SpeedFactory Titanium Transmission to Engine Bolt Kit B/D/K

Every B or K swap hits the same moment: the transmission is hanging on the jack, and the bag of 25-year-old bellhousing bolts you pulled is half rusted, mixed lengths from somebody's previous swap, or two bolts short. This SpeedFactory titanium transmission to engine bolt kit replaces the OEM 17mm-head hardware on Honda and Acura B, D, and K series engines with fresh M12x1.25 titanium flange bolts in the correct lengths, so bolting the gearbox up isn't a scavenger hunt.

What It Is and Why It Works

SpeedFactory machines these from Ti 6Al-4V, the same Grade 5 titanium as the rest of their hardware line, with a hollow-domed 6-point head that cuts weight over the solid factory bolt. Titanium won't corrode the way stock steel does, which matters on hardware you'll be removing again someday: a clutch job, a trans swap, a rebuild. These come out as cleanly as they went in instead of fighting you.

The kits are matched to the engine family. The B and D series kit runs five 65mm bolts. The K series kit runs six bolts, four 65mm and two 85mm, because the K bellhousing pattern needs the longer reach in two positions. That length mix is exactly the detail that trips people up when they try to assemble their own hardware from a parts store, and it's why the kit exists. If you're only missing or replacing one fastener, the 65mm bolt is also sold as a single in this listing.

Fitment follows the engine, not the chassis. B, D, or K series, FWD or AWD, factory or swapped: a B18C in a DC2, a K20 in an EG or EK, a K24 Accord, a D16 daily. If the engine-to-trans bolts in your hand have 17mm heads and M12x1.25 threads, this is the hardware.

Specs

Available Options

Fitment

The chassis table is a starting point, not the boundary. SpeedFactory confirms these for B, D, and K series in FWD and AWD applications, which covers swapped EG, EK, DC2, and EF builds the same as factory installations. Match the kit to the engine family in the car, not the badge on the fender.

What to Know Before You Buy

Double-check which hardware you're actually replacing, because SpeedFactory makes three different titanium transmission products and the names are close. This kit is the trans-to-engine bolts, the 17mm-head M12 hardware around the bellhousing. The transmission case bolt kit is smaller M8 hardware with 12mm heads that holds the case halves together, and the transmission mount hardware kit is a third thing entirely. If you're staring at 12mm heads, you want the case kit, not this one.

Install notes are the same as any titanium-into-aluminum pairing. Chase or clean the threads in the block and case first, run a nickel-based anti-seize on the threads to prevent galling, and torque to the factory service manual spec for your engine, same numbers as steel. Don't run these down with an impact. If you're mid-swap, this is also the right time to inspect the dowel pins between the block and case, because missing dowels are a classic source of trans noise that no amount of fresh hardware fixes. K swap guys should note the two 85mm bolts in the K kit are position-specific, so lay the kit out against your old hardware before you start threading things in.