AX-15 transmission popping out of gear

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rct2000

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'92 Wrangler with manual transmission. Say you are shifting from 3rd to 4th gear: if you don't hold the shifter while releasing the clutch, the transmission will simply pop out of 4th and into neutral. Also if you are in 4th and you let off the gas, it sometimes pops to neutral as well. Lately, it has started to do the same with 2nd gear. No grinding, it shifts smoothly, but pops out of 4th and 2nd.
I replaced 3 of the detent springs, but nothing changed. Has anybody gone through similar symptoms? Is it time for a rebuild?
 
check mounts first.
engine and trans, if the are bad and they shake hard, it can cause the gear shifter to move.

so to prove that is so easy, (besides testing mounts ,using levers) just remove the full set of shifter boots top and bottom
if still fails the box needs work. (bearings bad sure or shift fork rail detents , parts and balls and springs bad)
 
The car has a 4 inch body lift. Engine mounts are brand new, although the transmission mount condition is really unknown. I have noticed while shifting into 2nd, 4th or reverse, the shifter feels like compressing rubber. It doesn't feel like that with 1st or 3rd. I will remove the shifter boots and see if that makes any difference.
Detent springs are brand new, and the balls are in place.
 
rct2000 said:
The car has a 4 inch body lift. Engine mounts are brand new, although the transmission mount condition is really unknown. I have noticed while shifting into 2nd, 4th or reverse, the shifter feels like compressing rubber. It doesn't feel like that with 1st or 3rd. I will remove the shifter boots and see if that makes any difference.
Detent springs are brand new, and the balls are in place.
Click to expand...
The tall body lift is the problem. I’d suggest doing whatever you can to ditch that and get it down to a 1” or deleted entirely. I am not aware of 4”, it is probably a 3”. Regardless, it’s too tall and needs to be gotten rid of.
 
drive it with no boots (off dah boots) both.
what could be more easy.? IDK?
just do it.
new soft boots may fix it , but only if the drive boots off passes the test.
if not the tranny needs work. (i fall mounts are good and solid) gee the mounts are 30 years old, how can the be. good. this old ?

its winter fix the easy stuff first, no boots is like 30min work (screw driver inside , dry and warm)
if it drives ok , try new soft boots ( store bought)
if not well, good luck with that. (huge job ) but I'd make sure 1st if fails still, the shift forks. /rods and all detent balls and springs are all good first.
(as in bubba pulled cap bolt and lost the spring and or ball from the detent rails. ouch)
fully inspected step by step,

in a pinch (winter hard) put floor mat over the now all boots missing and drive it till spring. be happy it drives then worry it later ( called in ww2, GerryRIgged.)
Assumed exhaust pipes not cracked and spewing tons of CO to the cab (killer CO) okay I can see the car to make safe answers ever. only you can.
and check engine glowing
and CAT missing
and runs rich at 10mpg. oops.
 
machoheadgames said:
The tall body lift is the problem. I’d suggest doing whatever you can to ditch that and get it down to a 1” or deleted entirely. I am not aware of 4”, it is probably a 3”. Regardless, it’s too tall and needs to be gotten rid of.
Click to expand...
I am not particularly fond of body lifts, and I don't do off-roading either. The car just came like that when I bought it. I would rather bring it down to stock, but that means "uninstalling" the lift kit, which implies finding and buying a bunch of stock suspension parts. Rims and tires will probably have to be replaced as well. I am not familiar with lift kits, just showing the attached pic which claims 4 inches. Sticker is on a leaf spring, and you can find those springs here:

www.quadratec.com

Rough Country 4in Leaf Spring for 87-95 Jeep Wrangler YJ Front for 87-95 Jeep Wrangler YJ

Replace the worn-out springs in your Jeep Wrangler YJ with the Rough Country 4in Leaf Spring. This 100% bolt-on spring provides 4in of lift. Unlike other manufacturers, Rough Country includes bushings with all of their leaf springs. Rough Country Leaf Springs are sold individually.
www.quadratec.com www.quadratec.com

The car is pretty high. Transmission skid plate is attached to spacer bars (as opposed to directly on the frame), in order to drop it and help with the drive shaft angle into U-joints and differential.
Will remove the shifter boots this week and give it a try.
Thanks for your support!

