15 replies to this topic

[wmkccwhite]

Hello all.. i am trying to figure the end float measure ment on my mini. Can anyone tell me is .026 thousandths the same as .660mm?
Thanks and sorry for being.....slow

[MRA]

Hi,

I can confirm that 0.026" is NOT 0.660mm...................... it is 0.6604mm

0.026" x 25.4 = 0.6604mm

Regards Martin

[wmkccwhite]

Hi,

I can confirm that 0.026" is NOT 0.660mm...................... it is 0.6604mm

0.026" x 25.4 = 0.6604mm

Regards Martin

Thanks... i am trying to figure out this feeler gauge. maybe you can shed some light and educate me on it. Here is a Pic.......

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[wmkccwhite]

Just thought of this....are the primary gear end float measurements different on a metro 1275 than on a Mini engine?

[bmcecosse]

Nope - same. 1mm = 40 thou (near enough) if that helps any!

[bmcecosse]

What end float are you trying to measure anyway - because 26 thou sounds a LOT!

[wmkccwhite]

What end float are you trying to measure anyway - because 26 thou sounds a LOT!

its the primary gear end float...and i found out that its not .026 thous....its .026" i know its a lot now... dont even know how my Mini was running....

Edited by wmkccwhite, 26 June 2009 - 09:33 AM.

[GraemeC]

As the feeler guage is only printed to 3 decimal places you can assume that .026" and .660mm are essentially the same in this instance. Technically there is a slight difference as Martin pointed out.

[wmkccwhite]

ok i used the two feeler gauge method and tried the measurement again.. it got alittle closer... its now reading .023" any suggestions on which thrust washer to get to bring this into tolerance?

[GraemeC]

There are a few parts that can wear and give large endfloat on the primary gear - the top hat bush, the thrust ring, the c-washer and the c-washer backing ring. But 0.023" or 23 thou(sands of an inch) does still seem a lot!

I would start by putting in a new C-washer and backing ring, as you only have one size choice here. and see how that affected the end float. To confidently change the thrust ring you will ideally need a micrometer to measure what you presently have.

[wmkccwhite]

There are a few parts that can wear and give large endfloat on the primary gear - the top hat bush, the thrust ring, the c-washer and the c-washer backing ring. But 0.023" or 23 thou(sands of an inch) does still seem a lot!

I would start by putting in a new C-washer and backing ring, as you only have one size choice here. and see how that affected the end float. To confidently change the thrust ring you will ideally need a micrometer to measure what you presently have.

Thanks for the advise... i have pulled the C-washer and backing ring off and they do look worn. I am going to replace them and go from there.

[Cooperman]

The C-washer doesn't wear as it has no movement against it.
The main source of wear is the phosphor-bronze inner thrust ring. These come in several different sizes. What you do is measure the end float, then measure the thickness of the inner thrust washer. Work out how much thicker the inner thrust ring needs to be and order the nearest slightly lower size from the list (see Mini Spares on-line catalogue). Note that the 1275 engines have a different diameter ring from the 998's
26 thou (0.026") is one hell of a lot of end float for the primary gear. It needs to be between 0.001 (one thou) and 0.006 (6 thou).

[bmcecosse]

Yep - something seriously wrong if it really IS 26 thou!! That's not just normal wear - which would be one of two thou at worst.

[wmkccwhite]

The C-washer doesn't wear as it has no movement against it.
The main source of wear is the phosphor-bronze inner thrust ring. These come in several different sizes. What you do is measure the end float, then measure the thickness of the inner thrust washer. Work out how much thicker the inner thrust ring needs to be and order the nearest slightly lower size from the list (see Mini Spares on-line catalogue). Note that the 1275 engines have a different diameter ring from the 998's
26 thou (0.026") is one hell of a lot of end float for the primary gear. It needs to be between 0.001 (one thou) and 0.006 (6 thou).

Well turns out that it was mainly the C-washer.... it had worn in the past and someone turned it around and then it wore on the other side. I purchased a new C-washer and clip and it improved the tolerance quite abit. I took the old clip with me when i got the new one and the Guys there said they had never seen one worn like that before. Just goes to show the only Mechanic i can trust is me and a select few others. So long story short... the C-clip and back ring do wear as well as the thrust bearing. Now we all know.... Thanks for the advise and help everyone!!

Edited by wmkccwhite, 26 June 2009 - 04:21 PM.

[wmkccwhite]

Yep - something seriously wrong if it really IS 26 thou!! That's not just normal wear - which would be one of two thou at worst.

bmceccosse... i got it sorted out thanks for the help though..... I see you are into Steam Locos.... I am also into them.. I have a 16MM steam loco i run a lot locally. Nice to see someone else has an interest in Rail Roads