Detroit TrueTrac Available for 1st Gen Front Diff from ECGS

Thought I'd pass this along in case anyone was considering this option. I was, but now I'm selling my 1st gen.

ECGS now offers a Detroit TrueTrac for 1st gen Tacomas/3rd gen 4Runners.

I researched this months ago and found, while it's possible, it had some drawbacks that made it a no go. Those drawbacks have been addressed thanks to @JZiggy.

T4R Thread for more info https://eastcoastgearsupply.com/i-157180-tacoma-4runner-7-5-reverse-ifs-clamshell.html

 

I don't know much about the 4WD diffs since I have a 5 lug. The front diff is 7.5 right? My rear diff is 7.5. Can i use the front diff TrueTrac in my 5 lug rear diff?

 

Looks like you get one specifically for your application. Check compatibility.

https://www.drivetrainshop.com/Detroit_TrueTrac_p/eat-911a445.htm

 

Sweet, I think I found it: http://www.drivetrainshop.com/Detroit_TrueTrac_p/eat-911a342.htm

 

JZiggy in that toyota-4runner.org thread described issues with snap rings and axle shafts yada yada yada. I wasn't quite following all of it. If one were to purchase that front 7.5 reverse IFS clamshell from ECGS (2nd link above) with a TrueTrac pre-installed... does one avoid all the problems JZiggy described?

And... was JZiggy's issues he had to work around because he had manual locking hubs? Are all his heartburn avoided if a Tacoma with an ADD front end is involved?

 

The addition of the TrueTrac for 1st gens is new. I was only their site a few months ago and it wasn't available. Being the professionals that they are, I would assuming they've found a solution to the problem and that's why they now offer it as an option. What their exact solution is, I don't know. I'm sure someone at ECGS would be more than happy to explain it.

 

I know from reading his post over on the 4runner site, that JZiggy had to overcome some issues... I don't fully understand what those issues were.

But, in the interest of trying to make sure I'm on the same page as you... I understand you to be saying that since this is being offered by ECGS, that were one to purchase this assembled 7.5" IFS Reverse front clamshell differential from ECGS... and choose the option for them to put a TrueTrac in it, it should be "issue free"? That is, whatever JZiggy had to contend with, or any other issues were addressed by the pros @ECGS ?

(Sorry for being so verbose... it's probably because I don't fully understand / comprehend the issues JZiggy had to overcome.)

 

From what I understand, the CV shaft doesn't seat all the way into the diff. He shows a picture of the gap in that thread.

This is part of my conversation with ZUK:

Me: I've been trying to find info on this installation a few times and came away without a definitive answer. I guess I should've tried harder because today I found a thread on toyota-4runner.org by JZiggy that mentioned your name. I was glad to see you're a member here also. With all the ADD, reverse clamshell, CV issues talk, I'm hoping you can give me the answer.

Can a TrueTrac be installed in my front diff?

Me: Pardon my ignorance, but does having manual hubs make a difference?

 

@1997tacomav6 that's cool. But you have me at a loss what your post has to do with TrueTracs & Taco front diffs?

 

Wrong section, it’s gone

 

I have a Trutrac in the front on my 02 Taco. I’ve had it in for over 2 years now and also battled this issue, but before there was ANY info on it and even Eaton didn’t know if the issue... I went round and round with them...

The issue is the Tacoma axles splines are millimeters shorter than the 4Runner and other 7.5 equipped trucks..
Why? Who the hell knows...

There are 2 ways to handle the situation, 1. Modify the axle as stated above
Or
2. Modify the Trutrac. If you modify the axles and it fails you on the trail, you are now SOL, because you cannot go buy another custom axle.

So I chose option 2.

I disassembled the Trutrac assembly, removed the Drivers side spider gear, and turned it in a lathe to cut down the surface area where the snap ring lies.
I don’t remember the measurement, but I measured a factory 4Runner axle and Tacoma axle and used that difference to decide how much to take off.

Worked flawlessly and I can put any stock axles in and out if I were to have have a catastrophic failure..

If anyone has any questions, PM me and I can give you my phone number to call if you’d like, my thumb hurts lol

 

Option 2 seems like the smarter way to go. I wonder if that's what ECGS is doing. Maybe I should just email them and find out.

 

Googling "TrueTrac Toyota 7.5 IFS Reverse Front" is turning up TrueTrac differentials in the $520-530 range. The @ECGS webpage lists the TrueTrac option, on the web page that you linked in your OP, at $650. Would $120ish reflect a machining operation as described by Faster_n_you98? Or would that $120ish just reflect properly installing it?

I have an e-mail in to @ECGS yesterday asking them some questions, but 1) I think I sent the e-mail before Faster_n_you98 had posted his reply and 2) I feel like I don't know what the hell I'm talking about (yet), so my questions may have been malformed and I may have been asking the wrong things. When I hear back from them, I will post what I have learned.

But I say... fire off that e-mail 2BP...

 

It would make sense the extra would be for machining. I believe the 911A445 is the front 7.5 model. Eaton's installation guide states, "911A445 Will not fit selector disconnect 'shift on the fly.'"

 

Kinda sucks that I finally found out I can run a TrueTrac in front right after I buy a new truck. My 1st gen will be for sale soon.

 

If you had known you could have put a TT in the front of your 1st gen, would you have kept it and foregone buying the new truck?

 

Possibly. I think the TT up front would make a very capable truck just that much more capable and fun to drive off road.

I'm not regretting the purchase. I like the new truck a lot. I'm sure I'll like it more after upgrading the suspension and getting some armor on it so I can go play again. I'll probably put a TT in the new truck eventually. Have to get used to the size difference. I'm not driving a compact pickup anymore.

 

In your experience, has the TT proved to be worth the cost? Has it improved your off road performance?

 

Is this an accurate Problem description(?):
Without being terribly technically detailed, is it accurate to say the problem with installing a TrueTrac in the front end of a 1st gen Taco with a 7.5 IFS frontend has involved the front axle shafts not properly fitting (or seating) into the front differential with the TrueTrac installed which has resulted in leaking gear oil from the 7.5 IFS frontend?

Solutions:

1. JZiggy discovered a workaround and described it here: . Ziggy's workaround involved removing 0.015" material using a lathe as he described in that post. The disadvantage being an estimated loss of 10% strength in the axle.
   
2. Faster_n_you98 described his solution: "disassembled the Carrier (Trutrac) and removed the left hand spider gear and machined it. The axle on the RH side will still snap in just fine...." (Post #22 of this thread) The amount of material removed was determined by measuring a Taco axle and a 4runner axle and comparing the measurements.

We are presently wondering if the Toyota 7.5 IFS Reverse front with TrueTrac option installed, as offered by @ECGS addresses this problem, and if so, how.

Question(s):

1. JZiggy installed a TT in the front of his T4R with manual hubs and had issues. But he mentions Taco axles(?). Was JZiggy using Taco axles because of the manual hubs?
   
2. Faster_n_you98 installed his TT on his 02 Taco. I assume (dangerous) that he had a factory stock 7.5 IFS ADD front diff and was using factory stock Taco axles?
   
3. Is this problem with a TrueTrac in a Toyota 7.5 IFS REVERSE ADD front diff caused by Tacoma axles? Does the problem exist with 4runner axles? If someone wanted to put a TrueTrac in the front of their 1st gen Taco, could these problems be avoided by using 4runner axles?

 

I think that's about right. As for using 4Runner axles, I can't comment. I think one of the spares I have is a 4Runner axle. I can take some measurements tomorrow.