New to the forums and sort of recently picked up a 1995 Disco 1, automatic transmission. 154k on the clock. The previous owner said the transmission did not work. I've been doing a lot of searching and looking at the car, but coming up empty and some more guidance would be helpful. So trying to get it back in shape to at least drive. The car starts fine and then engine is ok after a new fuel pump. It will not shift into D, 3, or 2, but will shift into reverse and 1 (and move). It will only do this in 4 low-locked. Any other xfer case position and it clunks and goes nowhere. I'm not sure if the two are related, but I will try lubricating the linkage and look at the mechanism on the box to see if it's not fully engaging.

I have only changed the trans fluid and filter and added some BG to try and clean out gunk (I know, that could make things worse). My initial thought was xyz switch, but all I can find is the inhibitor switch in Rave and all xyz switch posts are disco 2 related, how does the disco 1 decide what mode the trans is in? Is this purely mechanical? The car will start only in P and N, so it seems the inhibitor switch is working correctly (I can also hear the relay).

Any help is much appreciated!

 

I have recently ripped out my transmission & t-case and am in the process of final assembly on the vehicle to get it moving. I had similar issues from when I purchased my '98 disco and just junkyarded the fix (I could only start in 1 and then had to gear up to drive otherwise it would stall out)

Starting with the t-case, there are two switches that you would want to consider: 2/4 & Hi/Low. The 2/4 is up on the top portion of the t-case. This can get stuck because owners will put it in 4 and leave it there for life. But, if the vehicle is in park and running, you should be able to flip that back & forth. Ostensibly, the 2/4 would show on the dashboard - along with H/L. Since you have a 95, I do not believe you have the solenoid. My '98 has a solenoid and I think the '97 & '98 were the first. But, since you have 1 - but not 2, 3, & D, likely you do not have any issues there. Nonetheless, the t-case is mostly bomb-proof and can withstand a ton before finally going. Having the ability to drive in 1 tells me you more likely have a transmission issue.

There is a park solenoid on the side of the gear shift - at least on the '97 & '98. I know this can be an issue but, this typically prevents the vehicle from starting or changing gears. That solenoid is replaceable - but pricey.

Outside of the park solenoid on the gear shift, there are only two things that really attach to the vehicle for the transmission, outside of the actual transmission. The gear shift cable & the kick down cable. The kick down cable runs up into the engine compartment to the back of the throttle body area. This tells the vehicle you are slowing down and will initiate gearing down inside the transmission. You may have an issue with that. Then there is the gear shifter for the transmission itself that comes out of the gear shift box - in the back of the box - and runs down into the inside of the transmission itself, into the top portion of the valve body for the transmission. The inside of the cable looks similar to an old bike brake cable with a ball at the end. This is what initiates the gears. If you do drop your pan, you would want to ensure the valve body is not gunked up, but that requires dropping the valve body as well. The other thing is the innards of the transmission itself. This is where the gears & clutches are. If these are bad, no amount of any fix -t fluids will work.

Start trouble shooting with these items and ensure the transfer case can switch gears. Then, maybe consider dropping the transmission oil pan and swapping the oil filter and looking around, and trying to shift he gears to ensure that is working properly.

 

Disco 1 is purely mechanical. Sounds like you're probably lost the "A" clutch if it won't move forwards with load (in high ratio), and possibly the one way sprag.

Transfer case position makes no difference to the trans shifting or power output, but low means it might put out enough torque to the wheels to make it creep. If it has to be locked, then you may also have a broken diif, or halfshaft or cardan shaft.

Either way, it's not able to output power from the trans correctly. You either need a rebuild or another trans.