Are these models prone to pinion squealing and is there a preferred solution?
I purchased a SD7 and a SD9 new in box recently from to separate sellers on ebay. They appear to have never been used. I tore them down, cleaned out the old grease and cleaned the green gunk off of the pinion bearings. I greased the gears with Atlas grease and oiled the pinion bearings and motor bearings with Atlas bearing oil.
After reassembly they test ran fine. I ran them at various speeds and low to moderate load a few times. Last night I attempted to speed match them and the SD7 started squealing. I tore it down and oiled and greased it again. No more noise. Tonight the SD9 is squealing.
Before I tear it down is there something I am doing wrong or should do different? I feel like I put more than enough oil and grease on the bearings and gears.
Chris
Try a small amount of oil on the bearing where the shaft exits the motor on both ends.
If you've applied "more than enough" lube in the trucks, it's too much and will cause more trouble down the road. Clean it out now while you have thing tore apart. Excess lube can leach out onto the axles over time and cause contact issues (most oils act like an insulator).
Mark.
¡ uʍop ǝpısdn sı ǝɹnʇɐuƃıs ʎɯ 'dlǝɥ
What is "pinion squealing"? What are "pinion bearings"?
Ed
I've had a few Life-Like "squeakers" over the years. In my case I traced the sound to the motor brushes.
I carefully removed the brushes, cleaned the armature with a pipe cleaner and alcohol then reinserted the brushes after rotating them 180 and slightly roughing up the curved surfaces with very fine crocus cloth. Then I slightly reduced the spring tension on the brush holders.
That Cured the problem, for me. It seemed to occur as the train was descending a grade or the locos were otherwise "coasting". Check to be sure the thrust bearings are "snug" enough, too. It helps to limit the axial force on the worm shafts.
Some of the early Proto Geeps had worm shaft bearings that were made of a poor alloy. Athearn uses a similar square bearing (some of the later Athearn bearings have a smaller bore) and the quality of the bronze alloy is much better.
I'm not sure if the 40052 is the exact replacement but it might be worth a try. The SD7 and 9 trucks were Kato clones and some may have used different bearings, though.
Good Luck, Ed
I had an old LL GP-9 "squealer" that stopped squealing when I replaced the axle gears - the old "broken gear" problem usually causes a thump-thump but can squeal too, apparently due to the axle turning and the gear not.
I would like to thank everyone for the replies and I will added some comments.
I believe the sound is coming from the worm gear bearings. With the shell off I am able to locate the sound as coming from one of the worm gears/bearings while moving forward and the other one when moving in reverse. When the sound starts the speed drops and when it stops the speed increases. The sound is more of a screach and less of a squeak. After tearing one of the models down, cleaning the worm bearings and relubing the sound went away. We will see how long it last this time.
There may be something to the poor quality bearing comment. I will see if the Athearn replacements fit. I will also try some of the Lebell oil next. The Atlas oil seems to dry sticky on the bottle so maybe a different oil is in order.
Hello All,
I will admit I have no experience with LL Proto 2000 locomotives.
However, I have do have extensive experience with Bachmann diesel locomotives with cracked couplings between the worm gears and the "dog-bone" drive shafts- -hex couplings.
When these couplings fail there is a sharp whine/grinding noise along with a loss in power, especially on curves.
Other than replacing the worm gear assembly with OEM parts, I have successfully used A-Line components: Female Worm Couplings (#12033) along with the Brass Sleeves 2mm ID x 3/32 OD (#12053) adapters.
An easy way to check if the coupler has failed is to remove the shell. Then hold one worm gear static and try to rotate the flywheel.
If the flywheel rotates the worm gear coupling is cracked. If the flywheel doesn't rotate, and there is significant resistance against the worm gear assembly you need to look elsewhere in the drive train for the noise.
Good luck, and...
Hope this helps.
