|Author: Jim Brink
Photos by Tim Coffey
Transmission swaps rank fairly high on any four wheel drive owner's list of modifications. For the Toyota Land Cruiser, this is more the rule rather than the exception. When the time comes to make a transmission upgrade, many options exist for the Land Cruiser owner. For some, the solution to this dilemma is clear: KEEP IT STOCK. Land Cruiser purists will know immediately what is meant by this last statement. Others are simply seeking a lower crawl ratio or compatibility with another popular Land Cruiser modification, an engine swap. What this all boils down to is what the owner is ultimately seeking. In the case of the owner of this 1987 FJ60 wagon, a slightly lower 1st gear for trail use was desired as was an overdrive gear for the long highway stretches the driver encounters on trips to Northern California from his Southern California residence.
To the owner of this particular wagon, staying as close to stock was relatively important as was a bolt-in installation. While the GM/New Venture NV4500 transmission was a possible option, the owner wanted a more simple solution. The NV4500 offers a lower fist gear and taller overdrive but requires bellhousing to transmission and transfer case adapters (when used with the Toyota six cylinder engine and stock transfer case) plus driveline modifications. For our project vehicle, "The Mammoth Project", there was no better time to undertake a transmission swap as the original, tired 4 speed was showing it's signs of age and mileage in the form of subtle auditory "hints" known as gear whine and howl...
|The (old) H42 4-Speed on left, new H55F 5-Speed on right|
After much research, it was decided that a swap of the standard H42 4 speed in favor of a non-U.S. market H55F 5 speed was to be done. Now, sourcing an H55F is not as easy as a domestically produced 5 speed. However, they are out there and can be found after a little searching. Also, the price difference between the two is often very close. H55Fs can also be purchased new from some Land Cruiser specialty shops.
H55F transmissions were produced beginning with the 1983 model year. It is still in production today but it is only available in non-US markets in the 75-Series heavy duty Land Cruiser. Some subtle changes were made to the H55F over the years, mostly to the case. Almost identical to the H42 4 speed in later versions, the H55F is as close to a bolt-in swap that you can get. Be aware that transmissions placed behind "B" Series diesel engines will not bolt in to petrol-engined (gasoline) Land Cruisers. The input shaft from a petrol "F" or diesel "H" series equipped tranny will have to be installed.
As one can see, while the H55F does not provide a significantly lower (higher numerically) 1st gear ratio, the change is enough for the driver to notice during slow speed trail work. Even more significant however is the overdrive that allows the 2F to spin at a more leisurely rate while on the highway. As any 2F engine aficionado knows, the more time spent away from the 2F's low redline (~4,000 RPM), the better.
It should be noted that at this time, all of the clutch components (save for the hydraulic pieces) were replaced during this swap. There is no better time than now to perform clutch service. It only takes a few extra minutes and the piece of mind that goes along with having a new clutch is almost priceless. We also had the flywheel surfaced and replaced the rear main crankshaft seal at this time.
|Initial Testing Revealed a Better Crawl Ratio in 1st/4-Lo|
In addition to new clutch parts, we also chose to replace all of the external seals in the transmission and transfer case. Being a used transmission, we took this additional step to assure leak free reliability. This included all output seals, input seal, drain plug gaskets, top cover gasket, etc. All of these parts were sourced from Land Cruiser Connection in Sterling, VA. LCC owner James Asti was a huge help in providing these parts and spent countless hours via e-mail and the telephone answering our seemingly (to us) silly questions...Thanks James!
|FJ40 Output Flange (L), FJ60 Output Flange (R)|
Upon installation of the clutch parts
and with all new seals in the transmission, it was time to hoist the new
(used) beast into position to install into it's new home. Just before doing
this, we took a quick peek at the two transmissions side-by-side, noting
any differences. One thing that stuck out was that the driveshaft flanges
were completely different. Hmmm....The previous owner of this transmission
did say he ran it in his FJ40, but we don't recall the year. No big deal,
the flanges were easily swapped over. A few minutes work with the impact
wrench and the flanges were changed over.
|FJ60 (L) and FJ40 (R) Crossmember Mounts|
The second minor problem didn't crop up until it was time to bolt the crossmember up to the transmission (why do these little problems always arise just minutes before you're ready to turn the key once a new modification is done?). It became apparent that the rear engine (transmission-to-crossmember) mounts were different...Was the difference in the FJ40 and FJ60 chassis being different? Again, putting the air tools to work remedied this glitch and transmission was well on it's way to being installed.
|5-Speed Shift Lever in it's new Home|
With a new shifter seat bushing installed in the top cover (4 speeds do not use this bushing) and a "new", $0.95 5 speed shifter knob from a 1979 Toyota Celica (thanks Ecology Auto Wrecking!), the transmission was in! All that was left was to do was attach the ancillary items removed initially and to fill up the transmission and transfer case with Mobil 1 synthetic gear lube.
From the time the Cruiser first rolled out of the driveway it was obvious that choosing this transmission was a wise move. Not only did idling, clutch out, in first gear allow more vehicle control, but the overall ratios in the 5 speed just seemed better suited for all around driving. Fifth gear cruising was of course, an added bonus, making runs on The highway much more pleasurable and quiet. Those two merits topped with the fact that this transmission was in better shape than the aging 4 speed made the expense of the swap beneficial. Not only that, it adds to the value of the truck as well.
Editor's Note: This transmission swap was performed prior to the Mammoth Project's latest additions of a spring over axle conversion, regearing, and 35" tires. With 4.88 gears and 35" BFG Muds, cruising speed RPM is right around 3,000. At this speed, the engine is at it's happiest, providing enough power for passing yet keeping it out of the 2F's infamous danger zone (~4,000 RPM).
I want to thank James Asti of Land Cruiser Connection for his assistance in obtaining the rare service parts for the H55F, a non-USA transmission.
For technical assistance with gear ratios, history, and specifications, I'd like to thank Henry Cubillan of the Toyota Trails, the TLCA's membership publication. Thanks for your support and patience Henry!
For assistance in locally obtaining the little O.E. Toyota parts, I would like to thank my friend Rob Chapman of Manhattan Beach Toyota, Toyota Parts Guru, for his assistance in finding the most obscure parts for this project.