Lionel 671R running issue

[earl08]

Hello all, I am having a problem with my 671R engine from my 4109ws set. The issue is that it runs like a scared rabbit in reverse. But in forward it reaches on about 2/3 of the reverse speed. I have cleaned and reoiled/lubed the motor, gears, axles and side rails. I installed new brushes in the motor. Cleaned the e-unit. I have been at this one for 2 weeks and still no solution. I have researched and am running out of ideas. I have noticed that the side rails on one side have scrap marks from the center wheel raised areas which appear shiny. I know that maybe an issue in itself buy not sure if or why it would impact only forward motion. any ideas or suggestions? thanks in advance.

[ADCX Rob]

The right rear axle bushing is worn out. This is always the one that wears out first(from forward operation), pushing the axle left, the right rear wheel into the frame, and the worm wheel off center.

In lieu of complete dis-assembly to replace the bushing, there are work-arounds.

Use one(or two or as needed) 671M-22 clips/retaining rings and snap them on to the drive axle to the left of the worm wheel inside the frame / gear box.  You want to have between half to the full width of a 671M-22 clip of end play in the axle for best performance. Keep the entire gearbox & axle lubed well with a synthetic HP grease(Lucas Red 'N' Tacky #2, eg.).

If you can source some clips with the same inner diameter as the 671M-22, but larger outer diameter, that would be beneficial.  The last good tip I heard was to use an appropriate number of plastic bread closure clips(cut to be round) instead of the 671M-22.  Very little friction with that method and they too slip right over the axle and stay on.

[earl08]

Thanks Rob, I think you maybe onto something there. I disassembled it. Looked at the wiring again. That was all good. Then holding it in place I saw that the worm gear on the axle is shifting 1/8 of an inch to the right in forward. And back to the left in reverse. Reverse is nice, fast and quiet. why I didn't notice the gear noise before I can only blame old ears. When I put it in forward it is very noisy. (like gears not meshing properly) If I use a tool and nudge the gear to the left it smooths out and seems to run fast. Would this mean I would need to put spaces on the right side of the axle gear? That's a lot of spacers I think. Is it possible to pull the wheels and change the bushings? What would I need to do that job? thanks again Earl

[ADCX Rob]

To pull the wheels and change the bushings means pulling all 4 rear driving wheels, pressing the worm wheel off the rear axle, pressing out the old and in the new bushings, then reverse the process while carefully quartering the wheels and keeping them square on the axles.

The spacer/clip/washer trick works, and there's not as much space to take up in that well as it looks at first.

[earl08]

does someone have any pictures of the spacer solution installed? I want to make sure I understand the how to place it. thanks