Detroit TrueTrac Available for 1st Gen Front Diff from ECGS

When faster_n_you98 commented about measuring the difference between 4runner and Taco front axles, and I recalled JZiggy mentioning using Taco axles in his 4runner frontend... it got me a wunderin...

 

The Issue is with the Tacoma axles designed for manual locking hubs.
I failed to mention the important detail in my post.
I would HIGHLY discourage anyone from putting a posi or locker of any sort up front without manual locking hubs.
It is just too hard on your axles and hub assemblies.
You need to be able to disconnect the hubs and let the axles be stationary during normal operation.
On top of that, if you have a catastrophic failure of the front diff or axles, you can just turn the knob and drive home.

Yes my axles were factory Toyota, but I also tried 2 aftermarket from parts stores with same luck.

I didn’t stick the carrier assembly on the lathe, I disassembled the Carrier (Trutrac) and removed the left hand spider gear and machined it. The axle one the RH side will still snap in just fine...

If there is enough interest I can find the extra spider gear I modified, but it’s buried and I will only dog for pics by request lol

 

I'm interested in any pics you might dig out / find. First round's on me should we ever meet.

 

@Faster_n_you98, can you expand a bit on why you "HIGHLY discourage anyone from putting a posi or locker of any sort up front without manual locking hubs"?

How is it "too hard on your axles and hub assemblies"? For context, I am specifically asking with regards to a fully mechanical LSD -- the TrueTrac. From what I have read it operates extremely smoothly. If not running a modded Taco in AWD mode, then when in 2WD (i.e. with no power to the front diff) and with the ADD having disconnected at least one front axle, I am trying to understand better what issues may (will?) arise with a TrueTrac in the front along with ADD axles?

Another reason I ask is that @bwawuz02 has turned his 2nd gen Taco into an AWD traction grabbing beast with Torsen differentials (at least one is a TrueTrac) as described in his 8" IFS Clamshell w/FRS Torsen thread. He didn't seem to share (or be aware?) of your concerns.

So I ask (politely).

 

I went with a Trutrac because it is the smoothest posi when transitioning power from the right to left.
Clicks/Clunks from a locker are asking for a snap somewhere in the axle, a traditional posi with clutches doesn’t transition the power very well imo.

Watch the link below of my truck.
The transition of power from the right front to left front wheels with a Detroit Trutrac installed in the factory 7.5 Clamshell Front IFS Differential.
Notice it massages (if you will) from right to left, but never lets either wheel actually stop as an open carrier would.

https://youtu.be/FF066gUJ-z0

Also regardless of my opinion of posi/locker/open up front, there’s nothing to have an opinion about when it comes to disconnecting and driving home with manual hubs. If the w/o manual locking hubs you are stranded.. or have to swap and axle on the trail.

 

@Faster_n_you98, re-reading what you have posted... you are NOT saying don't put a TT in front, but you would not put, and advise anyone against, putting any locker or LSD (TT or otherwise) in the front without manual hubs. Because if something in the frontend with an ADD breaks on the trail... you are either stuck, or having to swap/repair axles & stuff. Is that correct?

At the time the above video was tken, did your little Yota have any traction enhancers (i.e. a locker) in the back? (Sorry if you posted and I missed that. Rewatching the video... is your back locked?)

Also, what size tires are in the video, what sliders and front bumper were you running?

Thx.

 

You understand correctly!

Yes the rear ended has a Detroit locker, 4.88’s, Chromoly Axles, Armor, and at the time 33’s.

Front bumper is an Addicted Offroad Front Bumper and the Rock Sliders are 1 of 1 I had a custom Fabricator make for me. They tuck and function extremely well!

I’d post a pic but I keep getting a 403 forbidden error when I try to add pics

 

The ADD's sure are nice, though, for shifting in/out of 4WD when the snow is flying and it's brrrr cold out (or worse -- freezing rain or sleet). They are just generally more convenient, IMO.

@Faster_n_you98, could you buy into the following statement:

For everyday driving, and for light/moderate off-road use, an ADD front-end is very convenient, and reasonably reliable and durable. Take note, though, that if something breaks in the front end -- an axle shaft, a CV joint, how a front axle mates or interfaces with the front differential -- with an ADD front-end your 4WD is FORKED! (You should be able to get power to the rear wheels in 2WD HI.) For serious / heavy duty off-road use, understand the risk that an ADD front-end presents: if off-road, on a trail or climbing rocks etc, if your front end pukes and it uses ADD, your are likely stuck / broken down / in recovery mode, unless you can drive out in 2WD HI. For serious / heavy duty off-road use, you are well advised to consider upgrading or otherwise modding your vehicle to use manual locking hubs and associated axles etc.

NOTE to reader: ADD -- Automatic Disconnecting Differential (i.e. you do not have to get out of the vehicle and manually lock the hubs at the front wheel.)


