That's exactly what mine was doing when I rebuilt it. It was worn out and had some internal issues. Rebuild with some upgraded parts fixed it. Been two years now with no issues.

 

Did you replace the converter too?

 

In a ZJ 5.2 from 1998, with 44RE. I would like to know your opinion.

I've had a problem with the transmission for a few weeks. When I increase speed smoothly, with the throttle smooth and steady, on flat ground, it shifts well. But, when the ground becomes sloped, or if I increase the accelerator a little hard, it begins to sliping making a noise similar to a friction. This happens more easily when the revolutions are low, below 2500 rpm .

For example: position D, from stopped I start on a sloping terrain, it begins to slip until it reaches 1500 rpm. From there, I can accelerate hard until the 2nd gear that I have no slip

Another example. Going up a hill, in 1st gear, steady revs, 1,200 rpm, steady low throttle, no problem. If I step on the gas, it slips. But if I go to more rpm (for example 2,000 rpm), constant throttle and I step on the throttle, it does not slip.

The problems appear when starting in 1st, and in the changes from 1st to 2nd especially. Less slip from 2nd to 3rd

With the T-case in 4-low position, I have no problems. It works well.

I replace the oil (Mopar ATF + 4) I replaced the oil filter. Also the solenoid and the pressure sensor, I adjusted the bands according to specifications, but nothing has changed

I am not very familiar with automatic transmissions. I always drove manual shift. Could it be the torque converter? Oil pump not giving enough pressure?

Could be a bit of both.
I just replaced my 44RE with a 46RE due to similar issues, and since i had my old tranny on the bench i decided to tear it apart.
The clutches for 1-2 were... "fine".
The clutch pack för 3rd gear, which was my main issue, were totally fried. It would engage 3rd if i got it up to speed and then let go of the throttle.
It had one side with friction material in either "end" of the clutch pack. The rest was just steel on steel.
So likely your clutches are fried and that ain't no easy or quick fix i'm afraid.
If you're lucky you can find a decent used tranny to swap yours out with. If not, have it rebuilt.

 

Replace 46RE to 44RE is a good swap. Is it a direct replace?

 

In a ZJ 5.2 from 1998, with 44RE. I would like to know your opinion.

I've had a problem with the transmission for a few weeks. When I increase speed smoothly, with the throttle smooth and steady, on flat ground, it shifts well. But, when the ground becomes sloped, or if I increase the accelerator a little hard, it begins to sliping making a noise similar to a friction. This happens more easily when the revolutions are low, below 2500 rpm .

For example: position D, from stopped I start on a sloping terrain, it begins to slip until it reaches 1500 rpm. From there, I can accelerate hard until the 2nd gear that I have no slip

Another example. Going up a hill, in 1st gear, steady revs, 1,200 rpm, steady low throttle, no problem. If I step on the gas, it slips. But if I go to more rpm (for example 2,000 rpm), constant throttle and I step on the throttle, it does not slip.

The problems appear when starting in 1st, and in the changes from 1st to 2nd especially. Less slip from 2nd to 3rd

With the T-case in 4-low position, I have no problems. It works well.

I replace the oil (Mopar ATF + 4) I replaced the oil filter. Also the solenoid and the pressure sensor, I adjusted the bands according to specifications, but nothing has changed

I am not very familiar with automatic transmissions. I always drove manual shift. Could it be the torque converter? Oil pump not giving enough pressure?

I would recommend if you are handy and want the best performing results, take your 44re and converter out and bring or ship them to Martin Saine the best mopar transmission guy around and have him do a rebuild along with his performance tweaks and send it back. his contact info is: thefastman.com/transmission.php You will love the way it drives afterwards. I would stay away from a swap to a different model like the 46re because of a few reasons. They arent identical and will require some minor alterations to either electronics, or other minor headaches. It has different gear ratios and will make your acceleration suffer. You will feel a big difference around town but highway speeds will be the same. I remember back in the day the later model ZJs with the 44 did 0-60 about a half second quicker than the earlier ones with the 46. same 5.2 engine same hp. the gearing for the two are

44re is 2.74, 1.54, 1, .69
46re is 2.45, 1.45, 1, .69
Also the 46re is a heavier and larger unit but unless you are making serious power its not really much stronger than a 44re and will mostly cost you some gas mileage from the extra weight and rotating weight.

