Differential Case Installation With Universal Shims 

I can build a diff every day of the week and twice on Sunday using this method and everyone would turn out consistently correct.

Thanks

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@Lennox Hunter definitely, have been watching on InstaFlixxer for since december myself :)

Glad you found value in this video.

Glad it worked out for you.

Typically when changing gear ratio the pinion depth shim also needs to be adjusted. The best way to do this is to install the original pinion depth shim and assemble the diff but leave out the crush sleeve and pinion seal. Set the pinion preload and backlash to spec or very close then run a gear contact patch and based on the contact disassemble and adjust the shim size. Then recheck. You may need to do this a few time to get it right. Once it correct disassemble and reassemble using the crush sleeve and pinion seal and adjust the backlash and case bearing preload to spec. check out my pinion depth and contact patch videos. Pinion depth and contact patch explained: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-w2kneEjXw6E.htmlsi=USWMLQyKJsHltqcc . Pinion depth shim change: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-_bUh9NEMldI.htmlsi=NV5NoQ-Oh8TfEOKo . Contact path: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-UIIk305-zlQ.htmlsi=1QTL3bIB1_YqKCy2

First of all you really don't need a case spreader these days to setup a differential. You noticed that I used the shim punch to hammer in the last shim. This spreads the case slightly which adds the preload to the case bearings. The more the case spreads the greater the preload on the case bearings. When it comes to pinion depth shims you have to go with what ever the manufacture has designed. Some manufactures do place the depth shim between the outer race and the housing but this too can be problematic. You often have to rest the punch on the shim to hammer out the race. This can damage the shim. If you can find shims to put between the race and the housing for a design that uses shims between the pinion and the bearing you can use them. They will work the same. The problem is finding shims that will fit. The reason for the case spreader is most OE shims are cast iron and if you hammer on them they can crack. But if you use a case spreader to expand the case and drop the cast iron shim in place you can relax and remove the spreader which will apply pressure onto the shim which pushes on the bearings for a preload. If you have replacement shims that are made from steel they can be hammered on without cracking. So no spreader is needed.

@@DrivelineMaster The shim would need a bigger OD and ID to fit correctly. Would be very narrow. I seen earlier that what I thought was a spreader w is a vice on the pinion video.

Oh, your talking about a bearing splitter that is used to remove the pinion bearing. There is something called a case spreader that is used to spread the housing for setting up the case bearing preload and ring gear backlash. Well, you can remove the old bearing without a bearing splitter but you will destroy the bearing because you have to cut it off. If you need to remove the pinion bearing without destroying it you will need a bearing splitter or what is even more expensive is a specially designed pinion bearing puller tool. You can get a puller to work with a splitter or you need a press. There is just no way around it. So, yes if you can find a shim that will fit under the bearing race that would reduce the tools you need. Problem is finding shims that will fit on a diff design that uses the pinion shim. If you feel that you may need to R&R the pinion bearing several times to swap out shims there is a trick you can do but it will cost you the price of a second pinion bearing. After removing the old bearing take one of the new bearings and hone out the inside diameter just enough so the bearing just barely slide onto the pinion. There should be some drag. Now you can slide the bearing off, change the shim, reinstall the pinion and check the depth and or pattern. If you need to adjust the shim just disassemble, slide the bearing off, change the shim and repeat. Once you find the correct shim remove the modified pinion bearing and press on the new bearing for our final assembly.

I suppose I could measure the rotation force before I tear it apart and at the end try to end up with the same amount of rotational force. And if it’s higher I would have more carrier bearing preload than factory and the opposite if it is less? My goal is to have the same backlash as factory carrier too

Measure the pinion bearing preload with the case and ring gear removed. Install the case and use the shims to adjust backlash and add a preload. Put the bearing caps on the case and remeasure the pinion and case turning force. It's basically a pinion bearing preload measurement with the case installed. The measurement should be approximately 3 - 5 inch pounds greater than the pinion bearing preload. If your gear ratio is near or above 4.89:1 shoot for 3 inch pound difference. With a smaller gear ratio use a little closer to the 5 inch pound difference. Here is a suggestion. You are replacing the case maybe your adding a limited slip or a case upgrade. Your replacing the case bearings but reusing the ring and pinion. This is very common. I would recommend while you have it torn down this far that you also replace the pinion bearing and the oil seal. Last thing you want is 20K miles down the road is to have to go back in there to replace the pinion bearing when you could have done them now.

That is not much of a gear ratio change. Are you looking for more low end torque? I'm not sure you will feel much of a difference with this small change but your speedometer will be off slightly.

