New clutch not working - can you tell if the disc is backwards?

This site may earn a commission from merchant affiliate
links, including eBay, Amazon, Skimlinks, and others.

lelandEOD

lelandEOD

SILVER Star
10 Year
Joined
Aug 21, 2012
Threads
214
Messages
2,217
Location
Dayton, Nevada
Ok, it's been several days since I discovered a serious problem with my newly installed 3FE and have finally calmed down enough to ask the question before I assume the worst and pull everything apart again.

I just put this replacement 3FE in my truck about 4 weeks ago. It seems to be running fine (bonus) but the clutch will not disengage (I just get grinding gears). If I start the truck in 4th, it just jumps forward until I let go of the ignition switch. I've checked the MC/slave circuit and everything looks good there. I bled the system and am seeing plenty of slave piston/release arm throw as well. Next, I pulled the inspection cover and had a helper depress the clutch pedal. I can see the pressure plate flexing and the disc, sandwiched between the flywheel and pressure plate, seems to be relaxing (spreading) as the pedal is pressed. I'm going to take some photos/video shortly to illustrate what I'm talking about. Looking up there with a flash light, it does like of look like the pressure plate fingers aren't "arched" quite like they should be... but that could just be my imagination.

I am 100% positive that when I assembled the clutch to the flywheel (over a month ago) that I pulled up ih8mud mobile on my phone and reviewed archived topics to confirm the disc orientation before I put it together. What I'm not so sure of is if I may have removed the disc as I had to lift the engine a bit more to get the pressure plate under the bellhousing (because of the way I had it sitting on my shop floor). The only thing I can think of is I may have pulled the disc out before I lifted the engine a bit higher and may have oriented the disc incorrectly when I put it back in. At the time, I was more concerned about the TO bearing orientation, which I also confirmed via ih8mud mobile...

What I'd like to know is if there is anyway I can visually check for a backwards disc BEFORE I pull the engine and transmission back out. I imagine, the only thing worse than installing the disc backwards is pulling everything back out just to find that it wasn't backwards to begin with. I'm out of ideas though as to why it will not disengage.

Thanks, Gents.
 
the heavy side of the splined center section on the disc goes away from the fly wheel irrc........or the other way around.
 
Last edited:
What brand of clutch did you use? Most are labeled 'toward engine'. If you used an Aisin/ASCO, the 'snout' goes toward the flywheel.

clutch0002-jpg.251313
 
Thanks for the replies, fellas. I'm actually hoping someone can help me confirm whether the disc is oriented correctly or incorrectly before I commit to a full R&R of the engine/transmission.

Here are a few photos which I hope will help identify a potential problem. This shows the clutch engaged (pedal at rest):


Here is a shot of the TO bearing and pressure plate fingers, also engaged (pedal at rest):


Now, here is a photo of the disc with the clutch disengaged (pedal depressed):




You can see the gap between the disc and the flywheel, but no gap between the disc and the pressure plate. I have no idea if this is normal or not.

And here is a shot of the TO bearing/pressure plate with the pedal depressed:


Ideas?
 
Im not an expert but the throw out bearing looks reversed. I thought the flat service on the TO went against the pressure plate. Maybe this post will help the exchange of ideas.


...via IH8MUD app
 
I'm going to hazard and guess and say the disc may be in backwards. With the clutch pedal fully depressed can you get a feeler gauge between the pressure plate and the disc? From the pictures it seems as though the disc wants to stay against the pressure plate and not the flywheel. This is telling me that part of the disc is pressing against the flywheel and keeping it against the pressure plate even with the pedal fully depressed.

With the pedal depressed you should be able to get a feeler between the pressure plate and the disc.
 
Snout goes towards the flywheel? That's backwards iirc. That will jam the snout into the flywheel and cause the fly wheel bolts to jam into the "springs"

The "flat" side of the clutch disc goes towards the pressure plate.

I've never tried it, but I can see the pressure plate being able to release the friction surfaces on the disc and still have the hub of the disc jammed into the flywheel.
 
How hard was it to tighten the bolts from the pressure plate to the flywheel?
 
Snout toward flywheel. Snout is on the flat side. Snout is the protrusion that slides over the output shaft as in the pic above. Other side of the disc is raised.

This is why this gets fawked up alot.

Page CL-21 in chassis FSM 84-90

Mace said:
Snout goes towards the flywheel? That's backwards iirc. That will jam the snout into the flywheel and cause the fly wheel bolts to jam into the "springs"

The "flat" side of the clutch disc goes towards the pressure plate.