 

Also the 46re is a heavier and larger unit but unless you are making serious power its not really much stronger than a 44re and will mostly cost you some gas mileage from the extra weight and rotating weight.

46RE has more than 50% more friction material surface area as stock in the main transmission clutch packs. Band surface area is about the same, and OD is identical between a 44RE and 46RE.

You are correct in that a 44RE built to higher specs, better torque converter that is matched to the cam being used, and a M.Saine recalibrated/ upgraded valve body will make a big difference in how the transmission feels like - and can handle well over 500hp/ 500 lbs.ft. With the shorter 1st and 2nd gears and lower rotational mass it gives a bit more "oomph" compared to a 46RE behind the very same engine.
As stock, a 44RE in my opinion is a bit too light duty for a ZJ, but can somewhat handle a stock 5.2 if the transmission is kept cool and fluid changes done according to service specifications. I would never use a stock/ rebuilt to stock specs 44RE behind a 5.2 in a Jeep that sees offroad or tow use, nor would I use a stock-spec. 44RE behind a stock or built 5.9

All this being said, if I already had a 44RE I would not hesitate to use it as long as it was rebuilt with proper upgrades no matter if I was running a stock 5.2 or a built 5.9 - friend has a 44RE behind his 408 with an M.Saine valve body, M.Saine converter and internal upgrades we did based on M.Saine suggestions. It performs absolutely wonderfully in every possible way :thumbsup:
I myself will be rebuilding my 46RE for my 408 stroker project, with M.Saine parts/ suggested upgrades.

 

I have a 2500 converter in mine (408/46RE), it absolutely launches..

 

Been driving my Heep most of this weekend (can't afford to drive it too much, 95 octane "regular" gas in sweden is @ ~2$/litre right now... �� ) and i seriously can't complain about the performance from the 46RE.
The ZJ with a 5.2 ain't that quick of the line anyways and i can't say i "feel" the difference in gearing between my car and my buddys ZJ.
I'm still happy with my swap

That said, i sure wouldn't mind changing the gearing in the axles for when going off road. Although i have stock 3.73s now i'd like to change that to 4.10 or 4.56 at some point.
That will probably never happen with the stock D30LP/D44A though so i'll just drive it as is for now.

If i had the options again that i had when starting this swap, of choosing between to trannys in similar shape, i'd still go with the 46RE.
Just looking at the substantially beefier internal parts (the forward drum at least, the bands are the same, as already pointed out) makes me all warm and fuzzy inside ��

 

I'll keep the transmission as it is for now, because it still works, although it doesn't work well. But after reading your comments, I think in the future I will rebuild the 44RE.

I would like to know what spare parts I need to reinforce the transmission. (reinforced clutches? ... updated torque converter is necessary?) ...
Where can I buy these reinforced spare parts?

 

I'll keep the transmission as it is for now, because it still works, although it doesn't work well. But after reading your comments, I think in the future I will rebuild the 44RE.

I would like to know what spare parts I need to reinforce the transmission. (reinforced clutches? ... updated torque converter is necessary?) ...
Where can I buy these reinforced spare parts?

Something about spare parts to reinforce the 44RE?

 

For some reason, the 98 ZJ went really low end. No transmission cooler and the lines are all unique.

I would find a 97 ZJ V8 and use it for parts. You can then use the replacement parts.

I just can't kill it... 256K and it runs great. 19mpg. AC cranks... Such a great 24 year old vehicle...

 

For some reason, the 98 ZJ went really low end. No transmission cooler and the lines are all unique.

The reason for the auxiliary cooler delete is because they have a redesigned radiator with a much larger transmission cooler built in. It's still not enough though. I broke open my 5.9 radiator when I was replacing it about of curiosity. The factory radiator are copper core. Definitely superior to the aluminum replacements but they don't seem to be made like that anymore.
Ive always put a huge auxiliary transmission cooler and bypassed the radiator cooler anyway.

Sent from my SCV46 using Tapatalk

 

In terms of upgraded parts, you're looking at things like higher-capacity clutch drums, thinner pressure plates to fit more clutch packs, higher-performance clutch materials, upgraded planetaries, that sort of thing. The servos/accumulator pistons can be upgraded, as can the kickdown/reverse bands. The kickdown apply lever can be upgraded to higher ratio. A Transgo shift kit is (IMO) the most important upgrade for long life. Torque converter upgrade is (again, in my opinion) only needed if you are producing more than factory horsepower.

 

Any reliable company to get these spare parts and to advise me?