@@DrivelineMaster Thank you for your reply..Yes I would like a little more low end to help turn the 35" tires I'm running. I almost bought a 4.10 gear set but was afraid it would raise my rpms too high at cruising speed and I do quite a lot of highway commuting with this truck.

I have a 9.5 semi float that I want to install 4.88 for 35's.

@@jamesfarmer2748 Depending on how your using the vehicle and the type of vehicle and engine along with what your original gears were. This will have a significant effect on torque and engine RPM especially on the freeway. Gas millage will be effected. If your doing any off road fun this gearset will help with the fun factor.

The aftermarket gear set typically marks the head of the pinion with the proper depth measurement but this requires that you use a measurement tool. If your willing to do a little trial and error method you can set your pinion depth by using the contact patch. I have videos on measuring pinion depth and one that explains pinion depth and contact patch readings and I have one on how to perform a contact patch test. ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-w2kneEjXw6E.html or ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-UIIk305-zlQ.html or ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-QL-dmhfSj6k.html and ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-gk6imita0cc.html . Here is a trick that is cheaper than buying a depth tool if your only setting up one differential. If the depth shim is between the head of the pinion and the rear bearing buy an extra rear bearing. Use a small hole hone and hone out a few thousandth of an inch from the inner race. Just enough so it slides on and off of your drive pinion with a little force that you can overcome with hand pressure. Now you can quickly change the shims without a press. When you find the correct shim by testing the contact patch replace the setup bearing with the bearing the new one that needs to be pressed on. If you do this make sure to fully clean all honing material from the setup bearing and re-oil it. Good Luck.

@@DrivelineMaster Oh ok. Thank you for the info!

I learned the math technique many years ago at a GM training center. A lot of manufactures do not refer to case bearing preload this way but it clearly is much more accurate because over time and many, many heat up and cool down cycles the elasticity of the housing metal relaxes. So adding 0.008 in. additional shim thickness to a pair of case bearings when the diff is new will have a reduced effect on a 15 year old diff. Some manufactures simply say add 0.008 in. or 0.010 in additional shim to a case that is set to zero preload and zero backlash. Others will have you measure the case spread and some will tell you the pinion and case turning force should be 2 - 4 inch pounds greater then the pinion bearing preload. 2-4 inch pounds greater that pinion bearing preload is what I typically look for however this is relative to the ring and pinion gear ratio. So if this is the factory spec but you put in bigger gears that spec. is no longer valid. Here is what I use based on my experience. If the gearset is below 3.73:1 use an increase of 2 - 3 inch pounds greater than pinion bearing preload. Above 3.73 up to 4.54 use 3 to 5 inch pounds greater than pinion bearing preload. If you have some really big gears keep going up. Used bearings will be slightly less but why in the devil would anybody put used bearings back in when you have it all apart is beyond me. As for the pinion bearing preload I believe in specifications. Which means that I don't shoot for the high end, low end or middle. I believe that specs are designed so the diff will last a good long time if it is built within specifications. I also believe that this holds true as long as break-in procedures are followed and proper oil change intervals are followed with the correct lubricant. So during my builds if I tighten the pinon nut and my pinion bearing preload turning force is withing spec. I stop. I don't try to tweak it to the middle or high end or anything like that. The diff I was working on was an old GM 10 bolt diff. I don't remember if it was a Saginaw or American axle or what.

In order to find a rotational force case bearing preload specifications you need to look at newer GM vehicles. The older vehicle specs just tell you 0.004" shim increase per side. This is not very exact. Even if it's not the exact model the preload is pretty generic. For your differential is using new case bearings use the calculated rotational preload force specification of 15" lbs. to 35" lbs.. If you have 30" lbs. of rotational force your good.

@@DrivelineMaster Thank you for the prompt reply. I am using new timken bearings for this build. Do you use 15 to 35 in lbs of rotational preload the default when you cannot find a standard? Lastly, keep doing what you do. Your educational techniques are spot on for me.

I use 15" to 25" lbs. as a generic rule of thumb for all differentials. I also consider the size of the bearings. For larger diffs I don't mind going as high as 35'" lbs. and for smaller bearings like in a Dana 10 I will use closer to 15 - 20" lbs. for the case bearing preload. Also GM is the only manufacture I have seen that uses this technique to calculate case bearing preload. I think it is a great way to do this because it eliminates error and a change in gear ratio or a loss of elasticity in the differential housing.

@@DrivelineMaster Thank you for all your assistance.

INCH pounds.... to be clear. NASA burned $1.3 billion into mars surface as the software was written in Germany (metric) but used in the US (inches/feet) so the ppl running the show , when they read deploy parachutes at 1000... FT? Meters? ass u me d that they meant 1000 ft... it wasnt... it was 1000 METERS and... with the very very thin atmosphere in mars atmosphere... $1.3 billion of the US taxpayers $$$$ is now junk on the Mars surface.

