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Vintage T98, D18 and Overdrive

Discussion in 'Early CJ5 and CJ6 Tech' started by Danefraz, Jan 12, 2014.

  1. Jan 12, 2014
    Danefraz

    Danefraz Well-Known Member 2020 Sponsor 2019 Sponsor

    Chico CA
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    -- 20 April 2019 --
    -- image repair from broken hosting --

    Hey all,

    I picked up a what seems an interesting find today.

    -----------------------------------------------------------------
    [EDIT: 2016-Feb-18] This is for a T98, not a T18...
    -----------------------------------------------------------------

    T18, D18 and an overdrive.

    After $10 at the car wash...

    I see it has a T98 top cover and verified right-over-up for reverse.
    No reverse light indicator switch anywhere.
    T18 marked on case, too much goo still remains to see the rest of the casting numbers, present but buried under more smutzschtick.
    D18 looks like its 1 1/4", single stick.

    I now have this great find and a 1988 era T18. Do these two transmissions share any common parts?

    Came off a buick 350 ( BOP bell). PO kept the bell. I have to look, but it seems like it will bolt to my 225 bell and should have the right length. (Gotta measure still).

    Came off a BOP bell housing (buick 350), have the adapter to the bell.

    images:
    I also have a T98 that pictures will start showing up for here below.

    Reverse is 'over and up':
    [​IMG]

    T98 top.

    This is the thrower: T18 case with T98 guts

    [​IMG]

    [​IMG]

    [​IMG]

    [​IMG]

    [​IMG]

    [​IMG]

    [​IMG]

    [​IMG]

    [​IMG]

    [​IMG]
     
    Last edited: Apr 20, 2019
  2. Jan 13, 2014
    tarry99

    tarry99 Member

    Northern California
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    Looks like a good find with the OD............I think that is an earlier T-18 though , maybe 1978 version , did you check the low gear ratio? .......the input shaft stick out length with the adapter looks corrected to a 6-1/2" length which is good. The bad news with that adapter up front means your rear drive line on a 81" early CJ will be quite short.
     
  3. Jan 13, 2014
    Danefraz

    Danefraz Well-Known Member 2020 Sponsor 2019 Sponsor

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    Hmmm. Tomorrow is another day. Need to look closer at the transfer to see if it's 1 1/4 or if it's smaller. Want to remove the goo before I open it up to see what the internals look like.

    Turning shafts all seem good, no slop or grinding felt.




    Sent from my iPad using Tapatalk
     
  4. Jan 13, 2014
    timgr

    timgr Eppur si muove. 2020 Sponsor 2019 Sponsor

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    Well, the only factory Jeep T18 and Dana 18 was in the 225 1971 CJ, with very limited production. That transmission would have bolted up to the Buick 350 with no changes. If it is this transmission, it is the close-ratio version of the T18 with no granny gear and a 4.0:1 first gear. The usual T-18 is the wide ratio version, with the 6.32:1 granny gear.

    The stickout looks a little too long for the CJ transmission, but maybe...

    It could also be from a Buick 350 Wagoneer or J-truck, and in that case it would be a wide ratio transmission. However, I had though all of those came with a goofy looking one-piece bell with a long stickout, ie no engine-transmission adapter. Could be one of these with an aftermarket adapter.

    The stickout looks a little too short for the FSJ transmission. IIRC the V8 FSJ has about a 11" stickout.

    What I would do is look inside the transmission and count the number of teeth on the input gear. Per Nick, the 6.32: input gear has 17 teeth and the 4.0:1 input gear has 23 teeth. What you can do with this changes a lot depending on the ratios.

    Are the adapters iron or aluminum? IIRC the factory trans-TC adapter is iron. Aftermarket should be aluminum.
     
    Last edited: Jan 13, 2014
  5. Jan 13, 2014
    jpc

    jpc Sponsor

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    here is some information I got off of a web page that is no longer found. (saved a pdf, it is quite complete, pm is anyone wants a copy.)

