FJ55 on road performance (Speed without strain?)

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Big tires, overdrives, or a 5 speed are options.

Personally like the H55F option and taller tires. Lower first on the H55F helps make up the loss for taller tires on the low end. The 74 still has the skinnier high range gears. Low range gear while wider were not as low in low range as the three speed case. H55F uses a split transfer case which is stronger and quietier. Also has options for low range gearing. Taller tires and higher 3.70:1 diff ring and pinion in the diffs both suffer on the low end. If your only concerned with on pavement driving those are fine. If I wanted a vehicle I didn't plan using off road a 70s Land Cruiser would not be it.
 

ToyotaMatt

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So I’m still new to the FJ55. Since I’ve purchased it I’ve been trying to iron out a few minor issues but have had the opportunity to drive it about 60 miles on road. As I begin to learn the driving style and quirks of a 48 year old vehicle i have noticed so far that speed performance is less than what I anticipated. I don’t expect sports car performance, but speeds should I be seeing? My initial impressions are that it would have a difficult time running at even low highway speeds. It will run 45 no issues, but any faster and I feel like it would be putting unwanted strain on the old girl.

My model is a 1974 with a four speed. I don’t know if the gearing has been changed from factory. Motor seems strong as expected…



Supply chain parts availability is almost always less of a big deal than it seems.

As you gain skill and knowledge in the rig and how to scrounge for it, the easier it gets to find the parts you need.

The longer I drive mine, the more I like stock-ish configurations.

One exception for me is the ignition system. When my igniter took a dump, I priced the individual parts to restore it to stock and went with the DUI ignition.

I'd strongly suggest making the most of what you have right now, and only modifying as absolutely necessary.



 

Devils Paw 80

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So I’m still new to the FJ55. Since I’ve purchased it I’ve been trying to iron out a few minor issues but have had the opportunity to drive it about 60 miles on road. As I begin to learn the driving style and quirks of a 48 year old vehicle i have noticed so far that speed performance is less than what I anticipated. I don’t expect sports car performance, but speeds should I be seeing? My initial impressions are that it would have a difficult time running at even low highway speeds. It will run 45 no issues, but any faster and I feel like it would be putting unwanted strain on the old girl.

My model is a 1974 with a four speed. I don’t know if the gearing has been changed from factory. Motor seems strong as expected…
What's your RPM at 45? I'm sure the beast gets noisy as all get out, but you should be able to run up at least a bit above 3000.
 

brian

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Personally like the H55F option and taller tires. Lower first on the H55F helps make up the loss for taller tires on the low end. The 74 still has the skinnier high range gears. Low range gear while wider were not as low in low range as the three speed case. H55F uses a split transfer case which is stronger and quietier. Also has options for low range gearing. Taller tires and higher 3.70:1 diff ring and pinion in the diffs both suffer on the low end. If your only concerned with on pavement driving those are fine. If I wanted a vehicle I didn't plan using off road a 70s Land Cruiser would not be it.
the 74 case would still have the "three speed" low range gearing.
 
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the 74 case would still have the "three speed" low range gearing.


Might want to do a little research. 1/74-4/75 with a four speed had a transition case. The low range part of the idler gear and the low range gear themselves are wider and have the same 1.99:1 gearing like the 5/75-7/80 transfer cases.
 

brian

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Might want to do a little research. 1/74-4/75 with a four speed had a transition case. The low range part of the idler gear and the low range gear themselves are wider and have the same 1.99:1 gearing like the 5/75-7/80 transfer cases.
that ratio is incorrect. my 2/75 has the lower ratio. where as a 4/75 case i have on the floor has the higher ratio.
 
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Supply chain parts availability is almost always less of a big deal than it seems.

As you gain skill and knowledge in the rig and how to scrounge for it, the easier it gets to find the parts you need.

The longer I drive mine, the more I like stock-ish configurations.

One exception for me is the ignition system. When my igniter took a dump, I priced the individual parts to restore it to stock and went with the DUI ignition.

I'd strongly suggest making the most of what you have right now, and only modifying as absolutely necessary.
I agree on making the most of what is present. Great advice. I am trying not to get ahead of myself with a “vision” of what could be and focus on creating a sound mechanical truck.
 

65swb45

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If you can get a dwell meter on it, you may find that the 48 year old distributor is interfering with higher rpm/ operating speeds. While I am not a fan of the DUI, almost ANY new distributor will outperform a worn out one. Plenty of good reading on this forum about distributors, stock and otherwise.

And a good valve adjustment will help a lot too.
 
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the 74 case would still have the "three speed" low range gearing.


Have a 79 that came with 74 case. Bought a transmission and transfer case that were pulled from a 78. That had a 74 case as well. My information comes from Amayama. Three speed low range gear has 43 teeth. The E-4/75 and 4/75-7/80 four speed had 40 teeth. It shows a different part number for the two but the later is a sub for earlier one.
 

65swb45

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Yup. Pre-74=2.3/1 lo range
9/73-4/75=1.99/1
4/75-7/80=1.95
 
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73’ completely original non emission 1.5 F, 3 spd trans and stock gears… does 65 all day long.
What do you mean “non emission”? Did you remove all emission stuff? If so can you detail? I would love to remove all emission stuff off mine.
 

Blastservices

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What do you mean “non emission”? Did you remove all emission stuff? If so can you detail? I would love to remove all emission stuff off mine.
My truck is from Venezuela. The distributor and the amount of open ports on the intake is about the main differences. It has one for booster. That’s it. There is two vacuum lines on the carb one is to the vacuum advance (above the throttle plate by idle adjustment) and one is on the choke breaker (below throttle plate opposite side). I’m working on installing the fuel tank venting because that was all removed at some point and it doesn’t like full tanks. The head doesn’t have air injection ports even machined into it. They were never drilled.

My tank has been split in half for an unknown reason. Wether it was original to the truck I don’t know that either. It had the 4 ports on one side another vent port on the front passenger corner and a larger vent by the filler.

I wound up struggling to find another and took what I could get. So the same tank you have is what I wound up with and is in my truck running now but not vented.
 
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