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crank - input shaft bronze bush

Posted: Fri Apr 11, 2008 7:48 am
by Ralphh85
the bush which goes inside the crank and locates the gearbox input shaft,

how tight should the input shaft fit in to it? miles got maybe half a mm or so wobble? and its a tight ish fit in the crank, is this how its suposed to be?

by the looks of the input shaft its never had much wear on the end so i wouldnt have thought its very inportant?


Ralph

Posted: Fri Apr 11, 2008 8:30 am
by russell_ram
Ralph,

Sounds about right. There has to be some 'play' to allow for misalignment of crank and gearbox axes as there is no adjustment possible in the Rover bellhousing.

I have new parts at home which I can measure for you later if you like - I'm sure the numbers have been posted on here before though.

Russ

Posted: Fri Apr 11, 2008 9:24 am
by Ralphh85
i think i have descoverd that my gearbox (PG1) is not designed to have a bushing or anything here,

suposidly as engines have been developed better and tollerences made better they dont bother with it anymore, the input shaft does not have a proper bearing surface there anyway just a little spigot thing which locates in to the crank on the k series engine,

i will probly fit a bronze bush but i dont think its really required.

bush is showing 19.15mm /ID and the spigot is 18.77 OD but the bush is a bit worn.

cant hurt to have it there!

Ralph

Posted: Fri Apr 11, 2008 1:20 pm
by Ian Anderson
Ralph

I believe the correct material is Oilite

It is a bit more self lubricating than bronze

Ian

Posted: Fri Apr 11, 2008 2:45 pm
by katanaman
The modern arrangement is generally a roller bearing instead of the bronze bush. As far as I know you will always need a bearing of some sort or the force of the friction plate starting to bite could very easily throw the shaft off centre. If you made the crank tight enough to stop this then you will get wear on the crank which isn't an easy or cheap thing to replace.

Posted: Fri Apr 11, 2008 3:40 pm
by kiwicar
or if your clutch bights unevenly (one side first) it would trie rto regress forcing the end of the input shaft to describe a circle in the opposite direction to that of engine rotation.
Mike

Posted: Fri Apr 11, 2008 4:06 pm
by stevieturbo
Ralphh85 wrote:i think i have descoverd that my gearbox (PG1) is not designed to have a bushing or anything here,


Ralph
Most modern FWD style gearboxes do not locate the input shaft into the crank.

Posted: Fri Apr 11, 2008 11:54 pm
by Ralphh85
ok i have finally had some good info on this,

older rwd style boxes had to have a bush as they had short "first motion" shafts, (input shafts) sometimes with only 1 bearing, so they needed an extra bearing here at the end,

newer FWD style boxes like the PG1 and R65 dont need this as they have a very long input shaft going the hole length of the box, with a bearing at each end, therefore the shaft is alot more firmly fixed, and the do not require a bushing or bearing here.

however im goign to fit a bush just to show that i do have it located properly.


so i should be safe....

cheers for the help tho people!

Ralph

Posted: Fri Apr 11, 2008 11:57 pm
by stevieturbo
But there is no spigot on a PG1 gearbox for anything to locate into a bush ???

Posted: Sat Apr 12, 2008 6:33 pm
by Ralphh85
stevieturbo wrote:But there is no spigot on a PG1 gearbox for anything to locate into a bush ???

there is a bit sticking out which is ment to locate in to the crank, tho its not a bearing surface by any stretch, it will do fine to locate it correctly tho!


Ralph