    ID DUTY 1 2 3 4 R APPLICATION
    T18B (H) 4.32 2.26 1.51 1.00 5.08 Ford '65-85
     
  6. Jan 13, 2014
    timgr

    timgr Eppur si muove. 2020 Sponsor 2019 Sponsor

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    From what I understand, you cannot rely on the cast-in numbers to determine a T-18's ratios.

    I believe the ratios given here "4.32 2.26 1.51 1.00 5.08" are wrong. And Ford never offered a close-ratio T18. A T19, yes, but no T18.

    Novak has some good information about the T18 and T19 on its site: http://www.novak-adapt.com/knowledge/t18_t19.htm - I believe the ratios they give there are correct.
     
  7. Jan 13, 2014
    Danefraz

    Danefraz Well-Known Member 2020 Sponsor 2019 Sponsor

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    Excellent info. Time to count teeth.

    Cast iron adapters out front. Don't know about the transmission to transfer case adapter, looks iron, but too much grease still hiding details.

    Digging out calipers to measure some stuff tonight.

    Was digging around on Novak site last night.

    Will compare with the other late ford T18 I have and may be post a few more Picts.

    Thanks.


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  8. Jan 13, 2014
    timgr

    timgr Eppur si muove. 2020 Sponsor 2019 Sponsor

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    Magnet.

    Iron should be Jeep. Guessing it's the elusive '71 CJ V6 T18. They exist, but in very small numbers.

    If it's close-ratio, it pretty much is what it is. The gears are all different from the Ford or Jeep granny gear transmission.

    Didn't Patrick run one of these in his CJ5? If so, he could tell you about it. Should be an easy swap if that's what it is, and we know it works ok in the CJ chassis.
     
    Last edited: Jan 13, 2014
  9. Jan 13, 2014
    oldtime

    oldtime oldtime

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    Tims posts are dead on.
    The T98 shift tower with Jeep T18 case indicates it is most likely from the early 1970's. (possibly from 1969 -1975 )
    Overall stickout length from transmission should help identify it's original application.
    Also need to verify maindrive (input) tooth count.
     
  10. Jan 13, 2014
    timgr

    timgr Eppur si muove. 2020 Sponsor 2019 Sponsor

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    Just to follow up on this -- the close ratio T18 is a big upgrade, but may not be what you are looking for in a truck 4-speed. According to Nick, you can use the mainshaft and trans-TC adapter from this transmission and combine it with a Ford transmission to get a 6.32:1 transmission with a Ford front pattern that accepts a Texas pattern D18 or D20. Some minor machining is required (drilling and plugging holes) and you have to pick the right front main bearing, but it can be done. Nick has written about this process several times in his earlier posts - diligent search should uncover quite a lot of info.

    That's assuming it's a close ratio transmission.
     
  11. Jan 13, 2014
    Posimoto

    Posimoto Hopeless JEEP Addict

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    My Ford T18 is an '86 and reverse is to the right and down, not up. It also has a backup light switch.
     
  12. Jan 13, 2014
    timgr

    timgr Eppur si muove. 2020 Sponsor 2019 Sponsor

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    So is my '82 J20. Pretty sure that both Jeep and Ford changed in the late '70s.
     
  13. Jan 13, 2014
    oldtime

    oldtime oldtime

    St. Charles,...
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    T18 went from over and up to over and down in 1979.
    Post 1978 T18 cases and shift towers do not interchange with pre 1979 transmissions.
     
  14. Jan 13, 2014
    jpflat2a

    jpflat2a what's that noise?

    Riverside CA
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    Unless I'm wrong, that adapter is incorrect for a T18 CJ V6 71 and prior application.
    The 70-71's had the 1 piece bell, so the bell adapter would have been iron and very thin, much like the transfer case adapter for this application.
    I see a factory part number tag on the transfer case intermediate shaft retaining bolt.
    Can you post a clear picture of that tag?
    May be a moot point as any transfer case could be put in any Jeep this late in the game.
     
  15. Jan 13, 2014
    Danefraz

    Danefraz Well-Known Member 2020 Sponsor 2019 Sponsor

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    I also have one of these in the shed. I have a NIB Novak adapter kit and a rebuild kit for it (this in addition to the one we're talking about).
     
