Report on low-range gears and part-time kit
Report on Installation of Marks Part Time Kit and Marlin’s Low Range Gear Set on 1995 FZJ-80
I have a 1995 FZJ-80 with 167000 miles. Tires are 35 inch with stock gearing at 4:10. Speedometer is uncorrected and reads approx 10% slow due to larger tires. Both diffs have ARB Air Lockers installed. Center Diff Lock Switch had been previously installed (required for P/T Kit installation).
Installation was completed in one day by Slee Off Road in Golden, Co. Since the transfer case was out, we elected to install all new seals and bearings, completing the overhaul.
Prior to installation, I engaged low range and locked the trans in low to determine the speed at 3000 rpm. Speedo indicated 10mph at 3000 rpm. The following are the readings after Low Range install:
1st - 3000 rpm – 7mph
2nd – 3000 rpm – 14mph
3rd – 3000 rpm – 21mph
4th – 3000 rpm – 28mph
My 4:10 gears indicate 56mph at 2000 rpm on highway driving (GPS indicates 62.2mph)
Impressions –
Part Time Kit – The truck steers easier in 2wd and seems to accelerate more quickly. I suspect the milage will improve somewhat, but that mainly depends on my driving habits.
Low Range Gears – Much improved crawl capability with 4:10 gears.
I had been thinking of going to 4:88 gears, however I like the ability to go 75 mph at approx 2500 rpm with the 4:10s. For hills I can just drop down a gear and it is about what 4:88s gearing would be. My real reason to regear was for better low range (crawl) performance and this new gearset addressed the problem at much less cost. Just my preference.
I hope this helps any one thinking of doing either of these mods. Obviously, doing both while the transfer is apart is the way to go.
One more note, I cannot say enough about Christo Slee’s operation. Ben, Amory and the best tech, Joe are top notch. Good fair prices and excellent service, done right the first time!