Jerobee Commando Radio and Servos Junk or Fix?

[Simulatedwoods]

Hey all. First post for an RC newbie here, so be prepared for goofy questions! This Jerobee Commando McLaren has been in my family since the '70s. I want to get it going again and keep it. There was only one crystal stamped NKD 26.640mhz, so I bought a Traxxas #3 orange 27.095 set #2033. I hooked it all up with a Panasonic PP9. No response. I heard the servo motors spinning, so I opened each one up. It looks like the plastic gears and case shrunk after nearly 50 years. The motor gear spins freely and does not engage. My questions are: 1) Did I get the crystals right, and if not, which crystals should I buy? 2) Are the servos shot? 3) Are the electronics worth repairing? I know next to nothing about electronics troubleshooting, so I think it might make more sense to get a new transmitter-receiver set and upgrade the brick with new servos and components. Here's a photo of this morning's fun

[RC10resto]

Welcome.
First question, are you sure that car was ever run?
It looks very clean and complete.

Second question, are you sure you want to run such a preserved example?

[Simulatedwoods]

My Dad and I ran it a few times back in the 70s! IIRC something in the radio quit or a crystal got lost, or something. It sat in a closet until a few years ago when I tried to get it working again. I would like to run it, but keep it as original as possible. I don't want to hack it up. I restore and drive old cars and motorcycles. I keep those mostly original with a few mechanical upgrades for modern drivability. That's what I'm thinking here. A mild restomod.

[Dadio]

With regard to the servo gears it might be worth trying rehydrate the plastic , many forms of nylon and other similar plastic have a water content that dries out and leads to loss of strength and shrinkage , simply soaking them in warm water for 24-48 hours might restore them .
If you do plan to run it I'd highly recommend keeping the old electronics to one side and simple replacing them with modern far more reliable 2.4 g radio gear , the range is many times better and there's no interference and they are cheap , it would be a shame to have a crash due to a radio problem .

[Simulatedwoods]

Way cool. I'll try the water soak method on the gears. Full replacement with 2.4ghz stuff seems like the best plan. I'll extract the original equipment and store it for a future return to factory stock. The idea is for very occasional use. More than anything else, I just want to see it running again after all these years. The car has a lot of sentimental value to me. I'll post an update when I get it together. One last question: did I get the crystals right the Traxxis 27mhz set, or should I try another set? Thanks a million for the knowledge and guidance on the electronics. I appreciate your help!

[GoMachV]

Going only from memory, I believe crystals could be positive shift or negative shift. I also seem to remember that the transmitter and receiver actual crystals have slightly different numbers under the tag that is on them and the label represents the frequency once tuned in the transmitter/receiver. Using airtronics crystals in a Futaba radio for example may not work properly or at all. For that reason, I would say to try to locate original crystals before abandoning this- but at the same time a modern radio would be by far better and more reliable. A replacement case could easily be 3D printed to house modern radio gear so the original could be kept intact. I may have to work on that... it’s been on my to-do list for a while.

[Simulatedwoods]

I've tried searching for original Jerobee crystal sets for years, sadly without success. The circuit boards have Jerobee printed on them if that helps. The one crystal I have is stamped NKD 26.640 MHZ. The Traxxis orange set I bought has a TX 27.095 and RX 26.640, but it didn't solve the problem.

[RC10resto]

Full replacement with 2.4ghz stuff seems like the best plan. I'll extract the original

If you do this you won't have to worry about the crystals.
Your Retro-Mod idea could be good if executed properly.
Sneaking modern electronics into the yellow brick would be cool.
Or you can pull the brick and mount the servos and receiver where you want them.
Cars were sold without electronics back in the day allowing the Hobbyist to select his gear.

[Cano1818]

What is a suitable replacement for the stock servo? I need one for my Jerobee.

[Simulatedwoods]

What is a suitable replacement for the stock servo? I need one for my Jerobee.

I don't know what servo would work as a direct replacement. I'm planning on extracting the original equipment and upgrading it to a 2.4ghz setup.

[Cano1818]

Ok thanks I would do that as a last resort. Thanks.