  16. Jan 13, 2014
    Danefraz

    Danefraz Well-Known Member 2020 Sponsor 2019 Sponsor

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    I'm off to find Nick's T-18 articles. I've read most of the recent ones. Need to refresh.

    OK, a few measurements and other info:

    Adapters are IRON. My IRON magnet works, my brass and aluminum magnets fail.

    Please excuse my approximate measurements - I used my RCBS analog calipers (decimal numbers) and my Stanley Tape (fractional numbers):

    Please also excuse my terminology - it's not correct and I'm up for learning.

    Bell to Transmission adapter is 2.665" mating-surface-to-mating surface.
    Bell hole outside diameter: 4.670"
    Bell adapter 'ridge' is 0.256 for the inset to the bell

    There is a bell-adapter-to-transmission-adapter:
    It is 0.810" thick mating surface to mating surface

    This makes the two adapters about 3.475" thick in front of the surface of the T-18.

    The transmission to transfer case adapter is 0.890" thick.

    The main shaft is 10 spline.
    It is approximately 9" from the face of the front bearing retainer (cannot get to base of retainer).

    Laying a metal ruler across the input shaft and the bell-stickout, there was 6 3/8" of main shaft (including what goes into the flywheel bushing). need to add the 0.25" of the Bell insert lip to that.

    The insert for the flywheel / bushing is 0.632" by 1.440" from where the radius meets the splines.

    I went out an measured the depth of my BOP bell on my 225. It's about 5.5" deep in the dark, under the tarp with a flashlight (still mounted in the chassis).

    So I took a paint pen and marked one of the splines on the input shaft and the transmission output shaft.

    I found first gear and put transfer in high.

    rotating the output shaft (to the rear axle), I rotated the input shaft 6 full rotations with some left over.

    I put it in low range and it was about 16 full revolutions and change with transmission in first gear.

    In reverse, I got 7 full rotations with transfer in high with some left over.

    In reverse, in low range, I got about 19 rotations.

    No time tonight to pull covers and count gear teeth. Will do that tomorrow.

    Many thanks for all of your input and mentoring...

    I'll get better picts of the factory tags in the AM too.
     
    Last edited: Jan 13, 2014
  17. Jan 15, 2014
    oldtime

    oldtime oldtime

    St. Charles,...
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    Yeah so you have 2 adapters up front.
    I've never had one but that sounds right to me for a 1969 -1971 CJ having Dauntless and a 4 speed.
    It's a normal 2-5/8" thick Dauntless adapter with an extra adapter to change the T18 pattern over to a T86/T14 pattern.
    Come to think of it... 1971 probably used the 1 piece bellhousing so that would imply this to be a 1969 or 1970 vintage outfit if it came off a CJ.

    If it was originally mated to a Dauntless V8 350 then it must be from an early Wagoneer.
    When you remove the shift tower take a good look at how the forks are attached to the shift rails.
    Does it use set screws or does it use roll pins ?
    Set screws are pre 1968 while roll pins are post 1968...
     
  18. Jan 15, 2014
    timgr

    timgr Eppur si muove. 2020 Sponsor 2019 Sponsor

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    This is the Wagoneer Buick 350 setup - courtesy of rstep at FSJN -

    [​IMG]

    T18 above, nailhead TH400 (no adapter ring) below.

    Pretty sure the OP's trans is not Wagoneer.
     
    Last edited: Jan 15, 2014
  19. Jan 15, 2014
    jpflat2a

    jpflat2a what's that noise?

    Riverside CA
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    transfer case tag might shed some light
     
  20. Jan 15, 2014
    oldtime

    oldtime oldtime

    St. Charles,...
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    Tim that's one ugly bellhousing.
    So I wonder why the CJ's would use 2 adapers instead of the ugly D350 bellhousing.
    Unless that Dauntless 350 bellhousing was not available before 1971.

    Hmmmm this says D350 was 1969 and 1970: http://www.jeeptech.com/engine/dauntless350.html
     
    Last edited: Jan 15, 2014

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