• Welcome to SVTPerformance!

Differential temps too hot.

Discussion in 'Driveline' started by seethesvt, Jun 2, 2019.

  1. seethesvt

    seethesvt Member Established Member

    Messages:
    63
    Joined:
    Oct 4, 2016
    Location:
    Georgia
    The differential in my car has Eaton truetrac, a temp gauge and cooler. I bought the car in November and haven't really driven it much. I drove it on a 20 mile ride on the highway to work and the diff temp gauge pegged over 250 (definitely too hot). So, on the way home I turned on the diff cooler and it got up there too. I don't think the diff coolers working. But at regular highway speeds I shouldn't need the cooler anyways.

    I saw a puddle under the back the next day so I figured it had a leak from the cover and the oil was low. I ordered the FTBR kit (might as well while I'm there) and took the IRS out. Turns out the cooler pump was leaking. Not the diff cover. When I drained the diff (without measuring) it looked like it had enough fluid.

    Now that the diff is out, what can I check to figure out the cause of this heat? I'm not gonna race the car and I want to remove the diff cooler, and eventually the temp sensor too.
     
  2. railroad

    railroad Well-Known Member Established Member

    Messages:
    1,601
    Joined:
    Dec 9, 2003
    Location:
    warrior, al
    Only thing I can think of is bearing preload is too high.
    If the gears were set wrong, you would hear it or see the wear on the gears.
    I think the resistance on the pinion, free turning is 25 inch lbs.
    The carrier bearings should let the carrier turn without binding.
    If you are not running syn lube, I would recommend it.
    With the cooler and pump working correctly, you should be good.
    Not that it is critical to your question, but many do not tell what automobile you are discussing. I am going to guess, it is not a Honda Civic.
    Year, make, model, mods, etc are really relevant to addressing an issue.
    If your exhaust does not exit from under the car, make sure the exhaust is not directed toward the gear housing, any amount!
     
    Last edited: Jun 2, 2019
  3. seethesvt

    seethesvt Member Established Member

    Messages:
    63
    Joined:
    Oct 4, 2016
    Location:
    Georgia
    Just went out and it turns with just less than 25in Ibf. Haven't broke open the cover yet.
     
  4. gt347mustang

    gt347mustang Well-Known Member Established Member

    Messages:
    2,282
    Joined:
    Jun 29, 2006
    Location:
    Colorado
    How? That doesn't make sense.
     
  5. seethesvt

    seethesvt Member Established Member

    Messages:
    63
    Joined:
    Oct 4, 2016
    Location:
    Georgia
    I put a torque wrench in the nut on the pinion yoke (think that's the name). Set the torque wrench to 25in and it turned. Set it to 20in and it clicked before it turned.
     
  6. railroad

    railroad Well-Known Member Established Member

    Messages:
    1,601
    Joined:
    Dec 9, 2003
    Location:
    warrior, al
    That is the proper way to check. It is not trying to prove anything. It is, what it is.
    Make sure the pinion will not move in and out. That is front to rear movement.
    How are the gear faces? They should be smooth on both sides. It sounds like you have the ring gear already out, be sure to keep up with the shims and which side they go. Same for the bearing caps, right and left, top and bottom.
    Still wondering what car we are working on?
     
  7. P49Y-CY

    P49Y-CY selfie deaths ftw Established Member

    Messages:
    10,234
    Joined:
    Jun 21, 2003
    Location:
    south oc, cali
    He is posting in the SVTP Terminator Driveline section, and mentions his IRS and FTBR kit. While not always 100%, in this case it seems very clear what vehicle he is working on. I do agree it is important information to answer a question like this, though.
     
  8. seethesvt

    seethesvt Member Established Member

    Messages:
    63
    Joined:
    Oct 4, 2016
    Location:
    Georgia
    Correct. It's a 03 termi.
     
  9. seethesvt

    seethesvt Member Established Member

    Messages:
    63
    Joined:
    Oct 4, 2016
    Location:
    Georgia
    I'm going to go out and remove the pumpkin from the IRS in a little bit and pop the cover off and see what's up. I'll check everything and report back.
     
  10. seethesvt

    seethesvt Member Established Member

    Messages:
    63
    Joined:
    Oct 4, 2016
    Location:
    Georgia
    Got the cover off and removed the bearing caps. Could not pull the diff out of the housing by hand. On a visual inspection, The bearing caps and races look good for what I can see. The ring and pinion gears are not worn, and the carrier bearings don't have any play in them and operate normally. I can't see the inner pinion bearing, but the yoke doesn't have any in/out or side/side play.

