Re: Tapping / Clunking under load from gearbox, propshaft area of Berly

Could be propshaft UJ?
Check for play.