I get a lot of my diff parts from www.randysworldwide.com. I call them speedy shims but that is not what they are called. Ask them for a universal shim kit for your case bearings.

I get most of my diff parts from www.randysworldwide.com. Very reliable, professional and friendly and I have no affiliation to them. I call them speedy shims but they have a different name for them. Just describe them to the sales person on the phone and tell them your application and they will send you the right ones. You may even be able to ask them the brand or who makes them.

Here is another tip when torquing the ring gear bolts. Do it in two steps. Step one, torque to 27 FT lbs. then go around again and torque to 55 FT lbs. Some diffs use locking tabs on the ring gear bolts. These are the only bolts that can get away with not using thread locker on the ring gear bolts. I also caution on using an impact gun to tighten the pinion nut when crushing the sleeve and setting pinion bearing preload. I use a flange holder and a torque multiplier. I have many people on RU-vid who tell me they set pinion bearing preload using an impact gun on the pinion nut and never have a problem. Never yet or at least none that they know of. Good luck.

The outer and inner diameters of the shims are specific to the differential. If it's critical that you know this information I can measure a shim for you.

To answer your first question this is the initial setup of backlash and case bearing preload. The procedure is proven reliable and consistent every time. Notice that Backlash is started out smaller than spec so when I add extra shims on one side only backlash is corrected at the same time that I'm adding case bearing preload. What you were taught is correct only when you want to change backlash without changing the existing case bearing preload. The pattern is checked in another video however the dial indicator verifies the backlash so the pattern test would verify that my pinion depth is correct. Pinion depth measuring is covered in another video and I'm working on a video that explains what happens to contact patch depending on pinion depth position.

Hmm, I was wondering, but how do you know how much shims are too much, its like sandwiching thick sandwich buns in the same thickness burgers used at mcdonalds and maybe the buns you can buy from safeway lols. What i'm trying to say is if you add more thickness shims depending if you add to one side, it'll move the backlash away or close or something along those lines but the case bearing preload is not perfect yet and i saw you placed shims on the other side to counter that. Also realistically if you place too much shims to each side wouldn't that place the tapered bearings possibly too tight and could cause it to prematurely fail compared to as if it was using a slightly less shims on each side with the same differential and everything in another setup or so. I saw you just place shims of different thickness according to how what you had on had, Ex: lets say, .003" .007" .009" .012" .015", you would add .003"+ .007" to get .010" if the single .009" is still too lose right? Sorry for being so complicated, sometimes you gotta be complicated in order to understand 100% of everything. One favor to ask :D, Is it possible if you are working on other videos on the differential to possibly once you do these different part segments of a "WHOLE Differential setup" could you do one maybe where all you have to do is splice your videos in a video editing software to make it seem "whole" so i can truly see how its 100% done. Its complicated to explain, i don't know how to explain the things i'm thinking in my head. The reason why i ask is your username is DrivelineMaster but some people call themselves master but are not good enough to call them the greatest because all they do is steal information from others or watch a "How to video" and boom they are now a differential master or something xD, I want to question myself, why you do the things you do in this and if i were to reorganize some of your steps in different ways, like ex: right now everything you do is 1, 2, 3, 4, 5, 6, 7, 8, 9, 10. lets say hmmm... Step 8 should actually be between step 3-4 because it seems there could be a situation where it could be used there. Sorry for being hard to get :\ If you understand what i'm trying to say, could you reply back "your spin" on things for me :) Note:** I know micky D's burgers don't age and are extremely disgusting.

Case bearing preload has been measured or set multiple ways over the years from manufacture to manufacture. Years ago GM would teach to set backlash to specification with zero preload and zero free play. Then they wanted the tech to increase each shim by .004" on each side. This is a total of .008" which is what I used. GM now uses a technique similar to mine and uses rotational force in inch pounds to know if the preload is correct. Measuring case bearing preload is done by subtracting the breakaway rotational force of the pinion and case from the rotational breakaway force of just the pinion (also known as pinion bearing preload). Then the difference is multiplied by the gear ratio to calculate the rotational force of the differential case and case bearings. This varies but is often between 14" lbs. to 24" lbs. Nissan doesn't get that detailed. They just spec. what the difference in rotational force should be but this only works if you use OEM gear ratio since gear ratio plays a part in rotational force. Some Mazda removable diffs and Ford 9" straddle mount pinion designs measure case housing spread with a dial indicator. Measuring rotational force in inch pounds like GM does is now the most accurate. Start with a preload (sandwich "your words") of .008", measure the rotational force and add or take away as needed making sure to keep backlash within specification.