    Is the differential usually difficult to pull out? I didn't try prying it out because that seems risky. Also the bearing cap bolts were incredibly tight. Impact took some time to them loose.
     
  11. seethesvt

    seethesvt Member Established Member

    Messages:
    63
    Joined:
    Oct 4, 2016
    Location:
    Georgia
    Also, there are no shims... Think I'mma go rent a tool to measure backlash. 4bwwQAK.jpg KVyfALa.jpg
     
  12. seethesvt

    seethesvt Member Established Member

    Messages:
    63
    Joined:
    Oct 4, 2016
    Location:
    Georgia
    .
     
  13. slo984now

    slo984now AKA 01yellerCobra Established Member

    Messages:
    15,127
    Joined:
    Oct 5, 2005
    Location:
    San Diego
    You need a case spreader to get the diff out. Those cast iron rings are the factory shims. I made my own spreader when I rebuilt my centri section. 5ed005a23cb3f78d2b658ac5c4cc73ba.jpg
     
    1wild-horse likes this.
  14. seethesvt

    seethesvt Member Established Member

    Messages:
    63
    Joined:
    Oct 4, 2016
    Location:
    Georgia
    Well that explains it. I don't really think I need to take it out though... Wish I knew what was causing it to be so hot.
     
  15. railroad

    railroad Well-Known Member Established Member

    Messages:
    1,601
    Joined:
    Dec 9, 2003
    Location:
    warrior, al
    I would clean everything up and put it back together.
    Be sure the caps go back on like they were originally installed. Be sure you do not get anything between the caps, bearing races and case. Find the tq numbers for the bolts. You might check the recommended wt of gear oil for the Eaton. If they offer an option, I would go with a heavier wt.
    Another thing, make sure your tire diameters on the rear are not drastically different. This would keep all those side and internal worm pinion gears working on highway runs. Good luck, let us know how it does after assembly.
     
  16. seethesvt

    seethesvt Member Established Member

    Messages:
    63
    Joined:
    Oct 4, 2016
    Location:
    Georgia

    Will do. I also ordered a new sensor for the gauge and I'm going to check the gauge ground.
     
  17. slo984now

    slo984now AKA 01yellerCobra Established Member

    Messages:
    15,127
    Joined:
    Oct 5, 2005
    Location:
    San Diego
    What's considered normal range for diff temps? I've never monitored it. It might be worth running without tailpipe just to see if it makes a difference.
     
  18. seethesvt

    seethesvt Member Established Member

    Messages:
    63
    Joined:
    Oct 4, 2016
    Location:
    Georgia
    I've read that between 180-210 is normal, but no solid data.

    Sent from my SM-G975U using the svtperformance.com mobile app
     
  19. seethesvt

    seethesvt Member Established Member

    Messages:
    63
    Joined:
    Oct 4, 2016
    Location:
    Georgia
    So, I was thinking, the temp sensor was Installed in place of the fill plug, so fluid never really got to the sensor. I'm thinking that and the added heat from the exhaust caused high temp readings. Plus, the fluid wasn't bad when I drained it. The new frpp cover has a drain plug, so I'm going to put the sensor there and see.

    Sent from my SM-G975U using the svtperformance.com mobile app
     
  20. seethesvt

    seethesvt Member Established Member

    Messages:
    63
    Joined:
    Oct 4, 2016
    Location:
    Georgia
    Installed the FTBR kit this weekend. The new FRPP diff cover had a spot in it to drill and tap for a temp sensor, so i got a new sensor and did that. When I went to test drive the car this morning, as soon as I turned the key the temp said 120ish. Since it was only 80° outside I knew its definitely reading wrong. After a 10 minute spirited drive around the block it was reading 200°. So I grabbed a jumper and jumped the ground of the gauge to a good ground and the temp went down to about 120, and back to 200 when I let go. Upon further inspection I saw that whoever installed it didn't crimp the terminal for the ground. Easy fix. Can't get an alignment for a couple days, so can't take it out to really heat it up. I will take it out this weekend for a couple hours to verify that the temps are good and to shake down the IRS and recheck torques.

    Sent from my SM-G975U using the svtperformance.com mobile app
     

Share This Page