[Tijoe]

I would like this thread to stay focused on the installation of an Eaton Truetrac 913A477 differential. If you contribute, please do not speculate about the merits of LSD, or weather one should use a locker or other type differential. I would like this post only to list descriptions, P/Ns, supporting kits and results of forum members who have installed, or are about to install a Torsen type differential. (I read all the postings to date and they are all filled with conjectures, opinions and side-bar discussions, that make if difficult for anyone to quickly determine what they need to install LSD in their transit.)

Ford 9.75" Eaton Detroit TrueTrac | 34 Spline - 2017 street price - $539.99
- P/N 913A477
- Requires: 1.370" diameter 34 spline axles.
- Type LSD: Torsen
- Torque Bias Ratio: 3.5:1
- Cover = 12 bolt
- Pinion nut: 1-1/8

- Fits all OEM Transit gear ratios

This differential is installed the most in 2011-2017 Ford F150s with 9.75 rear ends.

Other rebuild kits that may be needed for installation, depending on mileage of van.
Crush sleeve and Master bearing kit
Example: Yukon Gear Bearing kit BK F9.75-D

To help stiffen up the pumpkin, F-150 forums recommend that you replace the steel cover with an aluminum girdle cover: Such as a Yukon YP C3-F9.75 - Street price around $200.
(This type of cover has bolts in the cover that secure to the bearing caps to add additional stiffiness.)

There is also an "Axle Crush Sleeve Eliminator Kit" available. (Anyone use one of these?)

Enjoy.

 

[Lovemysan]

I have the factory Clutch type LSD in my transit. I put a truetrac in my 2005 suburban. The truetrac is reasonably civilized and my wife never noticed a difference after the install. You could provoke it to pop if you got a little frisky mid corner. The ford factory LSD is slightly more civilized but again my wife doesn't even know its there. Also if anyone has driven a GM G80 locker the eaton behaves similarly. Its also important that if you install the truetrac you need NON synthetic gear oil. If you use synthetic it will not want to lock as easily. I think the oem and the locking LSD serve the same purpose in an on road 2wd application. Off road I would probably go locker. I really don't think the aftermarket cover is necessary on a transit, its not like you can install 35" tires.

 

[keefer]

I purchased the Eaton TrueTrac from Summit Racing earlier this year and had my son-in-law who is a ASE mechanic install it for me. I am very satisfied with the TrueTrac as it is quiet and not noticeable in operation.

I was real happy with the service that Summit Racing gave me, they recommended that I purchase 12 new ring gear bolts, new carrier bearings, a shim Kit and 3 qts of the correct GL5 gear oil. I could return anything that I didn't use. I didn't use the shim kit as the Eaton diff. ended up having a better contact pattern on the differential than the stock Ford open diff. had. Excellent product. Excellent service and a prompt refund on the shim kit that I didn't use.

Ended up costing $712.31 for the parts. Your labor costs will be higher than mine.



Keefer.

 

[Tijoe]

...Ended up costing $712.31 for the parts. Your labor costs will be higher than mine.
Keefer.

I ordered the Ford Eaton 9.75 Trutrac LSD and supporting parts from Summit today. My total came to $977. I'll post the numbers of what I purchased. I must have purchased a more expensive Yukon rebuild kit than the parts you ordered.

I am looking for a company that sells the bearing cap stud kit. I like studs and nuts versus bolts for the bearing caps.

 

[Trialsalot]

Great Thread Idea! ...I bought a used 2015 T250 with no LSD and just recently bought a 913A477 Truetrac for installation by my local differential shop. I have also read about the importance of using GL5 dino oil for it's correct operation. I am also interested in hearing about the supporting kits for installation like the bearing cap stud kit, etc. Thanks!

 

[Tijoe]

LSD Installation update: Because of the weather, I went ahead and had a local auto service center install my LSD. Therefore no pictures.
A couple of comments.
1. They called me and told me there was a growling sound coming out of the rear end when the van slows down.
- I test drove it and sure enough the differential makes a sound only during deceleration. No noise steady state or accelerating.
- The shop claims the backlash is .008" and new bearings were installed and properly pre-loaded.
- I called the Summit technical support hotline and they believe that it is probably the gears. They stated to drive it for a couple thousand miles and see if it gradually gets quiet.

I also found out that my expensive B&M cover couldn't be used on my Dually. The rear sway bar sits too close to the factory cover. - I'll start working on a way to space out the sway bar mounts so it fits. Project for another day..._

I need to get my winter tires on the van and drive it in some snow.

