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Old 02-06-2017, 03:04 PM
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B. Santos
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Originally Posted by aracefan
Okay TB Evo6 experts, I need some help/advice.

I picked up a used TB Evo 6 MS w/Exo6 conversion off of here, used obviously. I got the car in and unfortunately it was in worse shape than described - and such is the risk of buying something used. I'm having an issue with the gear diffs/drive line... The car is "notchy" when rotating the spur gear. There are gear diffs in the front and rear of car, which is fine, I actually run my TC6.1 that way in USGT.

Here is what I've done:

Removed the gear diffs and rebuilt them both, both were not shimmed correctly.
Inspected all the internal metal gears (under magnifier) and they all look clean and straight.
Replaced incorrect shims with new and also shimmed it per instructions.
Replaced green diff seals. Replaced copper bushings with rubber shielded 5x8x2.5 bearings.
Inspected both front and rear gear cases and they look fine.
The screws holding the top deck were too long and didn't cinch down the top deck, so replaced those with the correct screws.
Cleaned, re-greased everything and reassembled the driveline, and low and behold it is doing the same thing...
It's not near as "clicky" as it was but it is still happening.

Now though, I can rotate the spur about 80% the way around and then it "notches" a few times, and then is free. Then does it again... I have no idea what is the issue. I checked the attachment of the stock gear to the Exotek drive shaft at the rear and also the attachment of the front drive gear and they are correct. Wasn't sure if there was a shimming issue there, but as much as I can tell all is correct.

I'm just at a loss on this thing - I have spent about 4 hours working on this car and while it's a little better it still isn't "right". I definitely don't want to run it with this notching issue.

Any tips or suggestions would hugely appreciated.

Thanks in advance,
-Barry
Sounds like it could be a runout issue with the center motor mount/driveshaft bearing.

This is the piece I am refering to:
http://www.exotekracing.com/exo-five...t-replacement/

Loosen the three attachment screws on the bottom of the chassis and align the mount so that it is perpendicular to the driveshaft. This should ensure that the inner wall of the bearing isn't contacting the driveshaft at an angle and is spinning freely.

In addition, check that the motor mount bearing is not seized and that the M2x4 screw attaching the drivecup is tightened down.

Last edited by B. Santos; 02-06-2017 at 03:56 PM.
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