Rear axles stability

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PonyGTrider

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It looks like the only downside to this product is the price. No clutches to burn out. I want one.
It looks like the only downside to this product is the price. No clutches to burn out. I want one.
It looks like thet
It looks like the only downside to this product is the price. No clutches to burn out. I want one.

I'm not sure what is the actual price of it, I bought and installed it about 10 years ago and still running without whining. And in my personal opinion the cost is worth it
 

revhead347

Apparently my ex-husband made that mistake.
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It looks like the only downside to this product is the price. No clutches to burn out. I want one.

I could go into endless details for why I committed to an Eaton Truetrac differential. It all goes back to an engineering publication my father (who designed propulsion systems for the Navy) read back in 1968. I'll spare you that torture. A truetrac differential runs about $700 to $800 just for the unit itself. That's the tip of the iceberg , because it does not accomodate factory style C-clip axle retainment. You are forced to modify the axle with C-clip eliminators or 9" bolt on style end housings. I am currently updating a "how to" thread on building a fully streetable axle with no compromises; full parking brake, ABS retention, and 4 piston caliper compatibility that will deliver over 1000 ft/lb of torque to the street. It will be the only "how to" on the internet that I can find after 8 months of research. It's not going to come cheap though. I have sunk about $3400 into this axle so far.

Kurt
 
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PonyGTrider

Active Member
Feb 27, 2019
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I could go into endless details for why I committed to an Eaton Truetrac differential. It all goes back to an engineering publication my father (who designed propulsion systems for the Navy) read back in 1968. I'll spare you that torture. A truetrac differential runs about $700 to $800 just for the unit itself. That's the tip of the iceberg , because it does not accomodate factory style C-clip axle retainment. You are forced to modify the axle with C-clip eliminators or 9" bolt on style end housings. I am currently updating a "how to" thread on building a fully streetable axle with no compromises; full parking brake, ABS retention, and 4 piston caliper compatibility that will deliver over 1000 ft/lb of torque to the street. It will be the only "how to" on the internet that I can find after 8 months of research. It's not going to come cheap though. I have sunk about $3400 into this axle so far.

Kurt

Well undoubtedly you have your father’s genes of research and development in yourself.
Proving a concept and fabricating a prototype always takes a chunk of money out of your pocket, many times ending as a simply satisfying experience.
Good luck in your project
 

Essn95

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Jun 21, 2017
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For clarity, what are you doing to assess this play? Is this from rotating the axle or tire? Or is is this from pushing and pulling the axle against the carrier?

If it's from rotation, you could have too much lash between the ring and pinion. This means that your gears weren't shimmed correctly. Usually this results in a big clunk when you tip in and out of the gas pedal while cruising. In this scenario the driveline winds up in different directions between coasting and applying positive torque to the rear axle. When you change directions, the added lash in the rear end allows the gears to slap and you get that clunk sound. This can also be caused by bad u-joints.
I have this same lash issue that makes the clunking noise. I presume it is in fact excess lash between the ring and pinion gears. It clunks in low rpm situations when you tip into throttle.
 
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PonyGTrider

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I have this same lash issue that makes the clunking noise. I presume it is in fact excess lash between the ring and pinion gears. It clunks in low rpm situations when you tip into throttle.

I will do a good inspection of the differential to eliminate any possibilities and to replace the gear oil.
Talking about gear oil, which oil and what weight works for truetrac differential? Thank you all
 

revhead347

Apparently my ex-husband made that mistake.
15 Year Member
Jun 14, 2004
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Well undoubtedly you have your father’s genes of research and development in yourself.
Proving a concept and fabricating a prototype always takes a chunk of money out of your pocket, many times ending as a simply satisfying experience.
Good luck in your project

The axle is done, and I can pick it up tomorrow. Will update soon.

Kurt
 
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revhead347

Apparently my ex-husband made that mistake.
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It's back. It looks pretty good. I didn't realize that Moser wasn't all that accurate on their axle machining, and the calipers will have to be shimmed to fit.

Kurt
 

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    Axle front.jpg
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  • Axle Back.jpg
    Axle Back.jpg
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  • Brake Left.jpg
    Brake Left.jpg
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revhead347

Apparently my ex-husband made that mistake.
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Looks good, so you have the truetrac differential in there with what gears?

Eaton Trutrac differential with Ford 3.55:1 gears. I've gone to the end of the internet, and as far as I can tell this is the only axle of it's kind.

Kurt
 
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PonyGTrider

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Eaton Trutrac differential with Ford 3.55:1 gears. I've gone to the end of the internet, and as far as I can tell this is the only axle of it's kind.

Kurt

Same gears as my truetrac with 31 splines mosser axles, and bullit brakes.
 
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revhead347

Apparently my ex-husband made that mistake.
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Had to bring in my paint guy to make it look good. The guy does great work.

Kurt
 

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  • Will Paint Axle.jpg
    Will Paint Axle.jpg
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  • Axle paint complete.jpg
    Axle paint complete.jpg
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PonyGTrider

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Excellent and helpful information you shared. Thank you much :)
It has been long time since my last posting and still cant figure out what is wrong with my differential/axles or whatever. I just open the differential, to start I measured the gap between the barrel or spacer and the axles with a feeler gauge. It measures exactly 0.25mm or bit under 0.010".Although I have no idea what it supposed to be because I can't find that specification from Eaton or Detroit but it don't seem to be too excessive for me.

Then I noticed and confirmed my suspicions that the tips were moving up/down/sideways inside the differential. There is no play in between the axles splines and the side gears, they are nice and snugged but the gears and axles move around inside the gears housing. No whining noise as the backlash in between the pinion and the ring is perfectly in specs. and the oil is nice and clean with a greenish/golden color. It could be very normal it just bothers me since I installed the truetrac long time ago. It sound almost like a loose shock mounting bushing or an excessive play on a bushing but everything is tight. This could be normal because I remember feeling almost the same way when I had my stock carrier. Probably my ear is way too sensitive wanting to eliminate any weird noise. Anyways I'm putting everything back together and see what happens down the road
 

revhead347

Apparently my ex-husband made that mistake.
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I'll update as well. Been running the car for 6 months. Absolutely no noises or monkey business. Runs perfect.

Kurt
 
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PonyGTrider

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I'll update as well. Been running the car for 6 months. Absolutely no noises or monkey business. Runs perfect.

Kurt
Awesome!!!!! Mine like I say no whining no other noises, only that axles noise but I'm getting to a point starting to believe it is normal. the oil is nice and clean without metal dust or shavings I just bolted the cover and will wait overnight to fill it with fresh gear oil