4 Speed Swap

I'm thinking about swapping out my 3 speed for a 4 speed so I can have the granny gear.

To that end what are my considerations?

I have a 1969 stock CJ5, 225 oddfire V6, T14 transmission currently,

What transmissions do you recommend and what will I have to do to make them fit.

Thanks

Kevin

 

Try searching the site.

Been covered Ad Nauseum.

 

Use Google - https://www.google.com/search?q=site:earlycj5.net T-18 swap 225 V6

There's lots and lots of material online. The Novak site has tons of info, and I believe Advance Adapters has a book for sale.

Read some background, narrow down your questions, and we would be happy to discuss. :driving:

 

Thanks for the generic replies and I do appreciate them however I've already been to Novak and advance adapters etc. What I am looking for is real life input from people who have already done this. What did you encounter that you didn't expect, are you happy, would you do it again, would you use a different transmission, what didn't you do that you should have? etc. etc. As for searching the site... I already did and didn't really find what I was looking for. Rather than simply suggesting a search it would be nice if you posted a link assuming you know of one that addresses my question.

 

What are you looking for?

Full on deep gears like an SM420? "Compact" like a T18?

T18

http://www.earlycj5.net/forums/showthread.php?39445-ford-t18-behind-v6

http://www.earlycj5.net/forums/showthread.php?54122-69-V6-T18-Swap

http://www.earlycj5.net/forums/showthread.php?33724-71-Cj5-with-V6-T18

http://www.earlycj5.net/forums/showthread.php?74206-T18-overdrive

SM465

http://www.earlycj5.net/forums/showthread.php?97137-SM465-Transmission-to-Buick-225

http://www.earlycj5.net/forums/showthread.php?41374-v6-sm465-swap-Motor-mount-location

SM465 VS T18

http://www.earlycj5.net/forums/showthread.php?80970-SM465-vs-T18-vs-other-options


SM420

http://www.earlycj5.net/forums/showthread.php?95208-SM420-V6-LUK-clutch-disc

http://www.earlycj5.net/forums/showthread.php?98588-Bellhousing-Buick-225-to-SM420

http://www.earlycj5.net/forums/showthread.php?101798-Trying-to-fit-SM420-Dana18-in-55-CJ5-ADVICE

 

I did a SM465 swap and it was one of the best swaps I did. It was much, much more expensive than I thought it would be. The transmission itself was relatively cheap. Remember if you decide to swap there are other items to consider.
1. New drive shafts.
2. I tore my D18 apart and rebuilt it.
3. A good friend helped with the adapter installation.
4. I tried to get the Transmission as high as possible, I had to fab a new trans cover.
5. Good friend fabbed a skid plate.
6. Prime time to replace clutch, pressure plate and TO bearing, have flywheel resurfaced.

Even after the expense it is well worth having the granny gear.

 

I personally like the T18, but I have not done a SM420 or 465. I rebuilt mine and installed the adapter with basic hand tools and no provious experience, in my garage. I found out much later that there are many variations of this transmission, I lucked out with the correct version that swapped easily to my AMC304. When it was all said and done I was into the swap for $1500, but that was 15 years ago. I did all the work myself except the drive shafts and reworking the exhaust. Exhaust work may or may not be necessary.

By far this is the best mod I have done. I think any of the above mentioned transmissions mate with the 225 with relative ease.

 

I really like my SM465 with 4.27 gears. Seems a good combo without an OD. And with the TBI 4.3ltr V-6, it's awesome.

 

Kevin,

In your first post you ask; "...what are my considerations?, and ...what will I have to do to make them fit?". In your second post you ask about personnel experience, dealing with the unexpected, and most importantly - what would you do differently. Having just gone through this, I will try to answer your questions. Remember, this is just my perspective.

My apologies in advance for the long response, but sometimes you have to see what lies at the bottom of the rabbit hole.

I have a 1953 M38A1 which popped out of second gear. My wife said, "fix it". So, I bought a freshly overhauled T-90, Dana 18, and a warn overdrive. A friend suggested some additional power, so i acquired a 225. Friday night, out in the shop the tear down begins. Out come the beers, it's just like high school, and somebody says, "Why are you wasting time putting a 3 speed back in it? What you need is a 4 speed." (Need, you will find is a relative term). 4 speed? What a great idea. Well if you're going to put a 4 speed in it, why not put in a V8? Another great idea. In an effort to get to my point - the end result of my tranny swap is: a custom built 2 x 4 square tube frame with a 105" wheel base, stock front clip with the tub spliced at the door and aft of the wheel well. Inside body panels and firewall replaced with 1/8 plate. Dana 44 front and 60 rear, lockers, 4 whl disc brakes, power steering, 37" beadlocks, spring-over with 4" lift, 1 1/2" body lift. Fuel injected V8, atlas transfer case, custom built drive shafts, on board air, and of course - a newly overhauled sm420. The list goes on but I think you see my point.

