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Old 01-09-2011, 12:57 PM   #1
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Default Need Help w NTC3 Pulling Right and Trans.

Hi All,

I would appreciate some help with my Nitro TC3. On full acceleration it pulls badly to the right, so much so it becomes hard to control. I certainly can't keep it accelerating in anything close to a straight line. I think it may be a bad bearing or bearings? There are two #3977 bearings on each axle, one on the inside of the steering hub and one on the outside. Do I replace both of these on the right front and/or right rear? Or replace all eight on both sides? Or is there something else that could be causing it to pull?

Second, I put in a new two speed transmission but it won't shift to second. It seems to wind out in first but again I can't stay on full throttle too long because it's too hard to control. Maybe its not going at full throttle long enough to shift. I think it may just be an adjustment issue. I adjusted it base on the AE recommended 4 turns out for the stock .15 engine. However I have the stock .12 engine, so I may need to turn it out another 1/2 turn? I think the adjustment may be too tight for the less powerful .12 engine.

Sorry for the long winded post and thanks for any help!
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Old 01-09-2011, 01:08 PM   #2
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Default NTC3

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Originally Posted by Jake C6R View Post
Hi All,

I would appreciate some help with my Nitro TC3. On full acceleration it pulls badly to the right, so much so it becomes hard to control. I certainly can't keep it accelerating in anything close to a straight line. I think it may be a bad bearing or bearings? There are two #3977 bearings on each axle, one on the inside of the steering hub and one on the outside. Do I replace both of these on the right front and/or right rear? Or replace all eight on both sides? Or is there something else that could be causing it to pull?

Second, I put in a new two speed transmission but it won't shift to second. It seems to wind out in first but again I can't stay on full throttle too long because it's too hard to control. Maybe its not going at full throttle long enough to shift. I think it may just be an adjustment issue. I adjusted it base on the AE recommended 4 turns out for the stock .15 engine. However I have the stock .12 engine, so I may need to turn it out another 1/2 turn? I think the adjustment may be too tight for the less powerful .12 engine.

Sorry for the long winded post and thanks for any help!
There could be numerous reasons why it is pulling this much. First off, shaft driven cars will have some torque steer under acceleration. Just the nature of those cars. But if it is really bad, check and replace the bearing, make sure the axles are not binding up, could be shocks not adjusted equally, droop could be off, different size tires<side to side should be equal in MM>.
Just many things. Start off with one end at a time, making sure there is no binding in the bearings,axles. Then start off checking toe out for the front, shocks <ride height> droop,. The NTC3 are famous for tearing up the diff gears also. Make sure the front and rear diff gears are good, and shimmed correctly. These would be some of things you should start checking.
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Old 01-09-2011, 02:45 PM   #3
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Thanks BRC for the input. I was very careful setting the toe, camber and other suspension settings. The shocks are shimmed the same and the wheels and tires are almost new, so I am leaning toward some kind of bearing issue.

Where is the best place to start? Replace the front and rear differential bearings first (the ones on the shafts) - I think there are 2 on each. OR should I start with the bearings on the axles? Any idea what might be the most likely culprit?

Thanks!
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Old 01-09-2011, 03:19 PM   #4
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Default NTC3

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Originally Posted by Jake C6R View Post
Thanks BRC for the input. I was very careful setting the toe, camber and other suspension settings. The shocks are shimmed the same and the wheels and tires are almost new, so I am leaning toward some kind of bearing issue.

Where is the best place to start? Replace the front and rear differential bearings first (the ones on the shafts) - I think there are 2 on each. OR should I start with the bearings on the axles? Any idea what might be the most likely culprit?

Thanks!
I would lean more to the axle bearings more than the diff bearings.
Depending on what kind of bearings are used, they may be able to be cleaned, oiled and reused.
A lot of times when the diffs, and suspension is worked on. the bearings are not reseated properly, and they can bind up
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Old 01-09-2011, 03:39 PM   #5
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Just do yourself a favor and replace all the bearings in the car
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Old 01-09-2011, 04:33 PM   #6
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Thanks guys for the advice, I will get started on some bearings and see if that does it.
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Old 01-09-2011, 05:51 PM   #7
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I would also have a close look at your diffs and CVD's if you have them.


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Old 01-09-2011, 06:30 PM   #8
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Make sure you double check the droop settings. I know on my tc4 when the droop is off it pulls hard to one side just like you mentioned.
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Old 01-16-2011, 02:05 PM   #9
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Default Found the problem...

I thought I would update this thread in case anyone having a similar problem searches for it in the future...

I took the advice given here and I tore the car down completely. The only thing left to do is actually take the outdrives apart and clean/regrease them but I am waiting for some diff lube to finish that.

When I took the front differential apart it was obvious the outer right bearing was destroyed. It had completely worn apart, I surprised the axle was still turning smoothly! So that explains the pulling to the right on acceleration, that side had to be dragging big time!

I also found that one of the rear differential bearings had basically "eaten" the shim next to it. It had become concave and wedged itself between the bearing and the outdrive shaft!

In addition, the front input shaft was missing a shim, but I don't think that was causing any serious issues.

I have replaced all the bearings on the axles, the old ones seemed OK but you never know - as someone said better to just do them all at once and be done with it. Especially when I got the whole set of 20 bearings for $20!

Once I get the parts I need (have a broken mount on a diff case as well) I will reassemble everything and post the results. I am thinking the car should be going straight as an arrow on acceleration after this!

Just for good measure I am also going to empty and refill all the shocks - and of course check the droop and all the suspension settings after reassembly.

I will post the results when everything is done and I have taken it on its first test run!
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Old 01-18-2011, 07:59 PM   #10
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Now your cooking with gas!!!!



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Old 01-22-2011, 04:59 PM   #11
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Talking Success! Thanks For The Tips!

Well it took a while but success at last!

I replaced all the bearings in the car, refilled the shocks, reset the droop, caster camber and toe. The car screams in a straight line now!

As I was rebuilding everything I changed the settings to me more "bump" friendly and lower traction, including softer shock springs. I only race this car on the street in front of my house and it is far less than perfect, so I need to be able to absorb the bumps. Once I got everything dialed in it is so much more fun to drive with confidence at high speeds, going around corners, even just flat out acceleration in a straight line to see how fast it can go!

I even removed the pull start and converted to the smaller bump start flywheel and motor mounts.

I also figured out the problem with the two speed transmission. It seems the shoes for that clutch were adjusted too loose. I tightened them down all the way then backed off four turns and that seems to be the sweet spot.

Anyway sorry for the long post - all the time tearing down and rebuilding paid off!
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Old 02-16-2011, 08:30 PM   #12
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Wink don't bump it.

on the ntc3 the two speed and the engine rotate opposite ways and cancel eachother out as far as torque steer. maybe not the single speed. when my ntc3 was pulling one way or the other, it was a tweaked chassis cause the stock ones are weak by the motor mounts. or the rear left tire was soaked in oil. also if you bang those things around, the suspension binds up easily. misalignment or bent hingepins or whatever else. sounds like you got things figured out though. for this reason and many others, i'm converting my NTC3 into a Nitro B44. almost finished. it looks wicked with blue aluminum B44 top plates.
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