|
Engine, Exhaust, Transmission Discuss the FR-S | 86 | BRZ engine, exhaust and drivetrain. |
|
Thread Tools | Search this Thread |
01-09-2023, 07:49 PM | #1 |
Senior Member
Join Date: May 2015
Drives: 2013 Subaru BRZ Limited
Location: Austin, TX
Posts: 121
Thanks: 71
Thanked 24 Times in 18 Posts
Mentioned: 2 Post(s)
Tagged: 1 Thread(s)
|
Help diagnosing what appears to be a bad/seized differential
Hey FT86 Fam,
My 2013 BRZ started making funny noises while pulling into the driveway one night... grinding, clunking, and vibrations were all included. The noise and vibrations happen when I have the car in gear, rev it up, and then shortly after the clutch engages the fly wheel, putting power down to the drivetrain, all hell breaks loose. I jack it up and take this video: https://www.youtube.com/shorts/O8Ci_8FnjIA Based on a friends recommendation, I replace the driveshaft. This yields no change. I then do some more digging around and see one of my axles has a huge tear in the CV boot. I go ahead and replace both rear axles. I also changed the diff fluid at this time, and see nothing out of the ordinary in terms of extra specs of metal coming out. Still, same problem after both axles are installed. I had a friend lay down while my car is on jack stands, and as I release the clutch to have the drivetrain engaged, he noticed that the differential is hopping/jumping up and down, which is what is causing my car to feel like it's hopping. I have driven the car pretty hard, and I have had a cusco differential brace installed for well over 50k miles. I am down to replace the diff, I just want to make sure I am not missing anything, as the diff is a pretty large undertaking. Am I safe to assume that something is bad in the diff case? If i go about buying a new/used pumpkin, should I remove the cusco brace? Any help is greatly appreciated. Blake UPDATED Videos below! Last edited by paintdude258; 01-13-2023 at 06:33 PM. |
01-09-2023, 09:47 PM | #2 |
Senior Member
Join Date: Jan 2018
Drives: Crapcan
Location: Oregon
Posts: 11,185
Thanks: 18,222
Thanked 16,350 Times in 7,394 Posts
Mentioned: 108 Post(s)
Tagged: 0 Thread(s)
|
If you get the rear wheels off the ground and put the car in neutral and turn one wheel, does it turn smoothly?
__________________
"Experience is the hardest kind of teacher. It gives you the test first and the lesson afterward." -Oscar Wilde.
|
The Following 3 Users Say Thank You to NoHaveMSG For This Useful Post: |
01-09-2023, 10:52 PM | #3 |
Professional wrench
Join Date: Jun 2020
Drives: 2020 BRZ ST RS
Location: BC Canada
Posts: 114
Thanks: 57
Thanked 37 Times in 28 Posts
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
|
if the diff is moving around abnormally, I'd replace and/or reinforce the diff mounts, trans mounts etc.
I'd also be looking at the clutch etc
__________________
2020 BRZ Sport Tech RS World Rally Blue
'18 TS Suspension, camber bolts, custom align Perrin intake pipe, custom airbox/cold air Gruppe-S UEL header/overpipe Wayne Rom Stg 2 tune |
The Following 2 Users Say Thank You to JohnH For This Useful Post: | norcalpb (01-10-2023), paintdude258 (01-13-2023) |
01-10-2023, 12:01 AM | #4 |
The Dictater
Join Date: Apr 2017
Drives: '13 Red Scion FRS
Location: MD, USA
Posts: 9,449
Thanks: 26,173
Thanked 12,459 Times in 6,163 Posts
Mentioned: 86 Post(s)
Tagged: 0 Thread(s)
|
This ^ is also the first thing I'd check. Also rotate the drive shaft by hand to see if anything catches.
__________________
If a picture is worth a thousand words, a model is worth ten thousand pictures.
Also: "Build Thread" |
The Following 2 Users Say Thank You to Spuds For This Useful Post: | paintdude258 (01-13-2023), x808drifter (01-11-2023) |
01-10-2023, 10:31 AM | #5 |
Member
Join Date: Feb 2022
Drives: 2013 BRZ HKS Turbo
Location: Chicago, IL
Posts: 60
Thanks: 1
Thanked 38 Times in 23 Posts
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
|
Have you inspected all of the diff mounting points to ensure the bolts are tight and the subframe isn't cracked? The diff shouldn't be allowed to hop/jump up and down.