"Uhh...I didn’t know it was 'impossible' I just made it work...sorry"
LastspikemikeThose little bronze blocks are just journal bearings as far as I can tell, the shaft just runs on the smooth bore of the inside of the block.
While quite true, I have noticed that some of the bearings used by Life-Like have more of a silver a color while the Athearn-sourced bearings are closer to a gold color. That might indicate a different alloy of tin or antimony to brass or bronze.
They both seem to be a sintered "Oilite" type material but the Life-Like ones are certainly more prone to squealing due to the lack of retaining the lube OR the higher "tin" content increasing friction.
Proto_gear-6 by Edmund, on Flickr
For a couple bucks, get a package of the Athearn ones and see if it helps.
A note on the wheelsets Alyth linked to: those are for the early E units with the "floating" journal box. The gear is not the same as on the Proto Geeps, either.
The Es are 11 tooth and the other, common to geeps, FAs, BL2s etc, is 12.
I have links to the Athearn bearing part in both my replies.
Hi,
bronze worm shaft were cause of excessive noise in my Athearn Genesis F7/FP7 (5 locomotives in total) and two LL E9. I would not describe it as "screeching", more as "rattling" noise - so this maybe is not the same issue as OP presented. The reason was simple, but not easy to find - there is too much play in the bearing, i.e. the bore in bearing is too big for worm shaft. This is easy to check - if bearing is held with tweezers, it can be "wobbled" left/right while on shaft - which is not good. In all my Roco locomotives, from 1981 until present day, worm shaft bearing can just freely rotate on shaft, but it is not possible to wobble it right or left while on shaft - there is practically no play there. When motor rotates with 10000 - 15000 rpm, it is not possible to avoid vibrations and related sound effects. I noticed it from time to time on one locomotive, then on another. Oiling the bearings helped a bit, but just temporarily.
I tried even inserting thin sleeve (made from thin brass shet) between shaft and bearing, but permanent solution that completely removed any vibrations and noise was making new bearings from brass rod (the whole LL E9 overhaul project I presented in discussion "Life Like E9 with new motors, ESU Loksound decoders and lights"). It is not easy to find someone to do that, because this requires proper machinery and knowledge, because this is precise work.
To check if worm shaft bearings are causing most of the noise (the rest is coming from motor and gears), a tower gear needs to be removed. Then, start a motor to rotate the worm inside a truck, and if noise is heard, just touch worm shaft with a toothpick while rotating. If noise dissapears, then bearing is the cause. Also, when touching worm shaft while rotating with a toothpick, a vibrations are easy to feel.
Below is picture of new shaft bearings.
Regards,
Hrvoje
IIRC, those early edition LL SD7s and 9s had worm gear bearings that were slightly too small (short, height-wise) to properly secure the worm gear when the worm cover was snapped into place. The result was the worm would float a bit and make different sounds. A squeal is possible.
The solution was to CA a strip of styrene to the top (or bottom) of the bronze bearing, thereby allowing the worm cover to keep the bearing properly seated.
I don't recall the dimensional thickness of the styrene recommended. I did this and it quieted down the worm assembly.
- Douglas
The bearings are definitely more silver looking than ones I've seen in Athearn and Atlas models. I ordered Athearn replacements along with light and medium Label oil.
I will check to see if the bearings are able to move around while snapped in. I will say there is no wabble in them. They fit in the shaft as I would expect.
cscannon222 The bearings are definitely more silver looking than ones I've seen in Athearn and Atlas models. I ordered Athearn replacements along with light and medium Label oil. I will check to see if the bearings are able to move around while snapped in. I will say there is no wabble in them. They fit in the shaft as I would expect. Chris
It kinda hard to check to see if the block-o-bronze is seated when the cover is snapped into place. How can you tell?
The problem still could be what I described above. The hole is the right size, but the bearing itself is too small for the pocket it fits into, allowing it to swim.
If the new bearings from Athearn don't work, they don't fit the shaft, try making the existing bearings bigger by adding the styrene as suggested.