 

[moose]

I have about 3k miles on mine and I remember there being some extra noise in the beginning. I'm not sure when it went away. I also noticed that it slowed down faster when I took my foot off the gas.

 

[kc8flb]

Had a Eaton Detroit Truetrac torsen type differential installed in my 2017 T-350 wagon. Was an open differential and will need the traction for the snow in Michigan.

Took it to a rear end specialty shop that was highly recommended and does many of these (Warren axle and gear in Warren, Michigan)

Cost:$930 total

paid $597 for the unit
$255 labor (3 hours @ $85/hr)
$40 for gear lube and shop supplies

Used normal non synthetic without friction modifier gear lube, as eaton recommends

Shop supplied everything including the truetrac unit

absolutely no driveability or noise difference from the stock open differential but i have only had it a few days

 

[Road_Ghost]

I'm seriously considering having this done, BUT dealing with Ford dealers is futile. I have the T350 148" MR 3.7 V6 w/3.73 open diff.

• 1st Ford Dealer: Said I could upgrade to the OEM LS. $190 for the gears and MAYBE (?) $146 for the clutch packs. $32 a litre for diff fluid (up to four bottles) and $6 for additive. To install it, I was was told 8 hours labour @ $115/hr.
  
• Local Drivetrain Expert: Said I needed to know what kind of rear axle it was and the specs so he could look up the correct parts. Est $1250 for parts and 4 hours labour (don't know their rate).
  
• 2nd Ford Dealer: I couldn't upgrade to a Ford LS. Asked about the rear diff specs, he couldn't tell me anything as nothing showed except a part number.
  
• 3rd Ford Dealer: See 2nd Ford Dealer.

Ended up calling Ford head office to get an answer (hopefully 100% confirmed) on whether I can upgrade with Ford parts or do I have to go aftermarket and get the proper specs for the rear diff so I can have a limited slip. I have a case # and to be escalated. I'm supposed to get a phone call mid week coming.

See what happens.

 

[GapRunr]

The specs for the rear differential are in the first post of this thread. What info are you hoping to get from Ford corporate?

 

[Road_Ghost]

The specs for the rear differential are in the first post of this thread. What info are you hoping to get from Ford corporate?

I want to hear what they say about the OEM upgrade foremost.

 

[86scotty]

It’s a Ford 9.75 axle, quite common. You don’t need a dealer to do the work and I can’t imagine why you might prefer to have a dealer do this type of work. I would imagine, sort of as you’ve found out, that it’s not a common thing for them.

Look around you for an off-road shop, someone that works on Jeeps, etc. A 4Wheel Parts branch can do it. You want someone who frequently does regearing/diff jobs.

Good luck and let us know what you decide.



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[Road_Ghost]

It’s a Ford 9.75 axle, quite common. You don’t need a dealer to do the work and I can’t imagine why you might prefer to have a dealer do this type of work. I would imagine, sort of as you’ve found out, that it’s not a common thing for them.

Look around you for an off-road shop, someone that works on Jeeps, etc. A 4Wheel Parts branch can do it. You want someone who frequently does regearing/diff jobs.

Good luck and let us know what you decide.


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I just find it funny that 3 Ford dealers cannot answer this simple question(s). Let alone the local drive train specialist. See what Ford head office tells me. That will reveal how trustworthy they are.

 

[86scotty]

I just find it funny that 3 Ford dealers cannot answer this simple question(s). Let alone the local drive train specialist. See what Ford head office tells me. That will reveal how trustworthy they are.

You don’t already know???

It is a surprise that your local drivetrain guy doesn’t know but Transits are still new. You’re just the first to take one to him. I was too. He’ll know when the next guy asks.

Since Transits stand out literally on a dealer lot I always look for them when I pass Ford dealers. I pass small town dealers every day with none and occasionally I’ll see one with 1/2, always white cargos. They just aren’t popular yet and never will be at some depending on the dealer’s location.

Are you in a sizable city?


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[Eiko]

I just find it funny that 3 Ford dealers cannot answer this simple question(s). Let alone the local drive train specialist.

I, along with @86scotty and several others (how could I forget @alarmist ) don't find it unusual that Ford dealers are not up to speed on anything except the most common repairs. I agree with everything @86scotty said. I wouldn't let the dealer do the install on my van.

Obviously there are some good dealers out there. And not to pick on Ford dealers in particular. I wouldn't let any make's dealer work on my cars. Unless it was an expensive warranty repair on the Transit.

 

[Road_Ghost]

You don’t already know???

