The VUK in the upper right corner of my TFTC is experiencing sporadic issues kicking the ball back up to the playfield. Sometimes it kicks the ball up on the first try without any problems and other times it takes 2, 3, 4, 5, 6 times or so until it is successful in kicking the ball up to the playfield.

Upon further inspection of the VUK/Coil assembly under the playfield there is quite a bit of slop when I wiggle the ball popper cap. I have attached photos of this VUK assembly below.

On the VUK assembly there are only two compression rings when the manual calls for 3 compression rings for this assembly. I am guessing that this may be the cause of the extra slop in the assembly.

I have ordered the following VUK component kit from Marco Specialties as it appears to have everything that I need to re-build this VUK on my TFTC.

http://www.marcospecialties.com/pinball-parts/565-0029-01

This kit also has 3 compression rings. I also checked the VUK on my JP which works basically 100 percent of the time and it too has 3 compression rings.

Do I need any type of special tool when installing the compression rings around the plastic ball popper cap to ensure that it is nice and snug and that everything works as it should?

Thanks.

Gord

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This posted by user 'Capinball' in the TFTC club thread regarding this topic.

I'm having this issue as well and had bookmarked an old post by Russ Myers to tackle it. Looks like you got the right kit. Here are his tips:

"Mark (Band;No-Band) the wires on the VUK coil and de-solder.
Unscrew the 4 screws and pull the entire VUK assy out.
Buy the DE VUK rebuild kit from Marco (or elsewhere if you can find it)
http://www.marcospecialties.com/pinball-parts/565-0029-01

Vertical Up Kicker (VUK) Component Kit
#565-0029-01
Vertical Up Kicker (VUK) repair kit contains plunger, cup, spring, spring clip and roll pin.
Contains the following components:
545-5227-00 plastic cup
515-5352-00 plunger
266-5025-00 spring
270-5010-00 compression ring
251-5004-00 roll pin

Replace everything in the kit (it's only 18 bucks) and re-install

Make sure the sliding "mushroom" cap moves very freely up and down and is activating the arm of the microswitch properly. The mounting screws on the side of the assy have oval holes so you can adjust the angle a bit until it works smoothly every time. The hardest part is taking everything off (those spring bands are a PITA) and re-assembling in the correct order. Watch for the tapered spring under the mushroom cap - it has to go in the right way or it will jam.

The cap that catches the ball is supposed to slide smoothly down and activate the switch so the game knows the ball is there, but the parts wear and get wonky. I put the VUK rebuilds into most of the DE VUKs - it's just best for longevity.
The B/W design with a simple piston and an opto switch is superior, as is the later Sega/Stern Y-fork and piston.

RussMyers"

Thanks guys for all the helpful advice.

Gord

My TFTC was recently restored and everything was rebuilt including this VUK. However there are only two compression springs installed and not 3 like there should be. I have mentioned that there is quite a bit of slop in the ball popper cap and that is what you are seeing and it is also what may be the cause of this intermittent issue.

The wireform appears to be lined up correctly as this VUK works correctly most of the time. I believe that the slop which may be due to the missing third compression ring may very well be the cause of this intermittent issue.

Do I need a special tool to install and tighten the missing third compression ring? All other parts on this VUK are as new. Parts have been ordered.

Thanks for your comments.

Gord

Thanks, will do.

Gord

I received the VUK rebuild kit today from Marco Specialties and installed a new ball popper cap with 3 new compression rings. Previously my VUK only had two compression rings installed. After installing the 3 compression rings this did remove a good deal of the slop that the ball popper cap was experiencing.

I have since played approximately 75 games with 100-125 or so successful VUK launches and no failed launches. I also took the glass off and fed the ball to the VUK several times (20 or so) and the VUK now kicks the ball out nice and strong every time.

Previously the VUK would sometimes take as many as 9-10 unsuccessful tries before the VUK would finally successfully kick the ball out. Thanks for all the comments.

Gord

Hi THM,

Sorry for the delayed reply as I just saw your post. I am glad that you were able to get your issue resolved with the assistance of the previous owner.

It is a good idea to have a roll pin punch set in your tool kit to remove/replace roll pins on these assemblies when necessary. The roll pin punch set below is reasonably priced and has a nice assortment of sizes.

https://www.lowes.com/pd/Stanley-FATMAX-Punch-Set/1000085213

Gord