need some direction

[payrion]

OK first off ...whats up guys.... i have a 91 MM 2.4 auto, its dropped and will be bagged as soon as we get the little problem worked out, history...... i have not had OD for some time, just fixed it tonight by grounding the plug in the engine compartment, thats fixed... WELL 3 weeks ago a noise has started... bear with me.... when i drive at 20-40 and let off the gas i get a noise, its between a HOWL, A MOTORCYCLE DOWN SHIFT, and A TORNADO SIREN..... it does it till i stop, i don't hear it when gassing it. after the truck warms up it seems to get better but still there, tonight i jumped in the bed and had the wife whip around town, it wasn't fun, so i can try to hear where its coming from, i couldn't hear it, but she did in the cab.... i changed the rear diff fluid, n o change, i replaced the tranny filter and changed fluid., if i cant figure something out ill take it in but i don't trust any shops out here. i just thought id throw it out here and see what i catch!

[raidinator]

welcome buddy. Honestly i have no idea what that noise is. my knee jerk reaction is a spun bearing somewhere in the tranny, maybe the tail shaft region if it sounded like the rear diff was even a possibility. I Like the idea of putting the little lady in the drivers seat and listening with a screw driver for vibrations (long screw driver, handle against the ear blade against solid object. If you didn't get what i meant) It's weird that ti's not going on outside of 20-40mph.

The thing is regardless of the cause, almost all possibilities include pulling the tranny, and rebuilding it at least in part. i say get a junk yard trans (rebuild it if you have green) and just swap them out. I think you'd have more success per hour than trying to fix a specific part. I vote either run it till it blows and swap or just swap trannys this weekend. anyway that's my 0.02

good luck buddy

[pennyman1]

Check your carrier bearing; its right at the back of the cab and would radiate noise into the cab but you wouldn't hear it from the bed due to road noise. You might just need to grease it; just drop the whole driveshaft, separate the 2 driveshafts at the bearing, and use a needle attachment to a grease gun and pump grease into the openings on both sides of the bearing and reassemble. if the bearing has dropped in the rubber or is flopping in the carrier, it needs replaced, they're on ebay for 50.00 and up. Its also a good time to check the ujoints for grease and add as needed.

[payrion]

this is a 1 piece shaft. well today i drove it and it only did it a couple of times, its not exactly between 20-40mph, i was just throwing up numbers. but it doesnt seem to do it until i start slowing down, and it is only when i let OFF the gas. its shifting very nice and the fluid isnt burnt smelling. i wish i could ride under the truck to hear this...lol well keep throwing up ideas and ill keep checking. im feeling its the tranny going out myself but if there is a chance of anything smaller then im all for it.
What if, now im not sure i can do this so please dont FLAME me.... can i drop the drive shaft and run thru gears and see if it does it?
like i said, im only hearing it when i let off the gas, but the truck isnt quite when im gassing it, so it might be doing it then too,well we will see....

[payrion]

OK, sorry I'm beating the hell out of this fourm..... i just took a 30 mile drive, i payed very good attention to everything happening and logged it as i went
1.... i am hearing this sound at all times, accelerating and braking at at all speeds its just louder at the lower speed with foot off pedal cause less road noise and exhaust noise
2.....it gets higher pitch the faster i go and quites down some with speed
3.....i can shift to neutral and it still does it
4.....i can drop it in 2nd or L and it still does it.
5.....when i manually change to 2nd or L or it automatically changes gears it doesn't change the sound, gears shifting doesn't influence it at all.
6.....right before i stop i can slightly feel it in the brake pedal, i mean right at the stopping point.
7.....turning, hitting bumps... nothing like that influences it.

its actually my wifes truck, i have an s10 bagged and bodied, i told her no bagging this till we have it running in top notch condition, so I'm really trying here for her.

could it be the rear end, i changed the fluid a few weeks ago. maybe wheel bearings, i just don't want to be told tranny...lol
also great forum, i think ill stay:)

[payrion]

i have another question, the truck has an A500 42re tranny i believe, well there are jeeps and dodges that have the same model...a500 42re, are they the same tranny, can any a500 42re be installed?

[pennyman1]

That it not an A-500 mopar tranny, it it a japanese tranny made by aisin for mitsubishi. It does sound like a rear end bearing issue; is it a hollow sounding noise? For info on the tranny, try Force 10 transmissions, they have parts and a shift kit for this tranny.

[payrion]

not doubting you at all since im totally new to these MM... but when i got the tranny filter and gasket it was listed as an a500/42re, and when i almost bought a new on on line last week it was listed as that as well.. now please explain, i looked up on ebay for a MM transmission and thats the id tag for it. it shows in like 1990 they changed to the a500, i could be totally wrong but ive spent hours upon hours searching for info on my 91s tranny.

[DroppedMitsu]

Look on the pass side of the engine side of the firewall and there is a metal plate, will tell you the transmission that is in the truck.

[payrion]

well another troubleshooting update, still dont have a clue but..... i put up on stands and ran the hell outta it and no noise...... can someone tell me then... does that mean maybe my terrible tires or maybe wheel bearings? but i ran the shit outta it up on stands and it sounded real good.....