2F SM465/Orion Install

My inspiration for the SM465/Orion install was a J**P I saw on Kelly Flats. He waited patiently as the others in the group tried to get through a section of trail. After everyone was finished bashing their rigs into the rocks, he quietly drove the same line. Without using the brakes or throttle, he idled straight through. I couldn't believe how easy low gears made it look. Ok, I could have gone out and bought a Jeep, but I drive a Land Cruiser. That is why I decided to go with the SM465/Orion Combination.

For this conversion you need an SM465 with the 10-spline, 4-wheel drive, output shaft. GM produced this transmission from 1968-1991 with three different output shaft designs. I believe the 10-spline output is specifically 1968-1979. I chose the SM465 over the SM420 because it is newer, has a low enough first gear at 6.55, a reverse switch, and they seem to shift a lot smoother.

The Orion is available through Advanced Adapters. The benefit over stock is the 4:1 reduction and a cast iron case. Stock is 1.96 for a 4-speed transfer cases and 2.31 for a 3-speed. If you chose to use a stock transfer case, the input gear has to be the older 10 spline. The 4-speed transfer case can be adapted to run the 10 spline if needed. If you are building an Orion, keep in mind that Cruisers came with a course spline front output shaft and a fine spline on later years. The drive shaft flanges are offered in a few different configurations so pick one that matches your drive shafts.

To breed the two together you need a plate style adapter. When I started researching the Sm465, there were only two options available. The 5” adapter from AA and the 3/4” plate from Classic Cruisers. Brian Swearingen, aka Woody, offers a third option now. Woody's SM465 Plate Adapter is made from 6061 aluminum, it uses oversized studs, and eight Torx flathead screws so everything can be tightened securely. **UPDATE**Merl from Classic Cruisers emailed me and I made two corrections above. His adapter is 3/4” thick and is also made from 6061 aluminum. His adapter is available from Classic Cruisers.

You will need to modify four things on the SM465. The first is the front bearing retainer. It needs to be turned down to match the bell housing. Bruce Lawson offered to machine the parts for me and I cannot thank him enough for his help. The four bolts have to be replaced with Hex style bolts to clear the bell housing (5/16-18 x 7/8”).

The second is to sleeve the collar for the throw out bearing. A piece of exhaust pipe cut to 7cm has the correct inner and outer diameter (1 3/8” ID & 1 1/2” OD). Part #548530. Welding to cast can be done but I chose to solder the collar to the bearing retainer. Use acid flux solder, make sure everything is clean, and rough up both parts so there is a tooth on both parts for the solder to stick to. Heat will destroy the inner seal so why not just replace it. NAPA part #16054. The gasket between the bearing retainer and transmission is available at the dealer, part #12337932.

The third is to drill and tap the rear output shaft. This sounds simple in theory but harder than I thought. Bruce went above and beyond to help me. It is interesting to ask a machine shop to drill a hardened steel output shaft while it is still in the transmission. Thank you again Bruce. The secret is use a drill press and heat the very end of the shaft with an oxy-acetylene torch. The hardened material is only on the surface and once you can get the bit through, it cuts and taps without much effort. I used a grade 8 bolt (9/16-18 x 1 3/4”). Bruce turned down a thick washer for me as well.

The fourth depends on how you mounted the transmission to the bell housing. I decided to use larger bolts and thread all four bolts into the bell housing. Because they were larger, I had to drill out all four holes to match the larger bolts.

The new pilot bearing has a longer inner sleeve to support the input shaft of the SM465. The input shaft is approximately 1/4" shorter. I bought mine from A&W Bearing Supply ,800-535-9638. Part number BCA 202RRE. I pulled the info from a old TLCA BBS thread. If you have the transmission out of the truck, now is a good time to replace the rear main if it is leaking. Instead of the expensive SST, use the cone off the rear of a stock t-case. That and a rubber mallet work perfectly.

I am running the stock 2F inline six in my ’78 FJ40. Because it came with the 4-speed transmission, I needed to find a stock 3-speed bell housing. The older bell housing can be swapped in and bolts up exactly like the newer 4-speed. There are four bolts that attach the transmission to the bell housing and because mine were stripped, I chose to drill out and retap all four (9/16-18 x 1 1/2” for the top two and 5/8-18 x 1 1/2” for the bottom two). In the picture you can see that the washer for the clutch fork pivot had to be trimmed slightly to clear the transmission.

For the clutch assembly you can run either the 3-speed with the 3-speed flywheel or the 4-speed with the 4-speed flywheel. I reused the 4-speed throw out bearing, pressure plate, clutch fork, and flywheel. An 11” Chevy clutch disc replaces the stock disc because the splines are different. This was one of the biggest delays in this project because none of the major part stores will sell just the clutch disc. They only sell kits now. After some searching, Dial-A-Clutch came through with the disc. AutoZone is the only place I found that carries the alignment tool.

