Flywheel Identifcation

[reises58]

I have a Flywheel and Pressure Plate in my CJ3B that I cannot Identify. I need a new Pilot Bearing and maybe a ne Clutch Plate.

[Rus Curtis]

reises58,
I'll give you my .02 cents worth.  Oldtime could rattle this stuff off half-asleep. 

If you pulled the flywheel of your F-head 134, then its most likely the one for your engine.  Did you do a tooth-count on the ring gear?  (I think 129 is correct)

The good news is you can see what type clutch you have.  Auburn is printed right there on your pressure plate assembly vs. Rockford.  The only thing left to do is to verify yours is the standard 8.5" or optional 9.25" 

Since you can easily see the imprint from the friction plate on your flywheel, you can measure that (or the actual friction plate - if you still have it) or you can flip over the pressure plate assembly and measure the face (that makes contact with the friction plate (Plate and hub, driven per parts manual).

If you have a machine shop that's local, I'd recommend that path for the pilot bearing.  Simply because they can remove/install and, if necessary, ream it to fit.

Did you keep the tapered bolts?  I've seen online that there's a vendor that has new (I just reused mine).

Some will suggest that there's no need to disturb the pilot bushing if it was working.  I've been led, by others before me, while in there, replace: bushing, friction plate and throw out bearing.  Keep the old parts as emergency repair parts.  The theory behind this suggestion is to hopefully avoid having to open it up again to replace one of these other worn parts.

Be very carefull and ensure you install the friction plate correctly.  Also, if replacing the bolts connecting the flywheel to the crank, be aware they are not a standard size.  That was a costly mistake for me.   They measure 3/8" - 24 x 1 5/32" 

I got the next bigger size and could not disengage the clutch. The shop "fixed" it with a torch and there was some engine block damage that resulted.

[tow hook]

thanks that s some good info. Are f head and flat head fly wheels compatible ?

[Rus Curtis]

As I understand it, the ring gears can be different. Different starters had different bendix gear count.  That's what has to match.  As far as the actual flywheel, I was going to say they should be the same. It's awful dangerous to assume. 

After looking at the Parts Manual for the 2A, 3A and 3B I'm seeing three different numbers.

GROUP 10-21 -- FLYWHEEL AND RING GEAR
CJ2A   A-1443 (ring gear 97 teeth - this may be the older version where the flywheel housing had a bushing for the starter)
CJ3A   641960
CJ3B   804314

Both the 2A and 3A have L-heads, but I don't know if that means the flywheel's themselves are different or since in two cases, they're referred to as assemblies, do they include the ring gears - making them different.  I don't have any of those models to compare.

[tow hook]

As I understand it, the ring gears can be different. Different starters had different bendix gear count.  That's what has to match.  As far as the actual flywheel, I was going to say they should be the same. It's awful dangerous to assume. 

After looking at the Parts Manual for the 2A, 3A and 3B I'm seeing three different numbers.

GROUP 10-21 -- FLYWHEEL AND RING GEAR
CJ2A   A-1443 (ring gear 97 teeth - this may be the older version where the flywheel housing had a bushing for the starter)
CJ3A   641960
CJ3B   804314

i just found a peep hole on the dust cover from the front (passenger side of the engine) . it looks to be that 's how you set the timing on my 48. my 48 doesn't have a indicator on the timing cover. the trans is out, i have yet to pull the clutch and fly wheel

Both the 2A and 3A have L-heads, but I don't know if that means the flywheel's themselves are different or since in two cases, they're referred to as assemblies, do they include the ring gears - making them different.  I don't have any of those models to compare.

[Rus Curtis]

i just found a peep hole on the dust cover from the front (passenger side of the engine) . it looks to be that 's how you set the timing on my 48. my 48 doesn't have a indicator on the timing cover. the trans is out, i have yet to pull the clutch and fly wheel

Neat trick.  Looks like you embedded your response inside a quote!  I think I extracted your post.

That inspection window is for timing.  If I understand correctly, there are marks on the flywheel itself that help with setting the timing.  From what I gather over on the 2A forum, it's not easy.  Most say they static time and then when running, use dwell or vacuum.  But that's another tangent.

You may very well have the older starter setup where there's a bushing in the bell housing (behind the starter bendix drive) and if so, that would most likely identify the older ring gear with fewer teeth.

<putting my guessing hat on> With the similarites between so many components, I would assume any of the flywheels would bolt up to the crankcase flange.  I would also assume the clutches, of the same size, would bolt onto any of the flywheels (the mounting holes would have to be spaced for the size clutch).  I would also assume any one of the flywheel housings would mount to the engine block, with maybe some exceptions on mounting holes.  To me, that leaves the ring gear and the starter that have limitations. 

Probably the easiest way to tell would be to pull the starter.  If the starter bendix is fully contained in that "half cone" end, then you have the later version starter and the higher count ring gear (129). If the starter has a shaft exposed beyond the bidex gear, it requires the earlier flywheel housing and the lower count ring gear (97 teeth). 

The disclaimer here is there's others that know more about this than me without the guessing.