I've never tried it, but I can see the pressure plate being able to release the friction surfaces on the disc and still have the hub of the disc jammed into the flywheel.
Click to expand...
 
Hi
The fat bit of the clutch goes to the pressure plate. See photo
Turn it around the other way I don't think it will fit to well.
Your photos shows that the Pressure Plate has released the clutch. I would also say that the thrust bearing is the right way around . The tapered side of the bearing to the Pressure Plate.
Do you know how much of a fly wheel step you had before assembly?
Did you machine the fly wheel ?
Did you remove the bell housing?
Did you install and torque pressure plate screws a little at a time ?
Is pressure plate sitting square on the flywheel?
Is the fly wheel sitting square on the crank?
Possible cause of your problem.
Clutch plate and gearbox spline binding.
Bell housing not square to bock.
Gear box not square to bell housing.
A photo from the Toyota book.
Good luck
Cheers
ImageUploadedByIH8MUD Forum1402990634.742100.webp



...via IH8MUD app
 
I know I helped someone that had installed a new clutch disc and pressure plate. It would not release when the clutch was depressed. We ended up pulling the trans and bell housing, removed the pressure plate and there was a nice big greasy hand print on the pressure plate. That was making the disc 'stick' to the plate and it would not release. We cleaned the pressure plate and disc, slapped it together and it shifted smooth as silk.
Wonder if you tried spraying some cleaner up there in there? Even brake cleaner might do it. Did you clean the film off the pressure plate before installation?
 
Dont forget pilot bearing, if it gets messed up due to a hard trans install the imput shaft will spin even with the clutch disengaged and you cannot get into gear. Have you started it up in gear, clutch depressed? Looks like your disc might be backwards from your description
 
Btw, you can just pull the tranny to replace the clutch. No reason to pull the entire motor
 
Thanks for the input, guys. Again, just to be clear... I understand which way the disc should be facing; I have the FSM and checked a thread on the topic before I assembled the clutch. This is more of an issue of me being an absent minded dumbass and forgetting to double check my work after I repositioned the motor on wood blocks. ...Or did I? I just don't remember.

On another note, I did degrease the flywheel and pressure plate with brake cleaner before I assembled the parts and wore nitrile gloves while handling the parts. Everything went together as it should (I had this thing driving around the neighborhood last summer - before I had to swap the motor again due to a cracked head). The bellhousing is bolted snugly to the block and the flywheel is mated firmly to the crank. The flywheel was resurfaced by a local shop and was well within spec. I centered the clutch disc and sequentially tightened the pressure plate bolts until it was completely torqued down. I started the engine and visually checked that everything is balanced and spinning correctly. I did lightly lube the pilot bearing and used a strap sling from my hoist to position the transmission input shaft so I don't think I buggered up the bearing.

I'm just looking for some sort of confirmation (from what I can see visually and from my description) that this sucker was assembled incorrectly, or what other problems could produce the symptoms I'm describing.

I'm just hoping someone in the community can tell me if it is even possible to install the disc backwards and, if it is, can I see evidence of it to confirm the need to disassemble?
 
For the sake of future generations of idiots, I'll close the chapter on this issue.

Yes, you can put the clutch disc in backwards. Yes, you can assemble everything thinking it's ok. Yes, you can waste an entire day pulling everything apart.

No, your clutch will not work.






...yup, friggin' awesome:



 
s*** happens, my old co worker, an ace mechanic forgot to install a ring gear on a porsche 911( removable ring gear) didnt realize until he tried to start it and just heard a starter spinning! Had to pull engine and trans again and this was on the clock! Flip the disc, life goes on! Cheers
 
whitey45 said:
s*** happens, my old co worker, an ace mechanic forgot to install a ring gear on a porsche 911( removable ring gear) didnt realize until he tried to start it and just heard a starter spinning! Had to pull engine and trans again and this was on the clock! Flip the disc, life goes on! Cheers
Click to expand...

Lol,
Was his name Chuck Moreland?
 
You're not the first and won't be the last cuz as you can see, the FSMs are confusing, depending on which publication, revision, and type of disc you're using, etc. I did the same thing on my FJ60, but the engine/trans was out while I realized the mistake - and I knew which side went forward cuz I asked beforehand and still fawked it up !
 
You must log in or register to reply here.

Share this page

Back
Top Bottom