It is a surprise that your local drivetrain guy doesn’t know but Transits are still new. You’re just the first to take one to him. I was too. He’ll know when the next guy asks.

Since Transits stand out literally on a dealer lot I always look for them when I pass Ford dealers. I pass small town dealers every day with none and occasionally I’ll see one with 1/2, always white cargos. They just aren’t popular yet and never will be at some depending on the dealer’s location.

Are you in a sizable city?


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The drive train guy said for me to drive it down, but the vehicle is currently uninsured (need specialty insurance that is very difficult to get). I figured he was up to date with all things rear axles considering he works on all kinds of trucks and been around forever. And yes, I live in a populous area.

 

[GapRunr]

I want to hear what they say about the OEM upgrade foremost.

Keep in mind you are dealing with customer service, not technical support. Their standard answer based on the scripts they follow will be that factory installed options cannot usually be installed after the fact, but to check with your local dealer.


If you find a local dealer who knows what he is doing, he may be able to swap out the components for the OEM LSD. That being said, I'm not sure why anyone would do that when for less money you could get an Eaton locker of some sort, recognized in the off road community as a much better solution, installed by someone who does this every day instead of once a year.

 

[kc8flb]

Like the other posters have said, you have the Ford 9.75 rear axle. It is common and had been in many Ford vehicles including most variants of the f150 for the last 20 years. The rear end shop will be familiar with them.

Also like the other posters have said, dealerships don't usually do much rear end work and they don't usually install aftermarket rear end differentials. Your local rear end/drive line/off road shop will have way more experience installing this than a dealership would.

I noticed that you may be unsure whether to go with the true Trac or the factory Ford limited slip. The true Trac is the way to go. No clutch packs to wear out and smooth lockup. Perfect for on road snow traction and light off roading and beach sand. Should last longer than your vehicle with regular gear oil changes.

Make sure your installer does not use synthetic gear oil and does not use friction modifier. True Trac specifically calls for gl5 non synthetic non friction modifier gear oil. They specifically state that synthetic oil and/or friction modifier will cause a decrease in true Trac performance.

Synthetic oil is a better oil generally but It is NOT better in a True Trac.

This should cost you between $1000 and $1500 in parts and labor depending on if your installer can reuse bearings and other parts. My transit had 15,000 miles on it when mine was done and they were able and comfortable to reuse the bearings. I would have no problems paying the extra if they felt they needed to use new ones (I even told them that)

Good luck

 

[kc8flb]

I did a whole bunch of reading on various forums about the correct oil to use in your differential with a true trac

What Eaton recommends:

• Non Synthetic GL5 without friction modifier

They specifically state that friction modifier will change the rate of lockup and decrease performance. Many users believe that synthetic is okay, but its really hard to find synthetics without friction modifier.

It is not easy to find gear oil without friction modifier. Some state on the bottle that it contains friction modifier. That's easy to rule out. Many do not state that they have friction modifier but actually have friction modifier in them or are engineered to work like they have friction modifier in them. Many users have searched and said they found a bottle that doesn't have friction modifier in them, later to discover that the formulation actually has friction modifier in them or engineered to work like they have friction modifier in them.

If you call Eatons performance helpline, they recommend the Torco RGO (Racing Gear Oil) its non-synthetic GL5 without friction modifier. Its $12.95/liter and our Transit differentials take almost 3 liters of fluid.
http://www.torcousa.com/torco_product/rgo.html

Motorcraft recommends 75w85 synthetic gear oil in the stock rear axles for the Transit. 75w85 is thinner oil, but they use synthetic and thinner oil for fuel mileage and "lifetime" changes.

I will probably move up to 85W-140 on my next change which should provide better gear protection at the cost of potentially slightly less fuel mileage.

Hopefully the truetrac community can find a good synthetic that provides good gear protection/less drag and good true trac lockup performance (Bias ratio) than the dino GL5 that Eaton recommends.

It is also interesting to note that some users have posted that they use quality full synthetics and say that the true trac works just fine.

Maybe the performance degredation from using synthetics is not that big of a deal in the real world.

I am planning on using Torco RGO and doing 25k mile changes until something better comes along. I keep my vehicles a long time (10+ years/200K miles+)

 

[joefromga]

I think that the synthetic works fine in the Transit because it has traction control and will brake a wheel that is spinning thereby giving the True Trac the amount of friction it needs for spool lockup.

I would love to switch to this system but am wondering if anyone knows how it would affect the speedo and computer if at all, when I switch from 3.31 to 3.73.

I also wonder if mileage would be better or worse because it seems like the engine is always at boost especially in 6th gear.