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Monodado TR Rotor Torque value?

Discussion in 'Boxers/TR/M' started by c4b4the04, Jan 11, 2020.

  1. c4b4the04

    c4b4the04 Karting

    Jun 9, 2017
    80
    Northern Virginia
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    Cassidy
    Good afternoon all,

    Taking advantage of a lovely day in the winter (rare) and reinstalling brake rotors and fresh pads.

    I see in the WSM that the torque value for front "rotor to hub" is 2,5, which I think equates to 18 ft lbs. Those are fairly beefy bolts and I recall having to use an air tool to break them loose. That doesn't seem right to me. Rears are the same size and they say to go 5, which converts to 36 ft lbs. That is closer but it still seems low.

    The caliper bolts say to go with 10, which is about 72 ft lbs and that sounds about right so I think I am converting the Kpm to ft lbs correctly (online calculator).

    Thoughts welcome. I am just glad to see her going BACK together. Dealt with a disconnected parking brake cable on the passenger side (had been that way since 2001, best I can figure) and it all cascades from there (anyone else been there? One thing leads to another on a newly bought car).

    Thanks for the advice. These are the brake rotors that bolt onto the hubs for single nut wheels. I don't know if the later cars use the same setup (guessing not).

    Grazie,
    Cassidy
     
  2. vincenzo

    vincenzo F1 Rookie

    Nov 2, 2003
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    #2 vincenzo, Jan 11, 2020
    Last edited: Jan 11, 2020
    If you speak of item 27, it sounds correct to me (per Ferrari). I thought the same thing on the later car... and used locktite blue to ease my mind. The lubricant will load the threads a bit more than ‘clean and dry’ and help reduce any potential to loosen over time. I used the F-car torque values.

    Look at your bolt size and scan the F-car torque table for similar bolts. If you see that your size/application is abnormally lower than those in the table... then reconsider your options. Presumably Ferrari used a low strength steel in that bolt and made up for it by using more bolts (10 per hub) to ensure an even clamping force and no rotor warpage.

    A low strength steel bolt is typically more resilient than a high strength steel. High strength steel will snap - low strength will deform. The threads and shank of a low strength bolt will deform more easily and thereby not loosen. They will NOT accept the higher torques of high strength steel.

    Use a VERY thin layer of anti-seize on the hub to disc mating surface. Torque in a criss cross pattern in two stages.




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  3. vincenzo

    vincenzo F1 Rookie

    Nov 2, 2003
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    #3 vincenzo, Jan 11, 2020
    Last edited: Jan 11, 2020
    This chart may offer a comparative non-F suggested value to compare. Likely your bolt is a 8.8 - m10x1.25 (SWAG ???) - they call for 20 to 29 ft-lb. But... perhaps it is a 4.8 or 5.8. Any markings on the head?

    PS: even if the bolt can accept a relatively higher value, remember the hub as well. Likely it is a much lower strength steel than an 8.8 equivalent.


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  4. c4b4the04

    c4b4the04 Karting

    Jun 9, 2017
    80
    Northern Virginia
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    Cassidy
    Indeed those are the ones. Thank you for reaffirmation. It's a learning curve on this car for sure. Thoughtful design, even if not always practical. Thank you. I'll go per the book then. Strikes me so odd that they also only listed the center bolt hubs at 22, which I've been told to go 325 ft lbs and I wouldn't want them a bit looser.

    Cassidy


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  5. Steve Magnusson

    Steve Magnusson F1 World Champ
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    #5 Steve Magnusson, Jan 11, 2020
    Last edited: Jan 11, 2020
    What is the major thread diameter of these bolts? Does it match the 8x1.25 shown for that WSM spec? I can see this getting messed up in the WSM table as on the later 5-lug cars the front brake disks are first secured by just a couple of small M8 bolts with the pointed guide heads (as the wheel lug bolts are what really hold the front brake disc to the front hub) -- and 2.5 daN-m is very reasonable for these small ponted M8 bolts. If these bolts you have are M10x1.25 (like at the rear) = I think you are right to consider using the 5 daN-m specified for those - JMO. Or, stated differently, if these bolts are not M8 then that 2.5 spec does not apply to them.
     
