Page 1 of 15 1 2 3 4 5 11 ... LastLast
Results 1 to 10 of 141

Thread: M135 M211 2 speed transfer case mod

  1. #1
    Colonel DUUANE's Avatar
    Join Date
    Feb 2005
    Location
    Vancouver BC
    Posts
    292
    Thanks
    114
    Thanked 152 Times in 82 Posts

    Default M135 M211 2 speed transfer case mod

    Hi everyone. I'm starting this thread to consolidate the information relating to converting our stock tcases to 2 speed units for those who wish to do so.
    It looks like i will be able to lay my hands on a spare tcase locally here to do a bench test on.
    If anyone has info on this conversion please post it here.
    I have a couple of different options as far as machinists go so if it looks like a new shaft is in order i will look into that.
    As soon as i get the spare case to the shop i will post up pics of whats in there and dissassembly. Hopefully we will be able to do this without a complete teardown of the tcase or even better do it in the frame.
    Thanks for your time reading this and i look forward to hearing your experience.

    Cheers.
    Last edited by DUUANE; 10-12-2017 at 17:25.

  2. The Following 7 Users Say Thank You to DUUANE For This Useful Post:

    Ashley P (10-13-2017), firefox (04-22-2018), gentrysgarage (10-14-2017), tburk49760 (02-27-2018), topo (10-12-2017), USMC 00-08 (10-13-2017), wrenchturner6238 (10-12-2017)

  3. #2
    Colonel DUUANE's Avatar
    Join Date
    Feb 2005
    Location
    Vancouver BC
    Posts
    292
    Thanks
    114
    Thanked 152 Times in 82 Posts

    Default

    Ok..after staring at the tm for a couple of hours unless im missing something it looks like the input shaft sliding gear is always splined to the input shaft. The input shaft sliding gear also continuiously engages the pto drive gear.
    With the input shaft sliding gear engaged, the input shaft,input shaft drive gear and sliding gear all rotate as an assembly. They drive the front idler gear which is splined to the idler shaft clutch gear that is splined to the idler shaft rear gear that is keyed to the idler shaft.
    It was suggested that by eliminating the bearing between the pto gear and idler clutch gear and shrinking a spacer in its place that somehow the power flow would change.
    The front idler gear, clutch gear, and rear gear are all splined together and rotate as an assembly (idler shaft included) so as ive said unless im missing something if the pto drive gear was unable to rotate at a different speed than the idler shaft when the inpht shaft sliding gear was dissengaged you would add the reduction between the sliding gear and pto drive gear to drive the idler shaft and downstream gearing..but when you engaged the sliding gear with the input shaft drive gear you would effectively be in two gears at once now that the pto drive gear was a solid connection to the idler shaft clutch gear and its splined partners..and bad things would happen..

    Am i seeing this right?

  4. #3
    Colonel DUUANE's Avatar
    Join Date
    Feb 2005
    Location
    Vancouver BC
    Posts
    292
    Thanks
    114
    Thanked 152 Times in 82 Posts

    Default

    So..if the above is correct...the bearing eliminator/spacer would need to move the pto drive gear rearward in the case if possible and teeth on the input shaft drive gear would have to be shortened so the sliding gear was engaged with the input shaft gear or pto gear but never both .
    That should get us there.. but i think low range would suffer durabillity issues.
    If a cckw tcase is a straight bolt in that would be the way to play imho..

    My kingdom for a road ranger...a 15 spd with 5 in the basement deep reduction

  5. #4
    4 Star General USMC 00-08's Avatar
    Join Date
    Aug 2010
    Location
    Skiatook, OK
    Posts
    1,088
    Thanks
    970
    Thanked 638 Times in 392 Posts

    Default

    I have no experience to offer, but I have read where people have used a CCKW transfer case and transmission with success. These were old write ups with no pictures or video.

    It will be neat to see what you come up with.
    02-1952 M135 W/O #5314 - Reg. #4G3868 (winch added at some point in its life)
    01-1952 M135 W/O #4984 - Reg. #41143???
    12-1951 M135 W/O #3194 - Reg. #41122836 945th Maint Co, 945th Antiaircraft Artillery Bn., Milford Delaware
    11-1951 M135 W/O #556 - Reg. #41121215 5th Army, 816th Quartermaster, Ft. Leonard Wood

    Video of #4984 https://www.youtube.com/watch?v=1FUElX_64i4
    Video of #5314 https://www.youtube.com/watch?v=xYMiR2DT7Fo

  6. The Following User Says Thank You to USMC 00-08 For This Useful Post:

    DUUANE (10-14-2017)

  7. #5
    Corporal
    Join Date
    May 2012
    Location
    W. KY
    Posts
    49
    Thanks
    55
    Thanked 24 Times in 21 Posts

    Default

    I hope I'm mechanically inclined (as a pro car mechanic), but unless I've got a very good diagram or preferably a unit to look (touch/feel), I'm probably not gonna grasp the power flow path.

    The way I read the original post, the PTO output was sacrificed to get the other range. Was that your understanding?