For that first part, Rotational force in inch lbs, i remember that from class :D Using a torque beam wrench in inch lbs to test for turning torque. I didn't know Gear ratio plays a part in rotational force, i thought the only thing is if you go small gear ratio you'll have faster acceleration and bigger gear ratio a higher top speed. Toyota uses Turning torque = rotational force in inch lbs too, from what i can see or sounds like. Okay so let me get this straight on the money for the last part: Quote: "Start with a preload (sandwich "your words") of .008", measure the rotational force and add or take away as needed making sure to keep backlash within specification. What i should do is preload it .008", so .004" on each side right? then measure rotational force/turning torque, and add as little as possible to that like what i said before with adding different shims or using a bigger single shim to do the job. So when measuring the rotational force, should i take out the ring gear when doing so or should i just measure it with it in? There are so many "Ifs" and the MFR only puts in certain ways of doing things. Of course use the old crush collar to measure so i don't have to continually replace that "B****", thats another "if" lol. On the Honda S2000, J's Racing makes a upgraded collar for the differential which doesn't require it to be crushed and maintains backlash. So awesome. Should in essence never have to replace it and can be reused infinite amount of times. Has to buy the shims for the pinion. J's Racing SPL Differential Distance Collar Full Shim Set - Honda S2000 & J's Racing SPL Differential Distance Collar - Honda S2000. Shim pack cost $140 for like dozen shims -_- and i could buy each seperately but i like to buy all so i can mess with it some more some day. Everything cost $ :S Thank you for your words of expertise.

Hi Lime, Let me try and spell it out clearly for you if I can. Step 1, setup your pinion bearing preload with the inch lbs. beam or dial torque wrench. Pinion turning force only, nothing else. It doesn't matter if you use a crush sleeve or an eliminator kit with shims. (Crush sleeves should never be reused on a rebuild however I have sometimes gotten away with one reuse when replacing a pinion seal on a vehicle that has been in service for several years. Reusing a crush sleeve on a rebuild is asking for a comeback.) Step 2, install your complete case with ring gear and set it up as instructed by the video with your final step of adding .008" shim to the non-ring gear side. This will add the case bearing preload and push the ring gear away from the pinion to increase the backlash right into specification. Step 3, after bolting the bearing caps into place turn the diff over and with the inch lbs. torque wrench (beam or dial) measure the rotational force which will now be a combination of the pinion bearing preload you set in step one and the additional force needed to turn the case. The difference between this value and the pinion bearing preload set in step one is the results of the preload placed on the case bearings. Because you are turning the case with the pinion and can't turn the case directly the force needed to turn the case with the pinion is made easier because you have a mechanical advantage of the gear ratio. That is why we multiply the rotational difference between the two by the gear ratio. This gives us the exact rotational force needed to turn the case. The rotational force to turn the case is directly related to the preload exerted upon the case bearings. If your case bearing preload and backlash is correct you are done. If the backlash is correct and your preload is too small you will now add equal amount shims to both sides (e.g. .002" to each side). This will increase the case bearing preload without changing backlash. If preload was too much and backlash is OK subtract equal amounts from each side. There are a whole lot of other variable options if backlash was not OK or at the low or high end of the specification and if the preload was or was not in specification that I won't go into. As for your other statement about gear ratio depending on how you looked at it you might have it backwards. a 4:1 gear ratio is numerically high but in automotive we would call this a low gear ratio because this would be like 1st gear for the transmission. This will give use a lot of torque with very little speed. An input of 2000 RPM and 200' lbs of torque would come out with 500 RPM and 800' lbs. of torque. On the other end .5:1 gear ratio (overdrive) is numerically low but in automotive this is a high gear ratio because this would be high gear in the car like 5th or 6th. The results are reversed torque reduces and speed increases. The same input would result in 4000 RPM and 100' lbs. of torque. Just a side note. High gear in the vehicle is never .5:1. Most never get any higher than .7:1. Differentials never use an overdrive ratio this was just to explain gear ratios in general and automotive gear ratios are always to 1 turn of the driven gear or pulley. (We never us a ratio like 1:.5 or 1:2)

I'm really sorry. I'm not really sure what you are looking for or how I could help. I'm not in retail sales or have any contacts if that is your request.

You can make one from 3/16 or 1/4 in metal plate or order one. The one I used was an OTC tool but I googled Diff Shim tool and got several hits. Here is a ford tool. www.toolsource.com/differential-service-c-1321_119_124/differential-shim-installer-ford-t85l4067ah-p-99148.html

Answering my own question: Search for "shim driver tool" to find something that serves the purpose of the thing called a "shim punch" in this video.

The beauty of video editing.