Changing the clutch

[BDA]

So some (all?) of you know that I'm rebuilding my NG3 tranny and I thought that while I was at it, I might replace the clutch disk and throw-out bearing. But, of course, I've got some questions...

1. I probably have about 20,000 miles on this engine and clutch. It has been working fine though there have been some exceptions to that. Sometimes, not all the time, before everything warms up, it will be impossible to get off from a stop smoothly. Sometimes shaking the whole car until the clutch is fully engaged. This usually goes away after a few miles. Other times and more commonly, things are as smooth as silk.  Also, the throw-out bearing does not rotate as smoothly or as quietly as a new one. Does anybody have any guidance about whether to change the clutch given that situation?

2. I'm leaning heavily toward replacing the throw-out bearing at least given its less-than-smooth operation. I can't get my old one off. I don't remember how I replaced it when I built the car but I also don't remember any drama associated with it (I would think I would remember it if there was but then that was over twenty years ago and like pretty much everything else, brains don't work as well when they get beyond a certain mileage). So how do you get the throw-out bearing off?

3. I bought r.d.'s clutch alignment tool. It has the required number of splines but the part that should go into the clutch spigot bearing seems too large. Does anyone have the proper ID of the clutch spigot bearing? Interestingly, the end of the primary shaft has those splines but does not have a "nose" that would go into the clutch spigot bearing! I'm doubtful but I wonder if that might be a cause for my clutch issue in #1?

[TurboFource]

"If you see the throw out bearing, change it!", is what I have always been told and usually do!

[BDA]

Yeah, similar to the advice a buddy gave me when I asked him if I should change the tranny bearings - if you're wondering if you should change them, change them.

Now, how do I get the old one off?

[dakazman]

  I had to tap out the pins by drilling holes out in the bellhousing , but for a 336. I built a tool for pulling out the pins but found it easier to drill out, but that is on an S2. My arm was hitting the case stop. RD had the new pins. sadly I did not swap out the pressure plate and disc.
  I have a TC bellhousing out and can send you dimensions to drill out from the top if needed.
 After looking at the manual, check or lube the release arm seal.
  x2 on the release bearing.
 Dakazman
 
 
 
 

[Exlimey]

BDA, you have to have this to engage in the spigot ,or the clutch will wanderer around.

[BDA]

Thanks D’man. I’ll let you know about those holes.

Exlimey, that’s what I expected to have on the end of my primary shaft but I got nutten there but a lathe center - just as I received it from Richard. I can’t say whether the clutch disk wandered around or not unless my shaking or juddering was caused by that. I doubt it since it has behaved itself until recently (after 20,000 miles) and even now, it’s only from a start on a cold clutch but I won’t say it can’t be the cause. And then if it is, I don’t know how I can fix it as the primary shaft is certainly hardened and not something easily drilled.

[jbcollier]

I had an Fuego Turbo NG3 I picked up cheap so it wouldn’t be binned.  I gave it to a lister from Vancouver.  Unfortunately I never even looked at it but I recall that the NG transaxles (some/all/later/?) had your set up.  The input shaft is originally supported by an internal bearing inside the tube that the release bearing runs on.  Now your set-up uses the original Lotus TC bell housing (I presume?).  This would not have the correct support for this style of input shaft.  The shaft would be free to move at least somewhat and this would indeed cause clutch judder.

Grab a hold of your input shaft.  Can you wiggle it up and down at all?  Has the bell housing been modified with a support bearing/bushing?  If yes, what condition is it in?

[BDA]

My bell housing has that input shaft bearing/seal. Now I understand why it’s required!!

My tranny is all apart so I can’t grab the input shaft but I’ll take a closer look at that bearing/seal!!

Thanks for another lesson!!

[pboedker]

BDA, I know you have an NG box but if the clutch side of your bellhousing is still an unmodified TwinCam type, the release bearing is easy to remove and replace. No need for drilling unless you want to also remove the cross shaft.
Just unclip the spring from the bearing carrier (parts manual, section QA) and the carrier+bearing slides right off, heading for the press and the new release bearing.

[kram350kram]

Does not the input shaft run in a bearing in the end of the crank and or flywheel.? If you change transmissions, bellhousings and or engines, how do you align the input irt crank centerline? If the input is off center you will have clutch issues. Maybe the machining and adherence to factory specifications are of a very high standard for these transaxles and engines,  most people have no issues? In American engines you need to check alignment or you will have problems with input bearings, chatter, worn and blown clutches.

[BDA]

Thanks Peter!!! I knew there was a simple way to do it!

UPDATE: Spreading the springs hooked into the TO bearing carrier wasn’t too difficult. Now, just have the bearing pressed off the carrier and the new one pressed on. Thank you Peter!

Kram, using an NG3 requires that you have the Fuego pilot bearing pictured below. The chrome end contains roller or needle bearings to keep the input shaft aligned. I have that (Richard sold it with the NG3) but never really thought about why it was necessary till JB mentioned it. Unless mined is lunched it should not be the issue. While all this is apart, I'll be changing the clutch disk and inspecting the clutch cover.

edit: I forgot to add the picture of the pilot bearing!

[4129R]

The clutch plate alignment tool I bought had several sizes for both the spigot bearing in the end of the crank, and the clutch plate splines. None were the correct size, so I used smaller sizes and wound plastic insulation tape around them until I got to the right size for each.

[BDA]

I guess r.d. sells the cheapo alignment tool! It is plastic, the end that goes into the spigot bearing is way too big, and there is no adjustment provided.    I don't have anything I can chuck it into to sand it down while it spins so I may have to take it to a friend who has a lathe. Jeesh!

[TurboFource]

Just wrap tape around an extension until you get the sizes you need.

[kram350kram]

DBA, Cool pilot bearing, explains a lot.

Not sure how you check concentricity though? Are all potential mated candidates; engines, various transaxles, line bored blocks, belhousings, etc... that accurate that no matter what combination is bolted together all align within a few thou? I found very few such instances when checking most engine to bellhousing alignments.