1963 Chevrolet Biscayne Positraction Differential Overhaul - Part 1 - Disassembly

Weber State University (WSU) - Automotive Technology Department - Transmission Lab. We take on a fun and unusual project, the overhaul and restoration of the rear differential of a 1963 Chevrolet Biscayne. This 8.2" type 3 differential was used by General Motors from 1955-1964. The differential design utilizes threaded adjustable side bearing spacers to control side bearing preload and backlash.
This video is part one of a four-part series on the overhaul and restoration process. Part one includes the disassembly and inspection of differential assembly. Part two includes the positraction differential case setup and overhaul, Part three includes differential case problems found. Part four will include the complete reassembly and proper setup of the differential case in the housing including pinion depth shim selection, pinion bearing preload adjustment, side bearing preload, backlash adjustment, and contact pattern reading and adjustment.
www.weber.edu/automotive
This video was created and edited by John D. Kelly at WSU. For a full biography, see www.weber.edu/automotive/J_Kel...
Donate to the Department of Automotive Technology at Weber State University here: advancement.weber.edu/Automotive

Пікірлер: 77

  • @anthonyseger5701
    @anthonyseger570111 ай бұрын

    Very good info I have a 61 on the process of changing axle bearings and the pinion seal this is a very good video thank you

  • @bigstuff52
    @bigstuff52 Жыл бұрын

    Just coming back through to rewatch this video...Thank you for a wonderful instructional video and also you have a beautiful shop area professor..Thank you again...

  • @davidrichter2219
    @davidrichter22199 жыл бұрын

    I AM SO GLAD YOU REFERED TO THE UNIT AS THE CASE AND THE HOUSING AS THE CARRIER EVERYOINE MIXES UP THE TWO NOW TO WATCH THIS ALL!!!!!!!

  • @tomsgtr1
    @tomsgtr18 жыл бұрын

    This brings me back to automotive school except this is 10x better! I enjoy all your videos!

  • @WeberAuto

    @WeberAuto

    8 жыл бұрын

    +Tommy Tran Thank you!

  • @jamestregler1584
    @jamestregler1584 Жыл бұрын

    Glad I found you 😊

  • @echologged4986
    @echologged49864 жыл бұрын

    Thank you for these fantastic instructional videos! This stuff is better than TV!

  • @Hartz187
    @Hartz1872 жыл бұрын

    Awesome video.. very proffesional and easy explained. Big thank you from a self learned one in Northern part of Norway 👊

  • @danieltubbs5422
    @danieltubbs54228 жыл бұрын

    BW is a 3.08 open carrier. My 62 409 is an AQ which is a 3.36 posi with metallic brakes. Awesome video series. I'm local to the area and will be upgrading to a 3.73 in the near future, this is a great refresher. I teach part time for the University and had no idea they even had an automotive program.

  • @WeberAuto

    @WeberAuto

    8 жыл бұрын

    +Daniel Tubbs Thanks, the automotive program has been here since before this location on the hill at Weber College, Weber State College, and finally Weber State University. Out building was built in 1956. Stop by and visit sometime.

  • @gregparrott
    @gregparrott8 жыл бұрын

    Thank you for taking the time and effort to create such a professional, superbly documented and recorded tutorial. This video is perhaps the best I've ever seen on instructions pertaining to any mechanical assembly, (i.e. not limited to an automotive component).

  • @WeberAuto

    @WeberAuto

    8 жыл бұрын

    +Gregory Parrott Thank you!

  • @k5ryannc
    @k5ryannc25 күн бұрын

    You are a boss. Thanks for this great video!

  • @jimrider2911
    @jimrider29116 жыл бұрын

    Fantastic instructional video. I am about to have the differential rebuilt for my 59 vette (same differential) and this video provides super supporting information to what I have read in the service manuals. Thanks you so much !!!!

  • @WeberAuto

    @WeberAuto

    6 жыл бұрын

    Thank you!

