The big boy's tender is very top heavy and needs
the rear truck tracking and geometry to be as near perfect as it can be
to keep the tender from wobbling down the track. The tender will
be prone to tipping and clunking if the rear wheels are not aligned
correctly |
Lionel's tooling for the truck frame was not the
best and variances were the result.
Here is a fix that with a simple jig will allow you to get the truck
re-aligned correctly.
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The rear truck frame needs to be completely removed from the tender.
Start with the speaker removal |
Then remove the sound boards. |
The frame screws are removed next. Don't loose the insulators. There may
be shim washers between the truck frame and insulators. Be sure to
remove those shims, we will not re-use them. |
The alignment jig is simply a piece of 1/8 or 3/16 aluminum drilled to
match the truck frame mounting holes. The jig needs to be stiff, true
and flat. |
Assemble the truck frame on the test jig with all of the wheels in
place. Be sure to swap the rear two wheelsets so a blind set is
rearmost.
You want the blind wheelset in the rear as the frame is weaker there and
may distort over time. Also the truck tracks better in curves.
While you have it apart Locktite the coupler plate mounting screws |
You will need a piece of test track that is straight and square mounted
to a board for clearance testing.
Check the clearances between the blind drivers and track to be sure the
blind wheels are not bearing any weight. |
File the blind wheel's journals if needed so that the wheels clear the
track.
The reason for only the flanged drives to bear the weight is
to keep the flanges from riding up the sides of the rails and causing a
clunk when they fall back down on the rails. |
Now re-assemble the truck with only the flanged drivers |
Place the assembly on the test track and gently apply pressure diagonally
on the plate and try to feel any play when rocking the plate. Do both
the green and the yellow directions. You will probably notice that one
direction will be noticeably looser than the other. |
If you notice a difference in the diagonal play then you need to measure
all of the flanged journals. |
You only need to notice the difference in their measurements and the
goal is to adjust the frame so all are within +/- .001 or as close as you
can get them.
I write the measurements in pencil on the jig by each journal for reference.
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Then the critical job. VERY GENTLY press the frame at the largest
measurements in SMALL steps in a vise. This will reshape the bend at the
top of the frame where the screw attaches. Be sure to re-tighten the
screws after every squeezing.
Squeeze once and measure. Repeat if needed. Then do the other high ones until you walk all
to within +/_.001 . of each other. Then re-test the diagonal
rocking and it should be minimal now. Re-assemble tender when happy with
the results. |
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