Your considerations? - Know what you want as an end product, know what will satisfy you.

What will you have to do to make it fit? - What ever it takes, what ever you are willing to do. Could be as simple as an adapter, could be more. You will not be so lucky as to just swap one thing. Everything you change will have an effect on something else.

The unexpected - there's a lot of options out there.

What would I have done differently? - What you are doing - ask questions, not decide too quickly on what I wanted to do. Find someone with the mods you are considering and ride in their jeep. Make certain those mods are what you want.

The main thing, have a plan - know when to stop.

Would I do it again? Absolutely. The look on my wife's face when she saw the jeep - priceless.

 

Thanks for the story P38.

I swapped in the sm420 - best mod I've done yet.

Observations:
1. It's more work and more $ than it looks like. Clutch linkage/floor pan/cross member/adapter/driveshafts/etc.
2. Having the granny low is very helpful off road and even around the yard moving trailers.
3. I have the 225 OF and 4.10 diffs. This makes the stock speedo dead on. 4.27 gearing may be better but not needed.
4. I think any of the big 3 would work fine. sm420/465/t18.

Good luck and welcome.

 

I used a sm465 from Herm with the 1" adapter and the mount kit he sells. I thought it was going to be more plug and play that it ended up being, and it took a few trips to a machine shop for various things and some head scratching on others. I still have a hole in my floorboard where I'm trying to figure out how to cover the beast and still have room for the accelerator pedal.

I would do the conversion again because it is much better than the 3 speed on the steep hills and ledges I drive on.

 

I have not done the four speed swap yet, trying to figure out if I want to take care of any other upgrades first.

I have talked with a few people about different four speeds but the one thing I have come across is
the two jeep guys that where avoid the sm420, because some of the parts are hard to get (the shifter) this was about two years ago. I am not sure if this is still the case.
my truck had a SM420 that I thought about taking but I personally don't like how the SM420 shifts (too much play)

try the different transmissions whether they are in trucks or jeeps to get an idea of the shift.
I was hoping to to come across a factory t18 adapter to cut some of the cost (i'm hopeful)

 

I started with the T18 out of a Jeep J20. This gave me the proper adapter for the transfer case. Then, I ordered a shorter input shaft and a GM T-18 case from R&P. While you can do the work yourself if you have the welding skills, the case wasn't all that expensive and the dauntless bellhousing now bolts right up to the T18 case.
I don't have it installed yet but supposedly this combo will bolt up to the stock clutch and be seamless. I'll have to modify the crossmember and transmission tunnel sheetmetal, but it should give me a lower low and a higher high with 3.73 gears (compared to my current 5.38 gears).

Hope I helped!

 

I have run the T-18/D18 with 4.88 gears for 6yrs now and am very happy with it. The installation fit like it was factory. On the street, it behaves like a 3spd, but doesn't shred gears. Off road, 1st gear has been very helpful at many times.

You really need to grab your favorite beverage and sit down for an hour or so searching this site. Not sure what generic response you refer to. There are a lot of threads covering your question and the installation as it relates to ECJ5s ad nauseam.

 

I put a T-18 behind a 225 with 4.27 gear and am very happy with this combo. The reason I choose the T-18 was the shortest overall length and the ground clearance was the same as the old T-90 (see picture). I had some issues getting the correct distance between the throughout bearing and the pressure plate. I resolved this with the longest throughout bearing on the list and a long adjustable pivot pin they use in racing . And do your homework before you start by researching Novak and this site. good luck

 

^^^Your Jeep is Awesome^^^...someday I'd like to do a T18 swap, but she's my daily driver, so I have to wait until I can have enough downtime. Welcome and good luck to the OP...lots of good info here.

 

here is another alternative.
I have completed the work and like it so far.
The noise is very different, did not do the intermediate bearing upgrade, and it makes me concerned.
Jack is good to work with.

http://www.earlycj5.net/forums/show...of-O-brien-4-Wheels-West-is-still-in-business