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Old 08-19-2011, 03:06 AM   #1
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Default TC4 turning to the right under acceleration

Hey all, I have a pretty standard TC4, whenever I try accelerate the car drifts to the right. Yet when rolling the car drives straight again.

I checked all the measurements and everything seems right, I checked for any excessive play on either the hubs or steering but can't seem to find any.

I am using the standard Team Associated Steering servo too.

Any advice would be fantastic
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Old 08-19-2011, 03:37 AM   #2
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Sounds like torque steer.
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Old 08-19-2011, 03:40 AM   #3
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Couple of things off the top of my head that will cause that:

1) Bad bearing(s) on one side of the car. I had a similar problem, and found that one of my bearings was a little gritty. When I cleaned that, the problem was gone.

2) The car may not be balanced. Does the car veer to the side with the most weight?
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Old 08-19-2011, 03:51 AM   #4
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Quote:
Originally Posted by SpidarX View Post
Couple of things off the top of my head that will cause that:

1) Bad bearing(s) on one side of the car. I had a similar problem, and found that one of my bearings was a little gritty. When I cleaned that, the problem was gone.

2) The car may not be balanced. Does the car veer to the side with the most weight?

I thought it could have been torque steer but there was cars on the track that were much faster and had no issues.

All the wheels seem to be turning ok, it does seem like a night and day difference between rolling and accelerating. The steering turns considerably to the right.

I read up a few things that could influence it, one of which was maybe a weak servo, or loose steering components but those seemed to be pretty tight and strong.

I spent the whole day at the track trying to straighten it up with no prevail
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Old 08-19-2011, 05:42 AM   #5
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if the bearings are good, the servo is good, and everything else is square it sounds like your weight balance is messed up left to right. If there is more weight on one side or the other the car will tend to dart to the side under power.
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Old 08-19-2011, 06:37 AM   #6
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Try checking to see if the car is tweeked, or twisted.
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Old 08-19-2011, 08:44 AM   #7
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Buy a better servo as fast as you can, its holding power and speed will be MUCH better, and when you have one you wont be able to drive a standard-servo vehicle again without wanting to pull your hair out.
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Old 08-19-2011, 09:11 AM   #8
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Quote:
Originally Posted by tt01-demon View Post
All the wheels seem to be turning ok, it does seem like a night and day difference between rolling and accelerating. The steering turns considerably to the right.

I spent the whole day at the track trying to straighten it up with no prevail
In the case of a bearing being bad or just gritty, you might not be able to tell by just seeing the wheels spin. When I had the problem I couldn't tell. In my case, I ended up figuring out it was a bearing problem when I swapped the bearings from one side of the car to the other. My car then started pulling to the other side under acceleration. I then took all the bearings out of the car and cleaned them. I eventually found the bearing that was bad.

As someone else said, it could also be from tweak. It wouldn't hurt to take your car completely apart, clean all the parts...bearings etc. and then rebuild it.
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Old 08-19-2011, 10:24 AM   #9
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Tire wobble sometimes causes problems, even if the tire is balanced outside of the car !!!! You have to try a few sets of tires until you get all four tires spinning in the air with no visible wobbling , on top of all the things mentioned above ! Another issue is driveshaft wobbling under sudden acceleration torque !!! Make sure your shaft floats a little between the input cups !!!! Also if you diff or spool outdrives are worn more on the left side than the right, it might also cause the car to veer right . Lastly , a smooth acceleration after the turns is preferable to a quick jolt ! The object should be to reduce the veering effect ; eliminating it is extremely difficult !!!!!
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Old 08-19-2011, 10:50 AM   #10
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things to check
bearings
make sure the servo saver screw is tight..(go under the chassis to tighten it)
make sure none of the shock towers a loose..(when the shock compress the tower lifts)
make sure you have a good servo that have enough torque to make it center
make sure you ball studs & king pins are not to tight that it wont let the steering knockles move freely
make sure the servo horn is not stripped out

i cant think of anything else
i been running a tc4 for 3years & these are some of the problems i came across

hope this helps
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Old 08-20-2011, 01:57 AM   #11
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Thanks for all the heads up.

On further inspection I did notice a few things. The outdrives are quite worn, the spacing that the cvds normally slide into on the outdrives has worn considerably but it does seem constant amongst both sides.

The other thing I noticed is that one of the wheels does have a flat spot (but strangely enough still drives straight under no acceleration.

I will check out everything and I will likely strip the diffs and ensure everything is straight and true.

The servo looks to be the first thing to invest in.
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Old 08-20-2011, 03:10 AM   #12
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A good servo will last many years. I have been using the same KO PDS-2143 servo for the past 8 or so years in various TCs and it still holds fine. Bought a Savox 1251 recently as they seem to be decent for what they cost.
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Old 08-20-2011, 09:27 AM   #13
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I also forgot to mention that you will need to dremel the top of the servo saver screw that comes closest to the driveshaft front input cup . Make sure there is a good 4mm to 5mm between the servo saver and the cup . In addition make sure the symmetry in the steering system is the same from left to right as much as possible ..
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Old 08-20-2011, 10:37 AM   #14
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+1 on the tire wobble

Put the car on a stand and hold the throttle, it should rotate to the right.

Try another set of wheels/tires or swap them right to left to see if the problem transfers to the other side.
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Old 08-21-2011, 01:47 AM   #15
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Thanks for all the advice everyone, I got the good old verniers out to take some measurements, everything looked pretty straight except for one of the shockers, I believe it was the rear left one (which could explain why it was turning right). I noticed it was wound in a lot more than any of the others so I made sure it matched the rear right one. I am wondering if this could have influenced the issue?
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