​

The only (minor) bone of contention I might have with one of your posts a ways back, is that in "normal" DD use, and even in normal 4WD use on slick roads (snow etc) or gravel roads / trails, a TrueTrac will cause truly minimal wear; that is, IMO, the stress of a TrueTrac in the front diff on the front driveline components in DD and normal 4WD use will be well within the design constraints of those components. I don't have an engineering analysis to back that up, it is just my opinion.

NOTE to reader: the struckthrough text is left for readability / thread history. But @Faster_n_you98 raised valid points of contention. Please see Post #30 for a better statement about why you should strongly consider manual hubs for your IFS front axle.

 

Incorrect on 2 fronts.

If you break an axle or break internals on your front diff with ADD, you’re in need of a tow.. there is no getting it out in 2Hi.
You could even remove the front driveshaft... in an ADD diff if the front wheels are spinning, so are the axles and diff.. the input at that point will be the wheels not the front driveshaft.

That being said, in a posi of any sorts, the tires will want to spin at the same speed, even a slight turn will cause resistance/stress/heat/etc unlike an open carrier. In no way are the amounts of wear comparable.

With hubs you disconnect the differential stays stationary not spinning at all, which means it’s not wearing at all, less rolling resistance I bet you can get another mpg out of disconnecting the hubs..

If that’s still not enough to convince you of manual hubs superiority, how about the fact that you then have the option of 2LO!

 

OK, editing... @Faster_n_you98, how is this:

For everyday driving, and for light/moderate off-road use, an ADD front-end is very convenient, and reasonably reliable and durable. Take note, though, that if something breaks in the front end -- an axle shaft, a CV joint, how a front axle mates or interfaces with the front differential -- with an ADD front-end you will need a tow! For serious / heavy duty off-road use, understand the risk that an ADD front-end presents: if off-road, on a trail or climbing rocks etc, if your front end pukes and it uses ADD, your are stuck / broken down / in recovery mode. For serious / heavy duty off-road use, you are well advised to consider upgrading or otherwise modding your vehicle to use manual locking hubs and associated axles etc.

NOTE to reader: ADD -- Automatic Disconnecting Differential (i.e. you do not have to get out of the vehicle and manually lock the hubs at the front wheel.)
​

I concede that with an ADD, axle shafts ARE spinning and the presence of a LSD, TrueTrac or otherwise, will result in additional friction / stress etc compared to an open diff. However, in my opinion, I am not willing to say that additional stress is an issue for daily driving, occasional light/medium off-road use. For full-time, heavy duty off-road 4x4 use, it is probably not negligible. But in that case, we are back to your excellent point that an ADD frontend puking will ruin your day.

My biggest takeaway is this: for the most reliable, most dependable, strongest off-road 4x4 system, one should have manual locking hubs in the front, along with all the necessary hardware that comes with it.

 

Question: with manual locking front hubs, can you run around as a DD with the hubs locked BUT with the transfer case in 2HI (i.e. not in 4x4)? In the case of a 4runner with a center diff, could you run around as a DD with the hubs locked but the CDL unlocked?

I am not suggesting leaving the front hubs locked ALL the time, but perhaps you have a snow storm and during the storm and few days after, as snow melts or is plowed etc, could you leave the front hubs locked, but just take care to not lock the front and rear together via the transfer case (or center diff in 99-00 4runner Limited or 01-02 4runners)?

 

Of course you can leave them locked!
I will leave mine locked in this scenario of days of snow, but for short of time as possible.

When you lift an IFS truck you increase the angles of the cv joints increasing wear on both the joint and boot.

Mine is pretty high, so I prefer to leave mine I locked for that reason along with all the others I listed earlier.

 

@Faster_n_you98, does the (re-)wording of my post #30 meet with your approval / agreement?

 

For the most part yes, I think it’s fine

 

Thread revival, long term updates?

 

There's a Harrop front e-locker that looks great. Pretty pricy though. I like the idea of having the option to turn the front locker on and off on the go instead of having it always on like the TT.

 

Nah, don't want something I need to be switching on and off every time I need to turn or risk breaking something

The true track acts like an open diff when one side has no load like the diff is disengaged so it won't affect 2wd driving and doesn't lock or lsd up till you're on the gas plus everyone who runs them only has good things to say aside from those wanting to use manual hubs

But it seems ecgs corrects the 2 flaws they have, metall on metal cv/carrier interference and manual hub cv fit issues

 

i wonder if ECGS knows if the trutrac diff will now be compatible with both tacoma and 4runner axles? Most parts stores list these as the same fitment so i'm sure the cores for rebuilds get interchanged. Going to napa and ordering a 2004 tacoma reman'd cv may in-fact be a 1999 4runner core axle

 

I have Harrops front and rear and I LOVE them. They have a stupid simple electromagnet locking mechanism and a stupid simple wiring harness. But True Tracs are the best LSD since they're gear-driven instead of the usual wet discs. I was going to go with those until I found out about the Harrops.