HGT Precision Patent solves a Global Bell House issue for the Motorsport and Performance industry

Monday September 23, 2019
As the saying goes...necessity is the mother of invention.


Back in 2017, one of our customers was using a well known international brand of bell house with our HGT Precision Gearbox. At his annual gearbox servicing time, it was obvious from the wear on the input shaft spigot and the rumbly gearbox input shaft bearing, that there was an alignment issue. Our customer also had his engine out for servicing so we asked him to dial indicate the other XXX brand of Bellhouse to the crank. He had just assumed it to be 100% off the shelf, but when the process was performed, Lo and behold alignment of the XXX Bellhouse was off by a country mile. So it was offset dowel time - but where to buy them, which offset was required, and how soon could they be delivered? 

There's a myth that you can buy any brand of Bellhouse, bolt it up, and the centreline will magically align with the crank centerline within the tolerance that's needed. If the alignment is off in the X or Y axis, it's likely to result in hard shifting and premature clutch or gearbox damage that will eventually lead to failure. The reality is that some adjustment will be needed to create perfect alignment no matter which brand of bell you choose to buy, and therefore dial indicating the Bellhouse centreline to the crank centreline is a must.

Whilst dial indicating the Bell to the crank is "Motorsport 101" for professional race teams; many racers fitting after market Bellhousings and Gearboxes just "bolt 'em up" and hope for the best; a recipe that often results in disappointment. We began thinking, there just had to be a better and easier way than using offset dowels.

Introducing Vernier Bells.

This globally Patented device eliminates the need for offset dowels as the adjustability is built into the Bellhouse. This allows adjustment of the centreline in both the X and Y axis's that's needed to create 100% perfect alignment. You only need to do this once as long as you are using the same Bellhouse and engine block. Of course, if you line bore the block for a new crankshaft, the Bellhouse alignment centre will need to be checked again. Do it once - do it right as it's a small investment of time to maximize the long term reliability of your drivetrain and promote smooth effortless shifting. 

Vernier Bells are available for most popular Motorsport gearboxes and engines such as: 

BMW M50, M60, M62, S62, S65, S85

FORD Aluminator, Barra, Coyote, Duratec, Windsor

HONDA K Series in RWD, F20C

GM LS in OEM and Race formats

MAZDA 13B, 20B, 26B, MZR-L Series


NISSAN SR20, RB25, RB26, RB30, VG30, VQ35, VQ37, VR38 in RWD, L-Series.


We are always developing new setups, so if your engine isn't listed here just ask.


HGT Precision Sequential Gearboxes are now all shipped with Vernier Bellhousings. If you have another Gearbox brand and would like a Vernier Bell, there's more info at www.vernierbell.com