leaf spring.jpg
 
rct2000 said:
I am not particularly fond of body lifts, and I don't do off-roading either. The car just came like that when I bought it. I would rather bring it down to stock, but that means "uninstalling" the lift kit, which implies finding and buying a bunch of stock suspension parts. Rims and tires will probably have to be replaced as well. I am not familiar with lift kits, just showing the attached pic which claims 4 inches. Sticker is on a leaf spring, and you can find those springs here:

www.quadratec.com

Rough Country 4in Leaf Spring for 87-95 Jeep Wrangler YJ Front for 87-95 Jeep Wrangler YJ

Replace the worn-out springs in your Jeep Wrangler YJ with the Rough Country 4in Leaf Spring. This 100% bolt-on spring provides 4in of lift. Unlike other manufacturers, Rough Country includes bushings with all of their leaf springs. Rough Country Leaf Springs are sold individually.
www.quadratec.com www.quadratec.com

The car is pretty high. Transmission skid plate is attached to spacer bars (as opposed to directly on the frame), in order to drop it and help with the drive shaft angle into U-joints and differential.
Will remove the shifter boots this week and give it a try.
Thanks for your support!

View attachment 122410
Click to expand...
That’s 4” suspension lift. Body lift components are different that lift the body up higher above the frame. You probably have both body and suspension lift making it very tall and also screwing up the shifter. Suspension lift doesn’t affect the shifter.
 
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why do $2000 replacing all the lifted parts (body mounts, springs, pitman arm (no fun there). (even wrong shocks now after the drop)
or drive for 5miles boots pulled off the top of 5 speed shifter shaft boots only removed. (when you buy jeep this old ,all things the OP did wrong, did not service you get to fix. (expect anything)
costing zero parts (yet)

costing labor 1/2hr, and a used $1 screwdriver. ;)

learn what fails for sure first. if the boots are old and stiff after 30 years or the mounts are all a wreck. ( 30 years age things go bad)
if the engine/tranny motor mounts fail they move excessively and against old hard boots, and it jumps gear. (see both are bad and the effect is worse)
use a lever to test mounts, mounts can beat them self to death this is first. (or ask shop to do that)

why skip such an easy test (boots off). or ask others to guess what is wrong with your car, blind ,deaf and with no hands on driving. why?
why work the most expensive cure first?, are you floating in cash? guessing.

the fast cheap tests beat any kind of guessing, for sure.

also the rear prop shaft, if the pinon angle (done wrong) is excessive the rear of the trann/xfr case vibrates violently and can pop the gear, again take the boots off. the box. even drop the 4wd lever.
what is your rear pinion angle?. if not done right it will be a huge problem. is the transfer case pan, have the 2 drop rails there? or not./?
many jeeps the mount on top of the pan just above, is a wreck, and is weak, and small./
The whole jeep needs a full check out first. fixing the most dangerous problems first.

is the screw driver lost?:devilish:

with the boots off no kidding you can see if the tranny is jumping like mad, for sure 1 drives and 2nd watches safely:unsure:
 
I removed all shifter boot rim screws, leaving both outer and inner boots completely loose so they wouldn't offer any resistance to the shifter. Also lifted the rubber shifter cap on the transmission body. No more popping out of gear. I would have never suspected the pressure from the boots pulling the shifter into neutral.
I know the transmission shifter cap is brand new. Wondering if new boots will be soft enough so they wouldn't pull the shifter out of gear. I can always try new ones and see what happens.
Back to your question: the car has spacer bars/rails which drop the transfer case pan in order to help with the drive shaft angle.
I just replaced both engine mounts (they were completely destroyed) and will soon drop the pan and replace the transmission mount.
Checked today and there is no body lift as such. The body tub sits on the frame using what looks like stock bushings. There is barely any gap between body and frame.

body lift.jpg
 
Yep, those are stock body mounts. So the issue is your boots and the transfer case drop. New boots will usually be super stiff until they break in and loosen up.
 
great news, the 1s test free of cost, proves what is NOT.
the boot is bad. the most cheap fix on earth, why not get a new one, mine is super soft thin rubber. not 30 year old hard old rubber.
the causes are in order of PAIN (labor ) and part cost are: I presume the tranny is not bouncing up and down too. right in motion?
great no body to frame jackups, so we can end that panic. (just springs)
The rear ujoint will not like 4 + inches of lift, that makes it vibrate like mad, (U-joint 101 rules study it) and a very short life span listed at Makers web site for SPICER. the rear prop shaft is super short.

