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I learnt an interesting lession when changing the front bronze hub bushes on my KZN130 today and thought I would share it with all you lovely folks. Its a bit wordy but bear with me....
Last year I changed the two bronze bushes in the offside front hub. That was not a painless experience but it went ok.
So, recently I decided to do the other side. All was fine, the old ones came out, the new ones went in but on re-inserting the stub axle it would not push sufficiently far enough through the large, inner bush to seat properly and allow reassembly...
Anyway, I removed the bushes again and sure enough the large bronze bush would not slip onto its normal position on the stub axle. At this point I was convinced the bush was machined very very slightly to small
So, today I started the job again, but thinking ahead tried a brand new large bush on the removed stub axle BEFORE the bush was inserted into the hub. It fitted perfectly.
Inserted the bushes into the hub, then tried to insert the stub axle, and it just would not go - same problem as before. Stripped the bushes again and the large bush no longer fitted in its rightful place on the stub axle
I can only deduce that inserting the bush into the hub forces it to constrict very very slightly.
In the end I used some fine emery paper to enlarge the inside of the large bush very slightly, testing the fit on the removed stub-axle. Then re-inserted the bushes into the hub and this time the stub-axle slid into place with a snug fit. Yipee
To get the bushes into the hub I have been using a length of threaded bar with some large washers and drawing the bushes into place. This works real well and saves damaging them with a hammer.
Last year I changed the two bronze bushes in the offside front hub. That was not a painless experience but it went ok.
So, recently I decided to do the other side. All was fine, the old ones came out, the new ones went in but on re-inserting the stub axle it would not push sufficiently far enough through the large, inner bush to seat properly and allow reassembly...
Anyway, I removed the bushes again and sure enough the large bronze bush would not slip onto its normal position on the stub axle. At this point I was convinced the bush was machined very very slightly to small
So, today I started the job again, but thinking ahead tried a brand new large bush on the removed stub axle BEFORE the bush was inserted into the hub. It fitted perfectly.
Inserted the bushes into the hub, then tried to insert the stub axle, and it just would not go - same problem as before. Stripped the bushes again and the large bush no longer fitted in its rightful place on the stub axle
I can only deduce that inserting the bush into the hub forces it to constrict very very slightly.
In the end I used some fine emery paper to enlarge the inside of the large bush very slightly, testing the fit on the removed stub-axle. Then re-inserted the bushes into the hub and this time the stub-axle slid into place with a snug fit. Yipee
To get the bushes into the hub I have been using a length of threaded bar with some large washers and drawing the bushes into place. This works real well and saves damaging them with a hammer.