__________________
IG: @terboboost | Twitter: @terboboost | youtube.com/@terboboost | D-corp.co
|
The Following User Says Thank You to terboboost For This Useful Post: | paintdude258 (01-13-2023) |
01-10-2023, 09:01 PM | #6 | |
Señor Member
Join Date: Aug 2012
Drives: 86 GT/'74 TA22 Celica/Kangaroo
Location: Melbourne, Australia
Posts: 1,706
Thanks: 1,104
Thanked 764 Times in 478 Posts
Mentioned: 13 Post(s)
Tagged: 0 Thread(s)
|
Quote:
__________________
1974 TA22 Celica
2013 86 GT |
|
The Following User Says Thank You to Turdinator For This Useful Post: | paintdude258 (01-13-2023) |
01-10-2023, 09:11 PM | #7 |
Senior Member
Join Date: Oct 2013
Drives: 2013 BRZ, 2023 Model 3
Location: SF Bay Area
Posts: 2,297
Thanks: 1,218
Thanked 863 Times in 570 Posts
Mentioned: 15 Post(s)
Tagged: 0 Thread(s)
|
Post pics of rear cradle and front diff bushings. May need to remove that brace you have to get a proper look.
|
The Following User Says Thank You to norcalpb For This Useful Post: | paintdude258 (01-13-2023) |
01-10-2023, 09:54 PM | #8 |
Senior Member
Join Date: May 2018
Drives: 2022 BRZ Ltd, 2019 Ascent
Location: Oregon, USA
Posts: 238
Thanks: 158
Thanked 166 Times in 95 Posts
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
|
A long time ago in another galaxy, another junior mechanic asked me about an MG-B that came in the shop that was from a customer who asked for me. The service manager yanked that ticket and gave it to someone else which pissed me off royal. I had a full slate of work, so I got over it. The other mechanic who got the job asked what is suspected, so I gave him a snarky flip answer, "I don't know, but maybe the differential has a bad bearing." I still feel bad about it fifty years later as it turned out to be what I would have checked for if it were my job: an easy fix... bad rear prop shaft u-joint. I have overhauled my share of transmissions, overdrives and other drive-line components and you learn to eliminate the the easy stuff first. Assuming that the drive shaft and axles have been checked out, isolate the differential and check it. Aside from normal wear and tear from miles, the most common cause for differential failure in my experience is what comes after I ask a question of the owner, "What did you hit?" They never volunteer that bit of information when they bring the car in. The Torsen differential in the BRZ/86 I would not call it a true limited slip type as it is more of a torque bias gizmo. If one wheel has no traction at all, things go badly. With both wheels on the ground, it does a good job of putting the torque in the right place. Off road or ralley I would go with something with clutches in it. The design in the Torsen that makes it quiet in turns is also a major weakness. In my opinion, a sudden shock such as a pothole during a turn could mess up the little geerzmos in the diff. Can't tell too much from the video, but I would take a hard look at u-joints and then move on to the differential. Rebuild only if you can't find a replacement.
__________________
The ants are our friends, they’re blowing in the wind, that ants are blowing in the wind.
Last edited by Flarpswitch; 01-10-2023 at 09:55 PM. Reason: grammar |
The Following User Says Thank You to Flarpswitch For This Useful Post: | paintdude258 (01-13-2023) |
01-11-2023, 06:24 AM | #9 | |
Senior Member
Join Date: Mar 2015
Drives: 2014 GT86
Location: Latvia, Riga
Posts: 4,333
Thanks: 696
Thanked 2,086 Times in 1,436 Posts
Mentioned: 53 Post(s)
Tagged: 1 Thread(s)
|
Quote:
Meanwhile, saw interesting video along the line "why not have both" |
|
The Following User Says Thank You to churchx For This Useful Post: | paintdude258 (01-13-2023) |
01-13-2023, 06:13 PM | #10 |
Senior Member
Join Date: May 2015
Drives: 2013 Subaru BRZ Limited
Location: Austin, TX
Posts: 121
Thanks: 71
Thanked 24 Times in 18 Posts
Mentioned: 2 Post(s)
Tagged: 1 Thread(s)
|
Alright, first off, THANK YOU to all that posted!
