DIY Truetrac in rear D44

aro

aro

New member
I want to replace the stock Trac-Lok with Truetrac. (Why Truetrac and not lockers? It's cheaper and it will do the job for my wheeling.)

I want to do this myself, so I have a question to which I think I know the answer, but need to confirm.

Since I'm not regearing (yet), I have an easier job. I don't have to touch the pinion assembly. It's very tempting to simply replace the carrier assembly, reuse the old carrier bearing shim measurements, and then check backlash and pattern. It could work, but by not removing the drive shaft, I won't be able to check the overall preload.

Is it unreasonable to assume that the carrier bearing preload will be OK by using the old shim measurements? Or should I quit being lazy, remove the drive shaft and check the preload? It's probably the latter... and I'm not really lazy... but I'm curious what more experienced wrenchers think about it.
 
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OJK12

OJK12

New member
I have installed the true track in my last 2 door sport which had 3:73's and I'm assuming yours is a sport as well. Here is what you will find, the JK does use a true DANA 44 rear BUT...it's an axle that's never been used in anything else and the true track was designed for the regular 44 therefore the true track you have prolly will not be a "bolt in" deal unless maybe you have the 3:21's. My carrier used 1/2" bolts in the ring gear and the true track was drilled for 7/16 so I couldn't bolt it up. When I emailed Eaton about it they said to just drill out the holes to 1/2". We put it in a drill press in the mold shop where I work and the bits didn't even mark it and we were concerned about keeping the holes centered so it would bolt up. The guys measured the hardness and said it was too hard to drill so long story short I ended up buying 4:56 gears and the new ring gear was dual drilled with 7/16" holes and that's how I was able to use it by regearing. If you are gonna regear anyhow I would just get new gears and do it all at once that way it will be one and done. I also would not recommend reusing the carrier bearings, just not a good idea especially since all the '12's I've seen (3) the bearings were all starting to pit and the pinion race was pitting with all less than 30,000 miles. I loved my true trac and would definitely recommend it but it does suck they don't have one that is drilled correctly and ready to bolt in.
 
mudmobeeler

mudmobeeler

Caught the Bug
In theory, if you were reusing the same carrier, bearings, ring and pinon, etc. then yes you should be ok with reusing the bearings and shims. I would still check preload and gear pattern just like if you changed gear ratios. Since you are changing the carrier to something else then I would go ahead and do a full rebuild kit with new bearings and shims as the new carrier could be machined differently and need new shims anyway. I would look at re-gearing also as you are already there.

Might be beneficial to wait a little longer, specially if you weren't looking at re-gearing.
 
aro

aro

New member
Wow, OJK12, that's a game changer! I knew that there must be guys here who know more about it. Thanks!

As far as regearing... yeah... I would love to do it... I know exactly every single step required, I have in my mind the exploded view of the entire differential, I know what each part does... but I've never done it. I think it's more of a mental barrier.

If I had a buddy who's somewhat handy, even if he didn't know anything about differentials, I would go for it. I was actually thinking of getting a rental mechanic, one of those mobile mechanics. Just for the moral support and maybe some extra tools. It would probably end up costing as much as having it done professionally, but the experience would be priceless. If anything goes wrong, Rebel Off road is 5 minutes away.
 
jeeeep

jeeeep

Hooked
aro said:
Wow, OJK12, that's a game changer! I knew that there must be guys here who know more about it. Thanks!

As far as regearing... yeah... I would love to do it... I know exactly every single step required, I have in my mind the exploded view of the entire differential, I know what each part does... but I've never done it. I think it's more of a mental barrier.

If I had a buddy who's somewhat handy, even if he didn't know anything about differentials, I would go for it. I was actually thinking of getting a rental mechanic, one of those mobile mechanics. Just for the moral support and maybe some extra tools. It would probably end up costing as much as having it done professionally, but the experience would be priceless. If anything goes wrong, Rebel Off road is 5 minutes away.
Click to expand...

I don't want to simplify it but if you are mechanically inclined and have the proper tools and patience (time), it's not so difficult. I've only helped install but even with me helping I was told it took a lot longer with me asking questions and slowing them down to see exactly what they were doing. I will add, there are many places in the process if a shortcut or error is made it will cause it fail.
if you're going to tackle the job just make sure you have all the proper tools
 
aro

aro

New member
One thing I have is patience and time. Tools will have to be acquired. I read about a guy who spent 3 days adjusting preload and backlash the first time he did it. I'm fine if it takes days. I can always get another master kit if I mess up parts. The tough part is overcoming the initial reluctance to get started.
 
P

Pastor Scott

New member
BLD capability with Tru Trac differential

Cant seem to get a good reply.. what happens when you install a tru trac differential or even a loc rite in our JKs what does it do to the BLD system and traction control ?
I can only imagine complete confusion and code lights flashing..

anyone know

Ps Scott
 
aro

aro

New member
Pastor Scott said:
Cant seem to get a good reply.. what happens when you install a tru trac differential or even a loc rite in our JKs what does it do to the BLD system and traction control ?
I can only imagine complete confusion and code lights flashing..

anyone know

Ps Scott
Click to expand...