My ’78 FJ40 has the later shifter linkage. If you choose to, the vacuum can be adapted to work or it can be replaced with the later style. All the parts are pretty much bolt on. I cut a 5 x 5 1/2” plate out of 1/4” steel to mount the pivot to. The stock pivot has to be shortened to 2cm and secured with an M16-1.50 nut. With a flat plate, the 2-4 wheel shift fork ends up about an inch above the tab. If you bend the plate everything will line up without bending the stock linkage. I scored, bent, and welded the plate to make it easier. This worked out great but in 4low/2low the shifter may angle more toward the passenger than stock.

At this point, everything should bolt together without much effort. Because I was also switching over to the Orion, I needed to machine a bolt and a stud to clear the larger gears. AA supplied me with three different versions but Woody’s adapter is threaded for a 1/2-13 sized bolt. Bruce came through again and with a little help from the lathe, turned down the bolt head and the center of the stud to match the custom bolts supplied by AA. In this photo you can see the clearances between the larger 4:1 gears, high/low shift fork, and the stud that passes through the case.

Drive shafts will need to be modified. I took mine to Rocky Mountain Driveline Specialists and they had them done in a day with new Spicer 5-15111X u joints and .120 wall tubing.

Rocky Mountain Driveline

4210 Tennyson, Lakewood, CO

(303)433-8683

Not really needed but since the t-case and transmission were out of the truck, I added some neat looking breathers. If I am in water higher than this, I think I would have other problems but it is done now. Part numbers 55106(brass tee), 43276(brass hose fitting), and 43030(brass 90 elbow).These were simple and had a low enough profile to route under the tunnel. Tap is a 1/8 npt.

With a floor jack underneath and an engine hoist above, you can align the transmission. Even with a rock driveway, it is possible. Buy or borrow (thank you Dr. Simpson) a set of stubby wrenches because they make life a lot easier. The transmission tunnel almost seems like it was designed around these wrenches.

The SM465 weighs in at 175 and the Orion is around 90lbs so you might consider using a rear cross member. I wanted something simple and Energy Suspension makes a polyurethane transmission mount so I built around that. Part #3.1108. Since the SM465 output shaft doesn’t protrude through the t-case like the OEM transmissions, you can bolt a flat plate to the rear of the t-case. The plate is 1/4” steel. The braces welded to the plate are positioned so that all the bolts can spin freely and there is enough clearance for a socket. The polyurethane mount is spaced out just enough so that it clears the bolt heads as well.

On a pre ’79 FJ40, the gas tank recess sits just above the frame. To clear the tank, I ran 1/4” plates above the frame. Since a Cruiser frame tapers toward the front, the boxes bolted to the sides are angled to match. The square tube spanning the gap is 1”. It deflects slightly so you may want to go one size larger. It is welded solid to the plate on the driver’s side and for simplicity, bolts to the plate on the passenger side. Where that bolt passes through, I welded in 1” steel stock and tapped it so the bar is now the nut. The whole assembly can be removed by removing that bolt and the nut on the opposite side of the frame.

New holes will need to be drilled in the frame to bolt on the cross member. I chose not to weld because I wanted to be able to remove everything out the side of the truck. Unlike the propeller style mounts, nothing is on the inside of the frame so none of the gas lines need to be relocated. In the second photo you can see the clearance between the gas tank recess and the cross member plate.

I stole both shift boots off a wrecked FJ60. The SM465 puts the shifter 2” further back so the tunnel has to be modified. Mark a new hole just behind the existing one and cut out the overlap. Like magic, flip it around and weld up the old hole. The FJ60 boot is square instead of round so mark and re-cut. The 4 wheel shifter hole can remain where it is; just lengthen it to the rear to match the new boot. I used an impact wrench to break off all the nuts on the backside and rewelded them to match the new boots.

The stock bends in the SM465 shifter will work but it positions the knob almost under the steering wheel. I need to either cut and weld the stock one in or heat and bend the SM465 shifter. You can see in the second picture the 4wd shifter is angled slightly toward the right because of the bend added to the shifter plate. The stock knob was reused but the shift pattern is no longer correct. Reverse is in the opposite direction.

UPDATE: Orion neutral fix and metal in the lube fix

Take the time and do it right. Don’t rush and you will be happier in the end. Use the downtime to read the two sites that motivated me and made all this possible, www.pirate4x4.com and www.ih8mud.com.

Cruiser Gearing Options - Transfer/Tranny/R&P

TreerootCO's Power Steering Write-up

www.root45.com - FJ45LV home page