Total differential rebuild LS install, 60+ pics!!!

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Hey guys, I thought I'd share my weekend project. Rebuilding a Toyota 8" V-6 third member (pig, drop out, etc) and installing a Eaton TrueTrac Torsen limited slip. This is the rebuild of a spare that I had laying around and will be replacing the current one in my truck that I rebuilt about 60,000 or so miles ago that has a Detroit Locker mechanical ratchet type locking differential. There is nothing wrong with the differential in the truck but I have grown tired of its driving quirks especially considering I no longer get off road as much as I would like and therefore do not require the Detroit locker. If I use the truck off road more I might be able to tolerate the terrible driving quirks associated with a Detroit locker. Instead I decided to install something that was a little bit more pavement friendly I hope you enjoy the pictures as I walk you through the installation and set up of a complete differential for a Toyota.




Here is the rebuild the candidate in all of its greasy disgusting glory. I have no idea what it came out of but it is just one that I had laying around. You will note that the end of the Pinion is painted pink, in early Toyota trucks this indicates a 4.10 gear ratio. It can be identified as a V6 differential buy the additional webbing on the case and the four pinion differential carrier assembly.



The first step I always take prior to disassembling the differential is to place match marks to keep the caps where they originated.



Once that is complete you can remove the carrier assembly complete with ring gear. The carrier cap bolts are 17 mm the torque spec for them is 70 foot pounds. The spanner lock tab bolts are 12 mm.



Once the carrier has been removed you can remove the pinion I highly recommend using a press to prevent damaging the threads on the end of the pinion. In this case there was no pinion yoke, I don't know where it went it was missing when I pulled this out of storage. In the event that you need to remove the pinion nut and drive flange the pinion that is 30 mm, I recommend a good sturdy impact for this I use in a 2135TI Ingersoll Rand .



This is what the pinion will look like once you have liberated it from the case. Note the crush sleeve installed just above the lower Pinion bearing more on this later.



Once the pinion is removed you can pry out the pinion seal and drive out the pinion races with a bronze drift punch.







Now that you have the pinion out you need to remove the lower Pinion bearing. It is usually pressed on with a substantial amount of press. For this I use a clamshell style bearing puller to prevent damaging the bearing . Of note on this style differential there is a shim under the lower Pinion bearing, this shim must be reused, on other types of differentials there may or may not be a shim present. Since I'm not replacing the ring and pinion I will reuse this shim, on new ring and pinion I usually start with the factory shim and make adjustments for pinion depth from there. Additionally the shim is directional as it is relieved on one side with a baffle to prevent interference with the radius machined onto the pinion at the transition from the pinion head to pinion shaft.



In this picture you can see that everything is all apart now and has been cleaned. For this I find that a brass bristle brush and regular old brake clean generally works fairly well. For those of you with sensitive hands I would recommend using heavy rubber gloves for the cleaning portion. Of note and not photographed elsewhere is the pinion oil slinger visible in this picture near the head of the pinion it is installed between the upper Pinion bearing and the pinion seal.



Now we can begin reassembly with the installation of the upper and lower Pinion bearing races. I used a combination of race drivers and old races on the press to install the new races. Of note it is extremely handy if you do very many of these to keep old races for use on the press. In many pictures on my press you will see a combination of old races being used to press new components together.







The installation kit that I chose for this application comes with all genuine Japanese made Koyo bearings. Almost all Toyota differentials I disassemble come with this bearing in them. I have had excellent luck with this brand of bearings and generally seek out a kit with them in it I find them to be of superior quality to a comparable US made Bearing. The kit used here is a US Standard Gear installation kit.




Pinion bearings are installed on the press, don't forget to install the shim underneath the lower Pinion bearing prior to pressing the bearing on. When installing the shim install it with the bevel towards the pinion head or in whatever orientation it was originally installed in, in this application the bevel goes towards the pinion head.







If you are using a crush sleeve for your installation this step will not apply to you. I prefer to use a crush sleeve eliminator in by differential set ups. In order to get a baseline for the amount of shims to use for setting pinion bearing preload I measure the crush sleeve that I removed and I measure the crush sleeve elimination spacer, I generally add about 5 thousandths of an inch to the difference as a starting place for the shim pack. In this case through a little trial and error the final shim pack thickness was 0.047".



I preferred to measure Pinion bearing preload without the pinion seal installed to get a true reading of just the bearings. If you elect to use a crush sleeve this method is not possible. The final result was 15 inch pounds of rolling drag on the bearings. The spec for new bearings is 12 to 15 inch pounds.

Continued in post 2, too much for one post...
 






I prefer to install the pinion seal on my press as it allows me to slowly push the seal in to prevent disturbing the spring on the seal itself. The seal I am using here is sold by Marlin crawler and it is their eco-seal. I have had excellent luck with the seal in the past and I appreciate the sealing material on the metal portion of the seal as well as it's double lip design.