I don't see Truetrac interfering in any way with BLD or any of the other electronic stability gizmos in a JK. Sure, I could be wrong, but I don't see how that could happen from a mechanical point of view. You could even remove LSD from the rear diff and have it completely open and it shouldn't affect anything (not that it makes sense to remove LSD, just to make a point).
 
OJK12

OJK12

New member
In my 2012 sport I had absolutely no issues with the traction control coming on and freaking out. It was totally seamless and worked very well, but it was still not a true locker and did allow it to slip and the tires to spin at different speeds so it really never should cause issues but from what I have read about and learned from others here is a true auto locker like a Detroit or Lock Right will cause the traction control to freak out. Really in my opinion if you need/want a positive locking diff you really should get a selectable one. It just makes more sense and it's not as dangerous in the icy conditions. That is one thing I noticed the very first snowfall is although the true trac was only a limited slip it worked well enough the first snowy day I had to slow down as it wanted to fishtail a lot. I now have a Rubicon and the selectable lockers are the best of both worlds but like I said I did love my true trac in my sport, it combined with the traction control would let me crawl very well.
 
aro

aro

New member
OJK12 said:
My carrier used 1/2" bolts in the ring gear and the true track was drilled for 7/16 so I couldn't bolt it up.
Click to expand...

To get back to your point, it looks like Eaton has improved their design. This is from their documentation, page 34:

An example would be Dana 44 units. Ring gears exist with 3/8”, 7/16”, and 1/2” fasteners. Eaton performance differentials for this application are typically machined with both 7/16” and 1/2” clearance holes.
Click to expand...

Also, if you look at the bottom picture of the mounted ring gear, you'll see that indeed it has an additional set of holes. I guess I'm back in business. Just as I almost talked myself into regearing...
 
OJK12

OJK12

New member
aro said:
To get back to your point, it looks like Eaton has improved their design. This is from their documentation, page 34:



Also, if you look at the bottom picture of the mounted ring gear, you'll see that indeed it has an additional set of holes. I guess I'm back in business. Just as I almost talked myself into regearing...
Click to expand...

Mine was dual drilled but for 3/8" and 7/16" bolts, did you measure the hole sizes on the true trac to see? I didn't see the page you were referring as it only went to page 32. You will have to take the cover off and see what size bolts are in your ring gear if they are 7/16" you are good and I thought I heard someone say the 3:21 gearset used 7/16" bolts but don't take that to the bank as I've never seen one with 3:21's so I can't say. When I had emailed Eaton they said at that time they no plans to offer a true trac with the half inch holes just to fill the JK void but they could have changed their mind with so many JK's out there. The only way to know for sure is to take the cover off and see what size bolts you have. If you look at the pic (truetrac is in the upper left corner) you can see mine was also dual drilled. ImageUploadedByWAYALIFE1450764057.161246.jpg
 
aro

aro

New member
Mine is a 3:73. I guess the only way to tell for sure is to do what you said, remove the ring gear... at which point, I might find out it's not what I need. Great... (Page 34 on their document, not what the computer tells you is page 34)

What's the gray box? A set for driving races and rings?
 
jorgelrod

jorgelrod

Hooked
Pastor Scott said:
Cant seem to get a good reply.. what happens when you install a tru trac differential or even a loc rite in our JKs what does it do to the BLD system and traction control ?
I can only imagine complete confusion and code lights flashing..

anyone know

Ps Scott
Click to expand...

Only an auto locker on 2012+ models will do that, LSD will always allow differentiation in speed between tires and sensors so the system will not go all crazy unless you are trying to do donuts on ice at full throttle or some crazy stuff like that...

Remember, the Majority of Wrangler Sports are sold with traklok which is also an LSD, albeit inferior in all respects to a truetrac
 
jorgelrod

jorgelrod

Hooked
OJK12 said:
Mine was dual drilled but for 3/8" and 7/16" bolts, did you measure the hole sizes on the true trac to see? I didn't see the page you were referring as it only went to page 32. You will have to take the cover off and see what size bolts are in your ring gear if they are 7/16" you are good and I thought I heard someone say the 3:21 gearset used 7/16" bolts but don't take that to the bank as I've never seen one with 3:21's so I can't say. When I had emailed Eaton they said at that time they no plans to offer a true trac with the half inch holes just to fill the JK void but they could have changed their mind with so many JK's out there. The only way to know for sure is to take the cover off and see what size bolts you have. If you look at the pic (truetrac is in the upper left corner) you can see mine was also dual drilled. View attachment 179030
Click to expand...

My D30 Truetrac was dual drilled as well
 
aro

aro

New member
aro said:
What's the gray box? A set for driving races and rings?
Click to expand...

I'm answering my own question... Yes, that is for driving races. I always assumed I had to improvise a tool for that. Can't believe I never googled "driving race set" :rolleyes2: Can't believe how excited it makes me to see that set :D
 
Jeepfan30

Jeepfan30

Member
I have been thinking about getting a TT, or two, in my front and rear. I am already re-geared to 4.56 and curious who has real world experience with them in their JK? The BLD has worked great so far, I don't have many rocks to play in. I have read that they lock up like 60/40, but I know they are not a full selectable locker. Thanks,
 
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