Newer 4cyl Into CJ5?

Hello All,
Thanks for everyones help getting my CJ running again. I've been looking into possibly swapping out the drivetrain into something a little more modern. I like the idea of a V8 but seems fairly involved and expenses start adding up with adapters,etc.

My question is, could a newer 4cylinder/5 Speed (AX5 I believe) from a YJ being fitted into my 65 CJ5 and adapted to the Transfer case (I think its a T18)? Reason being, I don't need a hotrod but I do want an overdrive gear. At the same time I don't want to mess with the Axles as I like the steep gearing they have from the factory. This setup sounds like it wouldn't be a bad move and can be had very cheap.

I'm not worried about fuel injection/wiring - I'm in the middle of a restomod of my 1968 Mustang Coupe (swapping a 5.0 EFI /T5 / 8.8 into it).

Thanks!

 

It's doable. Check out Verne's AMC 2.5L swap out of a Cherokee into his 56 CJ5 in JP magazine. Search for Project Ground-Up. Verne used the AX5 trans and 231 transfer case. Based on his work I'm going to use the same fuel injected engine in my 67 CJ5 but I'm researching how to adapt my existing T98 or a T18 to the original bellhousing so I can keep a granny low gear with the overdrive of the D18 transfer case. Swapping an SM420 has already been done using an S10 bellhousing and Advance Adapters has a plate that bolts to the original bell that enables an NP435 to be used get a granny tranny behind it.
I'm still researching but I believe the only 5 speed I've discovered so far is the AX15. The AX5 isn't regarded as a popular swap due to it's lighter duty use so there doesnt appear to be any adapters made for it to the Dana 18. My current research is by no means conclusive at this point but this what I have so far.
I personally think the AMC 2.5 would make an awesome replacement for my old Fhead, and the increase in power combined with a granny tranny and overdrive (and fuel injection if you find one of those engines) would just be the Cat's Meow. Verne has the computer and fuel injection thing already sorted out and proven for us so I'm going for it.

Good luck on your project, and keep us posted,
Mike

 

"I personally think the AMC 2.5 would make an awesome replacement for my old Fhead, and the increase in power..."

I have an '88 YJ with the four cylinder. It often seems to me that it has very little more power than the F-head. I wouldn't really consider it an upgrade in that sense. Certainly it is inadequate for interstate speeds in the YJ.

On the other hand, later versions had more power, and in my 94 Cherokee the 2.5 seemed fine, and they are extremely reliable for high miles.

 

The transfer case is a Dana 18, or D18. A T18 is a Borg-Warner truck transmission.

The AMC 150 4-cylinder is a great engine. But the 5-speeds that go with them (AX5) are both kinda long and not very strong. The SM420 is a better choice, IMO. http://www.jeeptech.com/convtrans/sm420yj/index.html In general, the better Jeep 5-speeds (AX15, NV3550) will be long and will cause headaches. There is also a T5 that was used in Jeeps, but again likely too long and not very strong. All these transmissions have the wrong output pattern for your transfer case - that's why the conversion mentioned above used the NP231, not the original D18.

You can add an overdrive to the D18 without swapping transmissions. That's one of the best accessories you can add to an early CJ-5. Bolts right on. Look at www.hermtheoverdriveguy.com for more info.

The modern 4-cylinders are free-revving compared to the Jeep F134, and they make a lot more power at these higher speeds than the Jeep engine. There are other engines to consider than the AMC 150. Lots of Pinto 2000/2300 engines have been put into Jeeps; adapting this engine to the T-90 is pretty easy, if you can find the right bellhousing. Not my favorite, but the GM/Pontiac 151 "Iron Duke" is another one to consider. The better choice IMO would be the Chevy 153 or its GM Industrial/Marine cousin the 181 (3.0L) - these are great little engines, and popular for Jeep swaps. The GM engines use the same adapter setup used for Chevy V8s and original T-90 3-speed. Pretty easy to find the adapter on the used market, and not wildly expensive new.

http://www.novak-adapt.com/catalog/adapters/engine_to_transmission/kit_pc2.htm

 

Thanks everyone for the info. My problem with going with my T90 or any 4 speed is the lack of an overdrive gear. Yes I've looked at the overdrive units but for the price of one, I could find an entire drivetrain to swap into the CJ.

I've done a little more searching and it seems the AX15 or NV3550 (possibly the NV3500) have adapters to go on nearly any V8 (not the NV3500 as its part of the trans) along with a D300 transfer case. Wouldn't a NP231 have the front output on the wrong side?

As for length- couldn't the engine be placed further forward in the engine compartment to allow proper length of the driveshaft- If I was going to go with a V8 I'd use an electric fan anyways. Just tossing around idea's for now.

Main reason I want overdrive is the ease of higher speed (I live in Maine and our roads are faily long averaging 45-50mph), and lower RPM's (whether its a 4cyl or V8, it gets old listening to it after awhile plus the mpgs).

 

You may save money in the short run, but the Warn overdrive is a proven addition, and you'll enhance the value of you Jeep roughly in proportion to the cost of it. Plus they are easy to sell private party, if you choose to change direction. After everything is totaled up, I doubt that the 150-AX5 combo will be any cheaper than a more conventional swap. And you'll have way more time and effort involved.

Yes, the NP231 will drop on the wrong side. Read the JP article - I'm guessing that the author did a front/rear axle swap too ... since the title is "ground up." A Dana 300 will give you the right drop, but the output is centered, and you'll need a new rear axle.

