Hissy fit

[RidnRed]

I've noticed my '92 5 speed trans hissing at me in all gears except 4th, I pulled out the carpet about a week ago for floor pan repairs and heard it. Oil is good, clutch in or trans in N and the hiss quiets up, but doesn't go away. 4th gear is quiet as can be. Ideas?

 

[LIMA BEAN]

Must be a female transmission if its having a hissy fit. Is the vent partialy clogged maby?

 

[budro]

Possible that is the throw out bearing? I know they whine or make a hissing sound. Especially when you step off the clutch. If you step on the clutch and it goes away then thats probably what it is.

 

[RidnRed]

Good ideas, thanks guys, i've suspected the release bearing for a bit, but its quiet in 4th and makes no extra noise if I ride the clutch a bit, wierd. It almost sounds like a hole in an aftercooler hose, but that'd mean i had a turbo. Anyone else?

 

[scotts90ranger]

How many miles? If it doesn't do it in 4th as much it's probably the layshaft bearings or otherwise internal in the tranny...

 

[RidnRed]

135,000. I've always used the mercon, but i'm sure there is something better to use. I'll drop the oil today and have it analyzed, is there any brass bushings or plain bearings in these? I'm sure theres brass on the sliders right?

 

[scotts90ranger]

the only brass in the tranny is the synchro's (ok, probably some brass bushings on the shift rods but I didn't look as mine were fine), everything else is ball or roller, sliders are steel on steel

 

[john weeda]

How many miles? If it doesn't do it in 4th as much it's probably the layshaft bearings or otherwise internal in the tranny...

This is your problem 4th gear is is one to one direct drive so that bearing dose not spin only in 4th gear! keep it lubed you can even over fill your trany by .5 letter or so to keep this baring right in oil. do not over fill to much as your trany can then over heat if the oil dose not splash on to the case to cool it.

 

[RidnRed]

Good info, thanks. I'm gonna baby it and wait for it to get worse, which may take a while, I just finished putting my interior back together and I can't even hear it now... so it's probably been making the noise since I bought it.

Anyone know if there is something better to use in it besides mercon? I know thats what it calls for, but I want to see how far it wil stretch before it breaks...

 

[Earl43P]

Synthetic ATF.

 

[4x4junkie]

Is it possible you're just hearing normal tranny noise since you didn't have the sound insulator (that big rubber piece) and the carpet in place?

The M5OD isn't exactly a "quiet" transmission, however most actual concerns can usually be described as a whine or howl, not a "hiss" (plus you said the fluid still looked good).

 

[RidnRed]

I should've specified, the oil level was good, when I dropped it it was a bit dark with some fine brassy glitter. Also the magnet had a good coating of fine shavings, no chunks... I bet it has been making this noise for a while, so I'll milk it and see what happens.