I've noticed a sound coming from the tranny area of the truck almost exhaust part of the truck and i cant figure out what it is...
Its kind of like a grumbling grinding sound only when the truck is warmed up full running temp and in Drive. doesnt do it in any other position just Drive. its grumbling grinding when idling and gets worse when i give it gas from 1k-2k rpms. anyone have any ideas what this could be? i know its hard to tell without actually hearing it. also its a 99 3.9L 4x4

 

I have the same sort of problem.. Had the same problem in my 81' Ford F100... Kinda sounds like exausty grumbling sound..

Kinda hard to explain.. But I know what your talking about.. I would presume your hearing the exaust pipe being it runs right through there.. but I'm not sure.. could just be the sound of the tranny.. Torque converter?

I know mine has a bad converter I think, kinda got a jerk/shake/lope/ feeling right as you come to are from a dead stop with no gas given.. when you kinda roll or creep.. then kinda feel the same feeling when going up a step hill with out giveing it more gas..

if you find the cause.. let me know :P

 

Yeah I can't hear anything through the exhaust pipes themselves but like I said it's only while in drive which boggles me. I noticed when I'm trying to go up a steep hill it wants to keep shifting around and not just stay in a higher gear and when I'm coming to a stop it does a little lope right before a stop but I just assumed it was the tranny shifting from 2nd to 1st. Is there anyway to check if it is the converter? thanks for the help!

 

but also if the tc was going bad wouldnt it be stalling on me when its downshifting? i did a little bit of research on bad torque converters and it seems like different symptoms than what im having.

 

I asked the same question and was told to pull the trans to get the converter out and they have a machine that can test it.. but again your talking about dismounting and pull the trans..

Sounds kinda like my same problem..

You let off the break from a dead stop and feel a jerking, loping feeling like it wants to go but then it kinda doesnt? Also approching any low speed when you take your foot off the gas?

I've had this problem since i got the truck.. which is only a few months.. the mechanic could not find any fault motor wise.. if you watch your idle pully.. (forget the right name) you will see it kind jerking.. in park.. I think the converter is not releasing fully or engaging fully.. and think this is the problem..

Sometimes when backing up.. shifting out my drive way and shifting into drive sometimes the motor stalls.. sometimes i can give it gas and it wont stall.. one time.. i shifted to Drive and there was nothing there.. then it kinda engaged.. not the actual shift but rather the transfer of power..

Latley It seems its is shifting weird.. kinda wanting to float between 2-3 which I feel it is all related to the torque converter.

There is a TC mod about a clutch that smooths shifts or what ever.. I am thinking about doing this mod by disconnecting the wire that controls that 'clutch' and see if it resolves.. if it does then thats the problem.. directly.. if not.. I think its still the Torgue Converter it self..

Being we have similar issues we should stay in touch until one of us resolves.. hit me up with all the information on what you have done already and i will do the same..

 

Well I just talked to a life long Transmission guy.. I trust the guy and I know he's half way decent he diagnosed my Brother-inlaws Chevy in about 10 seconds flat.. told him what was wrong.. brother-in law took it strait to the dealer and confirmed the problem.. saved about 2 days of triage.

Anyways.. he basically flat out told me everything I described with 'mine' sounds like TC.. But.. could be though the TPS (Throttle Positioning sensor) sending incorrect voltage if its going out..

What he recommended first was a few things..

1. Drain and change the Tranny Oil Filter/Fluid as long as the fluid is at least a light pink color and not a dark dark dark dark reddish black.

2. While in there adjust/tighten the bands as the service manual out lines for..I forget somwhere between 97,000 to 130,000 it says to do this..

3. While in there see if there is 'sawdust' looking stuff in, coming out of the tranny/filter fluid.. (Not metal shavings but more sawdust..) if yes.. then that TC Clutch thing the TC Mod talks about.. is bad.. as they start to break down literally when they go out.. (problem found)

If no continue on..

4. Check/Replace the ICS.. if the problem persists after all that.. Torque Converter is the likely culpret..


TC going bad will not necessarily cause the engine to stall.. low RPM maybee.. but under driving.. it will just make the transmissing kinda float.. if you will delayed ****/hard shift in first and so on..

But as he said that just could be the bands.. the whole problem might just be the bands.. and he is recommending first to adjust/tighten and do the service work on the tranny first.. then go from there.

As far as the TC MOD.. he told me that was a very bad idea to disconnect that.. as that is basically what Ford Uses.. on their old C6 Trans. to disengage while it shifts.. other wise your going to shear your gears over time, overwork the trans or just plan throw a gear out..

Just his opinion..

 

Wow thanks for the info. Good thing you know that guy haha. What exactly do those bands do? I've never really heard of them. My tranny fluid right now is like a rich pink color right now so it's not too bad but I plan on staking and filter change along with rear diff drain and replace too.
As for my truck. I took it to Goodyear yesterday because I've been leaking a pinkish. Color for sometime now and they told me it was my front pinion shaft seal was bad so I hAd that fixed and they told me it was my catalytic converter that was bad. I guess when it's in drive the back pressure is different and that's what's causing my grumbling sounds when I do a lot of non stop short trips. And for when it was bogging down on me, it was the cat getting clogged for a moment.
Luckily I live about 15 minutes from the Ohio summit racing store and I have a friend that works there to get my some front stock shocks and a magnaflow hi flow cat for cheap. I'm glad it's not my TC so good luck with yours. That will be a pita if you drain the fluid and all then still eventually have to drop the tranny for the TC. Let me know what happens with that and I'll let you know when I get a new cat on and if it fixes my problem.

 

Hmm.. Interesting.. I would asume though if it was the CAT, it would run like crap worse when you gave it gas and put a strain on it.. but IDK.. maybe giving it throttle masks it.. Thats something else..

While i was on my long trip over the hills and through the woods.. when i kinda got the feeling it was lightly doing it.. I came to think perhaps its not just at low speeds, that is just when i can feel it the most.. perhaps its doing it at all speeds.

Anyhow.. please let me know when you get that Cat replaced if it fixes the issue I'll be sure to get mine checked. So far I have not had any signs it has a problem.. but who Knows.. LOL

As far as the bands.. per the manual your supposed to adjust them in the 100kish mark as part of the servicing. Not sure how you do it.. gonna look it up..

 

OH.. btw.. see how much a second one be.. :P maybee work a deal out.. ?

 

yeah im waiting to hear from him about some prices. yeah its making that sound at all speeds usually \really bad at 1k-2k rpms when i just give it a little throttle. plus gas mileage has been around 13 when theres no snow on the ground and around 11-12 when theres snow and ice just due to a little drifting here and there haha. so hopefully the new cat will help out with that. i've got a flowmaster exhaust and dual pipes so the hi flow cat will be a nice compliment to that. plus the truck doesnt seem to have all the power it should have. i'll let you know whenever i get it and throw it on there and see how it helps out. and i'll find out about possibly getting two if you want one and we'll figure something out with that.