Converting WET to DRY suspension 
 
The following is a practical way of converting your wet suspension to dry, acknowledging the fact that with enough skill, enterprise and facilities, almost anything and everything has been done to the Mini suspension. This advice is for the average Mini owner who may not have all the facilities available. The best way, it must be stated early on, is to obtain a complete and undamaged set-up from a breaker's yard off either.a dry suspension saloon, van or estate. 
 
Dealing with the front subframe first, this has to be replaced by the dry suspension type. These were all the same until 1976, when Leyland decided to rubber mount the front , rear. and towers of the frame in an effort to reduce interior noise. This latter type is very easily identifiable. Apart from the rubber mountings attaching it to the front panel and floor , it has a large, single rubber isolated bolt with a 15/16" head securing it at the top of the cone spring towers. The earlier type has two small 9/16" head bolts. Avoid this later type. A front subframe from Leyland will cost over £ 1 71 , and as you will still need many other parts, a trip to a breaker is definitely on the cards. Bearing in mind what has just been said about the differences in the front frames, you can take the complete unit from any of the Mini variants - ie. van, pick-up, estate or traveller versions. By virtue of the design, you shouldn't have a rust problem to look out for, but check the brackets welded on the front which hold the suspension tie bars as well as the general appearance of the frame , especially if it is on a damaged vehicle. If the floor is wrinkled inside the car, be extra careful. 
 
If you are removing the subframe yourself, make sure you also unbolt the top shock absorber brackets, which are held on by four bolts, since they are needed. They will bolt straight on to your own inner wings, although the mounting holes may be covered in dirt and/or underseal. You should also acquire the four top cone spring turret bolts since they differ from the original items. 
 
If you have a dry subframe and want to use as many of your original Hydrolastic parts as possible, you will definitely need two cone springs, two trumpets, two shock absorbers and the top brackets, as well as two lower shock absorber pins. The top arms should be changed, but if you use the Hydrolastic versions you will get a stiffer ride since the knuckle joint locating hole is farther out from the pivot shaft. Some rally/fast road drivers prefer this arrangement, but for the sake of this argument, we will keep things standard and straightforward. 
 
Other alterations involve drilling out the bump stop locating holes to accept the lower shock absorber pins to 3/8" and discarding the bump stops, since the dry set-up has these items bolted to the subframe towers. 
 
Finally, mention should made of overhauling the dry front subframe and suspension. It is always advisable to change the rubber bushes on the tie bars and lower pins. No special tools being required for this job. There are two types of lower arm rubber bush. The early version has a collar, straight sides and is all rubber. whereas the later type is a tapered shape and has a metal insert. If you look through the lower arm bush hole and the sides appear straight, then it takes the early, all-rubber type. If the hole tapers, the later metal insert type is needed. Just to confuse matters we now produce a replacement for the later type which has no metal insert collar in an uprated poly nylon material. 
 
The last bit requiring inspection on the front subframe does require a special tool which compresses the cone spring and permits the upper arm to be dismantled. This arm has two caged roller bearings and, along with the shaft. these should be checked for signs of pitting or wear. A kit for this arm is available as MSKl. 
 
You should always replace the nylon cup or complete knuckle joint that sits in the upper arm. because if either the cup or ball becomes worn through improper lubrication, the result can be an annoying squeak and/or reduced ride height. 
 
Another height-governing factor are the cone springs. The only way of checking them roughly being to take them off the vehicle and compare them side by side. The aluminium coloured strut. or front trumpet as it is called. can be cut off at the knuckle end to lower the suspension. Or alternatively. washers can be added to increase the ride height. The amount of metal to be removed or added is governed by a ratio of 3: 1. In other words. if you remove 1/2" from the front struts. the car is lowered by about 1 1/ 2". 
 
Unlike the front subframe. the rear does rust and therefore has to be replaced. So if you are fortunate enough to find a decent secondhand dry subframe complete with radius arms etc .. snap it up. If the frame is beyond repair. you still require the two radius arms. cones and struts. 
 
Ideally. you should buy a new dry rear subframe if you are converting from wet to dry suspension . since there are differences between the two units. If you have a good hydrolastic frame it can be modified by reshaping the Hydrolastic displacer retaining lugs. Where the lugs are bent in to hold the Hydrolastic unit. they should be bent back outwards so the cone can fit freely but firmly inside. The radius arms should also be changed since the knuckle joint seating lug is in a different position. although this problem can be overcome by lengthening the strut. Hi-Lo used to make a correct length rod for use with their units, but this item is now obsolete. 
 
The other problem with Hydrolastic arms is that the axle stubs are different. That is, the Hydrolastic type has a short rear pin for holding the helper spring, while the dry type has a longer. threaded pin for holding the shock absorber. These pins cost over £20 a pair and have to be fly-pressed into position so as not to damage them. Heating the arm is difficult and often leads to pin damage when they are drifted into place. 
 
You should also bear in mind that van struts give a stiffer ride since the part that makes contact with the cone is larger than that of the Saloon variants. This also results in a slightly higher ride height, which was standard on the 1275GT and Minis 1984 on. If you feel the ride height is too high. the rear can be lowered by the same method as the front (cutting the struts), but note that the rear suspension ratio is 5: 1. The brake pipes on a dry Mini are longer than on the wet versions. since they fit under the radius arms. Be sure to relocate them under the arms if using the original Hydro units. If using dry arms, the handbrake cables will need to be replaced with shorter ones. A final point worth noting is that the radius arm bearings and shafts should be checked as they always seem to need replacing due to a lack of maintenance (ie. grease). The earliest Minis, of around 1959/ 1960 vintage. had two bronze bushes. All later types had one outer bronze bush, which has to be reamed out, and one inner needle roller. 
 
So there you have it. Verification that it is possible to switch to dry suspension on a Mini and still retain the Hydrolastic rear subframe. We haven't quoted the relevant BL part numbers here due to a lack of space, but these are easily available. 
 
Keith Dodd

Importation rules regarding vehicles are very specific: Only those over 25 years in age may be brought in to the USA without compilance to Federal Motor Vehicle Safety Standards (FMVSS).