Sure Grip unit feels much better than Eaton TruTrac did..

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I built Jbc426's True Trac equipped third-member (among approx 100 others) about 5 years ago. At that time, I did not hear any complaints from my customers. See below:

Eaton Truetrac noise? Doctor Diff? | Moparts Question and Answer | Moparts Forums

In 2015 I started hearing complaints from a few customers regarding noise associated with the units. See below:

truetrac noise, finally found it, not sure I can fix it!

Even though the problem was hit-or-miss, I quit selling True-Tracs for over a year UNTIL that production run was depleated. I recently re-listed True-Tracs because I haven't heard any complaints with the latest production run.

Again, the problem was a crap-shoot. Read all the reviews on Summit, below:

Eaton Detroit Truetrac Differentials TT70P52790

The issue was not exclusive to Mopar 8.75" rears. Quality control on the Ford 8.8" version also suffered.

BTW, I 'm about to release my own version of the 8.75" True-Trac.
 
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You’re 100% off base about Cass, aka, DrDiff. That’s what I disagree with. I’ve done business with him for years, bought everything from axles to disk brakes, even a brand new 3rd member with an Eaton Trutrac for my Duster that’s going in with my t56. I’ve called him, emailed him, bought products, you name it. He’s helped me out a few times diagnosing differential issues, even though there wasn’t any parts I bought from him involved. Even shipped me a couple parts overnight to get me back up and running. His knowledge and customer service is the best I’ve encountered in the Mopar world. So yeah, I disagree with you suggesting his ethics are suspect, that’s total BS.

As for the truetrac, I haven’t heard of any issues with them before this post, and I talked to a bunch of people. I’m pretty sure @autoxcuda and @GMachineDartGT both run them in their cars that are seeing plenty of track time. I’m not discounting jcb426’s assessment, and I’m not saying his truetrac wasn’t the source of his problem. But lots of people run them successfully. I’m definitely concerned about some of the issues he had because I haven’t installed mine yet, but there are plenty of parts in motion. I’d be interested to know if anyone else with green bearings has the issue, because I know the folks I talked to all run tapered bearings. Or maybe jcb426 just got a bad unit with excessive clearance. Or maybe it’s some combination of parts. Sucks with an expensive part like that, but it does happen, nothing is 100%.

This is great to hear...and your endorsement is worth a lot in my estimation.

I think we're lucky in the Mopar world. While we have fewer choices and more expensive parts than the Chevy and Ford guys, the vendors who specialize in Mopar stuff seem to be the good ones.
 
I built Jbc426's True Trac equipped third-member (among approx 100 others) about 5 years ago. At that time, I did not hear any complaints from my customers. See below:

Eaton Truetrac noise? Doctor Diff? | Moparts Question and Answer | Moparts Forums

In 2015 I started hearing complaints from a few customers regarding noise associated with the units. See below:

truetrac noise, finally found it, not sure I can fix it!

Even though the problem was hit-or-miss, I quit selling True-Tracs for over a year UNTIL that production run was depleated. I recently re-listed True-Tracs because I haven't heard any complaints with the latest production run.

Again, the problem was a crap-shoot. Read all the reviews on Summit, below:

Eaton Detroit Truetrac Differentials TT70P52790

The issue was not exclusive to Mopar 8.75" rears. Quality control on the Ford 8.8" version also suffered.

BTW, I 'm about to release my own version of the 8.75" True-Trac.

It means a lot that you came here to clarify. Thank you.

How were you able to identify the affected production run? Is there a serial number range?
 
I think the reason that theres more "good guys" in the Mopar realm is that its such a smaller righter knit community , that bad word gets around a lot quicker to more of your customer base, then you lose most of your business.

I have had dealings with Cass and everything was great. Bought all my 3rd member parts from him. Gears, bearings, clutch type sure grip, axles w green bearings etc. Everything was as advertised, packed well and shipped in timely manner. I cant ask for much more than that.

The fact that he is trying to address the problem with faulty units is a testament to his good character. Plus he is coming out with his own true trac type limited slip which will likely be better than the Eaton one.

Jamie Passon is the same way with the 4 speed transmissions. He saw a need for a direct bolt in 5 speed that fits in place of a 4 speed with NO floor, bellhousing, driveshaft, or crossmember modifications. And named it the A-855. It looks like an evolution of the A-833, and is unbreakable.
 
You’re 100% off base about Cass, aka, DrDiff. That’s what I disagree with. I’ve done business with him for years, bought everything from axles to disk brakes, even a brand new 3rd member with an Eaton Trutrac for my Duster that’s going in with my t56. I’ve called him, emailed him, bought products, you name it. He’s helped me out a few times diagnosing differential issues, even though there wasn’t any parts I bought from him involved. Even shipped me a couple parts overnight to get me back up and running. His knowledge and customer service is the best I’ve encountered in the Mopar world. So yeah, I disagree with you suggesting his ethics are suspect, that’s total BS.

As for the truetrac, I haven’t heard of any issues with them before this post, and I talked to a bunch of people. I’m pretty sure @autoxcuda and @GMachineDartGT both run them in their cars that are seeing plenty of track time. I’m not discounting jcb426’s assessment, and I’m not saying his truetrac wasn’t the source of his problem. But lots of people run them successfully. I’m definitely concerned about some of the issues he had because I haven’t installed mine yet, but there are plenty of parts in motion. I’d be interested to know if anyone else with green bearings has the issue, because I know the folks I talked to all run tapered bearings. Or maybe jcb426 just got a bad unit with excessive clearance. Or maybe it’s some combination of parts. Sucks with an expensive part like that, but it does happen, nothing is 100%.

