Please help Glacier991.

[bigblackbronco]

since I'm asking for glacier991 I guess you pretty much know this is a trans problem.

here goes

1998 4.0 4r44(I'm pretty sure) 177k miles regular trans fluid changes and filter changes as well as aftermarket cooler(i put these on every vehicle I own that has an auto trans), trans works great until I'm up to speed. when I'm at 45 or above and let off on the throttle to coast I get a sound like a bad bearing whirr or a tinny grinding sound. as soon as I step back down on the throttle to accelerate the trans hesitates (flares slightly) and goes into gear and the sound goes away.

I ran Psi check it it as follows

cold oil
Park low idle 90psi 1800 rpm 95 psi 4000 rpm 100psi
reverse low idle 125psi 1800 rpm 2258psi torque converter stall maxes out my 300 psi gauge

neutral low idle 90 psi 1800 100psi 4000 100psi
drive low idle 115psi 1800rpm 150psi torque converter stall 235psi
(2) low idle 110psi 1800rpm 150 psi tc stall 235psi
(1) low idle 120 psi 1800rpm 150psi tc stall 235psi

Hot oil

(p) low idle 90psi 1800rpm 100 psi 4000rpm 105psi
(r) low idle 80psi 1800rpm 190psi tc stall maxes out my 300psi gauge
(n) low idle 85psi 1800rpm 100psi 4000rpm 100psi
(d) low idle 70psi 1800rpm 125psi tc stall 220Psi
(2) low idle 65psi 1800rpm 140psi tc stall 225psi
(1) low idle 65psi 1800rpm 140psi tc stall 225psi

there is no significant drop I can see anywhere and it looks to me like the hydraulic system is functioning properly. I haven't seen any huge jump in trans temp lately and when the trans makes the noise I see no drop in pressure (psi remains above 75 pounds).

I've heard of a coast clutch and wondering how that is set up, I'm pretty sure I have some kind of internal mechanical failure but not sure what....

someone help..... or at least confirm my fears.....
.... or maybe lets take bets an when I pull it apart we will find out who wins....

 

[BrooklynBay]

I've moved your thread to the transmission section. Did you check the fluid level? You have a 5R55E 5 speed transmission. It's possible that the torque converter is starting to fail or there is some sort of internal damage. Did you drop the pan to check for broken parts such as band parts, pieces of roller bearings or sprags? Did you ever adjust the bands? Do you have 4WD? Sometimes transfer case noises are mistaken for transmission related issues.

 

[bigblackbronco]

it does have 4x4, it isn't transfercase (at least it never changes when I shift the case between any of the ranges) no, i haven't dropped the pan.... that is a project for thursday night.


Think I'm gonna rebuild this badboy myself (after reading the posts here!) I have rebuilt many manual tranny's/rear ends this looks pretty simple, but I'll have to buy some tools.

If there is anyone that knows how to adjust the bands, or has the atsg book with the instructions, I'd like to try that first. But I'll bet I end up just rebuilding it.

 

[BrooklynBay]

# 4 & # 5 in my list of useful threads will tell you how to adjust the bands.

 

[gijoecam]

since I'm asking for glacier991 I guess you pretty much know this is a trans problem.

here goes

1998 4.0 4r44(I'm pretty sure) 177k miles regular trans fluid changes and filter changes as well as aftermarket cooler(i put these on every vehicle I own that has an auto trans), trans works great until I'm up to speed. when I'm at 45 or above and let off on the throttle to coast I get a sound like a bad bearing whirr or a tinny grinding sound. as soon as I step back down on the throttle to accelerate the trans hesitates (flares slightly) and goes into gear and the sound goes away.

snip....

Classic symptoms of a bad transfer case. Getting to be more and more common these days.

And for the record, your 98 is a 5R55E, not a 4R44E.

 

[jg09]

I'm almost thinking it's the transfercase, too. Although dropping the pan might tell more.

 

[gijoecam]

On a 98, it's almost surely the t-case. I'd be surprised if it was anything else... Run a search for 'shift rail bore' or 'transfer case grind' or 'grind on decel' or 'grind on coast' and there will be a plethora of info.

 

[bigblackbronco]

On a 98, it's almost surely the t-case. I'd be surprised if it was anything else... Run a search for 'shift rail bore' or 'transfer case grind' or 'grind on decel' or 'grind on coast' and there will be a plethora of info.

okay, that makes sense, and would explain the grinding sound following mph not rpm and tranny gear..... duh!!

I think you're right about it being the t-case. Is there an easy way to check it out? I didn't see anything in the posts besides tearing it down.

And do any of you guys know of a forum this helpful, dedicated to grand cherokees? just a shot in the dark.....

 

[gijoecam]

Watch it!! Them's fightin' words 'round here!!

There's about a million forums for Jeeps... One of them is bound to have some Grand Cherokee devotees... Can't say I know of a specific one though. (I don't understand that 'Jeep Thing' they're always talking about....

 

[bigblackbronco]

okay, look..... I paid $900 for the jeep.... and it's a 94..... and it has 277000 miles on it..... and it has never left me stranded.........

and it's the first car I've ever owned that wasn't a ford..... I've also got a 84 bronco (rock crawler) and a 91 f-150, 79 f-150, 78 bronco, 76 highboy...... oh, and this one pain in my @$$ a 98 exploder......

but seriously, I hated the thought of the jeep but for $900 I couldn't resist....... and it's growing on me.....

 

[jg09]

Hey, I got love for Mopars. I miss my old Durango, I want it back.

 

[bigblackbronco]

finally got around to taking the t-case out...... my low range shift slider looks about like the one in the bw4405 rebuild diary, and the t-case fluid looks like bronze metal flake paint..... I'll bet good money this is my noise. Both of the nylon guides were gone from my shift fork, and the shaft the shift fork slides on is chewed up too as well as having ovaled the front case half. But the transmission lives on (and I probably better change the filter in the pan and the fluid, you know while I'm under there).

Thanks to all. I would have rebuilt my transmission and never cured the noise.
and thanks to glacier991 for all his rebuild diaries, what a great help.


And a big fat up yours to whoever has his tools and hasn't returned them!
c'mon..... grow up you friggin idiots!