Atomota_Man

The photo is of the front driveshaft, or propshaft as you say in the UK, for a 1999-2004 Jeep Grand Cherokee. The plunging CV joint on the bottom left is 100mm x 40mm, top right CV is 100mm x 32mm, both CV’s. My thoughts are that this driveshaft could be purchased secondhand from a local DIY junkyard for around 35 dollars. Then it should be possible to remove a section from the centre of the propshaft tubing, press in an inner sleeve and then weld the two halves back together. First, the inner CV normally requires a 94mm OD CV for chassis clearance reasons, but for my application, that is not an issue. Both CV’s have an inner spline count of 25, as do the stub shafts, so perhaps a more traditional wheel side CV joint could be used? LÖBRO part no. 305152 for an Alfa Romeo, has 25 splines for the wheel hub and the 25 internal splines. While I would assume this CV would fit the Jeep stub shafts, I have been burned by making assumptions in the past. Any thoughts as to this line of thinking or is there something I am overlooking?

The Volvo 340 cv joints that are 22 splines are getting hard to find. Some 2 liter 340’s and 360’s used a 94mm joints with 24 internal splines. What about using the driveshaft from a 1974-1978 Alfetta which used 24 spline 94mm CV’s on both ends, with an overall axle length of 410mm (very close to the R100 axle length of 404mm)? Then replace one end with a CV joint from the Fiat 500L (25 external splines, 24 internal splines). The later 1978-84 2 liters Alfetta’s had a longer overall axle at 453mm (too long). The 94mm CV joints themselves are in stock (albeit made in China?). Currently, only 453mm axle is in stock, the 410mm is not in stock. I believe Alfetta’s were not imported to the USA, so no help over here, don’t about the UK or if any are still around there or have all rusted away long ago?

Hi Nick, VW axles are available in various lengths from Swing-A-Way, EMPI, Summer Brothers Racing, Taylor Race Engineering and others. The 33 splines VW axles sizes from Swing-A-Way can be found here: https://swayaway.com/product/axle-set-33-tooth-vw-irs-16-14-long-33-spline/ and the description is as follows: “Sway-A-Way axles are designed to withstand the most demanding applications. CNC machined from solid aircraft alloy steel, heat treated, and centerless ground for a smooth consistent finish. The end diameter of all axles has been maximized for maximum face contact possible between the axle and CV, minimizing wear. The spline length has been increased by 2 3/8” to allow the CV to float on the axle. The axle diameter is sized to twist like a torsion bar under heavy loads absorbing a large portion of the shock transmitted from the wheel into the gearbox. The axles are marked on the end with an L for left and an R for right. Once installed, they should stay on the correct side. They can be flipped end for end as long as they stay on the correct side. Sway-A-Way IRS axles are available in a wide variety of lengths and fit all Type I, Type II, and Type III CV’s.” If I remember correctly, from one of your previous posts, the Metro R100 left center bar length is 404mm or 15.9 inches? So, would the 16 ¼” axle be in the ballpark? Interesting that they do not use retaining clips and allow the axle to float within the CVs. Would the extra length of the splines solve the plunge length problems? Frank

I am planning a Triumph GT6 “Rotoflex” to CV conversion and have been collecting parts. I have the MGTF rear hubs, bearings and outer CV joints. I prefer the MGTF hubs over the GT6 so I can use the MGTF cartridge style bearing. With the R100 left side driveshafts and the Volvo 340 Lobro joints almost impossible to find, I came up with another possible solution. Knowing that the MGTF hubs have 25 splines, I was looking at other CV axles with the same outer 25 splines. I found that the new Fiat 500 also has 25 splines, and that then lead me to check the Fiat X 1/9. The 1979-1988 Fiat Bertone used an outer stub axle P/N 4311711 that has 25 splines and also has a flange to mount a 100mm CV joint. The X1/9 used P/N: OEM 92 601892 Lobro Joint kit on both the inner and outer locations. That CV joint also has 25 internal spines. But would it not it would be better to use the more common 100mm type 2 VW CV joints with 33 internal splines. The 33 spline center bars for the VW can also be had in multiple lengths in 12mm increments. Perhaps a slight miscalculation on my part is whether the 100mm CV flange on the Fiat stub axle will fit within GT6 or MGTF uprights? Looking at photos of the MGTF bearing installed in the GT6 upright, the bearing appears to be rather deep within the housing? The MGTF bearing appears to be closer to the inside face of the upright. I measured the distance flange to the bearing mounting face to be 25mm. I am hoping that the 25mm is enough to clear the inside face. I do not have the GT6 or MGTF uprights to check for clearance. Does someone on this forum have a MGTF upright that they can measure the distance from the inside bearing face to the inside face of the upright? Using a photo of the MGTF upright and the bearing bore is 68mm I was able to calculate the approximate location of the 100mm flange. Best Regards, Frank Maine

Hi Martin, if your input shaft has a larger diameter (1†x 10 splines) you probably have GT6 gears inside. The bell housing is different, in what way, the GT6 one? Yes, the bell housing is interchangeable. If you used a bell housing from an earlier 3-synchro gearbox you will need to swap out the front cover seal housing for the one in the other bell housing as it uses a proper oil seal. Check the input shaft length, needs to be the same length as the Spitfire input shaft. As for the clutch plate, perhaps you could contact someone like Borg and Beck, they do have a technical support line (or one of their vendors) and ask for the part number for a 6 ½†diameter clutch plate with a 1†x 10 spline center. I believe that the 4-synchro gearbox is also a bit longer than the 3-synchro gearbox so your propshaft may need to be shortened. BTW, the propshaft used in the MG Midget 1500 is same length as the propshaft in the mark 1 EM…..Frank

Hi Martin, What clutch diameter are you using, 6½� When fitting a GT6 gearbox into a Spitfire motor, the input shaft needs to be shorted by 1†if it is not ready. I believe that the clutch plate, with the same diameter but with the correct 1†x 10 spline center, was then sourced from another car. You cannot fit the input shaft from your close ratio 3 synchro Vitesse gearbox into your GT6 box. Both shafts have the same number of teeth, as the ratios are the same, but the gear will not mesh with the GT6 laygear as the helical angle was changed on the GT6 gearbox. The only gear that remained the same from the 1600 Vitesse to the GT6 gearbox was 3rd gear (part no. 132097). The original 1600 Vitesse input shaft (part no. 208820) is also 1†x 10 splines and 1†longer than Spitfire input shaft. Your close ratio Vitesse box has a special input shaft (part no. 211000) with the 208820 gear on one end and the 7/8†x 10 spline Spitfire input shaft on the other…….Frank