FE Power Forums

FE Power Forums => FE Technical Forum => Topic started by: TurboChris on August 11, 2025, 09:21:30 PM

Title: You guys wanna take a guess at what this sound is?
Post by: TurboChris on August 11, 2025, 09:21:30 PM
So once I completed the TKX swap it quickly became obvious that my old diff had a lot of slop in it. While the C6 kinda hid it, now that i have a clutch the clunking has become more pronounced. So I found a nice, newer diff with a better ratio (3.89 from my old 3.25) that I can take advantage of now that I have the a 5th gear.  I just haven't installed it yet. Going to upgrade to 31 spline axels while I'm in there so it might take a min. I drive it a couple times a week and it runs well.

Coming home last Sun from the local cars n coffee tho something happened. It started making a MUCH more pronounced clunking sound. Not so much all the time, when i ease in to it it doesnt really start until over about 30mph. And not really on decel.

 I suspected that my diff may be about to let loose. But when I got it home, jacked up the rear and ran it in 3rd (it's more pronounced in 3rd) and while I can hear it at the diff (I show the slop in the beginning of the video) but I'm getting LOTS of clunking / most of it from what sounds like from the rear of the trans.

What the hell? The TKX is brand new. Running a McLeod RST Clutch. I have well over 1000 miles since the install.

Take a listen guys and I'll look forward to hearing what you all think.

https://www.youtube.com/watch?v=4L1sujfrYEA

Title: Re: You guys wanna take a guess at what this sound is?
Post by: Chuck on August 12, 2025, 03:53:19 AM
  I didn’t have access to your video but my guess is broken tooth in the rear. Further out on the limb I’ll say pinion.
Title: Re: You guys wanna take a guess at what this sound is?
Post by: TurboChris on August 12, 2025, 09:06:04 AM
Whoops I think it's fixed now.
Title: Re: You guys wanna take a guess at what this sound is?
Post by: sixty9cobra on August 12, 2025, 09:40:00 AM
video unavailable
Title: Re: You guys wanna take a guess at what this sound is?
Post by: TurboChris on August 12, 2025, 09:47:46 AM
How about this?

https://www.youtube.com/watch?v=4L1sujfrYEA
Title: Re: You guys wanna take a guess at what this sound is?
Post by: DuckRyder on August 12, 2025, 09:49:18 AM
Private video
Title: Re: You guys wanna take a guess at what this sound is?
Post by: TurboChris on August 12, 2025, 10:05:56 AM
Ok should be good now.
Title: Re: You guys wanna take a guess at what this sound is?
Post by: DuckRyder on August 12, 2025, 10:11:42 AM
Works now, no idea on the noise unfortunately. exhaust is pretty prominent.
Title: Re: You guys wanna take a guess at what this sound is?
Post by: Jb427 on August 12, 2025, 10:43:14 AM
Kind of hard to tell in the video but to me it dose sound like its coming from the box. You could pull the gearbox sump plug and see if there is metal there or if the oil smells bad I would think a tkx would have a magnetic plug.
Title: Re: You guys wanna take a guess at what this sound is?
Post by: My427stang on August 12, 2025, 12:02:39 PM
That pinion should not have that much clearance to turn that much, assuming the wheels aren't turning.  If you think you are working the spiders or turning the wheels, put it on ramps or put the e-brake on and check again but the pinion should not be that sloppy.

If it is, pull the diff and see what's going on inside, could be a number of things, but getting it out, seeing if it's ruined the gears, and fixing what needs fixed is in order.
Title: Re: You guys wanna take a guess at what this sound is?
Post by: TurboChris on August 12, 2025, 12:09:42 PM
Yeah, I already have a new diff to replace the worn out one. There is that much play when it's sitting on the ground. It's shot for sure. But I'm having trouble wrapping my head around the possiblitly of a NEW TKX needing to be rebuilt.
Title: Re: You guys wanna take a guess at what this sound is?
Post by: shady on August 12, 2025, 12:20:02 PM
the pinion shaft that the spiders are on eggs out in the carrier housing causing that play. Most of the time, the gears are fine, you just need a new carrier. good time for a locker or spool.
Title: Re: You guys wanna take a guess at what this sound is?
Post by: TJ on August 12, 2025, 03:30:13 PM
Might try an automotive stethoscope to better isolate the clunk.  An actual automotive stethoscope (not just a long screwdriver) will reach the drive line with out having to get so close to the exhaust pipe and spinning shaft.
Title: Re: You guys wanna take a guess at what this sound is?
Post by: SSdynosaur on August 12, 2025, 08:19:03 PM
I you have access to a "spare" trans slip yoke you could remove the drive shaft: you will, mostly, be doing that anyway when installing the new diff., install bare slip yoke in trans and re-run test as before. That will isolate or eliminate the trans as possible contributor. Good luck.
Title: Re: You guys wanna take a guess at what this sound is?
Post by: TurboChris on August 20, 2025, 02:47:36 PM
Good idea, I did just that on Sunday and yep, it's all in the rear. Funny how it can sound like its up in the trans. Maybe the sounds was traveling up the driveshaft or something. I don't know but I'm happy it isn't the TKX.

Thanks!
Title: Re: You guys wanna take a guess at what this sound is?
Post by: Chuck on August 30, 2025, 10:51:00 PM
 That’s what happens, it goes up the driveshaft and comes out the trans like a screwdriver to your ear. Still didn’t hear the noise but interested in what you find.
Title: Re: You guys wanna take a guess at what this sound is?
Post by: TurboChris on August 31, 2025, 11:19:18 AM
If you listen you can hear the clunking.