  • @littlewingpilot
    @littlewingpilot7 жыл бұрын

    Excellent video, I have a '60 El Camino that has an open carrier like this one and I was in the process of trying to track down a housing for a posi carrier, after seeing this video I may just have the housing modified (as per that ground down area) and use it instead. Thanks for doing this series,...,on to the next video !

  • @WeberAuto

    @WeberAuto

    7 жыл бұрын

    Thank you!

  • @2004YZFR1
    @2004YZFR13 жыл бұрын

    Your videos are incredible good. You have a wealth of knowledge. Very well made and informative.

  • @ironhorse127
    @ironhorse1275 жыл бұрын

    Outstanding video. I believe, if memory serves, that this particular housing is not a posi housing. They posi housings featured a large P embossed on the housing. Missing on this housing. You mentioned that the inside appeared to have been ground down in one area. The open rear carriers had a rib in them that would not allow the posi unit to be dropped in. The housing with the P on them, did not have that rib, thus the unit fit right in. Again, its been a long time since I did one of these, but that what I remember. Anyone else agree with my assessment?

  • @WeberAuto

    @WeberAuto

    5 жыл бұрын

    Thank you, I have heard from others who have indicated the same thing.

  • @washedupguy2759
    @washedupguy27595 жыл бұрын

    Nice, informative video, Professor Kelly. It would be super cool to see Mr. Fultz's actual Biscayne from which the differential came.

  • @WeberAuto

    @WeberAuto

    5 жыл бұрын

    He sent me a photo, it was beautiful

  • @basketballcoachmike
    @basketballcoachmike10 жыл бұрын

    this video rocks, thank you so very much for showing me what I needed to know

  • @PosiP
    @PosiP8 жыл бұрын

    Thank you. I'm only missing the class lab work. I think I'm going to buy a car with a broken transmission and try to fix if because you have given me the confidence. Now the old Diff. This is my second viewing. :)

  • @menol1421
    @menol14219 жыл бұрын

    hey man aswsome demostration and a whole of good information you got here i just found you channel videos and i'am in love with it. specially that shop i wish i could work there that's the type of enviroment i want to work ,, keep it up

  • @darenm5691
    @darenm56913 жыл бұрын

    Best video on this topic. Thank you sir

  • @michinster
    @michinster8 жыл бұрын

    very good videos, thanks !!

  • @WeberAuto

    @WeberAuto

    8 жыл бұрын

    +Mauricio Martin Thank you!

  • @gregsparks7367
    @gregsparks73678 жыл бұрын

    The grinding modifications in the case appears to have been made by someone to convert an "open" carrier case into one that accepts a posi-trak carrier assembly. The case should have a "P" stamped on it to denote production posi assembly.

  • @WeberAuto

    @WeberAuto

    8 жыл бұрын

    +Greg Sparks Thank you! You are correct. I did not know about the "P" stamp.

  • @ApostleDavids8w

    @ApostleDavids8w

    5 жыл бұрын

    Greg Sparks ya I have trying to figure out what kind of rearend I have in my 62 c10 and just found out it’s a 55t wondering if it would hold up to bbc 496

  • @MagaRickn

    @MagaRickn

    4 жыл бұрын

    Yes, mine has a big P stamped in the case as well. Good point!

  • @jargonstarcraft9157
    @jargonstarcraft915710 жыл бұрын

    That shop...

  • @Yobettev
    @Yobettev3 жыл бұрын

    GREAT video!!! The numbers on the housing though... ya got those a little wrong. Below is what they mean: The cast numbers L 11 62 L = December and then the rest is the day and year So this differential case was cast on December 11th 1962 The Stamped numbers BW 1220 BW = 3.08 gears; open differential mated to a 327 with Powerglide Transmission 1220 is the assembly date so December 20th Seeing as it was CASE was cast on December 11th it is reasonable that it would have been assembled 9 days later.

  • @geojor
    @geojor9 жыл бұрын

    excellent, thank you...

