21 replies to this topic

[AP2020]

 

using a lathe for this type of bush is not the way to go,..

 

It should be honed, as honing is far more accurate and is far better at producing round holes than a lathe ever will. but also creates a cross hatch pattern that is much better at oil retention, there will always be a little oil escaping between the tail and bush.

 

The larger the clearance the more oil that can escape, so too loose and you get oil leakage, too tight and you get seizing and resultant damage. 

The new old stock gear I used didn't appear to have any honing markings on it.

 

Honing can be from quite course to very fine ie a diamond polish finish with no marks to the naked eye, I usually rough them up a little on a honing machine and use a lithium grease the grease stops them from overheating on startup then polishes up to a smoother surface which then reduces friction and any further issues are eliminated

 

but looking at yours the front bush looks like its a different material, higher copper content, which would also be softer and more prone to damage from load and or heat. 

[Spider]

 

 

using a lathe for this type of bush is not the way to go,..

 

It should be honed, as honing is far more accurate and is far better at producing round holes than a lathe ever will. but also creates a cross hatch pattern that is much better at oil retention, there will always be a little oil escaping between the tail and bush.

 

The larger the clearance the more oil that can escape, so too loose and you get oil leakage, too tight and you get seizing and resultant damage. 

The new old stock gear I used didn't appear to have any honing markings on it.

 

Honing can be from quite course to very fine ie a diamond polish finish with no marks to the naked eye, I usually rough them up a little on a honing machine and use a lithium grease the grease stops them from overheating on startup then polishes up to a smoother surface which then reduces friction and any further issues are eliminated

 

but looking at yours the front bush looks like its a different material, higher copper content, which would also be softer and more prone to damage from load and or heat. 

 

 

The factory recommend Machining and when I worked in a Leyland Approved Workshop, that was also what they asked we do.

The Back Bush is Deva material. It's a special proprietary alloy of Bronze and Graphite. It's what every Mini left the factory with from 1963 to 2000.

[unburntfuelinthemorning]

Ah so only the rear bush is Deva.  Interesting to see that the Deva bush in mine is still in perfect condition even though the clearance was too tight whereas the front bush couldn't cope.

[Spider]

Ah so only the rear bush is Deva.  Interesting to see that the Deva bush in mine is still in perfect condition even though the clearance was too tight whereas the front bush couldn't cope.

 

Luckily for you, it wasn't the new age bushes you had in there or you'd also be looking for a crank too.

 

[AP2020]

 

 

 

using a lathe for this type of bush is not the way to go,..

 

It should be honed, as honing is far more accurate and is far better at producing round holes than a lathe ever will. but also creates a cross hatch pattern that is much better at oil retention, there will always be a little oil escaping between the tail and bush.

 

The larger the clearance the more oil that can escape, so too loose and you get oil leakage, too tight and you get seizing and resultant damage. 

The new old stock gear I used didn't appear to have any honing markings on it.

 

Honing can be from quite course to very fine ie a diamond polish finish with no marks to the naked eye, I usually rough them up a little on a honing machine and use a lithium grease the grease stops them from overheating on startup then polishes up to a smoother surface which then reduces friction and any further issues are eliminated

 

but looking at yours the front bush looks like its a different material, higher copper content, which would also be softer and more prone to damage from load and or heat. 

 

 

The factory recommend Machining and when I worked in a Leyland Approved Workshop, that was also what they asked we do.

The Back Bush is Deva material. It's a special proprietary alloy of Bronze and Graphite. It's what every Mini left the factory with from 1963 to 2000.

 

 

That's correct, honing IS machining ! :)

[mini13]

I thought Honing a bearing was a bad idea due to it being embeddable.

[AP2020]

I thought Honing a bearing was a bad idea due to it being embeddable.

 

No that's only when you use standard type stones, but there are so many different materials that don't embed that its not an issue.... as long as you actually use the correct stones that is .  Unfortunately there are a lot of people that don't know but think they do.