If you want cheap, look for the GM adapter for the T-90 on the used market. They come up pretty often, and won't cost much. Then you can look around for a cheap GM motor like a 4.3L Chevy (very common), or a Buick 231 V6, or the 151 or any of the GM V8s or a 153 from a postal. The 150 might work too, if you use the S-10 bell described in the link above.

Something else to consider - it's often cheaper just to buy the vehicle you want and sell the vehicle you have, rather than to make extensive mods. And there's a lot of risk in taking on a big project - people's situations and tastes change, and a big project requires a lot of commitment. Sometimes you can find an unfinished project that is selling cheap (they usually do), and either use what you have to finish it or take the parts you need for your Jeep and part out the rest.

 

Having an AX-5 in a YJ, I would say there would be NO WAY I'd swap it into a project. My YJ has not been abused or thrashed offroad. I may have had it offroad 10-15 times on the beach at Cape Hatteras. Yet with approx. 160K I am on my third transmission. To say they are weak is an understatement. If you want the 2.5 from a YJ look for a 4cyl Dakota bellhousing. Not sure what years, but some 4cyl dakotas had the same 4cyl with the somewhat stronger AX-15 trans

 

No matter what engine you put in, it will still be a jeep. I would save the long highway drives for a road vehicle, maybe a cherokee or such.

 

Newer transmissions get you O/D in the final gear (typically 5th).

With the Warn O/D (or Saturn), you get O/D in first, second, third, or fourth (SM420, SM465, T98, T18 ).

Far more versatile than most modern transmissions IMO.

If noise is too much, get an XJ, JK, Pathfinder, etc.

 

I am in the midst of doing this engine and trany swap from a 92 YJ. I'll be mating the transmission to a D300 with a new 21 spline input shaft from AA. My rear axle is center, and not offset, so that helps me.

I may be slightly stretching the wheel base an inch or two up front and out back to help with driveshaft length.

I amnot concerned abut the strength issues of the YJ four cylinder transmission, i've have experience with them, and have never run into weakage issues.

 

What comments are there from owners with the 4.27 axles? My understanding is that the top speed would be roughly the same as the 5.38 axles and an overdrive. And an axle swap has some practicality issues to look out for ... axles are heavy, and if they aren't available locally, shipping will be expensive. And the knuckles and king pins on any of these axles are likely worn out and in need or repair or rebuilding. So you aren't going to get off free... I'd expect the axle swap to need the axles plus a couple hundred dollars in parts. Herm lists his new overdrives at $875 - a fixed cost, and at least $500 of that you'll get back when you sell the Jeep or the overdrive. People like these overdrives, for good reason.

Apparently the OP has a source for a cheap AMC 150. I'd go with that, and adapt it to the T-90 with a GM adapter. I have a GM adapter on my shelf that I bought for $50, by being in the right place at the right time. They are out there - check eBay, Craig's List, etc. Or places like Herm and R&P probably have used ones occasionally. That adapter should work with the 150 and the bell that adapts the SM420 to the 150 should also adapt the 150 to the T-90 with the GM adapter. This will be a great and cheap upgrade .... and raise the top speed of the CJ a lot. The 150 will be happy (but noisy) at 4000 RPM, which will raise your cruising speed from 45 to 60. Then, when funds allow, add the overdrive.

 

I've been curious about using a Ford, maybe Ranger, 4 cyl. I believe the early 90's FI engines share the same bell housing bolt pattern as the early Pinto 2300 engines. Seems like it should be as easy. almost, as the Pinto conversion, mechanically. Not sure about the actual physical size, with the FI plenum, etc., etc. Or, I could be completely out in left field....................again.

 

A ford engine could then be mated to an NP435 providing a real good low range, but then an OD issues arises depending on alxe ratios.

In my case my axles are geared at 4.56, and with 31's I should be able to use the 5th gear on the highway. Plus with the D300 and the first gear in the YJ tranny, my crawl ratio should be acceptable, not extremely low, but acceptable.

And for others, Verne did use Xj axles in the retro Jeep, so he stuck with the NP231 with a real short SYE kit,

 

Maybe ... the Pinto is different from the larger Ford engines. I believe the 1600/2000/2300 cc and 144/170/200 cid engines all have the same bell pattern. There is a specific shallow Ford bell that works with the regular T-90 stickout and provides room for a plate adapter. Novak has a lot of info about their adapter - http://www.novak-adapt.com/knowledge/pinto.htm and http://www.novak-adapt.com/catalog/adapters/engine_to_transmission/kit_pc2.htm

The first generation of their adapter was just an adapter plate and a sleeve to go over the T-90 bearing retainer. This style of adapter could be made with some ingenuity and simple machining, and I expect you could also adapt the 144/170/200 inline sixes to the T-90 rather easily too. Though these sixes are short for inline sixes, they are still too long for the CJ engine compartment. You'd have to push the firewall back a few inches. It's been done though - and lots of Jeeps in Australia came with these engines from the "factory."

If you want to use one of the Ford truck transmissions with a 2000 or 2300, you might be able to get the bell from a 144/170/200 Falcon or Mustang, and that might be the right depth and pattern for the NP435 and the Ranger engine. Maybe ... depends on whether the Falcon and Mustang got a smaller 3-speed with a different front pattern from the rest of the Ford line. I expect that they did not, and instead got something like the regular big passenger car 3-speed (from which the Jeep T-150 originated). If so, the pattern (Ford "butterfly" pattern) would be right for the truck 4-speeds.

 

Yes. Enquiring minds want to know! 8)