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  6. Steve Magnusson

    Steve Magnusson F1 World Champ
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    #6 Steve Magnusson, Jan 11, 2020
    Last edited: Jan 11, 2020
    This can also be related to confusion between the early single-lug design and the later 5-lug design. The torque for the "screw securing wheels" is correctly shown as 45 daN-m (325 ft-lb) on page M8 of the TR WSM, whereas, on the 5-lug design there is a center front hub nut that 22 da N-m is an appropriate torque -- nut, item 5 here:
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    (and item 10 is the pointy head M8 bolt mentioned in the prior post)
     
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  7. xplodee

    xplodee Formula Junior

    Jan 3, 2017
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    When you put your wheels back on, its critical to ride around the block for a mile or two then come home and torque them again. Then ride for ten miles or so and re-torque. Do this until you don’t get any more movement on the bolt at 325lbs-ft. Youll be surprised just how long it takes...
     
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  8. Rifledriver

    Rifledriver Two Time F1 World Champ

    Apr 29, 2004
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    Caution needs to be used in reading the torque specs. Always confirm by at minimum looking at the fastener size to be sure it agrees. The translations are often not clear cut.

    As Steve pointed out. the wheel bolts are 45 KPM and are described as "Screw securing wheels" and are 40 mm diameter. What you had looked up was probably "Ring nut securing axle shaft to rear wheels shaft" and is shown as being 27 mm.
     
  9. c4b4the04

    c4b4the04 Karting

    Jun 9, 2017
    80
    Northern Virginia
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    Cassidy
    Gents I am grateful. Thank you. I will go back over things again and double check. My cooling system is apart currently so it isn't going anywhere this weekend (that and they are calling for snow in the mid-atlantic region). I certainly have the time. Most likely I looked at the wrong bolt value for the "screw securing wheels", that makes sense. My WSM does appear to be the one for the monodado car, so that's a start!

    Thank you all,
    Cassidy
     
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  10. EZORED

    EZORED Formula Junior
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    Cassidy, Did you replace your rotors with new, and if so where did you purchase them?
     
  11. c4b4the04

    c4b4the04 Karting

    Jun 9, 2017
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    Cassidy
    Sorry I didn't see this sooner....

    I didn't purchase new ones, they simply didn't need it. I had a slight pulsation after one extremely hard brake (DC traffic is notorious for short stops) and I thought it would be worth checking the run out. I set them on a lathe and had the run out flat within two passes. Still plenty of "meat" left, as this was the first cut on them ever. Should be true now for a lot more years. As for sources, I see that Eurospares has a decent price on them, as does AWItalia in the states.
    CN
     
  12. EZORED

    EZORED Formula Junior
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    When ever you see a good price, they are out of stock. Asking price if someone has them is North of $1200 dollars each. You might as well by the Brembo big brake kit for $3600 and get new rotors calipers and pads. at that price. Bill At GT Car Parts is trying to have a run of them made, so I am just waiting.
     
  13. ago car nut

    ago car nut F1 Rookie
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    Willwood has one very close, but I have not measured exactly.
     
  14. Rifledriver

    Rifledriver Two Time F1 World Champ

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    Needing new rotors is a little hard to imagine. Unlike most German cars they wear very little, since 1985 I have never replaced one. A friend had over 250,000 miles on his TR when he passed away and it still had the originals. The rotors were made by Brembo and about 10 or so years ago Brembo had a big house cleaning and blew out what they considered obsolete inventory. Tire Rack had them for sale at giveaway prices but even then I saw no reason to buy them.
     
  15. Natkingcolebasket69

    Rossa Subscribed

    250k miles! WoW ! Amazing stuff


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  16. Rifledriver

    Rifledriver Two Time F1 World Champ

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    The Germans make brake rotors that wear out almost as fast as brake pads but the Italians have never done that. The only time I have ever replaced Ferrari rotors is when someone has let them get metal to metal.
     
  17. ago car nut

    ago car nut F1 Rookie
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    The German rotors? You think different type of cast iron or type of recommend pad material?
     
  18. Rifledriver

    Rifledriver Two Time F1 World Champ

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    Iron. Often the same pad compounds are used but the Germans love butter soft iron. On a lathe the stuff cuts like brass.
     
  19. turbo-joe

    turbo-joe F1 Veteran
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    brain, you call now from german cars?
    or you mean that the german F have other rotors? I think you mean the first.then I have to agree partly. but also in germany the driving is much more aggressive than in the US and normaly every 2 pads change have to change the rotors in the front, in the rear mostly with each pad change also the rotors. muchbetter are the japanese rotors
     
  20. Rifledriver

    Rifledriver Two Time F1 World Champ

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    Not sure why aggressive driving requires junk rotors?
     
  21. turbo-joe

    turbo-joe F1 Veteran
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    I think it is only for making money. during warranty there is no problem but soon after then have to be replaced
     

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