80-81 CJ-5 Flywheel

I have a 1981 cj-5 with a 258 motor and a T-176 Trans.
and I need a Flywheel . Mopar Parts
no longer has this part and I've

been unable to find a After market vender's with one .
Can you tell me what is the difference between a 1972-79 Flywheel and 1982-89 Flywheel Verses a 1980-1981 Flywheel ??????
And how can i make a later model (82-89) work on my jeep?
The most important part is what is the difference .

PS.
I also have a tf999 Trans . Witch is 3" longer then the T-176 and will this fit ? I need both front and rear drive shaft's anyway so what is
the better way to go ?

 

The TF999 did appear in the CJ-7, CJ-8 and later in the Wrangler. No CJ-5 had an automatic because the rear driveshaft would be too short. There are folks out there with the TH350 in CJ-5s, but I've never heard of a TF999 swap.

I don't know the specifics of your flywheel, but I do know that the 258 got a major rework in 1981, so a 71-79 flywheel is less likely to be correct than a later one. Looks like there's a gap for 1980-81, though I'd expect that the 82-on flywheel would work. Maybe you could get your FLAPS to order one and then compare them - Napa Online shows one for an '82, and their stores are usually pretty good about that stuff.

<edit> Huh - Napa Online shows a flywheel for an '81 J10 with a 258, which is the same part # as an '82 CJ-5. The '81 J10 had the same engine as the '81 CJ. Probably just a lack of information from the supplier... figuring out the listings can require a little detective work. Find a good parts store that will work with you, and the process will be easier.

 

I had the t-176 in a CJ-7 and I liked it a lot. For me a CJ should be a stick shift. There is a jeep junk/salvage yard in SE GA near the FL line that is real knowledgable about things like your flywheel problem. The parts I bought from there were top notch. Of course I can't remember the name of the darn place.

I would thing the differance in years for the flywheel would have to do with balance. IIRC the 258 up to 79 had something like 12 counterweights on the crank, the 80-81 had less and the 82 on had even less of them.

 

I know AMC went to fewer counterweights in '81, when they introduced the lighter engine. The '80 was still the heavier engine (more counterweights, heavy cast iron manifolds, thicker block, steel valve cover), even though it was paired with the lighter transmissions like the T176. I'm pretty sure the engine was lightened only once (in 1981), although the total weight of the flywheel could have been changed. AFAIK all the AMC I6s are internally balanced (aka zero balance) so there shouldn't be any weights on any of their flywheels. If I'm wrong and there are, you should be able to determine that the flywheels are different by comparing the new flywheel with your old flywheel side by side. Also look for bolt placement and diameter.

Look, I'm pretty sure this is just a case of the supplier not being able to track down all the cross references without an extraordinary effort. There probably is a difference between the '81 and '82 flywheels (like one is heavier than the other), but it won't significantly affect the performance of your Jeep or its engine.

 

258 flywheels
1974-1979 258 = Jeep p/n J3212623
1980 = p/n J3236257
1981 = p/n J3238635
1982 and later = p/n J3240094
naturally, the Jeep parts book doesn't tell us what the differences are
ring gear and harmonic balancer the same from 1981 and on
ring gear and harmonic balancer the same for 1980 down to 1975

 

So the PN for the '81 J10 and '81 CJ 258 flywheels are the same?

 

correct

 

Well, there ya' go. Napa "SDF 1001" flywheel listed for a 1981 Jeep J10, 258cid.

 

I am running the fly wheel off my '72 232 on a '83 258. That's bolted to a '78 T-18a out of a J-series truck running a t-150 bell housing and a short shaft conversion.

It will work. Don't worry about it.

 

Thanks to all of you for your input and help

I'll be on my way to the Napa store tomorrow