Bronco II "weird" Trans Noise

[Nathan123]

Could it be the driveshaft clicking? Mine did it only under medium accelerations, not while cruising or idling around. I doubt that a u-joint style shaft would make a clicking without vibrations, so this is only an answer if you have a cv style shaft.

 

[PetesPonies]

Vibrations are difficult to find. The factor that might cause the vibration can be specific to many things, rpms, vehicle speed, gear reductions, harmonics etc. So don't rule out an exhaust noise because you can't reproduce it at idle.

As for needing a cat for the sake of mankind . . . jeesh

 

[unoleisu]

It might possibly be the Torque Converter. Inside the TC are empeller blades that are often rivited in place, the others are spot welded. They have been known to come loose, and gradually create sounds like you're describing. When they finally come loose, it trashes the TC, and sends metal shavings through your tranny.
Before you panic about that, do as sudgested, and crawl around under the truck trying to find loose stuff. It took me awhile to finaly descover my muffler was actually rusted out on the intake side. That, after welding the crap out of the heat shield on my Cat, that was also loose and rattly. (I only heard the rattle from the muffler occasionaly, on acceleration).

 

[unoleisu]

Save the children of the future from global warming, use a catelytic converter!!!
oh, sorry, global warming already started. never mind.

 

[BIICory]

SO i was underneath earlier and shaking/pounding like mad. Nothing seems loose, vibrating. I grabbed the driveshaft and it doesnt budge at all. it could possibly be the torque converter? i may change my tranny and torque conv fluid soon just to see if that changes anything. But its just nothing violent. Just noise. Not a vibration at all. SO maybe it is exhaust related. How does one troubleshoot though?

 

[unoleisu]

Did you check up front at the warm air intake to the air cleaner box? The thin metal intake that fits around the exhaust manifold on the pass side can get loose enough to rattle a little, as well....

Trouble shooting an exhaust rattle is not my cup of tea. Start at the front and work your way back. use a rubber mallet to bang around on it. (that's what I did, besides banging on it with my hand)
When you check your tranny fluid, your gonna be watching for tinny metal flakes in it. I use a small mag light to shine into it at different angles. If you see anything like that, you may have a problem.

 

[BIICory]

I removed that warm air intake when i durasparked it. It was rusted through and i was able to just pull it off. Im off to bang on the exhaust now, and maybe change the tranny fluid later. Ill try the mag light trick when i do it. Ill keep updating as i rule this out

 

[BIICory]

SO.. Was really banging around today with a mallet and everything seems pretty darn sound. HOWEVER, there is seemingly something sligtly loose in the muffler. It isnt an expensive muffler. Just one of the ones with edges curled/smashed around so they seal. not welded muffler. It takes some effort to create sound, but its there. So no exhaust noise at idle, but in gear? that would be considered normal?

 

[unoleisu]

Could be it. I don't know of a good way to check it beyound that.
Maybe:
1. stretch a hammock under the truck from bumper to bumper, and get a trusted friend to drive while you hang out under there checking it out....(you should video this if you do, we wanna see it)
2. get in a manhole and listen as it passes over you...
3. put it up on stands and listen from underneith while someone runs it through the gears....

Seriously, all kidding asside, I'm outa suggestions at the moment. I do want to see a video of #1 though....

 

[CHKNFKR]

put it up on stands and listen from underneith while someone runs it through the gears....

I've done that many times. Still if the noise only occurs under load this will not narrow it down one bit.

 

[Andy D]

Turn up the radio. I know I'm a big help. This problem will get louder if it is the exhaust. If it is the torque converter or the flex plate, you will know when the truck wont move.

 

[BIICory]

Today i changed the trans filter and pan gasket.. Fluid is clear with no shavings and smells/looks normal. Boy was changing that a PITA. But today i ran it through its paces with a buddy in the back. seems like the noise IS coming directly from the muffler area. definitly on the passenger side rear.

I guess im going to buy a new muffler, as ive been wanting one with a bit more sound anyways. Its sure not going to hurt. I can get dynomax on the cheap... Whats their quieter muffler out of the set? Thanks for the help. Pretty much eliminated the trans/converter possibility. And thats a weight off of my chest for sure

 

[joenorthcarolina]

I'm new at this so don't make me feel too bad if my guess is somewhat dumb.
However, is it possible the trasfer case could be slipping ? Second guess, the front dog bones maybe clicking ?

 

[BIICory]

Nah, theres really no clicking. Thanks for your bit of wisdom though! it all helps. Transfer case is fine. Pretty sure its exhaust at this point. Got a thrush welded muffler and will be putting it on this week. hopefully thats indeed the issue. if not, then i just have a better muffler anyways!

 

[Swepper]

does your driveshaft look like this? thats what i had when i bought mine, clicked and vibrated under acceleration only..went to jy bought a rear driveshaft out of a 90 bii u joint style fixed my prob.

http://therangerstation.com/forums/attachment.php?attachmentid=6369&d=1322685669