  • @gregmaggielipscomb9246
    @gregmaggielipscomb92462 жыл бұрын

    These carrier housings were made to only accept up to 3:40 or 50s . Any lower ration would need the lower geared housing. This goes for the 65' on spicer type diff. as well.

  • @sergiomaldonado3737
    @sergiomaldonado37378 жыл бұрын

    The Torque meter to set the bearing preload is expensive and seems to have limited use. What do think of using the AC Delco Digital Torque measuring adapter? It has a setting where it records the torque that has been applied. I've watch a few videos on rebuilding differentials. Yours is definitely the best. And it's interesting to see the sloppiness some of the tech guys do when doing the project. I never would have noticed nor been aware of the repercussions if I had not watch your video first. Thank you...

  • @WeberAuto

    @WeberAuto

    8 жыл бұрын

    +Sergio Maldonado Thank you for your nice comments. The Torque meter is expensive, but very accurate. I am not familiar with the digital measuring adapter from ACDelco. I think that most technicians try to do a good job, but without the proper education and tools they may not do such a good job (and not even know it). Have a good day!

  • @willgeorgiadis2025

    @willgeorgiadis2025

    5 жыл бұрын

    For measurements such as these you need very fine precision and you just wont get that with a digital or a click type micrometer torque wrench. You might get close but you wont be nearly as precise as with a dial type torque wrench.

  • @danieltubbs5422
    @danieltubbs54228 жыл бұрын

    Impala was the B body platform, the Chevelle, Cutlass, Skylark, Lemans was the A body.

  • @WeberAuto

    @WeberAuto

    8 жыл бұрын

    +Daniel Tubbs Thanks for the feedback!

  • @skn9895
    @skn98956 жыл бұрын

    Excellent video series! I have the exact same differential and you have given me the knowledge and confidence to tackle the rebuild myself. I was wondering, would the modern holding fixture work just as well as the original GM fixture? I imagine it would be very difficult to find an original GM tool such as this. Thanks!

  • @WeberAuto

    @WeberAuto

    6 жыл бұрын

    Thank you! We also use the OTC 7020 holding fixture. www.amazon.com/s/?ie=UTF8&keywords=otc+7020&tag=googhydr-20&index=aps&hvadid=229068935469&hvpos=1t1&hvnetw=g&hvrand=5775553529167804088&hvpone=&hvptwo=&hvqmt=e&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9029703&hvtargid=kwd-315476392930&ref=pd_sl_2wqzm290xh_e_p38

  • @MagaRickn
    @MagaRickn4 жыл бұрын

    Excellent video. I have one of those, 4:56 posi tracs in my 56 Chevy that I am restoring. I also want to change to higher gears, something around the 3:50 range.

  • @MagaRickn

    @MagaRickn

    4 жыл бұрын

    Like someone else mentioned, mine has a large letter P stamped in the case.

  • @rockinnathan

    @rockinnathan

    4 жыл бұрын

    @@MagaRickn you want to sell the 4.56? I got a 3.55 in mine amd want to leave the line quicker

  • @MagaRickn

    @MagaRickn

    4 жыл бұрын

    @@rockinnathan Yes sir, just saw this. I need taller gears for cruising. rick@rickn.com

  • @thegoprogroup3420
    @thegoprogroup34208 жыл бұрын

    Good job

  • @WeberAuto

    @WeberAuto

    8 жыл бұрын

    +HUNTER Livingston Thank you!

  • @Sophocles13
    @Sophocles133 жыл бұрын

    @ 22:22 Regarding the Brinelling, if that is a show car that is rarely driven, I guarantee that wear pattern is actually False Brinelling, or "Fretting". It looks similar but its cause is different. A bearing needs constant movement to keep lubricant between the parts. Fretting is when small vibrations/ micro-oscillations cause wear between the rolling elements and raceways. I can easily imagine a show car that is being hauled around in a trailer being subjected to the exact conditions that cause this phenomenon.

