Engine/Transmission (1994 - 1998) Clutch Change = LOUD Inside Truck?

[Mike Ellis]

My truck has 207K miles on it, and since I am planning to take my camper to the mountains this summer I decided to have a new clutch installed. The clutch that was in it had at least 160K miles on it (I know that for sure 'cuz I've owned it that long) and was driving fine. I figured since the engine was broken in now, I'd go ahead and upgrade to a stouter clutch in prep for bombing - truck is still stock.



So I go pick up the truck, shop is closing and the mechanics are screeching off into the distance, and after getting out of the lot and cooling down the interior I roll up the windows and immediately notice it is LOUD inside. Wasn't loud when I drove it in. Unfortunately by the time I turned around and went back they had all skedaddled and I had no one to answer questions.



What could they have done to make the truck loud like this - is there some insulation on top of the transmission or something, or a cover for the shifter opening?? Sounds like a paint mixer.



Wha hoppen? :{ :{

 

[hsmith]

No insulation involved, just the shifter boot below the one you see. Not sure what may be your noise problem.

 

[HBarlow]

What do you hear? Exhaust noise, gears whirring, etc? Is the noise coming up through the center transmission hump or ... ..... ?

 

[Vaughn MacKenzie]

Had the same thing happen to me, after a clutch job I had lots of road and engine noise as if there was hole in the floorboard. The inner boot was still there but I think there's some sort of insulation that goes under the inner boot but I just stuffed some foam in there and it helped but not as good as it was. Went back to the shop but they seemed clueless as to what could cause it and downplayed it, not ever going back to them (was a local shop).

 

[hsmith]

Mine never had any insulation there. Not a bad idea though.

 

[Mike Ellis]

Thanks guys, I really appreciate the rapid feedback. I did a search and found many references to loud noise after a clutch change. Looks to be common enough that it might be worth the admins putting it as one of the "things to watch for" for owners of manual transmission trucks so they will know in advance to tell the shop to take special precautions with the shift boot.

 

[GCroyle]

Mike,



You didn't state what type of clutch you had installed, and I'm not asking.



Most likely if it sounds like a can of marbles being rolled around, then the torsion damper of the clutch disc is letting the transmission make noise.



Certain stronger, durable damper designs are a compromise are far as strength vs. creature comforts in the cab. The torsion damper is designed to act as a noise reduction filter in the driveline, it absorbs the powerful engine pulses and creates a cleaner, filtered output for the transmission. If it was one of these types, it might also actually get quieter as you drive it, they sometimes actually break in.

 

[DEldredge]

Just put a New Clutch, Pressure Plate & Throw out Brg in My 96 Dodge 2500. I took it apart myself and never saw any insulation in or around the shift boot. Great design though as it had 218000 miles on it.

 

[Vaughn MacKenzie]

Mike,

You didn't state what type of clutch you had installed, and I'm not asking.

Most likely if it sounds like a can of marbles being rolled around, then the torsion damper of the clutch disc is letting the transmission make noise.

Certain stronger, durable damper designs are a compromise are far as strength vs. creature comforts in the cab. The torsion damper is designed to act as a noise reduction filter in the driveline, it absorbs the powerful engine pulses and creates a cleaner, filtered output for the transmission. If it was one of these types, it might also actually get quieter as you drive it, they sometimes actually break in.

The sound we are talking about is ambient engine bay, road and wind noise, not engine vibration noise being transmitted through motor or trans mounts or whatever.

 

[GCroyle]

"and after getting out of the lot and cooling down the interior I roll up the windows and immediately notice it is LOUD inside. Wasn't loud when I drove it in. " Wha hoppen? :{ :{

Vaughn,



I'm reading that the truck got noisy after clutch installation, truck was not moving at the time Mike made this comment.

 

[Andy Redmond]

If just an increased volume or louder "engine" noise in the cab, usually just a poor reinstall of the upper and lower shift boots, stripped screws, torn lower boot, the sheet metal was dinged up getting the trans in/out etc.



Often the difficult to reattach fuel line supply and return bracket strap goes missing or is reinstalled improperly or the lines reinstalled where they vibtrate on the floor pan.



Again once the boot is off this will be readily apparent.



Mike: if you'll repair my defunct Bel Radar detector, I'll make it be quiet like oe again. Somehow I think I'm getting the better end of this offer. .



Andy

 

[GCroyle]

Andy,



I agree any incorrect fitment of the boot will allow previously unheard noise to enter the cab and could be the source. Mike has not come back with further info from his truck. One other noise diagnostic is to have someone outside the truck, engine running, neutral, release clutch, pause, engage clutch pause and repeat through several cycles, if the noise is being turned on and off here's yer sign. The boot on our '07 wasn't correctly seated one tim, makes noise.



I have used brick walls to listen to gear noise and one time I rested an empty open plastic soda bottle against the stick, WOW it acted like a megaphone and really allowed you to hear the transmission.



Mike, good luck.

 

[Andy Redmond]

Thanks Gary, those are good diagnositic tips to use in the future.

 

[Forrest Nearing]

I always stuff rags in there on my manual trucks... helps cut down on noise even on a stock truck w/ everything sealed properly

 

[GCroyle]

Forest,



Does that mean that the RADIO is broken? We usually just tell em, hey that's what the volume control is for, use it.



It is amazing how sensitive we (me included) can be as to how our clutch feels or functions. I see it as one of those rare parts that the driver has complete interaction with. We feel it before we start the engine, each shift, every time we use a drive thru, each time we roll the coal, smoke the Michelins, tug a tree stump, bog it down, overload it, beat the crap out of it and then ask it to do it again.



One of the missing links about the clutch for us anyway is that we can get DTC's (Diagnostic Trouble Codes) for almost all major functions of the engine, we even get DTC's for automatic transmissions, heck Ford has over 50 on a certain F-Series automatic. But I have never heard of a DTC in the US market anyway for a clutch or release system related fault or problem.



One of our most challenging questions is when a tech states that the hydraulic system is bled, I ask them to prove that it is bled, can you test it? It is really easy on our Dodge's, you remove the slave cylinder from the housing, leave it attached to the hydraulics, remove the boot and pushrod, now use a steering gear puller, bolt it to the cylinder flange, use the screw to block the piston from extending, push on the pedal with your hand, does it move? how far? Just by going through this simple 20 minute test, you are so much farther ahead than you were by cursing and wasting DOT 3. Sure beats an un-necessary R&R.



Sorry for the long side bar, now back to our regular program.



Alternators have it made, just make electricity and don't make any noise while you do it.

 

[Mike Ellis]

Great info in this thread guys, thanks very much. Hey Andy, long time no hear! I am glad you are still reading the 12V forum. Send me that BEL and I will take a look, be advised though that once the smoke is let out of the circuits it is sometimes hard to get back in :-laf :-laf



The truck is loud sitting still or moving, it sounds just like what Vaughn said, louder ambient noise. It is definitely coming from the shift boot area. Can't hear anything "different", just louder.



It's driving fine, the clutch engagement is good, doesn't slip very much when letting the clutch out so a small amount of shudder is experienced - about like when it was new. Shifts are smooth, everything seems to be in order so far.



I'll take the boot loose later this week and see if I can figure out what to seal / tighten.



Does anybody have a picture of what it should look like under there, so I can tell what to look for? Thanks again for all your help guys!



Hey Andy, do you still work on trucks? If so send me a PM, I am about ready to do some mods and could steer some business your way