Deepest First Gear Or More Gear Options? Choose Your Th55.

When you’re choosing a transmission for your well service operation, the decision really is a no-brainer. The Cat® TH55 is the most powerful, durable option on the market, pairing perfectly with high-powered engines and lasting anywhere from 30,000-40,000 hours with two rebuilds. But you do have to make a choice: Which TH55 model, the E70 or the E90, is the best fit? It all comes down to gear ratios.

Need the deepest possible first gear ratio? Choose the TH55-E70.

This seven-speed transmission features the deepest first gear ratio in the industry at 6.25:1 — ideal if you’re working in jobs that require an extremely low flow rate, like pump down or coil tubing. As you upshift the TH55-E70, you’ll see a more traditional, broad range of spacing between the gears.

Need more flexibility in your gear ratios? Go with the TH55-E90.

This nine-speed transmission features tighter step ratios between each gear. That gives you more options within the working window of the pump — allowing for finer control in a typical pumping operation. The TH55-E90’s first gear ratio is shallower but still deeper than any competitor at 4.67:1.

What else is different? Virtually nothing.

In form, fit and function, the two models are practically identical. Installation, controls, service procedures and intervals are all the same, which makes switching between them easy. You can overhaul a TH55-E70 into a TH55-E90, or vice versa, as needed. That might make sense as pumping jobs change or as you move pumps into different fleets — you can line up the gear ratios in the way that makes the most sense for your operation.