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Propshaft question

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texaxile

Original Poster:

1,540 posts

72 months

Friday 4th August
quotequote all
Hi,
I'm in the process of rebuilding my prop, however the UJ's are worn out and need replacing. The UJ's are NLA from Mitsubishi so I've taken one to a local bearing company who have measured it up and can provide one of the same size, however the casting itself is slightly thicker (in the middle of the UJ) and it weighs a few grams more than the original.

Would I need the prop rebalanced when I replace the UJ's?. I've marked the prop up prior to taking it to bits so it goes back together in the correct way (yokes and castings aligned) but am unsure as to whether it would need a rebalance. Common sense is telling me that if I add or reduce weight then it might be a good idea, just need someone to confirm or deny, that's all.

TIA Pete


GreenV8S

24,739 posts

206 months

Friday 4th August
quotequote all
I've never done a change like that, but armchair theory suggests that it won't be necessary to rebalance. The component you're changing is on the center line of the shaft and close to one end. Even if the weight of the component has changed, it's very likely that either the old or new ones had a CoG far enough off center for that small change in mass to affect the balance of the whole shaft.

stevieturbo

12,647 posts

169 months

Friday 4th August
quotequote all
Swapping UJ's should not affect balance.

texaxile

Original Poster:

1,540 posts

72 months

Friday 4th August
quotequote all
Thanks guys, that's saved me a job and bit of money at least. I owe you both a pint.