1: a new boot.
2: 2nd cause ( shift lever and be actually too sensitive, (as in bad shift rails detents, or OMG they are missing parts by PO silly actions )
3: any manual transmission can jump out of gear to neutral if the box has (#2 above ) or bad bearings or forks melted to death even warped forks or the syncro ring is a total wreck most of this are from GL4 way way too low and looks like TAR drained, or using ATV in the 5sp box (never)
4: the tranny is bouncing like mad and or the rear pinon angles are way way wrong.

to learn what it is we discount what we know it is not. (SPOCK or Occam's razor) 2 classic answers, it's the simple one bad or , we tested all 10 possibles
and 9 pass the test so must be #10 a fully bad transmission or missing detent balls)

we can't see the tranny bounce here.
some boots are no good even new, from 12,000 miles away made from recycled , flip-plops or worse.
maybe crown parts and cross the fingers.?

when bearings in the box fail the gears jump around 360deg left and right and it will jump out of gear.
the shiftrails most do there job or it will jump out of gear. for sure with 5 lb custom shift lever ball put here, (I used Beer stine lever as dumb kit)
the dent balls not missing or there springs broken or missing
the gear yoke/forks, not bent or warped or galled or melted (the look funny colors they ) are are bad.
syncro's not cracked or wrecked.
gears have dogs , those too can wreck. we shift dogs not gears. see? and 4th gear is not a gear it is 1:1 ratio, main shaft lockup. so does it jump gear?
and the bearings.
ive rebuilt a few,with full rebuild kits and know what to look for inside, (and measure).
Overheat damage and bearings shot are easy to spot.

so do the rear mount first. if no handy new boots found.
sure.
and GOOD LUCK!!!, never seen a used car sold this old that did not have 10 more more super bad things wrong, missing or warn out.
Or done wrong, many lift kits are done wrong. (springs just thrown on)
FYI
a new rear u-joint is cheap. (to buy)
if you use a pry bar on any Ujoint (large screw driver) and lever the joint .
see no play?
yes the CROSS star can move outward. in and out of cups sure.(see rust draining from cups or its seals gone or a wreck)
it can rotate (pivot) as it does and is job 1.

but no illegal play seen that smacks of needle bearing DEATH in the cups big time.
make sure the front axle is not stuck on 4wd, front right axle lock frozen in 4wd.
if is the whole car bucks on pavement. (due to PART time 4wd realities)
that is all I can think of in short time.
on mine, 2"lift left springs x4 ,the rear came with wedge perch on top of rear springs (pair) that raises axle pig, it's angle upward so
the transmission pan/cross plate, drops it 1 more inch, and the total ANGLE is very little at all.
I cant see yours so can only wonder.
 
rear joints1w.jpg

if the angle is wrong even with 2 new , u-joints. the shaft lurches violently.
the effect is the tail shaft of the transfer case jumps around violently and if the mount is bad the worse it gets. (or is why it failed )

there are great youtube videos showing a great simulation of this nasty effect.

that is why CV joints are called Constant velocity, they are and the above is not. (make sure the rear perch angles are correct )
 
the rear mount is super frail. see the free shop manual in sticky #1 page Chapter 21 page 35?
page 39 is the detent ball, called lock balls missing page 39 Chapter 21.?
the torx plug there is stamped do not remove. all Ive seen/.
3 more lock dent balls , page 42.
the detents are for stock shifter lever , not extended nor with 5lb balling ball there, (jocking 1/2) or 2 lb metal SKULL knob, I cant see the car so.
the lever stock is heavy and if someone left out detent balls all hope is gone for 10 cent part.
this ends and covers the low hanging fruit.

i have lots more, if the GL4 drains and you see nuts and bolts or balls fall out the hole?
if I could feel the shifter my self I can tell if the dents are bad.
you posted with no engine told. and 4wd we presume. 4x4 , 2.5L fails more easy, 2 more parts to fail
tail mount.JPG
 
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