HTS Logo

Top Quality Transmissions and Differentials
for the Heavy Duty Industry

(916) 395-1353 or
toll-free (800) 962-8782
6890 Luther Drive, Sacramento
CA, 95823 - Get Directions
Open Monday-Friday, 8-5pm -
Contact HTS
If you have a question that is not listed here, give us a call or send us an email!


Gear Ratio Chart. Click to Enlarge.

Frequently Asked Questions


How do I tell the ratio and model of my differential if there's no tag?

The information is stamped on the end of the pinion shaft. On the front axle the pinion is not accessible until you remove the front cover, so the quick way is to check the rear. On the end of the pinion shaft you will find a series of numbers which indicate the ratio and model number, just call us and we will gladly figure out what you have. This method works for both three and two-axle trucks.



Which oil should I use?

Synthetic oils definitely cost more, but offer more protection and longer intervals between changes. Most current transmissions should use 50 weight synthetic oil. For earlier transmissions, 80-90 mineral is ok. 85-140 is not recommended. Most current differentials should use 75-90 synthetic or 85-140 mineral oil. We stock these oils for your convenience at competitive prices.



Should my transmission or differential be repaired or exchanged?

Down time is reduced to a minimum with an exchange, but depending on what is damaged, a repair may cost you less. To help you make the decision, we commonly give free estimates on repairs while you wait. All exchanges have a 1-year warranty.