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Old 04-10-2022, 02:33 PM   #1
44boggers
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Clunk coming from rear end (Truetrac problem)

I put an Eaton Trutrac in my 12 bolt. It is a build in progress. I just finished building a house and moved my truck to my new garage. the other week it was the first time in 7 years I moved the truck under its own power. I put new gears and a trutrac in it 2 years ago. Anyway moving the truck out of my garage and making a turn to load it onto the trailer, it felt like my rear end was skipping. Once it went straight it was fine. Keep in mind i did not move the truck more than 20 feet. I got it on the trailer and moved it to my new garage. Unloaded it on a gravel road, made a turn to go down my driveway and the skipping/clunking was not there. I havent touched it in two weeks. So today I move it to a different spot in my garage which required me to make a 90 degree turn and again i felt the rear end skipping/clunking, but once straightened out it was fine.

Is this because of the trutrac?? I cant seem to find any other issue. Bearings are good, leaf springs are tightened down. It is my first onroad experience with a locker.

Thanks for any insight.

Paul

Last edited by 44boggers; 04-10-2022 at 02:51 PM.
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Old 04-10-2022, 02:41 PM   #2
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Re: Clunk coming from rear end (Truetrac problem)

Doesn't sound like a trutrac...sounds more like a locker
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Old 04-10-2022, 02:44 PM   #3
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Doesn't sound like a trutrac...sounds more like a locker
It’s for sure a trutrac
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Old 04-10-2022, 02:51 PM   #4
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Re: Clunk coming from rear end (Truetrac problem)

Can you tell the noise is coming from the diff?
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Old 04-10-2022, 02:53 PM   #5
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Re: Clunk coming from rear end (Truetrac problem)

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Originally Posted by mongocanfly View Post
Can you tell the noise is coming from the diff?
I cant say the noise is 100 percent coming from the diff. I just noticed the minute i turned the truck i thought something was broke to the point i got out and crawled under the truck to make sure the leaf springs were tight as well as the wheels. But it is for sure coming from the back of the truck and you can feel it as well.

Could it be the sound/feeling of one tire skidding around while the other turns, or is that not how a trutrac would act?
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Old 04-10-2022, 03:00 PM   #6
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Re: Clunk coming from rear end (Truetrac problem)

Seems like I remember when you put that in..
A trutrac should act like a open diff..had no popping issues with mine
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Old 04-10-2022, 03:02 PM   #7
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Re: Clunk coming from rear end (Truetrac problem)

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Originally Posted by mongocanfly View Post
Seems like I remember when you put that in..
A trutrac should act like a open diff..had no popping issues with mine
Ok good to know. I think I need to have my wife drive the truck while i watch from the outside to see any visual cues.
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Old 04-11-2022, 04:58 AM   #8
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Re: Clunk coming from rear end (Truetrac problem)

I'm no help here, but will be interested to know what it is when you get it figured out. I was thinking about your project just the other day, I haven't seen the build thread pop up. If memory serves, there are a few new things that have happened: new house, used to be girlfriend, now wife, haha. Congratulations.
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Old 04-11-2022, 07:16 AM   #9
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Re: Clunk coming from rear end (Truetrac problem)

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Originally Posted by LT7A View Post
I'm no help here, but will be interested to know what it is when you get it figured out. I was thinking about your project just the other day, I haven't seen the build thread pop up. If memory serves, there are a few new things that have happened: new house, used to be girlfriend, now wife, haha. Congratulations.
All is correct! Its been hectic, but at least i moved out of a one car garage into a 1800 sq ft garage. now i should be able to get this rig finished in the next year.

Next step is to fnish the driveside fender then bedsides. other than that it will be ready for paint. And hopefully my diff doesnt explode
Ill keep you updated.
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Old 04-11-2022, 06:50 AM   #10
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Re: Clunk coming from rear end (Truetrac problem)

I think the no driving for a few years may have something to do with it. It might come out of it.
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Old 04-11-2022, 07:16 AM   #11
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Re: Clunk coming from rear end (Truetrac problem)

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I think the no driving for a few years may have something to do with it. It might come out of it.
Hopefully, ill let you know.
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Old 04-11-2022, 08:45 AM   #12
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Re: Clunk coming from rear end (Truetrac problem)

Since it sat for a few years, possible some type of small critter built a nest somewhere and the debris is causing the grabbing. Around here, mud daubers(type of wasp), like building mud nests, often in tight places. Fairly common to find their nests in places you wouldn't think had a way in.

Congrats on the new house and shop area. Nice to have a clean indoor area to work on projects.
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Old 04-11-2022, 10:05 AM   #13
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Re: Clunk coming from rear end (Truetrac problem)

Are you sure oil was put in it years ago.
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Old 04-11-2022, 03:39 PM   #14
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Re: Clunk coming from rear end (Trutrac problem)

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Are you sure oil was put in it years ago.
Funny you should ask, cause I remember draining the fluid one time after i built the rear end, so I thought about it today and wondering if i ever refilled it. But yes it has the correct amount of fluid in there and it is very clean.

I jacked up the rear end today to do a manual/physical inspection of the wheels, driveshaft feel of the bearings. Put the trans in every gear with just one tire in the air and no noises what so ever or the feel or sound of somethign beginning to bind up. Again it was only when turning, when i went straight everything was quiet.

Tomorrow I will have my wife drive the truck in the garage while i watch from the outside.
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