GMC Motorhome Parts & Service
7:30 a.m. - 5:00 p.m. Pacific Time
3.70, 3.55, & 4.10 Final Drive Assemblies - (A100)
6 Year, 70,000 Mile Complete Warranty
Will my gas milage suffer?
Overall driving average would result in same milage or better than before since the distributor vacuum advance will advance more and carburetor will deliver leaner mixture.
Why should I purchase the 3.55 and not the 3.42?
If you are going to get the most for your money, the 3.55 gives you better performance. GMC also had a 3.54 ratio on the drawing board. 3.42 ratio is a standard ratio for General Motors. Yes, you can put lower ratio in the original case than the 3.42. Our 3.55 is a 3.5454 ratio. 3.42 ratio when used with 16" rim will generally not perform better than 3.55. Only the 3.55 and 3.70 have the full 4-year warranty.
Are the teeth on the 3.55/3.70 thinner?
Our gears are as thick as our competitor and backed up by 6-year, 70,000 mile warranty.
Isn't the 3.50 ratio less expensive?
No, by the time you drop the transmission and work on the transmission, the labor cost has driven the overall cash outlay higher. Also the gear reduction is done by speeding up the 1/2 of the transmission which causes more stress on the clutch pack. Temperature of the transmission does not drop as much as those with 3.55/3.70.
Why not the 3.66?
Cost for the additional final drive of 3.21 will cause a cash outlay of over $700.00 for the unit and the special output shaft.
NOTE ON SHIPPING: THE FINAL DRIVE UNITS can be shipped from a facility in Ohio to save freight and core return – Please call us for details!