96 F-250 4X4 7.3L Trans noise-has solid flywheel.

[ktmlew]

Just put a LUC clutch & pressure plate in. Customer had previously replaced the dual-mass with a solid flywheel and LUC clutch several years ago. Fired it up and in neutral it sounds like an old Muncie Rock-crusher X 20...I think it's "neutral gear rattle" as GM calls it. The trans makes no noise when driven except when creeping in 1st gear. You CAN make it do it, but it seems to be a harmonic vibrating noise? The trans does appear to have 90wt in it so that probably hasn't helped the internals any...

 

I've never messed with one of these that were converted to a solid flywheel. I suspect the clutch sprung hub itself is the problem. Going to take the truck to the place he bought the clutch and let them listen to it...I couldn't stand to drive it myself. It would set you crazy at a drive-thru...it's louder than the knocking/rattling converters on the automatics.

[DwayneGorniak]

I would have to say it is probably the damper springs in the clutch disc. Did the clutch sound O.K before you replaced it? I have installed Luk single mass systems and never had an issue with them.

[ktmlew]

Was towed in with an exploded throw-out bearing. I disabled the clutch pedal safety switch so it would start and drove it in but it was screaming so bad from the TOB you couldn't tell what it was doing. The last time I saw the truck, couple months ago, it wasn't this noisy. I also believe it's the disc. Will see what the seller of the parts has to say...not looking forward to crawling around on the floor doing it over again...SOMEBODY will pay!!!

[DwayneGorniak]

If my memory serves me correctly, you can fire these engines up with the tranny out. Doesn't the starter bolt to the rear adaptor plate? /forums/images/%%GRAEMLIN_URL%%/scratchhead.gif I know I have had 7.3's running with the tranny's out. Man It's been a while. /forums/images/%%GRAEMLIN_URL%%/scratchhead.gif

[Bruce Amacker]

I have had excellent luck with Luk products and installed more units than I can count. Being local to one of their main engineering facilities proved great, and we were able to install "test" units that were not available to the public. We even participated as a Beta installer for their solid flywheels many years ago, long before they were available to the public. When you call their tech support number, it goes to a location 2 miles down from my old shop and the guys there knew/know more about clutches than perhaps anybody on this planet. Call their tech support number at

 

 

http://www.lukclutch.com/support/diagnostics.phtml

This web site is designed as a resource for the technicians who specify and install LuK products throughout the United States and Canada. Technical product support is available from 8:00 a.m. to 5:00 p.m. EST by calling 1-800-274-5001.

 

 

BTW, get a copy of their clutch catalog mailed to you. There's more tech tips in there than you'd ever believe on weird stuff like bleeding hydraulics and diagnostics.

 

Good Luck!

[ktmlew]

OK...Asked a couple of local techs to listen to it...they ALL said trans input bearing so I drained the trans in a clean pan. No metal except for enough "dust" to cover your little finger nail. Pulled one of the PTO covers. Everything looks fine, no excessive "slack" in the input/cluster gear when checking for "backlash". Trans tag shows it was a Ford re-man from 05/00.

 

Took truck to local Cottman Transmission Center for him to listen to it, buddy of a buddy deal, so I trusted him to shoot-me-straight. He says it's not trans related feels it is NVH noise. Cottman guy happens to be a Ford senior Master & Diesel Certified so? You can raise the idle about 100-150RPM and it goes away...drove it to the parts store to let them hear it. They called tech support and the guy basically very nicely blew-me-off...said either I assembled something wrong (disc backward and springs were hitting crank bolts, that would make other noises IMO...) or the trans bearings were bad. He could hear it over the phone.

