Drive Train Noise - Kato F7

[BCR751]

I have a Kato F7 that has terrible drive train noise, sorta like a coffee grinder.  It seems to coincide with the main gear teeth hitting the worm gear.  I'm not sure of the vintage of this unit.  It's the one that has the entire chassis as its weight.  I seem to remember one solution was to remove the inner of the two bearing blocks on each end but these won't budge from the shaft.  I know this issue has been mentioned before on TRW but I don't believe it pertained to the Kato F's.  I searched the archives but I can't seem to locate it.  Any help is much appreciated.

Doug

[Missaberoad]

I have a Kato F7 that has terrible drive train noise, sorta like a coffee grinder.  It seems to coincide with the main gear teeth hitting the worm gear.  I'm not sure of the vintage of this unit.  It's the one that has the entire chassis as its weight.  I seem to remember one solution was to remove the inner of the two bearing blocks on each end but these won't budge from the shaft.  I know this issue has been mentioned before on TRW but I don't believe it pertained to the Kato F's.  I searched the archives but I can't seem to locate it.  Any help is much appreciated.

Doug

Does it have the brass axle cup pickups or the inside bearings? Blue box or Green?

The early Kato F's were terrible coffee grinders, replacing the trucks with the new "low friction" design helped immensely.

[peteski]

Photos of the parts in question would be helpful.

[u18b]

If the box has a blue label, you need to beardenize it by removing the inner bearing blocks from the worms. 
Makes an astounding difference.

[Point353]

http://u18b.com/wp-content/uploads/2013/03/Bearingblock.pdf

[BCR751]

If the box has a blue label, you need to beardenize it by removing the inner bearing blocks from the worms. 
Makes an astounding difference.

I tried that but the bearings won't come off the shaft.

Attached is a photo of what I have.  The trucks toward the top of the photo are the ones that came with the unit.  They made the ride height way too high and one side was higher than the other on one of them causing the unit to list to the right.  I also removed the rapido couplers in favor of body, or should I say, chassis mounting MTL 1015's.  I replaced those trucks with the 'revised' version, the set toward the bottom of the photo.  This brought the ride height down to an acceptable level plus they had no couplers attached.

However, this truck change did nothing to eliminate or reduce the noise.  As I mentioned, I searched TRW and did find the "beardenizing" fix for four-axel trucks but I am not able to remove the inner bearing block.  As can be seen in the photo, they do have the brass cups inside.  I don't know what this means as far as the noise is concerned but if it has any effect, I'd like to know.

Doug

p.s.  The paper insert inside the box is blue.

[mu26aeh]

You can't remove the black piece that goes into the flywheel ?  I had a couple I had to remove that piece to get the inner block out, it took some firm persuasion but they did come off.

[BCR751]

You can't remove the black piece that goes into the flywheel ?  I had a couple I had to remove that piece to get the inner block out, it took some firm persuasion but they did come off.

I'm never sure how to go about that sort of thing.  One wrong move and the whole thing breaks.   I don't have a proper puller either. 

Doug

[mu26aeh]

I'm never sure how to go about that sort of thing.  One wrong move and the whole thing breaks.   I don't have a proper puller either. 

Doug

Neither do I.  I just placed the worm between my finger and thumb, and pair of pliers on the black piece and twisted.  If it's like one I did, it should just be press fit onto the shaft

[u18b]

That u joint can crack.

But I get them off with my fingernails.
Pull and twist slightly.  It will come off.

Remove the inner bearing and put the joint back on.

Be sure and tune it like I described in the PDF linked to above on my website.

Yours has the old drive with the new low friction trucks.
When adjusted properly, you will be absolutely astounded at how quiet it runs.

[BCR751]

That u joint can crack.

But I get them off with my fingernails.
Pull and twist slightly.  It will come one.

Remove the inner bearing and put the joint back on.

Be sure and tune it like I described in the PDF linked to above on my website.

Yours has the old drive with the new low friction trucks.
When adjusted properly, you will be absolutely astounded at how quiet it runs.

Okie Dokie, Ron.  I'll give that a shot tomorrow.  I hope it's as simple as you say 

Doug

[peteski]

I'm confused here.  How can the new trucks be compatible and also exact-fit with the old chassis?

The old trucks (with die-cast inner frames and black sideframes) in the old chassis conduct electricity in the area that the truck pivots on (in the center).
New trucks (silver) have metal tabs which are part of the sideframe. The pivot is plastic.  Those metal tabs are designed to contact flexible pickup strips attached to the chassis.  But the old chassis doe not have those flexible pickup strips. Even if the tricks fit and swivel freely, then will ride really hard and will not have any lateral play.

I suspect that the grinding noise is caused by the worm gear meshing too deeply with the worm. The worms seem to be larger diameter than the standard Kato worms used on most locos. Is it possible that both types of trucks are incorrect for that loco?  Doug, did you own that loco since new, or you bought it second-hand?

Another grinding noise suspect could be the universal coupling.

While I own both the original and the latest versions of Kato F units, but I haven't looked at the mechanisms for several years, so take my analysis with a grain of salt. 

[Missaberoad]

I'm confused here.  How can the new trucks be compatible and also exact-fit with the old chassis?

The old trucks (with die-cast inner frames and black sideframes) in the old chassis conduct electricity in the area that the truck pivots on (in the center).
New trucks (silver) have metal tabs which are part of the sideframe. The pivot is plastic.  Those metal tabs are designed to contact flexible pickup strips attached to the chassis.  But the old chassis doe not have those flexible pickup strips. Even if the tricks fit and swivel freely, then will ride really hard and will not have any lateral play.

I suspect that the grinding noise is caused by the worm gear meshing too deeply with the worm. The worms seem to be larger diameter than the standard Kato worms used on most locos. Is it possible that both types of trucks are incorrect for that loco?  Doug, did you own that loco since new, or you bought it second-hand?

Another grinding noise suspect could be the universal coupling.

While I own both the original and the latest versions of Kato F units, but I haven't looked at the mechanisms for several years, so take my analysis with a grain of salt. 

I've replaced original run trucks with newer low friction F unit trucks without issue. In fact in those cases that was all that was required to eliminate most of the "coffee grinder" noise...

Also Pre DCC low friction F units did not have frame mounted brass strips for pickup... The brass tabs on the sideframe had a 90 degree bend and contacted the frame directly.

I'm not sure if the latest DCC friendly runs use a different method or not...

[OldEastRR]

There were 3 different kinds of F unit trucks remember. All constructed differently.

[peteski]

I've replaced original run trucks with newer low friction F unit trucks without issue. In fact in those cases that was all that was required to eliminate most of the "coffee grinder" noise...

Also Pre DCC low friction F units did not have frame mounted brass strips for pickup... The brass tabs on the sideframe had a 90 degree bend and contacted the frame directly.

I'm not sure if the latest DCC friendly runs use a different method or not...

Sounds like I only have the 1st and 3rd releases.  It would be interesting to see what Doug's chassis looks like on the bottom. Especially since he mentioned that the ride height changed after swapping trucks.