Bfg Posted November 3, 2021 Report Share Posted November 3, 2021 Just a quick question regarding the forks on the ends of a prop-shaft (or drive-shaft) into which the UJ bearings fit - I wonder are they typically cast or forged.? Certainly it never used to be uncommon to cut a driveshaft to alter its length when building a special, and the forked ends are welded on, which would imply they are a forging. I ask because a friend with a Triumph Spitfire made a mistake when pressing the old UJ out. He caught the fork in the hydraulic press and bent one fork inwards just a mm or two, so that the circlip will now not fit. He is trying to open the forks up again, using a fine bolt with a nut as a jack, so I pose the question are those forks forged or cast ? If it's cast then it's very unlikely to have moved that much (and back again) without cracking ..even if not readily visible. If it's a forging then it will probably straighten but whether bearing alignment will still be good is another matter. Personally I'd scrap that piece and look for another, but what's your thoughts ? Thanks, Pete Quote Link to post Share on other sites
RobH Posted November 3, 2021 Report Share Posted November 3, 2021 What is he jacking it against? If it's the other ear of the fork he is likely to end up with the whole thing off-axis by a fraction, and so the shaft will rotate slightly eccentrically. Not a good plan I would have thought. Quote Link to post Share on other sites
Paul Parky Posted November 3, 2021 Report Share Posted November 3, 2021 They will be cast steel rather than cast iron. They will have a slight bit of flex to them but not much. Once a yoke is damaged in anyway i would replace it (I work on agricultural and construction equipment). You’ll struggle to align it correctly and it will wear the bearings and prove difficult to reassemble. Quote Link to post Share on other sites
harlequin Posted November 3, 2021 Report Share Posted November 3, 2021 Hi Pete If your friend takes his propshaft along to a propshaft supplier (most big towns have one) they will fit a new yoke and balance the shaft for not a lot of money. George Quote Link to post Share on other sites
Bfg Posted November 4, 2021 Author Report Share Posted November 4, 2021 (edited) Thanks Gents.. On 11/3/2021 at 8:29 PM, harlequin said: Hi Pete If your friend takes his propshaft along to a propshaft supplier (most big towns have one) they will fit a new yoke and balance the shaft for not a lot of money. George I didn't know of that being done ..mind you out here in Suffolk we might not have a propshaft supplier ! Still I'll mention it to him. Cheers, Pete Edited November 4, 2021 by Bfg Quote Link to post Share on other sites
ed_h Posted November 4, 2021 Report Share Posted November 4, 2021 (edited) I used the "jack" method to unbend a yoke arm maybe 2 mm. I was concerned, but didn't seem to have much to lose by trying. After the process, I couldn't measure any difference between the repaired yoke and an undamaged one. UJ went in fine. Ed Edited November 4, 2021 by ed_h Quote Link to post Share on other sites
Lebro Posted November 5, 2021 Report Share Posted November 5, 2021 Nice tool ! Bob Quote Link to post Share on other sites
Z320 Posted November 5, 2021 Report Share Posted November 5, 2021 +1 Quote Link to post Share on other sites
Bfg Posted November 5, 2021 Author Report Share Posted November 5, 2021 Thanks Ed., As Bob says neat tool. My friend with the Spitfire has similarly prised his apart again using a fine thread through and a nut with large washer against the inside of face of each fork. Your locating collars are a nice touch though and easy enough to home-make if one has a lathe. Anyway he tells me that his new UJ bearings are in, and the circlip is sitting securely in its groove. He'll try it and see. Cheers, Pete Quote Link to post Share on other sites
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.