I own a 997 Gen1 Turbo Tiptronic. My car is driven regularly (93,000 miles) and serviced and maintained by an independent specialist, Mark and his team at Addspeed in Horsham.
At the beginning of this year, I began to notice a problem. When gently stopping the car from a slow speed there was a significant clunk, as if the gearbox had dropped into first. However, it was still in second, which is normal when not in sport mode.
I immediately took the car to Mark who checked the transmission/engine mounts, suspension, prop shaft and drive shafts. He noticed that the rear prop shaft coupling had split and it was replaced. This appeared to solve the problem.
Unfortunately, because of family health issues, I was not able to drive the car for many months. However, in September I drove to the local main Porsche agent, a return journey of over 60 miles. During the drive I again noticed that the car still clunked when slowly stopping, but in addition, when in 5th gear at 50 M.P.H. if the throttle was feathered and then gently reapplied there was a significant clunk before the transmission appeared to reengage. This also happened in 4th gear at 40 M.P.H. Once engaged, gear changing was normal and smooth. I took the car back to Mark.
He now changed the gearbox oil, checked the filter, changed the front differential oil and front differential clutch oil. The car was road tested but the problem was still present. Back on the ramp, he showed me that when in neutral, turning by hand one of the front wheels hardly caused any movement on the opposite wheel; the suspicion was there was a problem with the front drive system. Mark suggested he disconnect the prop shaft, with the power just going to the rear wheels, and let me test the car to see if the problem was still there. After a drive of over 30 minutes, I could not get the problem to replicate. We concluded there was an issue with the front differential.
What were the options? Mark contacted his transmission specialist who said they could do nothing; since Porsche did not supply parts for the front differential, you had to buy a new unit at a cost of over £9,500.
I discussed the situation with Mark, who said he could try and strip the front differential clutch assembly to identify the root cause of the problem. The cause of the clunking was excessive bearing play and water ingress into the unit. With nothing to lose, he could try and repair the unit, but if that was not possible then a replacement would have to be ordered.
Mark contacted many suppliers to see if he could get parts. Most did not reply; a few asked for further details and one wanted pictures. However, one supplier said they could get the required bearings and seals and the relevant parts were supplied within a week.
The assembly was then cleaned, reassembled and refitted and the car road tested. Problem solved! Just to check, I took it for a long drive and totally agreed: it felt like new.
A new unit would have cost over £9,500, but the price of the new seals, bearings and oil was - wait for it - £700. The overall cost of parts and work was £1,700.
This experience has further taught me that a good independent specialist, like Addspeed, is worth their weight in gold!
At the beginning of this year, I began to notice a problem. When gently stopping the car from a slow speed there was a significant clunk, as if the gearbox had dropped into first. However, it was still in second, which is normal when not in sport mode.
I immediately took the car to Mark who checked the transmission/engine mounts, suspension, prop shaft and drive shafts. He noticed that the rear prop shaft coupling had split and it was replaced. This appeared to solve the problem.
Unfortunately, because of family health issues, I was not able to drive the car for many months. However, in September I drove to the local main Porsche agent, a return journey of over 60 miles. During the drive I again noticed that the car still clunked when slowly stopping, but in addition, when in 5th gear at 50 M.P.H. if the throttle was feathered and then gently reapplied there was a significant clunk before the transmission appeared to reengage. This also happened in 4th gear at 40 M.P.H. Once engaged, gear changing was normal and smooth. I took the car back to Mark.
He now changed the gearbox oil, checked the filter, changed the front differential oil and front differential clutch oil. The car was road tested but the problem was still present. Back on the ramp, he showed me that when in neutral, turning by hand one of the front wheels hardly caused any movement on the opposite wheel; the suspicion was there was a problem with the front drive system. Mark suggested he disconnect the prop shaft, with the power just going to the rear wheels, and let me test the car to see if the problem was still there. After a drive of over 30 minutes, I could not get the problem to replicate. We concluded there was an issue with the front differential.
What were the options? Mark contacted his transmission specialist who said they could do nothing; since Porsche did not supply parts for the front differential, you had to buy a new unit at a cost of over £9,500.
I discussed the situation with Mark, who said he could try and strip the front differential clutch assembly to identify the root cause of the problem. The cause of the clunking was excessive bearing play and water ingress into the unit. With nothing to lose, he could try and repair the unit, but if that was not possible then a replacement would have to be ordered.
Mark contacted many suppliers to see if he could get parts. Most did not reply; a few asked for further details and one wanted pictures. However, one supplier said they could get the required bearings and seals and the relevant parts were supplied within a week.
The assembly was then cleaned, reassembled and refitted and the car road tested. Problem solved! Just to check, I took it for a long drive and totally agreed: it felt like new.
A new unit would have cost over £9,500, but the price of the new seals, bearings and oil was - wait for it - £700. The overall cost of parts and work was £1,700.
This experience has further taught me that a good independent specialist, like Addspeed, is worth their weight in gold!
