# Squealing T-jets



## bolts69

I'm sure this has been asked before but what causes a t-jet to squeal and what can you do to stop it?


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## Bill Hall

That noise means it's thirsty and fixing to die if you persist in flogging it.

If you listen carefully you can hear it screaming, "oil mEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEE!


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## Boosted-Z71

It needs oil, very small drop on the armature shaft, top plate under the armature gear & chassis bottom between the brushes, also the cluster gear shaft top and bottom, and I have seen them squeal do to an axle binding

Boosted


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## Rich Dumas

That is the dreaded T-Jet Squeek of Death. The most important place to oil is the lower end of the armature shaft. Only a very small drop of oil is needed, excess oil will get on the motor brushes and degrade performance. Any sort of oil will stop the squeek, at least for a while. Back in the '60's the best oil was the red oil that Aurora sold and many people still use it. Thunder Oil is the modern version of the classic Aurora oil, but I have never tried it. I use Superlube from Slot Car Corner, it has never let me down.


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## wheelszk

Rich Dumas said:


> That is the dreaded T-Jet Squeek of Death. The most important place to oil is the lower end of the armature shaft. Only a very small drop of oil is needed, excess oil will get on the motor brushes and degrade performance. Any sort of oil will stop the squeek, at least for a while. Back in the '60's the best oil was the red oil that Aurora sold and many people still use it. Thunder Oil is the modern version of the classic Aurora oil, but I have never tried it. I use Superlube from Slot Car Corner, it has never let me down.




Hey Rich, what do you do when the squeek just won't go away? We have oiled everywhere. This is on a T-Dash.


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## slotking

> before but what causes a t-jet to squeal


being caught by a WV mountain man!!:wave:


> squeek just won't go away? We have oiled everywhere


eliminate other sources

the easy 1st step is move parts around swap the gear plates between 2 cars
does it follow the org car or the other car?? if follows the org car, the issue is the chassis and or axle/crown issue
or
so remove the rear axle and crown and test.
if you still get it, make sure the holes on the gear plate and chassis line up
while your there, make sure that none of the gear plate holes are binding on the chassis.


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## Bill Hall

Is that a free rev squeal or motoring down the track under load squeal?

On the track, other things squeal. Like front axles, rare, but they can fool ya. Sometimes the guide pin is too long and screeches along the bottom of the slot as it goes down the track. Like finger nails on a chalk board.


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## ajd350

Nobody likes a squealer, Wally.


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## Boosted-Z71

send it to me, I have a de-squealing chamber I can run it through.

All the above should get you a quite car

Boosted


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## Rich Dumas

In the 52 years that I have run T-Jets I have never had a squeal that could not be fixed by oiling. I did run into a strange problem with Johnny Lightning cars, those needed oil on the gear plate end of the motor shaft a lot more than Aurora cars did and the oil that I was using when I first started running those did not last for long. I had to mix some lithium grease with the oil and one application of that fixed the problem for good. I have ten Dash cars and have not had a problem with those. Are you sure that you are not getting gear noise? Dash cars have crunchy sounding gears and they are tough to lap because the brass alloy that Dash used is much tougher than normal. The Dash chassis is unique in that it uses a glass filled plastic formulation. If all else fails you could try the lithium grease.


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## Joe65SkylarkGS

To quiet down dash gear plate, I found the easiest way is to take motor magnets out reassemble, then use a stainless wheel in a dremel and kind of just push them all around till they quiet down. A drop of oil will help it along too. Very simple and quik with no real messy clean up like most lapping.


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## 60chevyjim

did you oil the rear axel at the ends ?


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## Bubba 123

Rich Dumas said:


> That is the dreaded T-Jet Squeek of Death. The most important place to oil is the lower end of the armature shaft. Only a very small drop of oil is needed, excess oil will get on the motor brushes and degrade performance. Any sort of oil will stop the squeek, at least for a while. Back in the '60's the best oil was the red oil that Aurora sold and many people still use it. Thunder Oil is the modern version of the classic Aurora oil, but I have never tried it. I use Superlube from Slot Car Corner, it has never let me down.


"Sewing Machine" oil & the little bottle w/ long needle-tip is perfect & cheap.
that "Red-Stuff" is Hydraulic/Auto-Trans/Power Steering type fluid thin & slick..
a Qt. will last "MOST" Slotters, a lifetime :thumbsup:

however, "Bribery" can get U "Secret-Concoction's Formulas".....
(usually only $$costing$$ U, by the questions U just asked  ) 

get ready, & TAKE-NOTES!!! :freak:

Bubba 123 :wave:


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## ajd350

Rich Dumas said:


> In the 52 years that I have run T-Jets I have never had a squeal that could not be fixed by oiling. I did run into a strange problem with Johnny Lightning cars, those needed oil on the gear plate end of the motor shaft a lot more than Aurora cars did and the oil that I was using when I first started running those did not last for long. I had to mix some lithium grease with the oil and one application of that fixed the problem for good. .