  8. The Following User Says Thank You to Ashley P For This Useful Post:

    DUUANE (10-14-2017)

  9. #6
    4 Star General m1010plowboy's Avatar
    Join Date
    Jan 2010
    Location
    Edmonton, Canada
    MVPA
    33518
    Posts
    3,004
    Thanks
    4,520
    Thanked 3,915 Times in 1,574 Posts

    Default Early Deuce Transfer Case 2 speed mod

    This is a great discussion piece for me. I watched a couple of buddies tear one apart, buy $800 in new bearings and it's still joyfully pushing his 52 deuce around. Lots to learn.

    Here is a breakdown of parts and pieces we can all put together with a 2 speed. Wouldn't that be nice! Great thread Duane, I'm all eyes.

    tmtcexp.jpgtmtc.jpgtcgoat exp.jpgtc goat.jpg

  10. The Following 2 Users Say Thank You to m1010plowboy For This Useful Post:

    DUUANE (10-14-2017), USMC 00-08 (10-13-2017)

  11. #7
    Colonel DUUANE's Avatar
    Join Date
    Feb 2005
    Location
    Vancouver BC
    Posts
    292
    Thanks
    114
    Thanked 152 Times in 82 Posts

    Default

    Well im working from .pdf TM's i've downloaded and unfortunately my phone wont let me screen shot the diagrams..
    I think that it is possible to make a 2 spd case from this, however..i dont think it would stand up to any real abuse. Pto gears generally are designed to transmit a %age of total engine torque not the full pull. It may survive for a while with a mild power plant and an auto. AT and MT series allisons tipically hit pretty hard and a cummins/stroke/duramax with a 5 or 6 speed manual would probably kill it in the driveway.
    Yes Ashley P ..that was my understanding of what Rosco had posted. Maybe he can shed more light.
    Sacrifice neutral and pto output for a reduction range. If my understanding is correct the pto output would still function but only in "low" range and the wheels would be driving at the same time.

    Its my feeling that we all want to spend time running our equipment,not repairing failed modifications.
    For the money the cckw route to a 2 spd seems like a wise investment. Install and maintain with regular service, wheel like a man with a plan, go home with the smile of Victory.

    If the spare case comes my way ill take some pics and measurements . My MT 653DR trans has a 8:1 first gear and a modest small block makes almost double the torque of the 302. Will i need the 18:1 of the stock trans 1st low? I bet at some point i probably will but id rather have to winch out than swap a tcase to get my rig out of the bush.

    I was excited about this too when it was mentioned..but im not sure about the viabillity.

  12. The Following User Says Thank You to DUUANE For This Useful Post:

    m1010plowboy (10-14-2017)

  13. #8
    Colonel DUUANE's Avatar
    Join Date
    Feb 2005
    Location
    Vancouver BC
    Posts
    292
    Thanks
    114
    Thanked 152 Times in 82 Posts

    Default

    I went back and re read rosco's post. I'm asking you's with winches..when you shift your tcase to neutral.
    1. Do you shift to neutral then keep moving the lever to engage the pto gear?
    2. Do you just disengage the drive to the wheels and pull another lever to engage the pto?
    My truck doesnt have a winch or pto so i have no feel yet. Im trying to get a better idea of the shift procedure.

    Thanks for your input and enlightenment.

  14. #9
    2 Star General
    Join Date
    Dec 2006
    Location
    farmington NM
    Posts
    767
    Thanks
    89
    Thanked 211 Times in 136 Posts

    Default

    Lever to shift the transfer case its in gear or out of gear. It just disconnects power to drive the wheels so you can use the winch .
    Lever to winch has neutral and cable on and cable off .

  15. The Following User Says Thank You to topo For This Useful Post:

    DUUANE (10-14-2017)

  16. #10
    General gentrysgarage's Avatar
    Join Date
    Nov 2009
    Location
    Lost Angels, CA
    Posts
    430
    Thanks
    818
    Thanked 278 Times in 184 Posts

    Default What I have found

    HiYa Duuane,
    I have been researching this also and never got anything concrete.."THIS IS WHAT I DID" sort of statements...always my friend's first cousin on his mother's side three times removed heard some one who did this...LOL! But I have to say I have seen alot of carnage of exploded 1000hp "Mud Truck" transfer cases and the weakness isn't the gears, if using M135 transfer cases (tc), it is the case itself. They do shatter but the gears looked fine, and one guy rebuilt his using his old gears. Back to the M135/CCKW strength there is a difference! They were only making the CCKW trucks strong enough to get to Berlin, they never planned on bring them back, all the better metals and heat treatment went into the airplanes.
    03-1943 g-7123 COE 4x4 REG# 3219442
    02-1952 M135 w/winch REG# 41144752
    My YouTube Channel https://www.youtube.com/channel/UCiU...7Zp-jBw/videos

  17. The Following 2 Users Say Thank You to gentrysgarage For This Useful Post:

    DUUANE (10-14-2017), metal magnet 1963 (03-23-2018)

Page 1 of 15 1 2 3 4 5 11 ... LastLast

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •