The myth about changing and not changing transmission fluid

[fredjacksonsan]

Originally Posted by manaswee

Wrightz28, thank you for sharing your knowledge, professional and personal experiences. I have read about the pros and cons of doing fluid change at different stages of transmission's life. It may be paradoxical but true that a fluid change for aged and ill-maintained transmission tends to cause clutch failure.

I've heard the same, about not changing fluid if it's been in there a long time.

Originally Posted by manaswee

I have read somewhere about it happening within two weeks or two months after fluid change as a general estimate. Question remains: Will my transmission of 250k survive the new fluid?

Although I have a friend whose transmission was going bad. He changed the fluid, it got better. He repeated this whenever the trans acted up (somtimes after only 15k or so), and got another 200k out of the car.

[manaswee]

Fredjacksonsan, thanks for posting both the general belief and the real-time experience ( in your friend's case). The 2.5 motor is still giving very smooth and strong performance; it hardly uses any oil (10-40w). The transmission is now revitalized with the new fluid. Between the motor and the transmission, I hope both can go hand in hand; neither one outlasts the other. My wife loves this Jeep.

[Scrapper]

i dono why new fluid would hurt it if anything it will help it.

[2000izusu]

Originally Posted by manaswee

I did the job lying under the Jeep without lifting it up. From the information I got from AutoZone, this is AW-4 transmission.

just information the, aw4 only came behind the 4.0L six cylinder
if you have a 89 2.5L you have the a904(31rh/32rh) three speed. mike

[fredjacksonsan]

Originally Posted by 2000izusu

just information the, aw4 only came behind the 4.0L six cylinder
if you have a 89 2.5L you have the a904(31rh/32rh) three speed. mike

If true, it should last a long time. Chrysler used the 904 with the 5.2Liter V8, back when it was called the 318c.i.d.

[manaswee]

I am totally blind to what model of transmission I have behind my 4 cylinder, 2.5 XJ motor, 1989 Cherokee Laredo, but I can confirm that, although I have never used four wheel drive, this transmission has that capability. Perhaps this information can help identify which one it really is. The shift marks show (from top down) P R N D 3 1-2 and there is another set of markings and shift lever on the left side. Whenever I go to the part stores for parts, I am always asked 4WD or R/WD. I have to tell them every time that it is a 4WD model.

[manaswee]

It has been confirmed by Chrysler of Cerritos, California that this transmission is in fact an AW-4 The information was obtained through the matching of VIN (vehicle identification number). If it is tough enough for the driving force of 4.0 it should be able to withstand that of a small 2.5L.

[manaswee]

It has been a week since the transmission fluid and filter change. There has been no cause for complaint whatsoever. It shifts as smoothly as usual; no slipping. Most of the times the shifting can barely be detected, realized only by observing the drop of the RPM and the increase of the MPH. Forgive me if the description sounds exaggerated, or unreal. Even so, it is not far from the truth. Maybe it is sheer euphoria.

Unless the condition of the transmission changes to the contrary, this is intended to be my standing update. I would like to thank all friends for contributing their knowledge, experiences and moral supports.

[manaswee]

Refreshing my "standing update," it has been three weeks since the transmission fluid change, and the unit (AW-4) is still working beautifully. The shifting is as smooth and as "subtle" as usual.

[fredjacksonsan]

Originally Posted by manaswee

Refreshing my "standing update," it has been three weeks since the transmission fluid change, and the unit (AW-4) is still working beautifully. The shifting is as smooth and as "subtle" as usual.

Sweet! Planning on going another 180k on it, or changing every 30k?

[manaswee]

I will do it at every 30k as you have been doing, for sure.

[fredjacksonsan]

Originally Posted by manaswee

I will do it at every 30k as you have been doing, for sure.

Another convert to fresh trans fluid!

[Mad MacGyver]

After working on my transmissions since '75 I can say that newer trannies have way different issues:
1) - New trannies have way smaller oil filters designed to starve the tranny at 160,000Kms /100,000 miles, so you have to change it or delayed shifts and damage occurs (GM 4T65E, etc)
2) - You want to get inside and also clean off the magnet in the pan, after a while it's so loaded to doesn't pick up metals as much anymore.
3) - I've carefully reused old Tranny oil if it's not burned or dirty, there's no combustion process or blow-by to mess up the oil.
4) - New trannies have shift solenoids soaked in oil that attract metallic particles and stick to it or the armature inside the solenoid if the filter and magnet have not been serviced on time. (solenoids are electromagnets!)
5) - SeaFoam 'Trans Tun' actually helped several GM 4T65E trannies after all the stuff above was done, so I keep a spare can on the shelf for next time.
COMPARED TO OLDER TRANNIES:
I drove MoPos with 318 V8s and TorqueFlite 727 tranny for 25 years, never needed repair. New cars designed to force a service interval, shallow oil pans prevent setting, thus filters 'load up', filters are way smaller too and are placed low so they sit right at the bottom of the pan. The TorqueFlites where the exact opposite!

[sljs]

I just changed my trans fluid today I have a gm4T65E. Mad your right shallow pan and magnet was coated. Now I can hardly feel the shifts it was slipping a bit but its gone now. Van had 85K on it.

[Mad MacGyver]

Originally Posted by sljs

I just changed my trans fluid today I have a gm4T65E. Mad your right shallow pan and magnet was coated. Now I can hardly feel the shifts it was slipping a bit but its gone now. Van had 85K on it.

Glad it worked out!! The key issue is to replace the GM tranny filter, they load up real easy, all they have to do is 'restrict' pump suction just a little and oil volume to the accummulators that are used to make instantaneous gear changes will cause delayed shifts and a nasty hard shift that will cause damage!

Update: I dropped the pan again on my 4T65E after 30,000 miles and put in 3 more magnets to try catch all the wear metals from the gears, filters cannot catch any of it! The OEM magnet is just barely adequate! Make sure the magnets are low profile so they don't jam up against anything when you put the pan back on. Check out my pal's GM dealer fraud website (download page) where we test products, do oil analysis and check out various auto myths: www (dot) wilsonniblett-ripoff (dot) com Lots to come in the next few months!