At first, the (5-sp manual) transmission on this 1996 Land Rover Discovery ("1" or "I"?) locked up, but now it just spins with no power reaching the wheels. Can I fix this without dropping the transmission down from the chassis?
1) Initial symptom was lock-up from the engine side: on an evening drive home from work, normal for several miles, but then at a stoplight, when the light turned green, all I could do was burn the clutch! I wasn't fiddling with the transfer case H/L during street driving, so I'm sure it was in H without diff-lock ("CDL", right?). But no motion at wheels in any gear 1-2-3-4-5-R. So I called AAA, imagining it was going to look like a puppy being dragged to doggy bath, wheels locked. But -- Surprise! -- the Disco just rolled up onto the flatbed towtruck without any resistance at all! We dropped it at shop that did recent brake work; they couldn't find the problem; so we rope-towed it home -- again, rolling free no resistance, but in any gear clutch out would kill engine.
2) Now a couple years later, after center console removal to inspect and confirm no shift lever linkage problems evident, oiled all eight cylinders, discovered fuel pump needed replacement, and engine fires right up. But -- Surprise! again -- now clutch-out in any gear, H or L, CDL or no, just spins with faint whine, no motion at wheels.
... So I don't completely understand drive train yet, and I'm trying to find out if there is any possibility of economical repair:
- Does clutch feed transmission first, then transfer case, then drive shafts, or the other way around?
- Is there any access to gears -- like inspection plate or oil pan -- to find transmission problems without transmission removal?
- Transmission dropping sounds like needing vehicle lift and heavy jack, $1k - $2k professional shop job, so it's "don't try this at home", right?
Any referrals to experience in Denver area appreciated.

 

It's not "locked up" it's not engaged. Flywheel, clutch disc, pressure plate, release bearing, release arm, hydraulic slave cylinder, clutch master cylinder...... When pushing on the clutch pedal it sends hydraulic fluid to the slave cylinder pin and that pushes the release arm and pulls the release bearing away from the pressure plate fingers, it disengages the motor from the transmission. I'd say something is sticking or hung up with the release arm or release bearing or the slave/master cylinder and the slave pin from release lever. You can check that without removing anything. Have a buddy look or operate the clutch pedal and watch the release arm. If you need to remove the transmission it goes in this order, drive shafts off transfer case, transfer case, transmission. Much easier to remove each separately.

 

Clutch was fully operative at onset, at that green light: clutch had to be depressed to shift out of N without grinding gears, and release of clutch bogged down engine until it died, without any motion at wheels.

Similar now, clutch must be depressed to avoid gear buzz on stick shifting out of neutral, but then release of clutch only results in slight spinning noise without torque on wheels.

 

If that’s the case then it’s in the transfer case or gearbox. Inspection cover on the T case, the trans is top or either end.

 

More observations; the following all with clutch out (engaged, foot off pedal):
1 - with transfer in mid-H neutral, transmission shifts into any gear with initial synchronizer resistance and then faint whirring, higher pitch in higher gears.
2 - with transmission in N neutral, transfer shifts have no apparent effect: no resistance on stick, no sounds; stick "flops" H-L-H-L with no feeling or noise, no detent or click.

The console and boots are off, so I can see linkage from lever to shaft into transfer case is connected and operative.

My suspicion is that something came loose or broke between the transfer selector stick and the high-low selector fork.

 

Really tiny hole to work through isn't it? There is a selector "finger" that fits into a cutout on the selector shaft within the t-case. With the motor off you can hear it and feel it click into either position by manually rotating the lever, same with the lock/unlock selector down lower on the t-case body. Both use the finger/shaft setup. I've heard of the selector shafts rolling so that the finger bypasses the cutout on the shafts..... or you might find a broken finger...... I enlarged the opening under the console to get both hands on the shifter mechs. There is also a ball and socket on the end of the t-case shifter stick, when that fails it won't allow shifting or rotating the yoke in the shifter housing.

 

The diff-lock linkage feels like there is a detent at the "mid" position, in between full left and full right. That doesn't make sense to me: I would expect detents at "locked" and "unlocked" but not "halfway"?

 

Mid detent is neutral between Unlocked/Locked.

 

Also unusual to me on the transfer stick is no feel of "gating" -- the "H" pattern is not apparent in motion or resistance: the lever can "flop" forward or back -- H to L and back -- no matter where how far left to right on the diff-lock axis.
I've managed to pressure-wash the top of the transmission assembly through the console aperture to clear some of the linkage of caked grease, so I'm going to open up as much as I can with the transmission in place.

 

here is what it looks like without a body. commentary is not mine. it is basically two pivot points 90 deg off.