November/December 2009

Hidden Mysteries of The Transfer Case

(Or How I learned the Meaning of 4-Low)

By Scott Leslie

Working on my Land Cruiser is a source of real enjoyment for me. I’ve spent so much time driving in and tinkering on my 1986 FJ60 that it feels like an old, reliable friend. The satisfaction derived from driving this big old chunk of iron more than makes up for the lack of fuel efficiency and acceleration. Call it smiles-per-gallon versus miles-per-gallon. Every once in a while, my truck decides to teach me something about machines and how things work, usually without putting me or my machine in peril. Occasionally though, my curiosity—or lack of mechanical expertise—brings me right to the edge of doing something catastrophically stupid. This is exactly what happened this past fall in the beautiful mountains of New Hampshire.

The Yankee Toys Fall Gathering is a great event, which I look forward to every year. New England in the fall is stunning and the Cruiser camaraderie at the Fall Gathering is second to none. The plan was to go up early in the week while my wife attended a fabric-weaving workshop in scenic Harrisville, New Hampshire. I, on the other hand, would drive idly around on the back roads and do a little maintenance on the truck. It had been too long since the valves were adjusted and I wanted to see if I could conquer the sometimes-balky 4-Low setting that had kicked me off some fun trails in the past. 

I did not grow up around 4-wheel drive vehicles, so the transfer case has always been something of a “black box” for me. I knew what it did but had no idea how it did it. A lifetime of nursing older and eccentric vehicles seems like a common thread with many people in Cruiserdom. That’s probably why when we finally get our hands on a Land Cruiser, we hold onto it, taking pleasure in the common sense Toyota design and tank-like qualities throughout. 

For the most part, the knowledge gained from working on other vehicles has helped me in maintaining my Cruiser. The transfer case, however, refused to give up its secrets to me, even after many evenings staring at the Toyota manual and the exploded diagrams. There are just too many gears, shift forks and bearings to gain understanding from a two dimensional illustration. All too soon, my ignorance would be dispelled with a healthy dose of gear oil, 40 pounds of aluminum and steel and some New Hampshire grit and gravel thrown in for good measure. 

Crawling at idle speed up the side of a mountain behind the trusty, torque heavy 2F, I’m always amazed at the power that 4-Low sends to the wheels. At 210,000 miles, I became the third owner of this Cruiser and the first time on a serious trail, I discovered that something was amiss with this transfer case. Under load in 4-Low, it would sometimes make terrible high-pitched grinding noises. Others have reported the same symptoms, although I could usually make this disappear by engaging 4-Low while slowly rolling backwards. So it was on a balmy autumn morning in a gravel parking lot that I would choose to apply some “common-sense” adjustments to the t-case linkage. There is a slim possibility that I could have kept myself out of this mess if I had brought along my trusty Toyota manuals to do some serious “stare and compare” research but a hectic schedule kept me from including this (and several other important items on the list). 

After removing the access plate on the transmission hump, it seemed “obvious” that the grinding noise was due to 4-Low not engaging fully. What could be simpler than tightening up the linkage and who could blame the Cruiser for being a little out of adjustment after 345,000 miles? So after staring intently at the levers and connecting rods, I shortened the linkage, which should have allowed more pressure to be applied to the actuator lever on the top of the t-case, thereby holding the 4-Low gear in place. Hint: applying more force is not always the answer to every mechanical problem. 

After shortening the linkage, I started thinking about the tremendous amount of force through the drive train that causes the 4-Low gear to slip out of place and make the grinding noise. How could just a little adjustment make that go away? Impossible! I needed to apply even more force through the shifter in order to make 4-Low stay in place. If I failed in my conquest, it would show up during the middle of a trail run, relegating me to the business end of a winch line or worse. I drive a Land Cruiser for that independent, invincible feeling that I can go anywhere under my own power. Being pulled along by winch or tow strap is not my idea of fun. It was clear: more force was necessary to solve this “simple” problem in the t-case linkage. After staring at the linkage and conjuring an idea of what might actually be happening inside the t-case (did I mention I had never seen the inside of one of these units?), it was decided by me, common sense and common-sense’s younger brother, stupidity, that we should adjust the 4-High/Low actuator. 

The shape of the actuator, which does the work of selecting High, Low or Neutral, resembles a hockey stick. In fact, those who actually know what they are doing refer to this part as “the hockey stick.” The hockey stick is connected to the world outside of the transfer case by a yoke, which is then connected to the shifting linkage. If I had taken the time to clean off all of the goop and grime from this yoke I would have ended up on the trails that weekend with my buddies, instead of covered with sweat, gravel and 90-weight gear oil. Instead, I mistakenly assumed that the yoke and hockey stick were joined with a splined joint. Simply lifting the yoke off of the hockey stick and rotating it several degrees would make the linkage apply more force to the gears and since more force is usually the answer to any mechanical problem, this would magically solve the problem of the grinding 4-Low syndrome. I would then triumphantly announce my findings to the other stricken Land Cruiser brethren and ingratiate myself to them with many hours of happy, trouble-free and winch-free trail riding. 

However, to my great dismay, after being released from the yoke, the hockey stick quickly disappeared into the bowels of the transfer case. The end was still visible through the hole but I could see that it was not a splined fitting but was beveled on one side—my assumptions and hopes of easy adjustment were dashed by the reality of my ignorance. I tried in vain for an entire afternoon to coax the hockey stick out of its resting place. After a panicked call to a good friend who actually knows what he is doing, it became obvious that there was nothing left to do but pull the case apart.

The pleasant aroma of 90W gear oil soothed my now jangled nerves as it drained from the transfer case. Nervousness gave way to a sense of adventure and discovery, as the driveshaft was set aside and the bolts holding the case together were removed. After some grunting and pulling and pushing (more of this to come later) and some light tapping with a hammer, the case halves began to part and my arms became coated with the remaining gear oil in the case. Then suddenly, oomph! The back half of the case was cradled in my arms and I was reminded that it had been a long time since I went to the gym. 

The first glimpse inside the case revealed how little I understood from the long nights of staring at diagrams. So that’s what idler gears are for! How could I have missed that? Look, there’s the hockey stick! How did it not get crushed when I moved the truck? The Land Cruiser gods look askance at those who purposely abuse the machine but protect those who are merely stupid or ignorant. The more I looked and stared, the more it became evident that I had no idea what I was doing and even less of a chance of getting this all back together in a drivable form. Even the smell of gear oil and the sight of those big beefy gears could not calm the queasy feeing in the pit of my stomach. Visions of pleasant afternoons on the trails with the Fall Gathering crew were quickly being replaced by a 300-mile ride to southern New Jersey in the cab of a flat bed.

I tried my best to remember the factory manual diagrams...