89 nissan sentra axle going in and out of transmission when i had it up on a lift & engaged. What hold that in?

The clutch isn't working correctly if you have to go through all that to get it into gear. You can check the shifter rails on top of the transmission, but that takes removal and dis assembly of the top cover on the transmission.

Bummer,has to be an internal trans . problem,snapped the input shaft or something,however,should make sure it's not an axle. That should make noise tho,but check anyway,like put it in reverse and set the brake and just look under the front and make sure one axle isn't spinning.

Might have a hole in transmission pan,need to get under and check it out.

tech the way its ment to be done is to drop it out the bottom...if you have a lift..this way its possible to do it without the removal of the trnny or the cv axles...but if no lift avalible it has to come out the top with the half shafts removed

check and adjust linkage 

u r better off buyin a rebuilt axle its cheap and comes with it and its less of a headache

look very close you will see screws at the bottom of your cap usually they are phillips head.Undue them and lift the cap off.remove and replace your wires one at a time Always.

I do not have a vacuum diagram for the 89 Cherokee, but my 89 had the same issue several times and all it was is that the block of vacuum lines that go into the front axle on the rear of the axle on the passenger side of the vehicle. I ended up having to put a zip tie around the axle and hose block to hold it on. Have not had the issue again since doing this. Hope that helps.

is it a manual or automatic?if it's manual check clutch.if it is automatic check transmission fluid.

The front drive-axles on your sentra are held in my circlips. Once you have the axle loose from the steering knuckle, you can get a big flat blade screwdriver between the inner CV joint and the transaxle housing and give the screwdriver a shot with a hammer or your palm and they will pop out of the transaxle. Use a lubricant (I use Sil-Glyde, but you can also use Vaseline) on the circlip when reinstalling. Push the stub with splines into the hole it was removed from and twist it to make sure that the splines are engaged and push the outer CV joint (where the axle nut threads are) toward the transaxle. You may need to tap with a rubber mallet to get the circlip to compress allowing the axle to go into the spider gear. If you don't have a rubber mallet, put the axle nut on the axle so that it is flush with the end of the threaded protion of the outer stub. This will help prevent damage to the threads.

Hope this is helpful!

Nissan Scope Technician- 10+ years experience in Nissan dealership.