Help with T-18?

My 79 Cj-7 has a factory T-18 with no adapters of any kind. Of course this could be a whole differn't ball game than the Cj-6 since we are talking a differn't T-case here.

 

Statements from the last two posts:
"The CJ T-18 is a perfect swap candidate for the T-150, as long as it is complete with all the adapters".

"My 79 Cj-7 has a factory T-18 with no adapters of any kind".

If I’m taking these two statements as fact I would need to add adapters to the factory CJ T-18 to fit into my CJ that now has a T-150???

 

1) "My 79 Cj-7 has a factory T-18 with no adapters of any kind".
2) "Of course this could be a whole differn't ball game than the Cj-6 since we are talking a differn't T-case here".

I believe both of these statements contain some error. Nick could address this with more authority.

Not sure about which CJ-6 we are referring.

A '79 CJ-7 is a Dana 20, the same transfer case as used in CJs since 1972. In 1980, Jeep left the "great transmission era" and started using the Dana 300 in CJs. The 300 has the round bolt pattern, the same as the several New Process chain drive transfer cases (NP208, NP229, more). The Dana 18 and Dana 20 have the so-called Texas pattern. Starting in 1980, Jeep used the NP cases for drivers side drop (DSD) applications like the truck and wagons, and passenger side drop (PSD) D300 for the CJs.

There were a very few T18s used behind the V6 in '71 and maybe '70. I don't have any idea what bellhousing or adapter combination these used on these "fabled" Jeeps.

In 1972, Jeep switched to AMC engines across the entire line. The CJs and Commando offered an optional close-ratio T18 with the optional 258 cid inline 6. This setup used the same Jeep T18 case as the trucks and wagons, except it had a 4.02:1 1st gear (hence "close ratio"). This setup featured the same bellhousing as used with the T15 transmission in V8 CJs, a plate adapter, and a Jeep-cased T18. The input shaft for this setup is unique to this application. All Jeep T18s use an adapter between the transmission and transfer case. This combination persisted at least through 1975.

Sometime after 1975, Jeep went to a wide-ratio T18 (6.32:1 first gear) for the CJ. Since the T15 was no longer offered (replaced by the T150), Jeep may have used a different bellhousing and adapter setup on these '76 (or'77) to '79 CJs. They still would have to have a transfer case adapter.

AFAIK, the close ratio and wide ratio transmission were never offered simultaneously on the Jeep CJ option list. Prior to 1976, I don't believe you could have made a wide-ratio bolt-together swap for a CJ from stock parts. The right length input shaft with the right number of teeth simply didn't exist.

In 1980, Jeep stopped offering the T18 in CJs. Instead, they offered the lightweight SR-4/T-4 or T176. They continued to offer the T18 in the J20 truck through 1987 with a NP transfer case and DSD.

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It's my impression that these wide-ratio T18s from '77-79 CJs are now rather few and far between. That said, I'd expect most who have these transmission realize their scarcity, and price accordingly. Like Nick says, if you get the complete setup, it will be the easiest installation possible.

The Ford T18 and <any complete Jeep or Scout T18 transmission and adapter> could be less expensive. Nick claims that you can use the Jeep/Scout trans-TC adapter with the Ford T18, thus creating a Ford bellhousing pattern T18 that will mate with a Texas pattern TC. I haven't done this, but Nick has seen/done/worked on a lot of these, and is your best info source.

 

My Jeep is a 71 CJ-5 with a V-6 and a close ratio T-18. Timgr presented the question on what adapters Jeep used to adapt the V-6 to a T-18. The mid 1970 and earlier V-6 CJ's used a bellhousing with the Chevy bolt pattern and a 2.656" thick adapter to mate the T-14 transmission. My Jeep has the bellhousing with the Chevy bolt pattern, 2.656" thick T-14 adapter and a .875" thick adapter that adapts the standard Jeep bolt pattern T-18 to the T-14 adapter. The input shaft stick out length is 10".

 

Nickmil here on Davea's Computer. Timgr's info is absolutely what I was talking about. I know for a fact the '77-'79 used an adapter between the bellhousing and the trans from the factory as my boss has one sitting in his driveway in a CJ-7 right now. As these are rare units, I looked it over carefully to check it out. I did not remove it but looked at it in the Jeep. I have converted a '72-'75 close ratio to a wide ratio, but couldn't tell you for sure what the main drive gear came out of. Possibly a '77-'79. I just happened to have one laying around that was the correct length. What most people don't realize is there is something like 12 different input shaft lengths for the wide ratio T-18 alone, so it is imperative to know what you are getting. Most people find a Scout or Jeep truck/Wagon T-18 and use the output shaft and adapter and put them on a Ford T-18 to give themselves the 6.32-1 first gear, and if running an AMC motor they use the T-150 bellhousing as the Ford trans will bolt right up, is the right depth, and the whole setup requires only the 1" thick factory adapter for the transfer case. Nickmil

 

Coming from knowledgeable gentleman I had to re-read your posts to fully digest the material presented.
Things to do if I choose to swap my T-150 for a T-18A.