Prior to installing the pinion yoke it is helpful to place a small bead of silicone on the inside surface of the splines as I am showing here, this prevents gear lube from leaking up the splines in operation.






Once the seal is installed and the yoke is installed you can install the pinion nut washer as well as the pinion nut with a healthy dose of red Loctite. After installing the pinion nut stake it into the groove in the pinion. As you can see here preload measured significantly higher once the steel was installed. Additionally do not forget to lubricate the seal to prevent tearing on initial start up.








Now it comes to the real reason why I am doing all of this work here is the brand-new true trac Limited slip differential. I must admit I was a little bit disappointed that it was made overseas however the manufacturing quality appears to be excellent. It was purchased from Amazon and shipped without an outer package thus resulting in damage to the original box fortunately the limited slip was not damaged.





Prior to installing the ring gear I make a point of ensuring the mounting surface is nice and flat I accomplish this by drawing a file across the mating surface in several directions to remove any high spots. Interestingly enough in this case the portion of the gear that was not supported by the original carrier was a little bit proud of the remainder of the ring gear.




Once the new ring gear is on it torque the bolts to spec in this case 70 foot pounds. Then bend the original bolt retention tabs back to prevent the bolts from loosening. I also use red loctite on the bolts as added insurance. Of note on Toyota differentials with the factory ring gear and factory and most replacement bolts, omission of the original bolt retention plates may result in the ring gear bolts bottoming prior to actually clamping the gear in place. If this is not caught it will result in catastrophic failure as a result, I make it a point to always reuse the factory lock tabs.





The carrier bearings can now be pressed on. When pressing the bearings ensure that you support the bottom of the carrier with something that will prevent placing load on the bearing retention cage while pressing the opposite side in this case I am using a 36 mm socket that fits inside the ID of the bearing opposite the one that I am pressing on. Koyo bearings and races are used on the carrier as well.

Continued in post 3.
 
Is this for the 4Runner that you took on the long trip to MI? Sorry if I wasn't supposed to post yet.
smile.gif
 
Quote:



Once the new ring gear is on it torque the bolts to spec in this case 70 foot pounds. Then bend the original bolt retention tabs back to prevent the bolts from loosening.


Thank you for sharing, mate.
Hey,I'm afraid the 10 pcs grade 2 bolts are not appropriate for this application.
Bolts of grade 8 is required , I suppose.
http://forum.longevity-inc.com/attachment.php?attachmentid=3069&d=1308428090
blush.gif
 
Last edited:
Thanks for hanging in there I got booted halfway through my third post and lost it all so here goes...







Now we're in the home stretch. Time to install the carrier. I find that it's easiest to install the carrier, then the caps, then the bolts finger tight. When installing the bolts ensure that the threads between the differential and carrier caps line up, I use a dab of ARP lube under the bolt heads and on the threads.







Now you can install the side adjusters hand tight and check initial backlash, being very careful not to cross thread them. I use a dab of ARP lube on these to ensure they don't gall when we torque them later. An initial check of backlash shows 0.008" the spec is 0.006-0.010". Now we can torque the cap bolts to 70 ft lbs which is the spec.

Following up the finale in another post to prevent loosing everything again.
 
Ok let's wrap this up! Time to set carrier bearing preload.






Now that we have an initial backlash set we can set carrier bearing preload by alternately tightening each adjuster to 150 ft lbs. of note if you need to open up backlash always tighten the ring gear side last to ensure no gap between the adjuster and the bearing race exists. I find that a healthy carrier bearing preload helps prevent ring gear deflection under load and helps to prevent ring gear breakage. 150 ft lbs in this application gives just a nice drag on the carrier. The high torque is why it's important to have some sore of EP lube on the threads and the face of the adjuster. Now that we have the preload set we can install the adjuster retainers with a dab of loctite and move on to check the pattern. Normally I would check it prior to setting preload, but since I'm reusing the ring and pinion I skipped that step.




I really like the GM marking compound. Add a few drops of gear oil to help it spread evenly and slow the drying.



Drive side looks great, just where I like to see it.



Coast side dried a little before I got it checked so it isn't as pretty but it also looks good! Ready to install, that's a next weekend project.

Hopefully you guys found this informative!
 
Originally Posted By: Taildragger
Tell me more about what you didn't like about the Detroit Locker and what to expect from the Eaton. Great post BTW!


Lots of things not to like about the Detroit Locker in a daily driver, this is the fourth or fifth one that I've owned, maybe more. The driving quirks are what finally got to me after 60,000 miles, they're accentuated by the truck having a short wheel base and a stick shift. It's much tamer with an automatic, in a heavier truck, but still there. Around corners it pops and ratchets and clunks and bangs, with a stick you can't coast around the corner, you need to push in the clutch to prevent getting caught in a vicious circle of coast/drive backlash which is jerky and downright violent. Driving down the road it yaws every time the Locker engages and disengages as you get on and off the gas going around any corner. Pulling in and out of parking spaces or making tight corners also results in much clunking and banging and drama. Then there are the notorious random violent, explosive bangs, so loud it sounds like someone hit the truck with a sledge hammer.