 

So tomorrow I pull it out again...the parts store wants me to bring everything back, including the old parts, so they can look it all over. Found a local place I can buy trans parts from, so if nec, I guess I'll pull it apart and replace the bearings. Wasn't really wanting to do that...landlord just got a big excavating job In GA so now we have a bunch of equipment to get ready to work...I'm tempted to send the truck to the trans shop if I don't find anything in the clutch. Just don't really have time/interest in rebuilding the trans. From what I understand these require several special tools and good press for disassembly of the mainshaft? Plus I have no access to manuals now and really like to KNOW what I'm taking apart...

[DwayneGorniak]

Do you remember if the starter bolts to the adaptor plat of the engine of to the tranny itseld? Gail, if you're going to pull the tranny out, try to run the engine with the clutch still bolted up. If you hear the rattling, it is definately not in the transmission. Just make sure your fan is not hitting the shroud. You may have to support the engine somewhat.

[ktmlew]

Well? The noise IS from the trans but it seems to be the gears rattling. When you raise the RPM's to 700+ it goes away. NO unusual noise in gear and under load...

 

I can start it with the trans out. Will know something in a couple hours.

[mchan68]

If my memory serves me correctly, you can fire these engines up with the tranny out. Doesn't the starter bolt to the rear adaptor plate? /forums/images/%%GRAEMLIN_URL%%/scratchhead.gif I know I have had 7.3's running with the tranny's out. Man It's been a while. /forums/images/%%GRAEMLIN_URL%%/scratchhead.gif

That's only on automatic equipped trucks. Manual transmission models didn't use the adapter plate on 7.3L engines. On the 6.0L, the rear engine cover IS the adapter plate for both automatic and stick.

[ktmlew]

You CAN start these. I put two bolts through the adapter plate so it doesn't move when the starter "hits". No noise running engine with trans out. Took clutch back and they said everything looks fine and all is normal. The clutch I just put in, is a new version of the replacement kit, that is a heavy duty dealio. So who knows...

 

Stopped at Ford dealer in Hickory NC and talked to their ZF trans/diesel tech. He said he didn't think I would be able to get rid of the noise by "replacing trans parts" but the 5spd version of the ZF's aren't at all difficult to work on if I wanted to open it up and inspect everything...

 

Found this info (page 7) which I happen to agree with:

 

http://www.zf-group.com/pdf/S5-47.pdf

 

So far...

 

1. Cottman trans guy listened to & drove truck-said NOT trans problem-NVH "problem" due to clutch/normal vehicle characteristic/don't worry about it.

 

2. Clutch shop (Carolina Clutch) called "their" trans buddy...he said they are known to burn up the cluster gear if the wrong lube is used and that was the problem...see page page 9 of above...which is what I told everyone that said "trans bearings/gear wear", it should make noise UNDER LOAD in 3rd & 5th if the input & cluster are worn!!!

 

http://www.transmissiondigest.com/tech/TD200604/UpToStandards/Up%20To%20Stds%20HTML.htm

 

Check this paragraph from above site...I know they are talking about the 6spd but still same effects from torsional vibration.

 

Quote:

Outside of the fact that they are heavy and require a few essential tools to rebuild, these units are no more difficult to work on than the earlier ZF five-speeds. One of the diagnostic issues to consider is that these units are used behind diesel engines. As a result, they are prone to gear rattle or neutral-rollover noise. You can save yourself some lost time and increase customer satisfaction by understanding the cause of this type of noise complaint.

Gear rattle occurs because engine harmonics are transferred into the transmission, causing the gears to rattle at idle or during acceleration. A quick test for this is to slowly increase engine idle in neutral and note at what speed the noise goes away or floats out. If you can rev up the vehicle to 2,000-2500 rpm and the noise goes away, the problem is not in the transmission. Look for a bad dual-mass flywheel, worn or damaged clutch damper springs, an incorrect clutch for the application, an out-of-time injector pump or a problem with the fuel injectors.

