View Full Version : Gen 3 Coupe, Gen 3 Coyote, IRS driveshaft bolt size or p/n
Discount Brain Surgery
02-24-2025, 09:16 PM
Installing driveshaft from TKX to the Ford IRS. I need the size or part number of the four driveshaft bolts that connect the driveshaft to the FFR IRS adapter. Manual says “bolts will come with the driveshaft”…not so much.
Anyone know the size…or the specific Ford P/N ? I bought some for a 2020 GT premium, they the are too large (dianeter). I have the M10/25mm socket head screws.
edwardb
02-25-2025, 05:53 AM
According to this thread, which also has an entry by Jim at Factory Five, they are M10's. They are socket heads. There have been some issues with 20 vs. 25mm length, so make sure everything is tight when torqued down vs. bottoming out. This is not an OE setup. The Mustang uses a different connection to the diff. So you won't find a Ford part number for this exact application. https://thefactoryfiveforum.com/showthread.php?35158-The-bolts-ARE-TOO-LONG!-(driveshaft-to-adapter-for-IRS)
Discount Brain Surgery
02-25-2025, 08:23 PM
According to this thread, which also has an entry by Jim at Factory Five, they are M10's. They are socket heads. There have been some issues with 20 vs. 25mm length, so make sure everything is tight when torqued down vs. bottoming out. This is not an OE setup. The Mustang uses a different connection to the diff. So you won't find a Ford part number for this exact application. https://thefactoryfiveforum.com/showthread.php?35158-The-bolts-ARE-TOO-LONG!-(driveshaft-to-adapter-for-IRS)
All seems snug. Thank you. I’m showing about 3 3/4 inches of spline from the rear tranny dust seal to the first u-joint. I thought more spline would be engaged with the tranny. Is your setup similar?
edwardb
02-25-2025, 09:55 PM
All seems snug. Thank you. I’m showing about 3 3/4 inches of spline from the rear tranny dust seal to the first u-joint. I thought more spline would be engaged with the tranny. Is your setup similar?
That's too much. Mine is about 3/4" to the seal and 1-1/4" to the housing on the transmission. Sounds like you don't have the right driveshaft. It happens.