I fixed one a while back of one of my racing buds. Oiling would only keep it quiet for 3 laps or so. Different gear plates and arms made no difference. Finally I tightened up the oversized lower arm hole in the chassis tub. End of noise. The arm shaft would start to wobble around in the loose hole and set up an oscillation that made the squeal. Only one I'd ever seen in 50 years of messing with these.


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## rholmesr

Al,

I have seen a few of those and it is frustrating. It's called a 'bearing whirl'. There is too much clearance in the bearing and it is an unstable condition. Instead of the shaft spinning on its axis it actually rolls around the whole clearance of the bearing at some lower frequency than the rotating speed of the arm, making a horrible growl/buzzing sound as it does so. 

You can lube the heck out of it and it could go away for a few seconds or a few minutes but once the oil runs down to a lower thickness then it comes back. Just freewheeling the arm on a powerpack you might hear "wheeeeeeeeeeeeeeeeeeeeeGrrrrrrrrrrrrrrrrrrrrrrrr", changing to the growl sound as the lube runs out. 

The culprit is usually the bottom shaft of the arm that is worn down. I've seen them as low as about .058" (worn down from .062/.063) where this occurs, or it could be that the chassis arm hole is reamed out too which seems to be the case in the one you worked on. Not much you can do to correct but peening the chassis could be done or maybe you could line the arm hole in chassis with a thin film of CA glue. Easiest fix is to replace the arm usually.

The very first fray car I ever built I used a worn out arm. The arm shaft was worn down to about .058" from the get-go. I should have used a different arm but at the time I was a Fray noobie and I liked that arm because it was so smooth running on my tester chassis. But it did the dry whirl in the fray chassis, so to get it to work I peened the heck out of the chassis arm hole, which of course made the motor brush holes oval- shaped so the motor brushes would stick so I had to jam in a .125" shaft to make them back round which made the arm hole in the chassis oval. Back and forth I went until I got it to work okay. Eventually that arm just plain wore out (comm failure) and I replaced it with new and then the chassis hole was way too small so I had to ream it out back probably to where it was to begin with. I still have that car as a runner at the Fray. Actually it's been in our team box every year - it's slow and handles really good.

See you at the Fray!
Ron S.


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## ajd350

+1, Ron. I've had a few that didn't squeal with that problem but were rattlers as you describe. On the arm would actually hit one of the magnets! The fix was the same. I have a way to push the plastic back inwards without distorting the comm brush holes. Whatever gets you there is good. It seems to be more common with the copper-colored late production shafts in my experience. They can be pretty bad.

Less than a week to go!


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## slotking

> then the chassis hole was way too small so I had to ream it out back probably to where it was to begin with


no need to ream.
I use a axle, and rotate it with a wide swing by hand. It will un-compress the hole. But with the brush hole changes you made, not sure how well it will work


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## rholmesr

Sk, that is basically what i did. It was the reverse of the original process and took a couple of iterations.


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## Rich Dumas

If loose armature shaft holes in the gear plate and the base chassis are causing the problem it is not difficult to fix that. The holes can be swaged to close them up. I have included detailed information on how to fix the problem in the article I wrote on tuning Dash cars. Drop me a PM with your e-mail address and I can send you a copy of the article.


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## slotking

> I have seen a few of those and it is frustrating. It's called a 'bearing whirl'. There is too much clearance in the bearing and it is an unstable condition. Instead of the shaft spinning on its axis it actually rolls around the whole clearance of the bearing at some lower frequency than the rotating speed of the arm, making a horrible growl/buzzing sound as it does so.


it not always the hole/shaft size. it can also relate to gears mesh or arm balance. (if it is not just a untrue shaft)


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## swingerguy340

I use Royal Purple SynchroMax gear lube (not thick lube typical gear lube) in slot cars, and RC bearings/motors. designed for small area's, it's synthetic, and $25/ qt so a qt will go A LONG WAY if all you use it for is your slots

I also use Slick7 VooDoo com lube - mainly for drag racing for a little faster acceleration (that's about how long it lasts) , but works great for breaking in new motor brushes..


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## Rich Dumas

I ran in a 4 hour T-Jet race this past weekend at LenJet Raceway in Ashland MA. We had two man teams, so each driver ran for a total of 2 hours. I use Superlube and I got through the entire race without having to oil the car. It would have been interesting to see how long the car would have gone before it needed oil. I did have to oil my team mate's car during the race, I don't know what oil he used when he prepped the car, but it started to squeek during his first heat.


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