The good, it always works, it always spins both tires, no matter what. It's magical off road, but I don't get there as much as I'd like anymore. So really the driving penealty isn't worth the return anymore.

What am I looking to gain? Smoother drive while maintaining the ability to still spin both tires. A limited slip without clutches to wear out, that doesn't require special fluid, and drives like an open differential without having to go back to an open differential for when I do get to venture off road.

I will report how I like it next weekend!
 
Originally Posted By: zeng
Quote:



Once the new ring gear is on it torque the bolts to spec in this case 70 foot pounds. Then bend the original bolt retention tabs back to prevent the bolts from loosening.


Thank you for sharing, mate.
Hey,I'm afraid the 10 pcs grade 2 bolts are not appropriate for this application.
Bolts of grade 8 is required , I suppose.
http://forum.longevity-inc.com/attachment.php?attachmentid=3069&d=1308428090
blush.gif



Those aren't grade 2 bolts, those are OE Toyota ring gear bolts, they just aren't marked on the head.
 
Originally Posted By: SatinSilver
Is this for the 4Runner that you took on the long trip to MI? Sorry if I wasn't supposed to post yet.
smile.gif



Yes it is, that's the same truck. Although the Locker was a godsend off road in the woods trip I took, the new pavement tires and new limited slip are better suited to the way I use the truck now.
 
Originally Posted By: car51
Very informative and thanks for the great photos
smile.gif



No worries. When I first started setting up differentials about 20 years ago I would have killed for something like this as a guide as the basics can be applied to any ring and pinion. Sadly I had to learn by trial and error. Hopefully you guys found it helpful.
 
Thanks for taking the time to document and post! I Don't see myself taking on such a project in the near future, but feel like I learned a few things nonetheless.
 
Originally Posted By: FlyNavyP3
Those aren't grade 2 bolts, those are OE Toyota ring gear bolts, they just aren't marked on the head.


Thousand apologies ...
blush.gif
 
Originally Posted By: FlyNavyP3
Originally Posted By: Taildragger
Tell me more about what you didn't like about the Detroit Locker and what to expect from the Eaton. Great post BTW!


Lots of things not to like about the Detroit Locker in a daily driver, this is the fourth or fifth one that I've owned, maybe more.....


For clarity, is the Detroit Locker you have a "Soft Locker"? They are supposed to be somewhat tamer...?

Nice pictures and write up...
 
Originally Posted By: 02SE
From what I can see of the contact pattern, it looks like it could use a little more backlash.


The differential had 0.008" of backlash when torn down, so I elected to maintain the same spec on the rebuild, partly because it's in the middle of the allowable backlash, additionally because it's what the differential ran at for the first who knows how many thousands of miles of it's life. I'm happy with the pattern, I don't think it's too deep, it may have improved by opening it by a couple thou, but the marginal improvement was offset by my considerations listed above.
 
Originally Posted By: DuckRyder
Originally Posted By: FlyNavyP3
Originally Posted By: Taildragger
Tell me more about what you didn't like about the Detroit Locker and what to expect from the Eaton. Great post BTW!


Lots of things not to like about the Detroit Locker in a daily driver, this is the fourth or fifth one that I've owned, maybe more.....


For clarity, is the Detroit Locker you have a "Soft Locker"? They are supposed to be somewhat tamer...?

Nice pictures and write up...


Yes it was a "Soft Locker" nearly all automotive "Detroit Lockers" produced since I bought my first one back in 1997 are "Soft Lockers" with the exception of a few odd ball applications and slow movers (IHC, oddball Dana, things like that). In terms of operation it's more Locker, than Soft, better than the original No-Spin from which the Detroit draws it's origins, but still not very tame. You really need to weigh your goals, it's hard to beat the Detroit reliability and ultimate traction for situations where one tire has ZERO traction (tire off the ground, one on ice, drivability with a broken axle) at the expense of on road performance. Honestly back to back comparison, I prefer the drivability with a Spool over that with a Detroit, however tire wear suffers greatly with a spool (the only real drawback IMHO). Really if you NEED a Detroit for traction, perhaps a spool is better suited in my experience with the exception of a few select applications where the vehicle is used a great deal on road but the spool would be detrimental to tire wear when the vehicle is seldom used on the pavement.
 
Originally Posted By: zeng
Originally Posted By: FlyNavyP3
Those aren't grade 2 bolts, those are OE Toyota ring gear bolts, they just aren't marked on the head.


Thousand apologies ...
blush.gif



No worries!
 
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