11 replies to this topic

[suuper]

hi, i am andreas from the south of germany and need advice. I have build an 1089 engine according keith calvers instructed in the minimagazine 2011. everthing is fine - the engine runs well with a good punch.

after 430 miles the cluth fails. the reason for that is a disturbed primary gear bush. my suspicion for that is a too small radial clearance. i have not checked the clearance because i have bought it from the same dealer who's done the crank - ready to fit.

so my request is: can anyone confirm my position or is my thinking wrong? i will attach files.

thanks for advice - cheers andreas

Attached Files

•  IMG_3694.JPG   46.1K   7 downloads
•  IMG_3695.JPG   49.41K   9 downloads

[Spider]

I'm guessing it also made a mess of the crank tail too?

 

I'm also guessing that it's not an original gear either?  The Front Thrust Face (the gear end) looks very poorly finished as manufactured.

 

The bushes in these are not made from the correct material and what you have experienced is not uncommon with these.

 

If you do a search on the forum, you'll find other similar ones.

 

There are still NOS Leyland Boxed originals still available for the small bore engines, I'd suggest getting a hold of one of these.

[suuper]

the crank has survived.

you are right - the primary gear is not original. bad quality!? - i have had the same problem with the first headbolts. made from butter!
ok - i have an original out of an 998 - i will look for measure tools and have a look if it fits.

if not i will go for an original. thanks a lot - cheers andreas

to get sure: clearance is the beginning of my problem?! i have some doubts cause the collar of the bush is gone also.

[Spider]

Yes the flange of the rear bush has gone too !!

 

No, not a clearance issue, just the wrong bushing material.

 

<EDIT: The Radial Clearance is 0.003 to 0.0045" and the End Float should be 0.0035 to 0.0065" >

Edited by Moke Spider, 26 August 2017 - 08:38 PM.

[Spider]

You'll find a few more like yours here;-

 

http://www.theminifo...ry-gear-damage/

[suuper]

only the material - so every of these bushes fails after starting the engine.

thats poor! thanks once more for your good advice. i looked with open mouth on the bush and dont want to fix it without having a reason for failure.

cheers andreas

[ACDodd]

I have used a couple of these aftermarket new gears and in each case the bushes are supplied undersized, the last I remember were sized at 1.501". They all need to be opened up to give a running clearance of 0.004" for the applications they were being used in.

All are still in service.

Ac

[suuper]

that make sense - less clearance open the issue - poor quality finish the job. thanks for sharing experience!

[Spider]

only the material - so every of these bushes fails after starting the engine.
 

 

Every one I've seen has failed, and that is well over 30 now,,,,,

 

Some guys have tried fitting them up with Grease and these do go longer, but it only puts off the inevitable.

[suuper]

i have mount my 998 primary gear looking for endflow - with an 0.112" washer there is massively 26 thou endflow. this means i would need a 0.132" washer.

cant find a 0.132" - does not exist!? - so i have to look for another primary gear.

[Spider]

How's the C Clip on the Crank?

They often get bashed about.

[suuper]

the c clip is straight, no wear, and without slack in the notch. the notch is fine also.

do you think about the big endflow? the 998 primary gear is A Series, the 1098 crank A+