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New buggy not going straight- could it be a bad bearing?

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New buggy not going straight- could it be a bad bearing?

Old 05-23-2020, 09:41 PM
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Default New buggy not going straight- could it be a bad bearing?

Hi everyone, I have a 2wd buggy i recently built. I'm looking to see if i can get it race ready by testing it out in a parking lot near where i live. One thing i have noticed is that the buggy whether under light or full power consistently tracks left. I don't have a setup station (yet), but the toe in looks fairly symmetric in the rear and the front with more toe in in the rear- as per the stock recommendations from the manual. The rear wheels spin pretty freely once i remove the pinion gear, with minimal noise. The camber and steering link lengths are all within 1/2 a millimeter of each other. The only thing i notice is that if i try to freely spin the front tires equally, the left tire consistently spins for 15 seconds longer than the right. This occurs even if I switch the wheels/tires and make sure i tighten the wheel nuts as equally as possible. It doesn't look like the front wheel or tire is hitting anything that would interfere with it on the right.

If it isn't the wheel or tire or the tightness of the wheel nut, it has to be a bad bearing, right? Could a bad front bearing cause a car to veer off like this? Keep in mind there is no grinding noise, i wouldn't have even noticed if not for the "spin" test.

Thanks for any input!
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Old 05-24-2020, 04:08 AM
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replace front wheel bearings then do a low speed run test
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Old 05-24-2020, 01:08 PM
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Your bearings would have to be really bad to make that much difference. Just checking the basics - you have the steering trimmed straight, correct? In other words, when your radio and car are powered on your front tires should be pointed straight. Then drive forward and use your radio trim to fine tune it.
One other possibility - sometimes cheap servos will not center properly, but that doesn not sound like your issue.
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Old 05-24-2020, 01:18 PM
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check rear bearings also..
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Old 05-24-2020, 02:52 PM
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When you say the setup looks symmetric, are you using a dial caliper to check it? You don't need a setup station. A handy dial caliper (even a cheapy from HomeDepot or Lowes) can make sure that you have the basics.
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Old 05-29-2020, 12:07 AM
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Swap bearings left to right to confirm. Also, 1/2 mm can be a (slightly) noticeable. Get a decent pair of calipers, it'll help you out no end.

Does this only happen on power or under braking as well? Is it slight or severe?

Bear in mind most roads aren't level for drainage purposes, so do a run in both directions.

Check your shocks for asymmetrical length (calipers will come in handy here).

Check if you have grossly asymmetric weight distribution left to right.

Check if transmission and diff have been built properly and and the diff is smooth. Check by removing the diff and feeling by hand. Do not simply check by spinning the wheels, it'll numb the feel massively due to the tire's diameter.

Check where the front arms mount (the kickup block/skid plate) is mounted square. A lot of kits have enough slop in the mounting to allow it to be mounted slightly misaligned, and can easily be tweaked after a big crash.
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Old 05-29-2020, 06:14 AM
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It is not necessary to measure within a millimeter - there is more than 1mm of slop in any steering rack. The lengths in the manual are estimates and they will change depending on setup.

It's just a trim issue, this is the rookie zone after all.

To the OP - what was it? Don't leave us hanging
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Last edited by heyscottn; 05-29-2020 at 07:00 AM. Reason: clarification
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Old 05-31-2020, 03:39 AM
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Sorry I got busy at work and didn't have time try to figure it out last week...going to replace the front bearings and go to slightly toe out from neutral in the front and let everyone know how it goes! Thanks for everyone's input.
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