The is on jacks, and i tried turning the wheels to be met with little to no resistance. Just sounds like the diff is doing its normal thing! I realized that the video i took is of a terrible angle, so I decided to help you guys out, and myself, and take a few new videos, one with the Cusco diff brace on, and another with it off. Take a look for your self. It look likes the driver side diff bushing is shot? |
01-13-2023, 06:25 PM | #11 |
Senior Member
Join Date: Jun 2017
Drives: BRZ Yellow, 2019 Ranger, 2011 Evora
Location: Dallas
Posts: 1,689
Thanks: 352
Thanked 1,478 Times in 773 Posts
Mentioned: 14 Post(s)
Tagged: 1 Thread(s)
|
Nope diff bushing is doing what is suppose to do. It is time to start doing exploratory on it. Pull half shafts and check, then pull drive shaft and check. If nothing turn diff by hand and check. If nothing open up diff and check. If not there time to check transmission.
|
The Following 4 Users Say Thank You to Grady For This Useful Post: | NoHaveMSG (01-13-2023), paintdude258 (01-13-2023), Ultramaroon (01-13-2023), x808drifter (01-15-2023) |
01-13-2023, 06:29 PM | #12 | |
Senior Member
Join Date: May 2015
Drives: 2013 Subaru BRZ Limited
Location: Austin, TX
Posts: 121
Thanks: 71
Thanked 24 Times in 18 Posts
Mentioned: 2 Post(s)
Tagged: 1 Thread(s)
|
I have lifted the rear of the car up, taken the drift shaft off, and found that the car ran fine. Problem starts when the drive shaft is bolted to the diff.
I have replaced both rear axles, so confident they are not the culprit. Differential looking more and more likely. Quote:
|
|
01-13-2023, 06:32 PM | #13 | |
Senior Member
Join Date: May 2015
Drives: 2013 Subaru BRZ Limited
Location: Austin, TX
Posts: 121
Thanks: 71
Thanked 24 Times in 18 Posts
Mentioned: 2 Post(s)
Tagged: 1 Thread(s)
|
I have had to replace the front and back right side coils several times from hitting curbs and pot holes. The roads are terrible in my area, and i diddd have to learn how to drift some how many many moons ago. I suspect this level of abuse has taken it's toll on the diff! Good call pointing out the beating that I have put the car through in it's years. I don't drive the car easy, as it's most fun when it's right on the tail edge of control.
Quote:
|
|
01-13-2023, 07:57 PM | #14 |
Senior Member
Join Date: Oct 2013
Drives: 2013 BRZ, 2023 Model 3
Location: SF Bay Area
Posts: 2,297
Thanks: 1,218
Thanked 863 Times in 570 Posts
Mentioned: 15 Post(s)
Tagged: 0 Thread(s)
|
How do the bushings on your driveshaft look? When I had mine replaced with the metal torque solution ones (a mistake), the stock rubber ones were super deformed. Not sure that could cause a noise though.
|
|
|
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
Review soon:OS Giken Super Lock Limited Slip Differential + Greddy differential cover | mav1178 | Engine, Exhaust, Transmission | 5 | 02-11-2021 01:20 PM |
Not an 86, yet appears really fun | ToySub1946 | Scion FR-S / Toyota 86 GT86 General Forum | 2 | 06-24-2020 08:15 PM |
It appears that the buts are gone.... | echo419 | Off-Topic Lounge [WARNING: NO POLITICS] | 66 | 10-25-2015 02:38 AM |
ft-86 II appears in GT Racing 2 for ios/android (free) | chickdigger802 | Scion FR-S / Toyota 86 GT86 General Forum | 1 | 11-14-2013 10:40 AM |
fr-s appears in Asphalt 8 | chickdigger802 | Scion FR-S / Toyota 86 GT86 General Forum | 6 | 08-23-2013 09:05 AM |