Keith Browning Posted October 30, 2015 Share Posted October 30, 2015 One of our customers with a small fleet of new Transits runs a large bakery and supplies Northern NJ and New York City, puts about 1000 miles a week on these things. Right rear brake is grinding at 17,000 miles. I pulled the wheels and the rears are simply worn out. Fronts still have a good 7mm left.I measured the rotor and decided I had enough to save it which I did with the final thickness measuring 15.47mm (min spec is 15mm) I had a hell of time though. I noticed that the rotors had worn concave - wearing heavier through the middle of the rotor on both sides. Some manual turning of the lathe feed was needed to knock down the beginning and end of the rotor faces.Couple of notes: I did use an on the car lathe which is a must have and its one of those vehicles you have to disconnect the driveshaft. If you want to replace the rear rotors you will have to pop the diff cover and pull the axle shafts. I want to slap the guy that approved that design. You will also need to remove the caliper brackets to allow the lathe arms all the way in to machine the entire rotor face. Quote Link to comment Share on other sites More sharing options...
mchan68 Posted October 30, 2015 Share Posted October 30, 2015 One of our other techs did a set of rear pads & rotors under FMPP on one awhile back. I vaguely recall he had a hell of time getting the rotors off too. Quote Link to comment Share on other sites More sharing options...
Matt Saunoras Posted October 31, 2015 Share Posted October 31, 2015 I did notice those rear rotors are super thick. Hopefully they take well to machining because they sound like a bitch to change. What kind of on-car lathe do you guys have? I ran across something interesting today, I've used our pro-cut lathe to do SRW super duty rotors before but apparently not any newer ones. Went to cut a set of rotors on a 13 F-250 today and the damn lathe is too small. I knew the 13+ brakes were bigger but it never occurred to me rotor diameter increased as well. Guess we're getting a bigger lathe soon Quote Link to comment Share on other sites More sharing options...
Keith Browning Posted October 31, 2015 Author Share Posted October 31, 2015 Yes, those rear rotors are thick - minimum thickness is 15mm and they actually cut well aside from the thickness variation issue I had which since I made my original post I discovered is due to the fact that the pad contact area is much narrower than the face of the rotor. So I anticipate running across this every time I machine these rotors. If you do a lot of truck work and do brakes often you really need to get your shop to invest in a good on-car lathe that will do trucks as well. I can't believe my company sprung for it because it is rather expensive... about 8 months ago we got a brand new Pro-Cut A10 Warthog which has more torque and is a larger machine altogether. I now regularly cut front and rear SRW rotors and fronts on DRW vehicles all the way up to F550's. They claim it will do F750 rotors as well. It is more common though for the rear rotors to be way too far gone (pitted or ground up) to machine. Otherwise, I commonly just do a level 1 service (especially with DRW trucks) and have no issues at all. There is an adapter you will need to bolt up to 8 and 10 lug hubs that does not come with any of the machines - part number 50-935 Quote Link to comment Share on other sites More sharing options...
the_twig_187 Posted October 31, 2015 Share Posted October 31, 2015 what model of transit did you have that you had to remove the diff cover to remove the axle? I repaired a transit 350 for breaking the left rear axle last week and i did not have to remove the diff cover to replace the axle. all I did was unbolt the 15mm bolts on the hub face and give it a couple taps with a hammer and the whole axle slides right out. same as a fully floating dana axle. 1 Quote Link to comment Share on other sites More sharing options...
Keith Browning Posted November 1, 2015 Author Share Posted November 1, 2015 You are right - that was a flat-rate assumption I made about pulling that apart. Since I didn't need to replace the rotors I never read the procedure in the WSM. At first glance it certainly looks a lot like the old semi-floating rear and those axle shaft bolts look like they are holding the rotors on. And the bearing nut socket is new too #205-1007 part of the TKIT-2014C-FL kit. Nothing like reading the fuckin manual eh? Quote Link to comment Share on other sites More sharing options...
Chad_Kelsoe Posted November 1, 2015 Share Posted November 1, 2015 I did a rear hub seal on a 250 single wheel a few months back. It's a full floating rear axle, so all ya gotta do is unbolt and remove the rear axle. Then rotate the rotor on the hub and remove. We had a guy bring a 350 dual rear wheel Transit complaining about the rear brakes worn out at 25k miles. He was upset that we wasn;t gonna warranty them, but this guy had been seen hauling an equipment trailer around with a mini-excavator around. Quote Link to comment Share on other sites More sharing options...
8WA Sman Posted November 2, 2015 Share Posted November 2, 2015 I have had real good results using cyro treated rotors on other applications. Quote Link to comment Share on other sites More sharing options...
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