6 cylinder transmission options

[wileyxs]

I recently bought a '76 Cherokee S. It had a blown 360, TH400 and Quadratrac. As far as I know this was the original configuration. My plans were to ditch the 360, find a 4.0 engine, bolt it up and head on down the highway. I cut off the 360 frame mounts, bought some 258 frame mounts and moved them to the rear holes on the frame. After measuring from the bellhousing to the motor mount, there is no way it will fit. The TH400 is as far back as it can go on the frame. I thought I read somewhere that the 258 came standard with the TH400. Did the 6 cylinders only come with manual transmissions? I would like to keep the 4.0, match it up with an automatic transmission with OD, and use Dana 18 transfer case, since my driveshafts are offset. Can someone shed some light on my situation? What are my options? Thanks, Joe

[mattmopar440]

If you gonna drop the V8 ( I personally wouldnt ) I wouldn't put a I6 behind a 3 speed auto I would get an entire 4.0 ho Aw4 or 4.0 ax15 5 speed manual

as far as axles go you just need to find a passenger drop Case either a 241 passenger drop or I think a NP208 came in a passenger drop

[wileyxs]

6 cylinder transmission option

Thanks for your reply. I failed to mention in my original post that I am going with a Clifford modified 4.0 engine. Going with carb and not using fuel injection. I'm am kinda old school and want to try to keep things simple. No sensors or computer. With that being said, is there an auto trans option or would I be better off sticking with a stick? What manual transmissions would be a good fit? Again, my drive shafts are offset to passenger side. Still thinking the Dana 18 would be a good choice. thanks

[mattmopar440]

Thanks for your reply. I failed to mention in my original post that I am going with a Clifford modified 4.0 engine. Going with carb and not using fuel injection. I'm am kinda old school and want to try to keep things simple. No sensors or computer. With that being said, is there an auto trans option or would I be better off sticking with a stick? What manual transmissions would be a good fit? Again, my drive shafts are offset to passenger side. Still thinking the Dana 18 would be a good choice. thanks

well a th400 QT or TH400 Dana 20 is your best factory options a TH400 with a 4.0 will be kinda slow

your other options are a T18/dana20 combo for a manual

[wileyxs]

6 cylinder transmission options

The 4.0 engine that I have in mind is a modified carbureted engine. Just over 300 hp. I would think it would be more than enough engine behind the TH400, seeing that the original 360 for that year had 150 hp. The 258 that pulled these Cherokees had 95 hp. Can you tell me if the TH400 was ever an option for the 258 in 1976? Or did the 258 only come with manual transmissions? As mentioned earlier, there is nowhere to move the cross member to allow for the 4.0. Thanks.

[wiley-moeracing]

I think the turbo 400 was only if you had the quadratrac and it did come behind the 258.

[tenoverthenose]

Not sure if this will help you, but I swapped in a 4.0 & AW4 into my '81 Wagoneer. I had to move the crossmember back (created new holes past the rear holes) because that combo was too long. Mine came stock with a 4.2 & TF727 and with that combo, the crossmember was mounted in the rear holes.

[tgreese]

I think the turbo 400 was only if you had the quadratrac and it did come behind the 258.

With the 258, there is no room for the low range behind the Quadratrac. You could buy a 258-TH400-Quadratrac combination in the day, but not with low range. (Was available in the CJ-7, however.)

You could move the gas tank to the rear, and there should be enough room for low range. Been done for a lot of these rigs.

I agree with above, take the 4.0L with AW4 and find a suitable passenger drop transfer case, maybe a NP241C. I don't know of a full-time case that has the NP pattern and passenger drop; maybe somebody here does. Likely a rear axle swap would be the easiest route, if the driveshaft angle is excessive. Let the early CJ guys keep their leaky, noisy, short-lived Dana 18s.

IMO the best part of the 4.0L HO is the excellent Mopar-Bosch multiport fuel injection. Not sure under what conditions I would ever want a carbureted 4.0L. The 4.0L has a stroke ratio that makes more power than the 258, but I believe much of the power increase comes from the higher compression ratio. The knock sensor built in to the MPI makes this practical, and allows more advance (when conditions allow) than would be possible without spark control. It's a neat package, even though the overall engine design is quite dated.

Another possibility would be a SBC swap with multiport and an automatic overdrive. This would solve the length problems, and provide an integrated package with power and economy. Lots of these conversions have been done ... plenty of advice and experience available online.

[brielly]

The aw4 is a great tranny, if not the ax15 or nv3500 if you don't mind a stick shift. I'd actually recommend a stick because an auto behind a 4.0 is going to be a dog.