[ Post a Response | Tech, Parts Exchange Forum ]
Posted by Kevin on 4/12/2004, 2:40 am, in reply to "Re: 1st FJ, 1st post - looking for improved top end..." Mike is correct in asking you what your plans are for your Cruiser. Looking at this question can help you avoid costly choices or redoing your drive train because you're not happy with the end result. But remember, making changes of this kind involves compromises. Mike's low cost daily driver suggestion is a good one. But you will see a big reduction in performance if you keep the 3 speed transmission and change to the 3.73 axle gears (ring & pinion) and larger tires. One or the other will give you better top end cruise speed. My recommendation would be to swap in the Land Cruiser 4 speed transmission (`74 & up) coupled to your existing transfer case. Then change the axle gear ratio to 3.73 and run 33" tires. On the street, this setup would be almost like the stock 3 speed with an added overdrive. Plus, this would be a small improvement in the off-road low range crawl ratio. The 31" tires that are on it now would work well with this set up. Also, if you were to go to 33" tires, you would need a 2"-3" suspension lift to provide tire clearance for the rear tires. If you think that you might want 33" tires somewhere in the future, check out Jody Potter's 72 FJ40 in the "Members Page." If you'd like it to be better off-road and still have some improvement in the top end cruise. Then go with the 4 speed and run 33" tires. The 33" tires will act as an overdrive. While the 4 speed compensates for the performance loss from the larger tires and improves your off-road gearing. One thing that you need to look at when doing a transmission swap, is the frame cross member that is located behind the transfer case. I don't think that it needs to be relocated when doing the 4 speed swap. But, it will need to be relocated if you do 5 speed swap. And don't just cut this cross member out and not relocate it, as some have done. It is needed for frame strength. As far as 5 speeds go, if you are going to keep the Cruiser 6 cylinder, I'd go with the Toyota H55F. It is a better match for the 6 cylinder than the NV4500. But, the H55F will require you to change to the later style split transfer case. The split transfer case will require either a transfer case parking brake adapter or a change to the later axle style parking brake (basically swapping in later style rear axle is the easiest). Now the NV4500 is a good transmission too. It's just that it will need to have adapters at both ends if you're keeping the stock 6 cylinder. One advantage though, your existing transfer case can be mated to it with an adapter. There are a number of people that have installed this transmission in their FJ40s and they seem quite pleased with it. Plus, the NV4500 has the deepest overdrive (35%), for a truck transmission, that I know of. There are 2 more lesser known 5 speed transmissions that have been swapped into 4x4s. The better known of these 2 is the Clark 5 speed and it has been swapped into Land Cruisers. The other is the SM520. Both of these transmissions were used in old school buses and are becoming harder and harder to find. Another note about 5 speed transmission swaps, due to the combined length of the transmission, adapters and transfer case, the rear drive shaft can end up being to short or have to steep of angles on trucks with greater than 4" of lift. You stated that the clutch needs some attention. Well, the clutch pushrod at the slave cylinder can be adjusted. If adjusting it doesn't correct it, then plan on doing a clutch when you do a transmission swap. That is, if you do a transmission swap. It's good to hear that your 40 runs great, even after sitting so long. But, a number of our members will tell you to get rid of the Holley and go back to the factory stock carb. The factory Asin carburetor, when correctly rebuilt, will work better on and off road than the Holley. You have plenty of choices when it comes to changing to an electronic ignition. There are conversion kits for your existing distributor. Later model Toyota electronic distributors. GM HEI units can be swap in and I even know of a Jeep HEI distributor being modified to work in a Cruiser. Don't laugh, I drove that FJ40 that had the Jeep HEI distributor in it on a trip and it got 19 MPG on the highway. Go to the links page of our site and check out these site for more information: Man-A-Fre, Spector Off Road, IH8MUD (tech page) and the TLCA (tech page). If the bushings in your springs and shackles are in good shape, then a shackle reversal isn't really necessary. This is another issue that has lots of pros and cons that should be considered before doing it. If you do a shackle reversal, you do not need to have Popeye arms to drive it on a daily basis. So you want to have your cake and eat it too! Well, I don't know if we can do that. But here's the best bang for your buck. Do a Toyota 4 speed swap and change to 3.73 axle gears. If that doesn't give you enough on the top end, then when the 31" tires wear out (or sooner if you choose), install a 2" lift and get 33" tires. Check out Jody's 72 FJ40 in the "Members Page" for the lift and tires. If you'd like to check current prices on the 5 speed transmissions go to our links page and check out these sites. I know that this was long, but I hope that it was helpful. Good Luck, Kevin
64.12.116.133
Hi Manny
For the Toyota H55F go to, Man-A-Fre, Spector Off Road and Cool Cruisers (Man-A-Fre has had the lowest price).
For the NV4500 go to Advance Adapters.
Responses: