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make my '74 jeep more of a fuel miser-thoughts?

Discussion in 'Intermediate CJ-5/6/7/8' started by joe28, Feb 4, 2011.

  1. Jan 15, 2022
    Allan

    Allan 74 Renegade

    Olympia
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    Dana 44 is a 3:73 and the tires are 215/75 R15, total height is 27 inches. Original fan. I just have some short 3foot straight pipes coming off original exhaust manifolds for the time being, till I get to the muffler shop.
     
  2. Jan 15, 2022
    Allan

    Allan 74 Renegade

    Olympia
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    Can I ask what motor you are referring to for the 4000/4500 RPMs at 60 MPH? I am seeing my 304 run 3000 RPMs at 40 MPH
     
  3. Jan 15, 2022
    Allan

    Allan 74 Renegade

    Olympia
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    I calculated the RPMs, should be 1856 at these specs given a 1:1 3rd gear ratio. I wonder because it doesn’t feel like there is a difference between 4H and 2H is it possible that it’s stuck in 4H?
     
  4. Jan 16, 2022
    timgr

    timgr We stand on the shoulders of giants. 2022 Sponsor 2021 Sponsor 2020 Sponsor

    Medford Mass USA
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    There is no difference in the final drive ratio between 2HI and 4HI. Same with 2LO and 4LO. Only difference is whether the front axle is connected. Or not.
     
  5. Jan 16, 2022
    timgr

    timgr We stand on the shoulders of giants. 2022 Sponsor 2021 Sponsor 2020 Sponsor

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    This is an old thread. Looking at his profile, joe28 was last online here in March of 2011. Unlikely you will get a reply.
     
  6. Jan 16, 2022
    timgr

    timgr We stand on the shoulders of giants. 2022 Sponsor 2021 Sponsor 2020 Sponsor

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    Look at the TSM. Free to read and download at the Tom Collins site. https://oljeep.com/gw/74_tsm/8-TransferCase.pdf Note that figure 8-1 and 8-2 captions are backwards.

    You have two shift rods, one for the front axle and one for the rear axle. The interlock in the transfer case prevents you from shifting into front high and rear low, and vice-versa.

    Take the floors off and look at the shift rods as you shift. If you have the shift linkage put together right, it will move the shift rods according to the pattern on the knob. 4H-2H-N-4L is on the knob, but it's actually 4H-2H-N-2L-4L.

    I've mostly reached the end of advice I can offer - you have to look at the transfer case and its linkage and figure out what's wrong.
     
  7. Jan 16, 2022
    Allan

    Allan 74 Renegade

    Olympia
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    Thanks Tim, linkage looks correct, I thought maybe it’s just sticking somewhere elven though it’s linked correctly
     

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  8. Jan 17, 2022
    TheBeav1955

    TheBeav1955 Member

    Wyoming, Mi
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    Not sure what you have going on but my 72 has the same drive train and gearing and I'm less than 2000 at 55mph. At 4000 it would be really be winding out. I am running 235/75/15
     
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  9. Jan 17, 2022
    Allan

    Allan 74 Renegade

    Olympia
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    I have to be stuck in 4hi, it just doesn’t indicate that when I shift, linkage is fine, I don’t know what else it could be other than the transfer case not being able to find 2hi
     
  10. Jan 17, 2022
    Ol Fogie

    Ol Fogie 74 cj5 304, 1943 mb 2020 Sponsor

    Jasper Georgia
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    The rpm's are the same for a given speed in 4Hi or 2Hi.
     
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  11. Jan 17, 2022
    Ol Fogie

    Ol Fogie 74 cj5 304, 1943 mb 2020 Sponsor

    Jasper Georgia
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    Exactly the same here with my 74, and the same tires and 3.73 axles. around 1975 rpm's at 55 mph.
     
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  12. Jan 17, 2022
    Allan

    Allan 74 Renegade

    Olympia
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    What is your transfer case shift pattern?
     
  13. Jan 17, 2022
    Ol Fogie

    Ol Fogie 74 cj5 304, 1943 mb 2020 Sponsor

    Jasper Georgia
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    My shift pattern is exactly as timgr pointed out above.
    All the way forward the leaver will go, the leaver is standing about vertically straight up is 4 Hi.
    Next position back toward the rear of the jeep(next detent feeling) just a inch or two is 2 Hi.
    Next position back toward the rear of the jeep(next detent feeling) another inch or so (the leaver is angled at about a 45 degree now) is neutral position(out of any gear) just like your main trans when in neutral.
    Next position toward back or on downward about an inch or so untill you feel the leaver engage a gear(no detent feel yet this time) is the transfer case going into ''low range'' and 2 wheel drive(jeep will drive away in this position in low range with only the rear wheels pulling.) Continue rearward and downward with the leaver another inch or so to the last detent position, your shift knob will be almost to the floor or tool box lid (maybe even touch the floor if your shift linkage is worn a little. This lowest position of the leaver will be in 4 Low.
     
    Last edited: Jan 17, 2022
  14. Jan 17, 2022
    Allan

    Allan 74 Renegade

    Olympia
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    That’s what I thought, and I don’t have that detent feeling going to 2Hi, I’m not sure what could be wrong other than the spring and ball in the wrong place, or the fork isn’t moving the proper gear inside, I thought these can only go back together one way?
    Thanks for the help.
     
  15. Jan 17, 2022
    Allan

    Allan 74 Renegade

    Olympia
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    So this is what I know:
    1. When the transfer case shifter is full forward I can shift the transmission and move the Jeep with the front driveline engaged but is still 40 mph @3000 RPMs
    2. When the transfer case shifter is one back from full forward I can shift the transmission and move the Jeep with just the rear drive line engaged but still 40 mph@ 3000 RPMs
    3. When the transfer case shifter is 2 back from full forward it appears to be in neutral, cannot engage either driveline while shifting
    4. Cannot engage or find 4Lo 1 back from neutral as it should.
    My question at this point is, since only the rear driveline turns while in what is assumed to be 1 back from full forward (2HI) why would I still be only able to obtain 40 mph @3000 RPMs. Is it possible to install a gear back inside the transfer-case in a manner that would explain this. Sorry for being difficult in advance but this this Jeep drove fine in the 60mph range at 2500-3000 RPMs before I rebuilt the Transfer-case
     
  16. Jan 17, 2022
    Ol Fogie

    Ol Fogie 74 cj5 304, 1943 mb 2020 Sponsor

    Jasper Georgia
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    Oh, you have had it disassembled and put it back together? probably did not reassemble something correct. More likely something in the shift linkage rather than inside the gear case. I would probably get myself a good diagram maybe a 74 TSM and study it intensely, you might discover what is not right. Sounds like for sure your transfer case is remaining in low range regardless of the shifter position. If you study the linkage without finding any thing wrong the next thing to do would be drain the oil and remove the bottom cover. Looking in there you should be able to see if anything is assembled wrong. Once you see it ,it should be obvious. Transfer cases are very simple once you study them a bit.
     
  17. Jan 17, 2022
    Allan

    Allan 74 Renegade

    Olympia
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    Linkage looked fine, Thank you, I will pull bottom cover and go from there,
     
  18. Jan 17, 2022
    Ol Fogie

    Ol Fogie 74 cj5 304, 1943 mb 2020 Sponsor

    Jasper Georgia
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    Double check, triple check that shift linkage set up first. If nothing becomes obvious-
    Then get yourself some good photos of the transfer case gear set, with photos of the gears in low range and another photo with the gears set in Hi range and so on to compare. Maybe place main trans in neutral and jack up a rear wheel so that you can turn it and watch what is happening in the TC in each gear position. Should be easy to spot any abnormality's. I cannot think what it could be unless a shift fork is slipping on it's shaft or??? possibly a sliding gear installed backward?? study, study.:study:
     
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  19. Jan 19, 2022
    Allan

    Allan 74 Renegade

    Olympia
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  20. Jan 19, 2022
    Allan

    Allan 74 Renegade

    Olympia
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    Well it looks like my dyslexia prevails, looks like I put the rear output sliding gear in backwards, anyone disagree?
     

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