larryowner Posted October 6, 2019 Share Posted October 6, 2019 Wanting to fit a double cardan prop to the rear of my D1 based RTV trialer. The phasing of flanges on T/box and diffs is not right any more, at the front I have fitted standard D2 front prop and larger T/box flange. But the rear is not so strait forward, changing to the larger flange would require machining of the hand brake drum etc. So apart from spending around £500. with Gwyn Lewis, is there another way. I see a lot on the forum about front props and double cardan joints but can't find much on rear's. Although for trialing the set up fine I drive to events some times, but vibration between drive and over run above 30mph is worrying. Quote Link to comment Share on other sites More sharing options...
lo-fi Posted October 6, 2019 Share Posted October 6, 2019 Get an adaptor plate made up? Think wheel spacer... I reckon 1/2 - 3/4" thick should do it. It's simple enough, and could easily be made in a home shop if you have access to a lathe and pillar drill, or would be a cheap job at any local engineering firm for cash. Quote Link to comment Share on other sites More sharing options...
miketomcat Posted October 6, 2019 Share Posted October 6, 2019 I had a double carden front prop on the rear of my tomcat. From memory I re-machined the disco front flange to fit inside a td5 hand brake. I re-phased the prop by pulling the end out and re-fitting in a different spline position. Mike Quote Link to comment Share on other sites More sharing options...
Daan Posted October 10, 2019 Share Posted October 10, 2019 Are you sure a rear double cardan prop will solve your problems? a picture of rear prop angles would be good. 1 Quote Link to comment Share on other sites More sharing options...
larryowner Posted October 10, 2019 Author Share Posted October 10, 2019 As suggested I think the adaptor plate would be the easiest way. On the original donor vehicle the transfer box flange was facing down app 6 degrees and the diff flange up the same amount, so in phase, no vibe's. However the T/box flange is now vertical and so out of phase with diff flange. All 90's and Disco's are out of phase on the front prop, but can be improved by fitting a double cardan to the shaft, which i have done. So want to try same on the rear. Quote Link to comment Share on other sites More sharing options...
hurbie Posted October 10, 2019 Share Posted October 10, 2019 (edited) my 110 is out off phase on the front axle , you have to clock the driveshaft for being out off phase (there are 2 arrows on the driveshaft that need to align, i think there's 45 degrees between flanges) you can do the same with your rear drive shaft . undo the rear drive shaft , pull out the flange and put it back 1 spline apart from what it was , do a testdrive and adjust further if need be, i bet that solves the problem . see this old posting : Edited October 10, 2019 by hurbie Quote Link to comment Share on other sites More sharing options...
miketomcat Posted October 10, 2019 Share Posted October 10, 2019 On my tomcat with a standard prop on the rear I used to get vibration on over run. My tomcat had the engine shifted back 10 inches, enough to swap front and rear props on a 100 inch wheel base. When I built it I re-phased the the rear prop to suit the front location and vice versa. I fitted a front double carden prop on the rear (re-phased to suit rear location) this solved the vibration. Mike Quote Link to comment Share on other sites More sharing options...
larryowner Posted October 22, 2019 Author Share Posted October 22, 2019 Update. I tried turning the rear prop one spline at a time as suggested by Hurbie, but made no noticeable difference to vibration, thanks for your idea though. So decided to purchase a ready made shaft. Dunning + Fairbank made me a double cardan shaft with standard L/R flange sizes, fitted it today and happy days, all vibe's and strange noises gone. 1 Quote Link to comment Share on other sites More sharing options...
Carloz Posted October 27, 2019 Share Posted October 27, 2019 Strange... I see quite a big angle at the UJ at diff side... About the same angle as on the transfer box. I would expect that this situation would cause vibrations... 🤔 1 Quote Link to comment Share on other sites More sharing options...
cackshifter Posted October 31, 2019 Share Posted October 31, 2019 Mmm a useful company to know of, thanks for mentioning them Quote Link to comment Share on other sites More sharing options...
tuko Posted November 1, 2019 Share Posted November 1, 2019 @larryowner How long is your rear propshaft? I have an 88" hybrid which has vibrations/horrible noises on overrun but my rear prop is very short so I thought it might be too short for a double joint. Quote Link to comment Share on other sites More sharing options...
larryowner Posted November 1, 2019 Author Share Posted November 1, 2019 Tuko, on level ground the rear prop is 580mm long, and has 50mm movement either side of that as the slip joint is around 100mm long. Quote Link to comment Share on other sites More sharing options...
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