  • @Sophocles13

    @Sophocles13

    3 жыл бұрын

    False brinelling was first mentioned by Almen in 1937.[12] Almen found that wheel bearings were damaged before they were used by customers. Furthermore, he found that the bearings were more damaged for long-distance shipping of the cars and that the season of shipping also had an influence. The reason for the damaged bearings were micro-oscillations[13] which occurred due to the shipping. Because the damage has a similar look to brinelling, it was called false brinelling.[14]

  • @WeberAuto

    @WeberAuto

    3 жыл бұрын

    Great information, thank you

  • @RussellBooth1977
    @RussellBooth19778 жыл бұрын

    I have found there is no rule which is set in concrete as to how a differential should be overhauled,over a year ago I had to replace the pinion & side bearings (I could've just got away with the small pinion bearing behind the pinion seal) in my 2002 model Holden VY SS Commodore which has the Dana M80 IRS rear wheel drive limited slip differential,well, the dilemma I had was that the pinion assembly had lost its preload (was measured at zero newton metres) and the diff had started to develop a bit of a whine at around 60 km/h (40 mph). Since I have been unemployed (I don't know why in this great country Australia is) I couldn't afford to either take the gear set to a diff lapping service to have them relapped or I couldn't afford about $400 AUD for a new set of 3.91:1 gears (it was originally 3.46:1 from the factory but the first owner had the ratio changed & had the car tuned so it is now like a HSV clubsport in performance) so I just pulled it apart & since I didn't have a hydraulic press back then so I got a straight grinder with a slitting disc attachment,cut into the inner bearing race & used a chisel to crack the race in order to replace the bearings. The pinion gear & crownwheel assembly as well as the outer side bearing races were chilled in the freezer for a few hours then the bearings were heated in the kitchen oven then dropped onto the frozen diff centre & crown wheel assembly as well as the pinion gear, the Aluminium side bearing adjusters were heated with a propane torch then the outer races were dropped in. What happened when the pinion bearings lost their preload is the pinion started "rocking" from side to side & no doubt the pinion bearings thrust clearance would've increased too,this caused the gears to wear "out of plane" so the best I could do with the money I have is to refit the pinion gear with new bearings, I checked to see that pinion preload "could" be obtained be refitting the old collapsible spacer as in my experience sometimes that can't be obtained even if the bearings are the same part number ,not every bearing made is exactly the same (the Timken bearings were a bit different to the Koyo brand of bearings which were replaced). I did the pinion bearing nut up very carefully with an impact wrench after a new collapsible spacer was fitted as I only wanted to obtain a pinion preload of 1.8-2.8 newton metres (rotational drag when measured with a 1 - 7 newton metre torque beam gauge),I didn't want to go too far so I compromised at 2 newton metres,it was easier for me to use an air impact wrench as the diff was overhauled underneath the car. I set the backlash back up to 0.12mm (the same as before,note I didn't worry about pinion depth due to the fact I reused the old gears) & blued the gears so I could check the tooth contact pattern which was o.k. ,note I witness marked the side bearing adjusters but the specified backlash could not be obtained when they were lined back up ,so the marks no longer line up. The car has done 17,169 kilometres since the diff bearings were replaced but there was a bit of a hum & whine at certain speeds & under different loads,the noise in the diff is almost non-existant,there is a very faint whine when coasting down a hill at 70 km/h,that's how it works , if the old gears are refitted with new bearings the gears will wear the other way & polish off the high spots on the pinion & crownwheel,along the highway on Friday,I heard the gears touch for a brief second meaning there is nearly no more metal to metal contact on the gears. So, I was right in saying after the diff has done 20,000 kilometres it will be silent - I'm giving the diff up to 25,000 kilometres to stay quiet.

  • @WeberAuto

    @WeberAuto

    8 жыл бұрын

    +Russell Booth Hi, thank you for the explanation of how you repaired your axle, I enjoyed it very much! You obviously have a good understanding of how to properly setup an axle and the complexities of service, and replacement parts. I have found that there are four important steps to setting up any axle. They are 1. Proper pinion bearing preload. 2. Proper side bearing preload. 3. Proper backlash. 4. Run a contact pattern check and make the adjustments necessary for a good pattern (pinion depth and / or backlash). As long as your parts are in good shape and properly lubricated, these steps will cure almost any axle noise. Thanks again for your great feedback!