1) (76)-77-79 T-18A) Make sure that it has BOTH adapters
2) (Ford T-18A) Find a Scout or Jeep truck/Wagon T-18 and use the output shaft and adapter.
3) No adapter is required to adapt Ford T-18 to a T-150 bellhousing. The bellhousing bolt pattern for the T18 is the same as the T150.
4) I will still need to do drive shaft work (front driveshaft will have to be 3 5/8" longer and the rear 3 5/8" shorter), and move the crossmember, pilot bushing, etc.
5) Typically, the T18 will have a driver side stamp of 13-01-065.... The T19 will have 13-09-085....

Question, if I’m lucky enough to find a donor 77-79 CJ with a T-18A could I also use its driveshafts?

 

Yes. You also need the bellhousing, since yours won't work with this setup. The more stuff you can get with it, the better. I expect the trans mount (adapter to crossmember) is different, but the crossmember is the same. Other clutch parts would be good too - these should be the same as a CJ V8 T15, but it'd be hard to be sure without more research.

Yeah, the driveshafts will work fine since it's a stock config. Recall that the CJ7 came with this combo too - obviously the rear driveshaft from a CJ7 wouldn't fit. Not a stamp - casting numbers, raised numbers cast in.

 

Can't thank you enough - Tim, Nick and the rest of the guys

 

Here's my experience with a T-18A. When I rebuilt my CJ-7, I decided to go from an I6/T-150 combo to an AMC V8/T-18 combo. I got my T-18 from another '79 CJ-7 in a junk yard. I used my original bellhousing, there was NO adapter between the bellhousing and trans, there WAS an adapter between the trans and transfer case and I used my original skid plate/cross member. No special parts needed - a very nice straight forward swap! I did have new drive shafts made up - not sure if I could have used any factory ones or not. My understanding is that the T-18 was never offered in the CJ-7 behind the V8.

 

Daveg,
Sounds like someone had swapped a Ford T-18 into that Jeep you got the trans from. The Ford T-18 bolts right up to the T-150 bellhousing and has the correct input shaft length. The Stock Jeep T-18 DOES NOT bolt right up to the T-150 bellhousing without modification as the case has a completely different bolt pattern on the front and does NOT have the right input shaft length without the adapter. You actually have a better set up as it will be 1" shorter than the stock set up which is good for driveline angles and length. I've built literally hundreds of Ford T-18's to Jeep transfer cases because with the use of the T-150 bellhousing it is a virtual bolt-in, and because the '77-'79 CJ T-18's are so rare. I've also converted tons of Wagoneer/Pickup T-18's using the Ford case and Main drive gear for the same reason. This is a common practice that has been going on for many many years. Nickmil.

 

Nick, thanks for clearing that up. It looks like the least expensive way for me would be to pull and buy the Ford T-18 for $60.. Then find a Wagoneer/Pickup T-18 and use the transmission to TC adapter and main drive gear.
I have questions about the driveshafts. How do I find the right lengths? Do most owners construct their own driveshafts? If not, who does this type of work? How much would it typically cost to have both shafts done? I have never done anything more then basic mechanical work on my vehicles. That said, I’m going to strip down my 79 CJ5 and restore it. Hopefully, without spending too much $$.

 

I will need a different length drive shaft when I swap into the T-18. How do I determine what length to use?

 

Measure, measure, measure! Measure the yoke-to-yoke distances before you put the trans in, then again after. You can then tell the shop either the change needed, or what the yoke-to-yoke distance now is. Mike bought an all-new driveshaft - having your existing shafts lengthed and shortened should be less money.

 

That's exactly what most people do. It's about the most cost effective way to do it IF you can find both tranny's for a reasonable cost. You will need to drill and tap 6 holes in the back of the Ford case for the Jeep adapter and plug the lower left factory bolt hole or it will leak oil. You can also use a Scout T-18 as the output shaft and adapter will work fine also. It's virtually the same output and adapter as the Jeep with model 20 transfer case. Nickmil.

 

I would like to be as accurate as I can be, so midpoints of the U-joint bearing caps should be a good bet. Should I have body weight bearing on the springs when I take the measurement?

 

“Jeep CJ's from 1976 to 1979 had the option (though more rare than not) of the T18A, the wide ratio version (6.32:1 first gear). No front adapter plate is present on these models, and they have the shortest of the Jeep T18 input shafts.”
Statement from Novak




OK, I have it straight on what I need and don’t need for a Jeep to Jeep T-18 swap concerning adapters.

From all the information gathered from this forum and the statement above from Novak.

The factory JeepT-18 can’t be installed in any other bellhousing without an adapter

 

Well, anything is possible but I was right at the junkyard Jeep(1979 CJ7) I got the trans from as it was removed. Everything looked original and the vehicle looked pretty stock. I noted down the VIN # at the time. The third digit was an "M". According to my documentation, the original trans was a 4-speed. That would mean someone pulled the AMC 4-speed trans and installed a Ford 4-speed trans?????? Seems a little unlikely. Are there any tags, casting marks, etc that would identify it possitively?

 

If you can locate the production ID tag on your Ford T18 top cover, you will find a lettering code akin to “D7T3...”. This may help identify the year of transmission, as Ford uses the first letter to designate the decade (C=’60s, D=’70s, etc.) and the year is called out by the second digit.
Additionally, the T18 has three bronze synchro rings. You will also notice the power-take-off port at the right side of the case. Novak

I would like to add the FSJ factory T-18 does come with an adapter for the bellhousing.