I don't see any indication in the thread that the bores are too small, only the external dimensions and hence the locking of the blocks in position. There is relatively high force trying to displace the worm, and small depthing change on the worm engagement can dramatically change tooth engagement and accelerate distortion and wear.
Drilling out oilite bearings should be done only slowly and with great care so as not to deform the sintered structure or harden the oil in the voids. Grease introduced into an oilite bearing can be scraped into the voids leaving a great many points as asperities making point contact -- this might produce grooving and, yes, contact screeching when the shaft rotates at speed. If you use grease on the worm and driven gear, don't get it into the bearings, and let the plastic thrust washers between the worm and blocks do their job.
My procedure for cleaning oilites involved a protracted soak in a hot ultrasonic solvent bath, followed by ultrasonic flush and baking dry before relubricating with correct grade oil. I am not a fan of converting oilites to plain bearings by clearance-drilling and sleeving them or introducing solder, as you then have to keep them periodically inspected, including at the effective thrust faces which are easy to forget about. This is a high-load area of the drive requiring careful alignment to stay right.
I have a Proto2000 gp7 that screeched like the dickens when I first ran it.
I tried putting some oil on the motor shafts, it still screeched.
Frustrated, I put it in a box and left it up in the attic for at least 6-7 months.
Then, I thought I'd try working on it some more, expecting the resolution to be a tough slog if I found one at all.
To my surprise, I put it on the track, gave it a run, and not only was the screeching gone, it ran smooth as silk and quiet, too. Still does.
Perhaps it took that long for the oil to "soak in"...
OldEngineman I have a Proto2000 gp7 that screeched like the dickens when I first ran it. I tried putting some oil on the motor shafts, it still screeched. Frustrated, I put it in a box and left it up in the attic for at least 6-7 months. Then, I thought I'd try working on it some more, expecting the resolution to be a tough slog if I found one at all. To my surprise, I put it on the track, gave it a run, and not only was the screeching gone, it ran smooth as silk and quiet, too. Still does. Perhaps it took that long for the oil to "soak in"...
I've had the same experience.
Another experience, several times and I stop short of recommending it because it sounds so goofy:
I take these old DC locos, Life Like protos, and stick them under the hot water faucet. Angle differently, but always try to keep a bunch of water from entering the motor. The heat tends to melt the oil and flushes the dirt out from all parts. Maybe gets the oil to finally flow into tiny places it should.
I've fiddled around with tearing things down and rebuilding, only to get frustrated and heat the whole thing up under near scalding water. It was the final working solution several times.
Its a simple DC locomotive. Very robust really. You can wait until its bone dry before running, but I got so confident I was running the thing to dry it out, LOL.
Update:
While waiting for the Athearn bearings to arrive I remembered I had some Athearn BB wheels I removed from an F7 while switching to nickel silver wheels.
The Athearn wheel shaft measured .0005 larger than the Proto worm shaft. The old Athearn bearing thickness measured .001 thicker, .001 shorter and narrower than the Proto bearing.
I swapped in the used Athearn BB axle bearings and so far so good.
Next I will do some heavier running to see if the squealing comes back.
Update #2
The new Athearn bearings arrived and they measure the same height and width. However, they are .005 thinner. If I where to use these I would need to add .005 thrust washers to each end of the worm gear to keep the same thrust clearance.
That being said I am going to stick with the old used Athearn bearings I had leftover.
So far the SD9 that I switched to the used Athearn bearings is doing great. Tomorrow I am going to switch out the Proto bearings in my SD7 for old used Athearn bearings.
Fingers crossed I get the same results with this locomotive.
I checked to see how much the worm gear moved with both the new Athearn and the old Athearn bearings with the driveshafts connected there was a very noticeable difference. Enough for me to decide to run the old ones. In the end, the old Athearn bearings are working much better than the Proto bearings. Chris