1991 jeep wrangler not shifting into gear could this be clutch

a stick shift.
ok ill do stick shift 101..... (repaired many a box i have)
first off it can be 3 things, the stick bad. the box and the clutch.
so can you shift all gears , engine off, and parked.?
Q1: yes/no.?
if yes, can you shift to 2nd gear, parked & engine off
and then start engine and move in second gear using the clutch pedal.?
ill stop here, as most get lost , if i post the full diagnosis..... end.
we can go way beyond this. easy.

It is likely leaking at the slave cylinder

If the transmission oil is full and the clutch master cylinder is full, feels normal and does not slip going up steep grades, likely the gears in the transmission are worn (usually synchros). All items above contribute to proper shift engagement.

Sounds like the trans needs to be rebuilt as it's been abused. The clutch may be dragging during shifts and not completly disingaging or a lasy driver does'nt pust the clutch in all the way. If the clutch isn't the problem the oil in the trans should be ATF and if someone put in 80-90 it'll do this but jumping out of high and the shifter isnt itting the floorboard as a bad trans mount or motor mount may let happen, The trans is damaged and a used unit is cheaper and quicker to get done. Rebuilding the trans with all the parts it may need cost more than your truck is worth

yes it could be also check the fluid level!

U have what is called a hydraulic clutch, one of the hydraulic cylinders hs failed, there is a master and a slave cylinder. The most likely and most common cylinder to fail is the slave cylinder, this requires the transmission to be pulled out to replace it. the art is around $125.00, while the trans is out u might as well replace the clutch, the labor is about the same. Here is a picture of the part, let me know if u can see it.

Your clutch is not disengaging. If it a hydrolic clutch chk. the fluid in resavor, Or slave cyl. for the clutch is bad, Or it has got air in it and needs to be bleed. This is a clutch problem, nothing wrong with trans. If its a manual clutch linkage its an ajustment thing. My best guess if its hydrolic slave cyl. went bad, or resavor is out of fluid.

Auto parts stores have whats called trans. cooling line flush just ask them and they will know what you want.

Jeep #1: Sounds like a shift linkage problem. Possibly synchro forks are sliding back and forth on shift rails and are out of adjustment. This is internal and cannot readily be fixed without trans removal as far as I know. Hydraulic clutch system is non-adjustable. A new clutch should last at least 70K so, unless it was installed improperly, it should be OK. Check hydraulics for leaks & bleed. Clutch should "catch" about two inches off floor (not too low or not too near top of travel)
Jeep#2: Has a synchro or other internal gear problem... Symptoms are similar but gringing and clicking noises indicate worn or broken internal components!
Good luck to both!

Hi Mike,

Your description is excellent.

All the recent replacements make those components suspect. The symptoms point at two possible problems.
If the tranny had a linkage, I'd say that was it. The problem may be related though.

• Does the shift lever feel loose?
• Same shifting problems when trying reverse?
• With the engine off do the same shifting problems exist? (this one points away from the clutch)
  

I'd check the that the retaining ring on the shift lever is fully engaged (quarter twist against two pins on top of tranny). The book ha a long procedure for accessing it, but the easy way is through the shift lever boot.

The clutch system:

• Check fluid level
• Any leaking fluid from master cylinder, operating cylinder or connecting lines?
• Has the fluid level fallen to a point where air could have been drawn into the cylinder?
• Does the fluid look clean, no particulates?

To be thorough, I'd bleed the clutch hydraulics. There may be air in the lines.

With multiple possible causes, I usually check the least expensive solutions first. This is where I'd start. Comment me back, let me know how it goes.

Mike