Front Suspension Transplant
Suspension differences - 'Sud and early Sprint to 33 and later Sprint
Parts known to be different
The biggest difference is that the earlier system of disc brakes all round, with the inboard front calipers, discs and handbrake assembly has been totally revised. The 33 and later Sprints were fitted with conventional single piston sliding yoke calipers mounted on the front hubs, and acted on solid discs. (This alone is a major step forward in being able to maintain the car - no more dropping the engine for a handbrake cable change!) The rest of the front suspension has detail changes. The lower arms are subtly different lengths and shapes, and the lower balljoint connects to the new, very different hub assembly via a taper assembly rather than a pinch bolt. Some early 33's were not fitted with anti-roll bars. New driveshafts, held into the hubs by a staked 36mm nut, connect to a gearbox that has no mounting features for the early calipers, and output flanges that cannot accept the inboard discs. The lousy six allen bolt attachment method is still there though. The front shock absorber strut assembly is similar, but with a redesigned bottom spring mounting pan bearing, and a different bolt pattern where it mounts to the hubs. The series three struts also have detail differences to the upper mounting. The front suspension must be changed as a complete set.
The transplant itself
This should have been a very easy job, in theory requiring a straightforward transfer from one car to another. Wrong, as you will read. I have started the report with the problems because I believe that this will help others avoid some irritating pitfalls.
Koni shock problems part 1 - missing bits
Koni shock absorbers are very good, let me get that message through from the start.
The problem comes when you are not supplied with everything that should come with them. By this, I mean that the top mounting self locking nuts and the bottom setbolt should arrive with the shocks. If they do not, STOP THERE and get on to your dealer. These nuts and bolts are impossible to get apart from Koni direct. They are specials. These were missing from mine. The bottom bolt proved the real headache for me, as I luckily had an old pair of konis on the rear of the sprint that donated the top nut. The bottom bolt is a 12mm by 1.5mm pitch thread, and not having it is a show stopper. Remember that you have to cut the existing strut to get the old shock out, and you can't put it all back together again without that bolt. Added to this, I really got the runaround from the dealers, and in the end had to jury rig something just so that I could get the car back on its wheels. Very frustrating, and something like three days lost trying to find a suitable bolt and chasing this up.
Koni shock problems part 2 - series three suspension related
Due to the problems with the lack of bolts for the Koni's, the delay in fitting the front strut (singular, note) components back together again failed to highlight the other problem with the series three suspension. The top strut mount, which has a plate with four holes, a rubber bush and a top ball bearing in, it is too small to fit over the Konis. You would never believe the restraint I had to apply to not type that in capitals with a lot of words beginning with 'F'. I have checked with the correct persons, and yes, the Koni's are the correct ones for the job. Alfa, it seems, have changed the design quite radically, so if you want Konis, buy the series one or two struts. Funny how I specified Konis to fit the donor car that I bought, and that I bought them from the same 'specialist' that I got the car from.
Whatever, I found this out only during the mad dash to get the car back on its wheels again.
Front suspension replacement
This is relatively simple, but all or none can be changed, no intermixing of parts is possible.
Make sure that if you are going to fit Koni shock cartridges that you determine the type of top mount you have - the series three top mount is incompatible with Konis, it seems. However, if you are not going to change the shock, the series three strut will fit directly into the Sud or Sprint bodywork with no modifications, just remember that the whole set of suspension parts must be changed.
I was planning a 16 Valve conversion, so the other change I had to make was to fit the 16v front crossmember, but the standard crossmember is ok for any 8v applications.
If you are retaining the inboard disc gearbox with the later suspension, you may run into problems with driveshaft lengths - I did, and rather than try and to work out spacers etc, I just went ahead and fitted the later 'box that went with suspension and shafts.
The only drawbacks are that there is obviously a gearbox swap, and the speedo drive issue, which is simple if it all goes smoothly. Read about that issue in the gearbox section. I'm sorry that this is not much help to anyone who wants to retain their original 'box, but if you refer to people like Alfatune, they should be able to give some help.
My decision was based on simplicity, as I already had the gearbox out. If you do take the route that I did, and swap the speedo drive gear, make sure that spacers that go between the output shaft and housing assembly and the gearbox casing remain with the gearbox casing. Also, check the condition of the nylon speedo drive.
You will at some point have to undo the six allen head bolts that hold the driveshafts to the gearbox. These will be tight, and probably loctited in position. Doing it before taking off the rest of the suspension, while there is still a way of locking the driveshafts solid will make loosening them easier, although access is a bit restricted. My suggestion would be a GOOD QUALITY 6mm allen bit and a long breaker bar. Tap the allen bit home as far as it will go, then undo. Once the loctite cracks, it will be easy to undo.
If it happens to round off, which is depressingly likely, get hold of a piece of 1/4" AF allen key, about 12mm long, and hammer it into the head of the bolt. As 1/4" is equal to 6.35mm, it is a tight interference fit, so there is no chance of it slipping. You then try again with a 1/4" socket on the end of the allen key. My experience is that this solves the problem. Once the bolts are loose, carry on with the rest of the suspension.
Remove the struts by disconnecting them from the hubs at the lower end, the steering arm balljoints (using an appropriate splitter - do not damage the balljoint if you don't want to have to replace it!), and then the four nuts on the strut turret. The struts then come out.
The lower arms can be disconnected at their extreme ends, and the anti-roll bar from the front arms. The rear mountings of the rear arms are pains to get to, but can be reached by sticking a socket into the space at the back.
Undo the six allen head bolts that hold the driveshafts to the gearbox if you have not already done this. Refer to the driveshaft section above for tips. Once the bolts are removed, the driveshaft, complete with the arms and hub, come away as an assembly.
Assuming you have the correct gearbox fitted, assembly is basically the reverse, with the added items of the brake discs and caliper assemblies to consider. The brake hydraulics will be dealt with separately. Note, however, that the bolts that hold the driveshafts on for the 33 are shorter than the 'Sud /Sprint ones. I would also recommend new bolts and a drop of loctite when doing them up for safety reasons. Leave the suspension bolts and nuts semi-loose (except for the steering arm balljoints) until the weight of the wheels is on the ground. After replacing the front suspension, I would advise taking the car to someone who knows what they are doing to get tracking and alignment done.
Notes concerning the front suspension
I would take the opportunity to replace the six bushes in the arms and the two anti-roll bar bushes.
However, careful inspection of the two lower arms is advisable. They tend to be in a fairly poor state, with corrosion and impact damage from stones and bad jacking practices. If the rear arm, which contains two bushes and one balljoint each, looks in poor condition, with worn bushes and a loose balljoint, it is not sensible to try and repair it. Go for new arms, which are not as expensive as you think, or at least get a good second hand one.
The front arm only has one bush, so the economics of a new item are less convincing, so the best bet is to look for a good second hand one. Remember though, 'Sud parts are not interchangeable.
One final note: if you are using alloy wheels from your Sud / Sprint on the 33 suspension, you will need longer bolts - the ones from the Sud / Sprint will appear to work, but they only engage on a few threads. I sourced some from an Alfa 164.