I don't run a true trac. I've got an OE clutch in my Barracuda.

A Tru Trac WAS on my wish list. That might have just changed.
 
I don't run a true trac. I've got an OE clutch in my Barracuda.

A Tru Trac WAS on my wish list. That might have just changed.

My mistake! I thought you’d already gotten one.
 
I heard rumors Cass was considering a 8 3/4 aluminum case. That MP price is rediculous.
 
I heard rumors Cass was considering a 8 3/4 aluminum case. That MP price is rediculous.

It would be a great idea if he could put a dent in the Mopar Performance price and still make some money. The MP prices are getting totally out of hand on everything. An aluminum case 3rd member is one of those things I want every time I see one, until I talk myself back to reality. As in, I totally don't need that. I mean, maybe if I were competing or something I might be able to figure out some kind of advantage for the weight loss. But for what I do with my car I've already gone above and beyond what it needs to be for my capabilities.

Same thing any time I see a Dart Lite or Feather Duster trunk lid. Every time I see one I want one. But then people want a few hundred bucks for one (which isn't completely insane), and then shipping costs a hundred bucks because they're never anywhere near me. And finally I talk myself into how the trunk lid being a few pounds lighter will have no real effect on anything except my wallet and the setting on my trunk torsion springs.

Great stuff for the "cool" factor, but for it to be actually useful you'd need to be running against a stopwatch and be competitive about it.
 
I have a 4:30 TruTrac that I purchased from Cass about 5 years ago, works flawless. Sounds like I'm going to be looking into the new lighter unit now. If the aluminum one Cass is developing is at least 20% less than the Mopar ones I would think there will be a market for them. If Cass is involved it will be top quality for sure. Sign me up for one!
 
what do we like for rear gear lube? conventional, semi synthetic, full synthetic? I run walmart 80-90 semi
 
The G80 auto locker stopped locking in my 06 Sierra, so I just had an Eaton Truetrac installed. My initial impressions are very good (but very limited at this moment). It seems very smooth and both wheels hook up when needed.

I read through this earlier thread regarding fluid recommendations. Though the thread is somewhat old, the recommendations are still valid for the most part.

Here's what Eaton says today in the documents currently on their website:

Detroit Truetrac
A quality petroleum (mineral) based oil is recommended. Synthetic oils and friction modifiers should not be used, as they will decrease overall performance.

Detroit Truetrac®
What kind of oil should I use? Can I use synthetic?
Do I need friction additive/modifier?
Truetrac units perform best when using GL5 mineral /
petroleum based gear oil. Synthetic lubes are
discouraged. Do NOT use friction modifier additives or
lubes formulated with friction modifiers. See the
“Lubrication” section of this product manual for further
details and specifications.

Lubrication Specifications
Detroit Truetrac®
High quality mineral or synthetic gear lubes are
required for use in Detroit Truetrac differentials.
Regardless of the lube type, always use a GL5 rated
lube with the least amount of friction modifier. Mineral
lubes lacking friction modifiers (limited-slip additives)
were historically recommended for all Truetrac
applications because friction modifiers can slightly
reduce the bias ratio (limited-slip aggressiveness) of
Truetrac differentials. However, to address the
continually increasing power outputs of modern
powertrains, many vehicle manufacturers have
switched to synthetic lubricants as a counter measure
for increased axle temperatures and prolonged service
intervals. In general, consult the vehicle owner's
manual for the manufacturer's recommendations for
lubrication type, weight and fill volume. This will ensure
lube compatibility with the seal materials and bearings
used in the axle. Eaton Performance technical support
is available for any concerns in lube selection.

I was told that mine was filled with Mobil 1 when they did the install. I'm planning an oil change in a month or so, and I plan to install a conventional mineral oil without limited slip additive at that time. Unfortunately it appears most of the "majors" now include LS additives in all of their gear oils now. It appears that many of the "store brand" gear oils still lack the LS additive, so I'll probably choose one from among them.

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Re: Eaton Gear Oil Recommendations for the Truetrac [Re: Brian Barnhart]
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Registered: 10/04/07
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Loc: Oahu, Hawaii
It's probably saying syn is not recommended because most of them come with an LS additive that can affect the performance of the truetrac. There are a couple of syn gear oils without the LS additive such as Redline 75W90NS or Eneos 75W90.

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When I purchased my truetrac, I called them about the limited slip additive and told them I had put valvoline gear oil in. They told me that I needed to drain the valvoline out and use Lucas oil (no additive) or Shell in order to avoid any issues. I followed their recommendations and all seams good & would build another one if needed. Andrew
 
So here's a thing.

First, I have a few hundred miles on the TrueTrac now. There seems to be a minor vibration going on but I also changed the whole suspension and driveshaft at the same time and I'll be sorting things out on that for a while yet...not ready to blame the Truetrac yet. Plus, I have yet to go over 70mph or so...so who knows.

What I have noticed is that when turning right, I hear a scraping noise coming from the right rear. There's no noticeable noise from either side when turning left. I checked to make sure that the pads (disk brakes) weren't floating around, made sure everything was tight, it all looked ok. The noise has gradually become somewhat less pronounced but it's still there.

Any guesses?
 
Can anybody tell me if the Trutrac's are all good now? I was getting ready to buy one and came across this thread. I run a narrowed 8 3/4" with green bearings.
 
Update, I emailed Dr. diff with my set up and asked for recommendations. Cass got back to me right away.
He said the Tru trac is still hit and miss and he recommended the Sure-Trac. I ordered it this morning
Thanks Cass!
 
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