CJ7 4.2l 258 engine replacement

[dtrojcak]

I'm thinking it is a straight forward swap, but wanted to check with the experts just to make sure.

I have a '78 CJ7 with a AMC 258 i6 / 4.2l and T18a tranny.
I found a '82 AMC 258 i6 / 4.2l for sale.
Would this be a simple engine swap or would there be any adapters required?

I've never swapped an engine before, other than an engine hoist, are any special tools required?

 

[Hedgehog]

Should be fairly straight forward, I don't know if there is a difference in the carb/distributer set up, but the engine should be the same. While in there I'd resurface the flywheel and drop in a new clutch package. Those are the parts that wear out that are difficult to get to. With the engine out, most of the hard work to replace the clutch is done. ........ mmmmmmm T-18 .... I want!


Edited to Add: Don't be afraid to pull the entire front clip off (fenders, radiator, grill). There are only a few relatively easy to get to bolts holding things on. Well worth the effort for the added ease of working on removing and setting up a new (relative to you anyways) engine.

 

[Lumpy Grits]

That will be a easy swap.
FWIW: AMC V8 is also a bolt in swap.
LG

 

[Torxhead]

Could be some issues at the Transmission , depending what the '82 came with plus the '79 ignition and fuel system should be used.

 

[dtrojcak]

The '82 currently has a T-5 tranny bolted to it.
From what I've researched, it seems my current T18a is a better/stronger tranny, so I would be keeping it if it would bolt onto the '82 engine.

This would then leave me with a T-5 tranny that I don't need.

What is the demand/value for a '82 T-5 Transmission ?
Do I have a reasonably easy chance of selling it or would it end up being a scrap metal item?

 

[Torxhead]

I would look at something like Craigslist, as you might find a few guys still wanting them and get a price to ask for it.

 

[Kane]

I sold my T-5 pretty quickly for a couple hundred bucks. they are not worth a lot but people still want them who desire to keep a stock drivetrain.

 

[dtrojcak]

Just so I understand correctly, the '82 AMC 258 i6 / 4.2l should bolt right up to my '76 T18a Transmission , but most likely, I will need to swap my existing carbeurator and ignition system onto the "new" engine.
Correct?

The intake & exhaust manifolds are currently not installed on the '82. I'm still waiting on the seller to confirm if they will be included with the engine.
If they are not included, would my intake & exhaust manifolds fit onto the '82?

 

[Hedgehog]

I'd look up to see if they both take the same exhaust manifold gasket. If so it stands to reason that they both have the same foot print and are in fact the same.

 

[jpeck71]

I'd look up to see if they both take the same exhaust manifold gasket. If so it stands to reason that they both have the same foot print and are in fact the same.

I'd guess that they both use the same gasket. I just went through a similar swap, but I took an unknown year 80s intake/exhaust set and put it on a 78 engine. In my case the gasket was the same. The benefit to that route is I went from a 1bbl on the 78 to a 2bbl from the 80s. I'd check the condition of the intake/exhaust/carb set on the 82 and see if it would be worth using.

 

[dtrojcak]

Seller responded back, both manifolds come with the engine, along with the MSD ignition that was previously connected. So hopefully it'll be a simple unbolt, remove old, install new, tighten bolt type of project.

 

[Torxhead]

I would suggest using the '78 bellhousing, clutch, flywheel, pilot bushing, along with that T-18 install.

 

[Lumpy Grits]

The '82 currently has a T-5 tranny bolted to it.
From what I've researched, it seems my current T18a is a better/stronger tranny, so I would be keeping it if it would bolt onto the '82 engine.

This would then leave me with a T-5 tranny that I don't need.

What is the demand/value for a '82 T-5 Transmission ?
Do I have a reasonably easy chance of selling it or would it end up being a scrap metal item?

How long your T-5 lives, depends on your right foot, R&P ratio and tire size.
BTW: I have been run'n a T-5 for over 30 years. You'll see my specs to the left.
Hope you aren't still run'n the POS, OEM 2 piece rear axles-
LG

 

[dtrojcak]

How long your T-5 lives, depends on your right foot, R&P ratio and tire size.
BTW: I have been run'n a T-5 for over 30 years. You'll see my specs to the left.
Hope you aren't still run'n the POS, OEM 2 piece rear axles-
LG

I'm not sure what R&P ratio I have, but I'm pretty sure it's geared too tall for the 33" tires that are on it.

And yes, the rear axles were already upgraded to 1-piece when I bought it.
The rear bearings failed about 100 miles after I bought it because the idiot shop the PO took it to, pressed on the bearings backwards.

Would the T-5 bolt right up to my Transfer Case , or would it need an adapter?

 

[Petescj]

I'm not sure what R&P ratio I have, but I'm pretty sure it's geared too tall for the 33" tires that are on it.

And yes, the rear axles were already upgraded to 1-piece when I bought it.
The rear bearings failed about 100 miles after I bought it because the idiot shop the PO took it to, pressed on the bearings backwards.

Would the T-5 bolt right up to my Transfer Case , or would it need an adapter?

No the T-5 bolted to the Dana 300 Transfer Case , you have a Dana 20 behind your T-18 . You are correct about keeping the T-18 . It is the stronger Transmission .

 

[hole]

And as for selling the T-5 , I got $400 for mine here in SoCal in less than a week on CL

 

[Lumpy Grits]

T-5 is for the Dana 300 t'case.
The '18' is for the D/20 t'case.
Would do you good to learn just what R&P your running, and confirm they are the same front and back. I've seen more than 1 mismatched front and rear CJ.
LG

 

[dtrojcak]

And as for selling the T-5 , I got $400 for mine here in SoCal in less than a week on CL

That would be awesome if I could get that.
Especially considering I'm getting the engine, tranny, alternator, MSD ignintion and both the intake/exhaust manifolds for $300, lol.

T-5 is for the Dana 300 t'case.
The '18' is for the D/20 t'case.
Would do you good to learn just what R&P your running, and confirm they are the same front and back. I've seen more than 1 mismatched front and rear CJ.
LG

I've been meaning to do that, just haven't gotten around to it yet.
I'm pretty sure they're matched, they're no binding or anything when in 4wd.
But I definitely need to make sure just for piece of mind.

 

[dtrojcak]

I should've known a Craigslist bateau would be too good to be true.
Seller sold it out from under me.
Oh well.

 

[dtrojcak]

Dang auto-correct, should have read craigslist bargain, lol.