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Hi all,
I posted a question a couple of weeks ago about a noise I'm hearing in my transmission, only when in 1st gear (loud rapping noise that increases with RPMs. No noise like this in any other gear). Also, if I downshift from any gear, other than from 2nd to 1st, no noise. But, if I press in the clutch to downshift to 1st gear, even moving the shifter slightly to 1st starts to increase the sound of the noise.
I've read some comments in other threads about the possibility of the reverse idler interfering with 1st gear. What is the best way to determine if this is, in fact the issue my transmission is having? Does the trans need to be pulled to examine the idler and it's relationship to 1st gear, or is there a possible adjustment that can be made without pulling the transmission to try to resolve the problem? (for example, examine / adjust the 1st gear linkage to ensure it's going all the way into 1st)? Really odd that this just started out of the blue. I tried to attach an MP4 video/audio clip of the sound but I am unable to upload an MP4 to this site, unfortunately.
Thanks much in advance for any thoughts on this.
I did this repair recently. Removed the reverse idler, beveled the edge, reassembled, problem solved.
Quick way to check it is to start off in first gear and, while under acceleration, not decel, pull back on the shifter and see if the noise stops or at least minimizes. If it does, it's the idler. Not too difficult to repair once the transmission is out.
This is not an uncommon problem with these Muncies. New gears now come with the beveled egde.
Cheers, Greg
Thanks very much, Greg. This definitely describes my symptom. Is there a specific reason why, out of the blue the idler would start to interfere with 1st gear? Also. do you happen to know if someone makes a pre-beveled idler or if the only solution is to machine the original idler? Finally, is there a way to test that that is the problem prior to reinstalling the trans in the car?
Best regards!
The tolerance is very minimal between the idler and the shift collar so they tend to brush against each other in first gear on some transmissions. It doesn't really cause a problem, just an annoying noise. An over-looked design issue originally. I believe all the replacements are beveled now. The idler does not need to be machined to correct this problem, as it is not a high pressure/impact point, you can simply bevel the edge of the idler on a bench grinder. Then file the edges so there are no burrs and you're good to go. A five minute fix once the idler is in your hand.
Muncie Reverse idler