  • @romanescalera7752
    @romanescalera77523 жыл бұрын

    Señor, could you advise us what brand parts to use? Hope your doing very good .

  • @marioobermaier6911
    @marioobermaier69118 жыл бұрын

    Your awesome, would you be able to rebuild an limited slip diff, when ist sended to you ? Since i live in Austria and i could really Need someone for that what knows so good like you do. Hope you will see this and reply Greetings from Austria

  • @hotrodswoodshed7405
    @hotrodswoodshed74054 жыл бұрын

    Im fairly sure the casting date L 11 62 translates to: L being the month of december. Being the 12th letter in the alphabet it would correlate to the 12th month of the year. With the number 11 correlating to the day. And obviously 62 being the year. I highly suspect the other number: bw 12 20 = would correlate to the day it was actually assembled, as in 12th month December. And the 20th day. Leaving BWI most likely as the assemblers initials. I do know that on all of the 60s and 70s Chevy castings, the letter of the alphabet was considered the month of the year. And I would highly suspect this is the case

  • @tepp4083

    @tepp4083

    3 жыл бұрын

    your right about the L date code. the BW determines the gear ratio

  • @davebanes2263
    @davebanes22636 жыл бұрын

    where can I buy the holder that you are using

  • @WeberAuto

    @WeberAuto

    6 жыл бұрын

    eBay os the only source for the original GM tools; however, there is a nice generic holding fixture from OTC tools Part number 7020 on Amazon.com that woulds work great. Best wishes!

  • @thegoprogroup3420
    @thegoprogroup34208 жыл бұрын

    What type of camera are you using

  • @WeberAuto

    @WeberAuto

    8 жыл бұрын

    +HUNTER Livingston hi, it is a Canon HD Camcorder. Thanks for watching!

  • @georgec7798
    @georgec77986 ай бұрын

    I know this video is about 9 years old but If I were you I would have used a torque multiplier to tighten the pinion nut, it will multiply your strength by 53 foot pounds.

  • @mkoz1134
    @mkoz11342 жыл бұрын

    I have this same rear end in my 63 impala. It's stamped with a p so it's a true posi case. It has no drain plug just a fill plug. And I'm curious how to change the oil. Do you actually need to drop the entire thing and just let the oil come out that way or is there another way. I know this videos old and may not get an answer.

  • @WeberAuto

    @WeberAuto

    2 жыл бұрын

    Are you sure there is no drain plug? It could be covered by dirt and rust

  • @MrMikehancho28

    @MrMikehancho28

    2 жыл бұрын

    Have you tried a cheap hand transfer pump?

  • @burnoutnova
    @burnoutnova8 жыл бұрын

    I thought a 4.56 gear would be a 4 series carrier (i know its called a differential case actually) and need a 4.11 or lower (numerically higher) ratio for that carrier?

  • @WeberAuto

    @WeberAuto

    8 жыл бұрын

    +burnoutnova I do not know the answer to that question. Thanks for watching.

  • @johanzietsman6095
    @johanzietsman60952 жыл бұрын

    Hi Can you please help me out with same rear diff bearing

  • @WeberAuto

    @WeberAuto

    2 жыл бұрын

    I cannot help you. Thanks for watching

  • @user-oj9or8ox6m
    @user-oj9or8ox6m9 жыл бұрын

    goooooooood iran

  • @Olds_Gold
    @Olds_Gold3 жыл бұрын

    That was a factory posi, it should have a P on the case. Don't see that there

  • @WeberAuto

    @WeberAuto

    3 жыл бұрын

    You are correct. The housing had been ground out to make room for it.

  • @mistervacation23
    @mistervacation234 жыл бұрын

    The only mistake I could see is that you put to much peanut butter on the gears.