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M38A1s and T98A Transmissions

Discussion in 'Early CJ5 and CJ6 Tech' started by Don X, Apr 23, 2016.

  1. Don X

    Don X The Prodigal Moderator Staff Member 2023 Sponsor

    A few M38A1s came out with the T98A transmission but I've never seen one. I'm installing one in my A1 but have run into a problem. It's a much larger tranny. It's higher and longer. The length is easier to adapt but I'm finding the case is too high so it hits the bottom of the floor of my Jeep. I've trimmed a little but A1s have a 17 gallon gas tank :) so I can't trim enough to accommodate the transmission.:(

    I've looked at doing a body lift for additional clearance but I'm hoping there's an easier solution. I also thought briefly about trying to move the engine forward but it doesn't look like I would gain much more room.

    Is there anyone out there with an A1 that has a T98 in it? I'm hoping to find someone with an original factory install AND someone that has done a conversion. Here are a few pictures of what I have to work with. Thanks.

    [​IMG]

    [​IMG]

    [​IMG]
     
  2. PeteL

    PeteL If it wasn't for physics, and law enforcement... 2024 Sponsor 2023 Sponsor 2022 Sponsor

    Could you drop the crossmember a bit?
     
  3. Don X

    Don X The Prodigal Moderator Staff Member 2023 Sponsor

    It already has a 7/8" drop via some spacers. I'm not sure how much I could drop it without running into clearance problems and/or angle problems.
     
  4. jpflat2a

    jpflat2a what's that noise?

    Don is the trans mounted ? Is that the finished clearance between tank and trans ?
    or do you still need to go higher with trans ?
     
  5. Don X

    Don X The Prodigal Moderator Staff Member 2023 Sponsor

    It still needs about another inch.
     
  6. Danefraz

    Danefraz Well-Known Member 2023 Sponsor 2022 Sponsor

    I bought prothane pucks to go under the body on mine. I think that will give me about 1/2" more than the stock conveyor belting that was under mine. Not sure if those will give me enough clearance, but I only have the same 10g ejection seat option.
     
  7. noahlon

    noahlon Old Fart

    This is a couple photo's of a T98 install in my 68 CJ5 behind a Dauntless V6. The D18 transfer case moved back as shown in the first photo.
     

    Attached Files:

  8. oldtime

    oldtime oldtime

    FYI CJ's with T98 from the factory had 2 wood strips placed under the gas tank.
    Part # 694623

    Also rear engine support crossmember was dropped 1" with oak blocks part # 913057


    See: http://cj3b.info/Tech/T98A.html
     
  9. shaun

    shaun Member

    Mine clears fine. I have 62 with same transfer case and have 1 in. Body mounts. I'd try going that route first before moving a bunch of things.
     
  10. Don X

    Don X The Prodigal Moderator Staff Member 2023 Sponsor

    Oldtime, thanks for the CJ3b link. I'll have to study that later. A quick glance shows some of the types of parts are duplicated (i.e. # 911600 Lever and Tube, clutch control (8-1/2") and# 923636 Lever and Tube, clutch control (9-1/4")). As for the crossmember spacer, I assume you mean the middle x-member. I'm dropping that with 3/8" steel plate stacked on 1/2" plate for a total of 7/8". I figure it'll be more durable than wood. The wood under the gas tank is something I wasn't up on.

    noahlon, I noticed you dropped your skid plate as well as the x-member. Was that for parking brake drum clearance?

    Shaun, I'm leaning towards the body mounts too. Coupled with the wood blocks under the gas tank it'll make a difference. I'll have to check the clearance on my seat. The last thing I want to do is raise that an inch. I'll lose more sight line through the windshield. Just checking all of the options.
     
  11. Patrick

    Patrick Super Moderator Staff Member

    I'd just spend a few minutes and put a small body lift on it.
     
    jpflat2a likes this.
  12. jpflat2a

    jpflat2a what's that noise?

    or space the tank up as mentioned...maybe both
     
  13. oldtime

    oldtime oldtime

    If you need more info I have all parts mentioned in that article including the 1" oak crossmember blocks.
    The only thing I never aquired from the original 1956 with T98 was the wood that went under the gas tank.
    So I'm not sure of the original wooden tank spacer dimensions.
     
  14. Glenn

    Glenn Kinda grumpy old man Staff Member

    X2!
     
  15. noahlon

    noahlon Old Fart

     
  16. Rralphs

    Rralphs Old Member

    I mounted the transfer case mount on the lower step of the cross member so the tranny could be lower without lowering the cross member.[​IMG]

    Had to notch the top of the cross member for transmission clearance.

    [​IMG]

    If you look down the channel of the cross member you can see where I welded plate for the notch.
     
  17. Don X

    Don X The Prodigal Moderator Staff Member 2023 Sponsor

    Rralphs, the 2nd picture shows a spacer on the end of the x-member. That drops the x-member lower.
     
  18. Don X

    Don X The Prodigal Moderator Staff Member 2023 Sponsor

    I'm looking at a BL. I've seen some lift kits with 11 mounts but crawling around I'm not seeing that many attachment points. I checked my FSM and my M38A1 manual and didn't find any help. Does anyone know of a diagram or description that shows the mounting points?
     
  19. Howard Eisenhauer

    Howard Eisenhauer Administrator Staff Member

    Lesssee-

    four across the back

    two in the rear floor

    two on the riser

    three under the front floor

    I think thats eleven.

    H.

    p.s. don't forget the grill will have to go up too.
     
  20. scott milliner

    scott milliner Master Fabricator

    I did the same thing with my transmission mount. I also have 1" spacer blocks between the cross member and the frame.