Jumping in with both feet

[gump65]

Hello all!

Recently new here on SS with my first purchase and have started into a remove and replacement of the genhead on an 803A- it was known to be bad at time of purchase.
LID supplied me with all of the parts I need to be successful in my work - Shout out to LID!

I have been documenting my progress with pictures which for most would be routine. When I came across the failed drive disc, this I thought some might find interest in. During running operation it was noted that sparks were being produced from the area around the starter. Thinking others could use this as a history note for diagnosis on similarly troubles gens.
With the outer stator removed the rotor is very unstable where it is fixed to the drive disc.

Will add more pics as I get the Rotor assembly clear.

Andrew

 

[Guyfang]

Excellent! Thats what this Forum is all about. This is a rare failure. But when you have the main gen apart, should always be checked for.

 

[jamawieb]

Very interesting, I have never seen that before.

 

[pclausen]

Wonder if there was/is some sort of imbalance issue? Would probably be a really good idea to replace the rotor bearing as well. That drive disc is pretty stout, so I'm very surprised to see it fail like that. How many hours on that set?

 

[Light in the Dark]

Glad to assist in helping you dive into the MEP world Andrew. I am also glad you are documenting this repair for future folks looking to do the same. @kloppk was kind enough to help me diagnose this set in person, before it took a drive to Oro-Medonte. I have no doubts your low hour machine will be making power before you know it.

 

[Light in the Dark]

Wonder if there was/is some sort of imbalance issue? Would probably be a really good idea to replace the rotor bearing as well. That drive disc is pretty stout, so I'm very surprised to see it fail like that. How many hours on that set?

He got a NIB 10K genhead with his machine. Under 100 original hours.

 

[Ray70]

Only other thing I could imagine is if the generator was not assembled correctly originally, like if the endcap and stator or stator and bellhousing weren't interlocked correctly ( where you have the lip that centers the stator ) causing everything to sit crooked ?

 

[Guyfang]

I was told by a good friend that very early in the program, the flex plate would sometimes crack. It was indeed the bearing. Onan went to another bearing and the problem was more or less solved. It raised its head very seldom after that. I saw it a grand total of twice.

 

[gump65]

I will compare bearing cat #'s on the 2 rotor assemblies that I have. Hopefully they are a different number.
Guyfang, any idea of the replacement bearing number? Where would I search to get such a number?.......

 

[Guyfang]

Well, we ordered from the -24 parts TM.
TM 9-6115-642-24P
Figure 24
Item # 20
Part number 510-112
NSN 3110-01-160-9663

What is written on your bearing?

 

[gump65]

Ok, there was more then a minor crack in the drive disk.....

.

Guy, the info you listed in the -24P TM is perfect. I am hoping to take the bearings into a local Bearing supplier and source an equivalent there. As long as they aren't proprietary, things should work out.

I am hoping the back side of the bearing will have ledgible info as the exposed side numbers have rusted beyond what I can read. I've chalked them, rubbed them with paint ( removing the excess paint ), a black sharpie will sometimes raise the numbers when the excess is removed but also no luck.

I can only make out the identifiers on the 2 Bearing seals which are an SKF product. #06 119 and #06 186


Question regarding Torque values
I've been looking for the values for the rotor to drive plate and drive plate to flywheel bolts. No luck yet.
I found values in TM 253-24 Appendix E, pg 103 for flywheel to crankshaft.

 

[gump65]

Only other thing I could imagine is if the generator was not assembled correctly originally, like if the endcap and stator or stator and bellhousing weren't interlocked correctly ( where you have the lip that centers the stator ) causing everything to sit crooked ?

I did have in mind what you suggested but all seemed to be seated as they should when removed. In preperation for reassembly I have wired wheeled all mating surfaces to remove any spots that might give me some grief.

 

[G744]

I've seen that same type of genset failure, caused by the armature pressing on the flex plate too hard.

It was the improper longitudinal location of the support bearing.

DG

 

[gump65]

I've seen that same type of genset failure, caused by the armature pressing on the flex plate too hard.

It was the improper longitudinal location of the support bearing.

DG

I've seen that same type of genset failure, caused by the armature pressing on the flex plate too hard.

It was the improper longitudinal location of the support bearing.

DG

Thanks DG for the information. Will certainly find out about how to ensure the support bearing is located correctly to a longitudinal dimension.

 

[DieselAddict]

Ok, there was more then a minor crack in the drive disk.....

.View attachment 862414View attachment 862421

A little MIG wire will fix that right up!

 

[gump65]

A little MIG wire will fix that right up!

Lucky my MIG is out of wire....

 

[gump65]

Moving on,
Found the torque numbers for the Flywheel
TM 9-2815-253-24, Table E-1, Flywheel Bolts 50.1,51.3, 52.5

Haven't found the torque values for drive plate to flywheel and rotor to drive plate numbers. Is anyone able to point me in the right direction?

In the end I won the battle with removal of the fuel/water separator from the mounting bracket. Made a primitive rope wrench. Pic below
Used a 2' pry and she did not want to give up being seated there!!!!

Next item. Having replaced flywheel, I want to ensure clearence between Rotational Transducer and Flywheel is set or at least checked. Imagine somewhere around >.010" would work? I haven't adjusted yet it since replacing Flywheel and it just looks tooooo close. Again haven't found the correct chart for these sorts of numbers and probably just not looking in the right spot....
TM 9-6115-642-24P page 34 Motional Transducer Assembly




If I should start a new thread, I will copy this post to a new one.

As always thanks for any and all help!