Rear BMW Suspension/Transmission Transplant for Stag
Monarch has developed a bolt-on rear suspension and transmission kit for the Stag, using robust and reliable BMW components, which allows the use of much more powerful engines and modern wide low-profile tyres and wheels with suitably wide rims. This is made possible by virtue of the vastly reduced camber change geometry of the BMW rear suspension. The kit utilises a modified BMW 3-series cross-member and bolts straight up to the Stag bodyshell using the standard mounting points. There are several other advantages of fitting this kit as you get the whole BMW transmission train, (ie. the indestructible BMW diff & driveshafts with the wonderful BMW constant velocity U/Js), hubs and disc brakes as well as the chance to have those 225/50R16 tyres you always wanted on the back. With this kit you also get a brand new GKN propshaft and new rear springs. So in buying this kit you save the cost of having to buy my "standard" BMW Diff Conversion (which uses the Stag rear subframe) new driveshafts AND a rear disc brake kit conversion as these are all included with the new set-up. You will of course need new bigger wheels with much more offset to accommodate the wider track which I can also supply from Image, with BMW wheel stud PCD to fit the new hubs and different rear shocks. These are not included in the price. But the whole point of fitting this new rear end would be lost anyway if you kept your standard Stag wheels. I can modify the stud PCD of your front hubs to match so that all your wheels have the same stud PCD, or you could go the whole hog (and why not?) and fit my aluminium hubs which use bigger bearings and spindles and weigh HALF as much as the standard steel hubs. Less unsprung weight improves traction and handling. Also now available is my more powerful aluminium 4-pot caliper/ventilated disc/aluminium hub kit which uses bigger calipers (too big to fit inside standard Stag wheels).
To order this rear suspension kit you send me your payment for the full amount, then I will send you a drawing to enable you to procure the right BMW 3-series rear end complete (made 1985-early 1990's) with the correct diff (most important!) and disc brakes from your nearest BMW breaker. You dismantle it and send the BMW crossmember and your Stag diff mounting plate to me for modification, during this time you can refurbish the rest of it. I will modify the crossmember and return it to you along with everything you need to do the conversion.
NB. You will have to think about which diff ratio you want. The following are available: 2.98, 3.07, 3.25, 3.45, 3.7 The more powerful your engine the higher the ratio you can have (the higher the ratio the lower the ratio number). You should find a small tab under one of the rear case bolts with the ratio number stamped on. If not phone me and I will tell you how to check it. The standard Stag ratio is 3.7. 3.45 is popular with the standard Stag engine and 2.98 or 3.07 for more powerful engines.
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