tudorbroach
New member
Hi All,
I have had a rear suspension fright!!
I am going to go into some detail so that hopefully it will help anyone who can offer genuine advice.
My car is a 1997 993 C4S with a current mileage of 64,644. It has full official Porsche service history. I use the car every day and know it well!
15 months ago I noticed that when I drove through a sudden dip, as the car sat down on its suspension it felt as if the car wanted to turn right. It was more pronounced in the wet and was rather disconcerting. I took the car to my local Porche centre (which I use because they are 2 miles from home and because I generally have a very good relationship with them) and asked them to make a thorough check of the suspension. They said they could find nothing wrong and suggested fitting new rear dampers. The mileage at this time was 48,585.
One month later while driving along a dual carriageway at around 80 mph I went over some quite bad bumps (It was the A46 across the top of Leicester) and had an almighty scare as the car jumped sideways and had to apply a large amount of left opposite lock to avoid going off the road. I pulled over and as soon as I stepped out of the car it was obvious something was wrong with the rear suspension as the top of the right rear wheel was leaning in to the car by a good 1 to 2 inches. The cap head bolt which retains the top rear suspension arm to the subframe had disappeared completely!
OPC after some red faces fitted new cap head bolt, new eccentric washer (used to set camber), new captive nut and carried out 4 wheel alignment (Mileage 49,609). Having checked the history with the car I noticed that the previous owner had a full alignment check at 42,554 miles and on the invoice are 2 new bolts with the same part number. I put this experience down to bad luck and assumed that when the previous alignment was done the bolt had not been correctly tightenend.
If you are still with me I will now get to the really worrying part. I had the car in for its M.O.T. yesterday at an independent garage and was watching them go through all the checks and was alarmed when the tester could waggle the right rear wheel. On further inspection the same rear bolt had come loose again and could be unscrewed with fingers!!
Round to OPC, severe blasting to service department. Shrug of shoulders response. Car in for closer inspection this coming Monday.
I am an engineer having worked in the Aerospace and Machine Tool industry for the last 30 years and ought to be able to diagnose the problem but cars, especially Porsche's are different.
My thoughts are that the bore in the bush in the suspension arm may have become enlarged or the bush damaged when the bolt was loose and a new arm should have been fitted together with the new bolt, eccentric and nut. The M.O.T. tester has advised that there is movement in the rubber bush but that it is not excessive?? I will suggest to the OPC if they do not do so first (!!!) that they fit new suspension arm. I am also concerned that there is now slight damage to the two raised lugs on the subframe that the eccentric washer acts upon. This has been caused by the bolt and eccentric being able to move due to the loose bolt. I think that this part could be an expensive and massive job to replace but will have a look later.
So, are you all still awake after my ramblings. If so, has anyone had the same problem?
Also does anyone who is knowledgeable and has has genuine hands on experience of this area have an opinion?
I look forward to your replies.
Best regards,
Mark Thompson [
]
P.S.
I will be at Ragley Hall if anyone wants to have a look or give advice.[]
I have had a rear suspension fright!!
I am going to go into some detail so that hopefully it will help anyone who can offer genuine advice.
My car is a 1997 993 C4S with a current mileage of 64,644. It has full official Porsche service history. I use the car every day and know it well!
15 months ago I noticed that when I drove through a sudden dip, as the car sat down on its suspension it felt as if the car wanted to turn right. It was more pronounced in the wet and was rather disconcerting. I took the car to my local Porche centre (which I use because they are 2 miles from home and because I generally have a very good relationship with them) and asked them to make a thorough check of the suspension. They said they could find nothing wrong and suggested fitting new rear dampers. The mileage at this time was 48,585.
One month later while driving along a dual carriageway at around 80 mph I went over some quite bad bumps (It was the A46 across the top of Leicester) and had an almighty scare as the car jumped sideways and had to apply a large amount of left opposite lock to avoid going off the road. I pulled over and as soon as I stepped out of the car it was obvious something was wrong with the rear suspension as the top of the right rear wheel was leaning in to the car by a good 1 to 2 inches. The cap head bolt which retains the top rear suspension arm to the subframe had disappeared completely!
OPC after some red faces fitted new cap head bolt, new eccentric washer (used to set camber), new captive nut and carried out 4 wheel alignment (Mileage 49,609). Having checked the history with the car I noticed that the previous owner had a full alignment check at 42,554 miles and on the invoice are 2 new bolts with the same part number. I put this experience down to bad luck and assumed that when the previous alignment was done the bolt had not been correctly tightenend.
If you are still with me I will now get to the really worrying part. I had the car in for its M.O.T. yesterday at an independent garage and was watching them go through all the checks and was alarmed when the tester could waggle the right rear wheel. On further inspection the same rear bolt had come loose again and could be unscrewed with fingers!!
Round to OPC, severe blasting to service department. Shrug of shoulders response. Car in for closer inspection this coming Monday.
I am an engineer having worked in the Aerospace and Machine Tool industry for the last 30 years and ought to be able to diagnose the problem but cars, especially Porsche's are different.
My thoughts are that the bore in the bush in the suspension arm may have become enlarged or the bush damaged when the bolt was loose and a new arm should have been fitted together with the new bolt, eccentric and nut. The M.O.T. tester has advised that there is movement in the rubber bush but that it is not excessive?? I will suggest to the OPC if they do not do so first (!!!) that they fit new suspension arm. I am also concerned that there is now slight damage to the two raised lugs on the subframe that the eccentric washer acts upon. This has been caused by the bolt and eccentric being able to move due to the loose bolt. I think that this part could be an expensive and massive job to replace but will have a look later.
So, are you all still awake after my ramblings. If so, has anyone had the same problem?
Also does anyone who is knowledgeable and has has genuine hands on experience of this area have an opinion?
I look forward to your replies.
Best regards,
Mark Thompson [
]P.S.
I will be at Ragley Hall if anyone wants to have a look or give advice.[
]
