I have the dreaded driveshaft knocking on my 2002 FF172 and I've been damn near tearing my hair out.
I was experiencing it with -1.5degrees camber on high load left hand corners - awful, awful feeling. I have been speaking to people over here in Oz about it, there are a few guys here on OzRS who have the issue and also to my suspension guy who has experience with the issue (was posting on CS as robbieraver a while ago) and it seems the general consensus is that the driveshafts - specifically the driver's side - are too long when the car is running lowered suspension and a bit of neg camber (I am currently running Koni yellows with Sportlines) and are 'binding'. It also seems to not be a consistent issue, as some guys on OzRS have no issue even with very similar spec/build 172's - although tbh it looks like it is more of an issue with early 2002's build 172's - and even of the guys that have it some get knocking at differing levels of neg camber.
As the 182 driveshaft is 6mm shorter, one of the guys on OzRS actually managed to get a 172 cv/hub end succesfully mated to a 182 driveshaft and has cured the issue - went from knocking at -1 degree camber to running over -3 degrees with no knocking. Sounded like a good fix and after speaking to the guy that did it for him (basically just separating the 172/182 driveshafts and re-assembling the 182 driveshaft onto the 172 cv/hub end) I ordered a non-cup 182 driveshaft through Ktec. However when it was time to match it up to my 172 cv/hub end, the cv end inner spline on the 182 driveshaft was 1mm too large for the inner spline opening on the 172 cv/hub end (25mm dia. to 26mm dia.). Don't know why it worked for him - perhaps he managed to get a driveshaft from an early model 182 whereas later/reconditioned ones had a different cv end inner spline dimension. Bloody frustrating - especially as it is apparently a very easy procedure to do.
So I was thinking there was a couple of options:
1. Get the 172 driveshaft shortened by 6mm (thinking the gearbox end) but I'm not sure that you could just do that without having to have the spline grooves lengthened also? I found an engineering place that could shorten the driveshaft but not extend the spline grooves without costing big $$$. They could even actually manufacturer a shorter driveshaft to spec but unless I found quite a few people willing to go in for this option is even bigger $$$.
2. Try and source an early model 182 driveshaft but without pulling it apart and measuring it there is no guarantee that the cv end inner spline will match the 172 cv/hub inner spline opening so could end up buying a few with no luck. Also second hand 182 driveshafts are pretty hard to come by here in Oz, and second hand driver's side driveshafts aren't seemingly that easy to find in the UK either - which is why I ordered one from Ktec originally.
To complicate things even more, I recently fitted Ktec/vibratechnics mounts (upper engine and gearbox - already had powerflex dogbone bushes in) and it looks like I don't have the knocking anymore - well, at least on corners where I could definately generate the knocking before I haven't been able to since. My suspension guy seems to think that while it might have stopped the knocking for now (because the new mounts hold the engine more rigid and don't allow it to move around so much, reducing the available space for the driveshaft) but that as soon as I wind on anymore neg camber that it will start binding again. I don't mind -1.5 for the street but would really like to get -2.5 at least for the track.
Chip-mk1 has suggested to me moving the ball joint bolt holes outwards on the wishbone to allow for a few more mm clearance and which would give more camber and potentially more castor - as discussed in his 'got castor yo' thread.
So has anyone got any experience with this issue and managed to find a fix or had a driveshaft shortened or had the binding issue, fitted Ktec mounts and found they could wind on another degree of neg camber?
I was experiencing it with -1.5degrees camber on high load left hand corners - awful, awful feeling. I have been speaking to people over here in Oz about it, there are a few guys here on OzRS who have the issue and also to my suspension guy who has experience with the issue (was posting on CS as robbieraver a while ago) and it seems the general consensus is that the driveshafts - specifically the driver's side - are too long when the car is running lowered suspension and a bit of neg camber (I am currently running Koni yellows with Sportlines) and are 'binding'. It also seems to not be a consistent issue, as some guys on OzRS have no issue even with very similar spec/build 172's - although tbh it looks like it is more of an issue with early 2002's build 172's - and even of the guys that have it some get knocking at differing levels of neg camber.
As the 182 driveshaft is 6mm shorter, one of the guys on OzRS actually managed to get a 172 cv/hub end succesfully mated to a 182 driveshaft and has cured the issue - went from knocking at -1 degree camber to running over -3 degrees with no knocking. Sounded like a good fix and after speaking to the guy that did it for him (basically just separating the 172/182 driveshafts and re-assembling the 182 driveshaft onto the 172 cv/hub end) I ordered a non-cup 182 driveshaft through Ktec. However when it was time to match it up to my 172 cv/hub end, the cv end inner spline on the 182 driveshaft was 1mm too large for the inner spline opening on the 172 cv/hub end (25mm dia. to 26mm dia.). Don't know why it worked for him - perhaps he managed to get a driveshaft from an early model 182 whereas later/reconditioned ones had a different cv end inner spline dimension. Bloody frustrating - especially as it is apparently a very easy procedure to do.
So I was thinking there was a couple of options:
1. Get the 172 driveshaft shortened by 6mm (thinking the gearbox end) but I'm not sure that you could just do that without having to have the spline grooves lengthened also? I found an engineering place that could shorten the driveshaft but not extend the spline grooves without costing big $$$. They could even actually manufacturer a shorter driveshaft to spec but unless I found quite a few people willing to go in for this option is even bigger $$$.
2. Try and source an early model 182 driveshaft but without pulling it apart and measuring it there is no guarantee that the cv end inner spline will match the 172 cv/hub inner spline opening so could end up buying a few with no luck. Also second hand 182 driveshafts are pretty hard to come by here in Oz, and second hand driver's side driveshafts aren't seemingly that easy to find in the UK either - which is why I ordered one from Ktec originally.
To complicate things even more, I recently fitted Ktec/vibratechnics mounts (upper engine and gearbox - already had powerflex dogbone bushes in) and it looks like I don't have the knocking anymore - well, at least on corners where I could definately generate the knocking before I haven't been able to since. My suspension guy seems to think that while it might have stopped the knocking for now (because the new mounts hold the engine more rigid and don't allow it to move around so much, reducing the available space for the driveshaft) but that as soon as I wind on anymore neg camber that it will start binding again. I don't mind -1.5 for the street but would really like to get -2.5 at least for the track.
Chip-mk1 has suggested to me moving the ball joint bolt holes outwards on the wishbone to allow for a few more mm clearance and which would give more camber and potentially more castor - as discussed in his 'got castor yo' thread.
So has anyone got any experience with this issue and managed to find a fix or had a driveshaft shortened or had the binding issue, fitted Ktec mounts and found they could wind on another degree of neg camber?