Gear rattle will not damage the transmission but will bring in customer complaints. Taking the transmission apart will not solve the problem. If you want to see it in action, drain the oil from the unit and remove a PTO cover with the truck on a lift. Start the engine in neutral and you can see the gears shake and vibrate as the engine harmonics give them an epileptic fit. A careful evaluation of the clutch components and the timing of the diesel power plant will end the problem. If the noise does not go away with an increase in engine speed at any point, the problem usually will be internal, as gear damage and bearing noises only get worse with speed increases.

 

So...I'm waiting to get some bucks from the trucks owner...probably going to take the trans to a local shop that has a good rep for being honest...just talked to them. They have a way to dyno the trans to check for noise/problems. Costs $150.00 to dyno it. Tear-down cost to inspect is $300.00 and he recommends replacing the syncros at least due to the use of the wrong lube...

 

Geez...this is EXACTLY why I got out of this business...at some point you "age out" of knowing

everything. Then you just hope you can find someone that does know SOMETHING?

[ktmlew]

OK! Customer says button it up and he'll run it till she blows! I just hate spending someones money when I'm not SURE it will fix the problem. So I agree with him. Let-er-eat! /forums/images/%%GRAEMLIN_URL%%/rockon.gif

[Brad Clayton]

when they went to the 6 sp in '99 is when they did away with the adapter plate requiring you to unbolt the starter to get trans out.

[Brad Clayton]

Quote:

he recommends replacing the syncros at least due to the use of the wrong lube...

Them synchros are pretty damn expensive if you get em from ford, I don't think I would just throw a set in there.

[Keith Browning]

Years ago a guy came in with his pick-up after having Jiffy Lube change ALL of his fluids. They even changed his ATF to gear lube in his ZF trans for him. How nice of them! IT wouldn't shift so I doubt anything happened as a result. I changed the fluid, actually driving it and changing it again two more times before it shifted right. Point is, it was fine after a couple of changes and fluid changes are way cheaper than syncros it probably doesn't need. /forums/images/%%GRAEMLIN_URL%%/wink.gif

[mchan68]

They even changed his ATF to gear lube in his ZF trans for him. How nice of them! IT wouldn't shift so I doubt anything happened as a result. I changed the fluid, actually driving it and changing it again two more times before it shifted right.

Jim would love me for this, but I would definitely call this RTFM, or as Jim would call it, "the world's most expensive unread book".

[ktmlew]

Years ago a guy came in with his pick-up after having Jiffy Lube change ALL of his fluids. They even changed his ATF to gear lube in his ZF trans for him. How nice of them! IT wouldn't shift so I doubt anything happened as a result. I changed the fluid, actually driving it and changing it again two more times before it shifted right. Point is, it was fine after a couple of changes and fluid changes are way cheaper than syncros it probably doesn't need. /forums/images/%%GRAEMLIN_URL%%/wink.gif

The way I look at this...some of this is "common sense" diag. IF the wrong lube has "damaged" anything in this one, I would see other performance issues. Seems this is a normal performance characteristc of the vehicle but I just have never heard one make this much noise that wasn't spinng a PTO?

 

I told the customer, "if we replace all the bearings, input shaft & cluster (IMO the input & cluster HAVE to been worn SOME from harmonics) I would only expect maybe a 30% change in the noise"...of course that is just my gut feeling. It needs a 70-80% change to make "me" happy or consider spending that kinda "Jack". The trans was re-maned 5/00 and he "went away" for several years so it doesn't have a ton of miles.

 

I will snap a couple pics of the clutch dics...the new disc has twice ans many springs as the old style. They claimed the old style tending to collapse the springs and they would fall out. They claimed the new style is same design as the "over-the-road" trucks are using now. I STILL think the new style is too stiff in the sprung mechanism, but what to I know...???

 

If it seems like I'm obsessing over this, it's cause I am! /forums/images/%%GRAEMLIN_URL%%/whattodo.gif I like difinitive answers! Not opinions but "answers/facts"...

 

Run-er-till-she-blows is our motto!!! /forums/images/%%GRAEMLIN_URL%%/rockon.gif