I have recently done a complete rebuild/replacement of the rear end on my 04 Mustang, with a 4.10 and a Torsen T2R carrier.
However, I am having a strange issue with a thumping noise on gear shifts and in certain scenarios. For instance when I bring myself to about 50-60mph and then completely take my foot off the gas to coast for a few seconds when I reapply the gas there is a very noticeable thump and if I reapply gas hard the thump is much louder. This makes me think the noise is coming from the pinion banging into the ring gear due to excessive backlash, however it had a backlash of 0.010" which is within spec.
Due to this being the first time ever driving on a Torsen T2R I am unsure if this is normal or not.
Its been over 800 miles since I have installed everything so I decided to open the diff and drain it since its recommended to replace the diff fluid after break in, the fluid is an opaque gray color.
This is where I make an interesting discovery, the backlash between the pinion gear and ring gear is still the same at 0.010", HOWEVER, it appears there is a large amount of play from the gears inside the torsen carrier itself. If I grab the pinion from the back of the differential and turn it, the ring gear will spin and as a result the carrier will also spin, however the gearing inside the carrier will not immediately engage with the axle shafts. There is about 1 maybe 2 degrees of play between when the pinion spins and the axle shafts spin. As a result I can actually emulate the thumping by hand if I rapidly spin the pinion back and forth, the thump is coming from when the torsen carrier gear engages with the axle shaft.
Video of endplay
At this point I am unsure on what to think, either:
However, I am having a strange issue with a thumping noise on gear shifts and in certain scenarios. For instance when I bring myself to about 50-60mph and then completely take my foot off the gas to coast for a few seconds when I reapply the gas there is a very noticeable thump and if I reapply gas hard the thump is much louder. This makes me think the noise is coming from the pinion banging into the ring gear due to excessive backlash, however it had a backlash of 0.010" which is within spec.
Due to this being the first time ever driving on a Torsen T2R I am unsure if this is normal or not.
Its been over 800 miles since I have installed everything so I decided to open the diff and drain it since its recommended to replace the diff fluid after break in, the fluid is an opaque gray color.
This is where I make an interesting discovery, the backlash between the pinion gear and ring gear is still the same at 0.010", HOWEVER, it appears there is a large amount of play from the gears inside the torsen carrier itself. If I grab the pinion from the back of the differential and turn it, the ring gear will spin and as a result the carrier will also spin, however the gearing inside the carrier will not immediately engage with the axle shafts. There is about 1 maybe 2 degrees of play between when the pinion spins and the axle shafts spin. As a result I can actually emulate the thumping by hand if I rapidly spin the pinion back and forth, the thump is coming from when the torsen carrier gear engages with the axle shaft.
Video of endplay
At this point I am unsure on what to think, either:
- this is how the carrier is supposed to perform
- I got a faulty carrier
- I screwed up somewhere along the line and installed something wrong
- 2004 Base Mustang Automatic transmission 3.9 V6
- 8.8 Axle housing from 03 Mustang GT
- Upper Control Arm: J&M
- Rear end upper bushing: UPR Extreme Duty Rear End Spherical Housing Bushings
- Lower Control Arm: J&M Weight Jack
- Torque Box Reinforcement: BMR TBR005 & TBR003
- Axles: (Moser Engineering A883153)
- Ring and Pinion: Ford 4.10 (M-4209-88410)
- Carrier: Torsen T2R (M-4204-T31H)
- Sway Bar: Eibach
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