So my friend just bought a 97 extended cab F250 with the zf-5 transmission.

The issue for me is that his truck is WAY more quite than mine during driving and it's making me jealous! Okay.. so it's not quite like my truck is yelling at me, but it is significantly louder than my friends truck! I think this mostly has to do with him having a dual mass and me having a single mass, but there may be some other things in play as well. I do NOT have a muffler installed, but I don't believe he does either, and I don't think the loudness is my exhaust, but more so my transmission/engine. If I press on the go-pedal harder and the boost kicks in, my truck gets considerably quieter. It also seems to quite down a lot if I'm turning on a bend on the highway (I guess for some reason the sway of the truck aligns something where the transmission doesn't want to grumble so loud?)


Do the powerstroke trucks have some extra sound deadening/shielding compared to F-150s/Broncos of this era? I do have my truck lined with dynomat type material (the home depot brand ), so that's already done.

I also have tried filling my transmission with one extra quart of fluid to keep the sound down, but it didn't seem to help any.




What are some tips you guys have so I won't have to be on the verge of yelling when I want to have a conversation on the highway?


Should I try adding more transmission fluid and if so, what type and how much?

Should I try adding some foam under my vinyl flooring?

Is there something I should try and coat the truck underneath with?


Should I try a burnout and break my axles/driveshaft instead since I still they are still the 1/2 versions? (The answer here is no.)

And just so you guys now, ear plugs aren't an option! Any insight on this dilemma would be greatly appreciated!

 

Sounds like you body bushings may need replacing, I have mine already just to lazy to replace them.

 

Hmm I didn't think of that. I suppose that could make some sense since the transmission grumble disappears when I'm turning on a bend at highway speeds.

I don't know if that would help reduce any noise I'm having though, but I'll look into it.

Those bushing have over 130k miles and 10 years on them, or maybe are the stock ones (so like 245k miles then and 20 years). I don't know if they were replaced when the previous owner put a lift kit on the truck so if not, then they probably do need some replacing.

 

Just remember that polyurethane bushings are harsher than the OEM rubber.

 

Yeah that's right, my truck is already a pretty stiff ride, so I may go with oem rubber if they are in need of replacing.

 

Is your DP rubbing the firewall?

 

That's a good question I'll have to look and see if it is. I did have to bend part of the firewall out of the way for the 3" downpipe that came off the F250 so I may not have bent it enough. That could also explain the noise quieting down on bends (it seems like it's mostly right bends as well).

With part of my wisdom during the firewall bending, I almost broke my fingers so I decided to call it good after that. I was having my friend push up a bottle jack on a large pipe I was holding at the lip of the firewall that needed to be bent. It so happens the pipe wanted to bend out and squish my hand between the oil pan after a while instead of continuing to push the firewall back. Bottle jacks don't release very quickly either so that was fun.

The loudness isn't like a banging or anything though. If I never read about the single mass flywheel setup being louder due to the transmission "grumbling" (I forgot the exact term), then I would assume the noise was just the engine being very loud, but under mid to heavy throttle and taking bends at highway speeds, it quiets down considerably.

I was looking up dual mass flywheel setups today at work thinking I may switch to that to quiet things down thinking that was the cause of my truck being louder. Once I saw a few prices, I quickly ditched that idea. I need to save up for E-fuel to rid myself of fuel leaks, and would rather not spend 700+ on a new clutch kit when my current setup is basically still brand new.

 

These darn DP's like to move after being installed the first time. Turns, I mean bends lol, can make it rub or not.

 

also door seals can let a lot of noise in,
but as Glenn said check down pipe if it is rubbing on firewall seam it is real loud also loud if rubbing on transmission.

 

Not that this is making the noise you're hearing but you can put some additives in the fuel to help quiet the engine a bit. I was turned on the witches brew and I swear/think it quieted the truck a bit.

1 ounce per 4 gallon of diesel kleen and 1 ounce per gallon of 2 cycle oil. I know others use similar mixtures.

 

Well the dowpipe isn't rubbing on the firewall, but there is a heat barrier attached to the transmission tunnel/bottom of the firewall it is rubbing against (which I may try and push out of the way a little) and also the corner of the transmission. There is a little square section of the ZF5 that sticks out the the pipe is pressed against it pretty hard. If I push up as hard as I can, it does move off the transmission very slightly so I'm going to see if I can use a jack or something to bend it out of the way.

I think that may explain why the noise seems to go away when I'm taking right turns, it probably lifts the motor just slightly enough for the pipe to get off the transmission. I'm kinda surprised though if that's what's making it so much louder, but would be pretty excited if it was as "easy" as bending that pipe off the transmission.

Maybe I can get lucky and loosen the turbo downpipe bolt and adjust the pipe off the transmission(the downpipe is welded to the main pipe. I had to cut it out of the F250, but the section that is cut is about 3 feet down near the transmission cross-member so it's pretty much a solid piece.)



Edit: Well I'm not quite sure if that is it. I did manage to move it off slightly, but the noise didn't change at all. After driving, it did look like the pipe may have gone back down to it's original position though.

 

I kinda like it when my DP rubs the firewall.....

 

That part on the trans is usually grinder away by most when they install DPs. It is a known rub point.

 

Depends on who is doing the rubbing!

 

Yeah I wish I read about that before installing everything. IF possible, I may try to squeeze the pipe up with a jack, then take some flat file or sandaper or something and slowly file it down until I cen gut up there with something a little more powerful.

I'd rather not take the transmission down to try and grind that away... I had to use several ratchet straps and my jack to put the tranny in and it took a little while. This transmission is a little heavier than the M5OD gas tranny that was in here before!