Trans and transfer case swap in cj5

[cj5ben]

I have been building my 70 CJ5 with a buick 231 and T-14 Transmission T-18 transfer off set Dana 44 rear axle for a few years now. The jeep as it sits right now is a basically a rolling chassis with the engine mounted. I am wondering how easy it would be to do a T-18 4 speed Transmission and 20 Transfer Case swap? What would be the estimated cost and ease of swap? Where would be a good place to find them?

Thanks!

 

[MN CJ7]

have the T-18 /Dana 20 CJ5 Combo in the classified. The axle is centered and works with this Transmission . I would have to look and see if axle mtds & such is correct for 70's version.

Send me a pm about your interest and what you would do as they say.

Fred



T-18 Transmission and Dana 20 Transfer Case …. Came out of a mid 70s CJ5 so its correct one
http://www.jeep-cj.com/forums/classifieds/viewad-230

AMC20 with moser 1 pc axle… this is a centered axle
http://www.jeep-cj.com/forums/classifieds/viewad-224

 

[MN CJ7]

Info on axles for your review....



http://www.jeeptech.com/axle/d44.html



Dana 44 Swap into CJ7



Several variations of the Dana 44 have been used as the rear axle in Jeeps, all of them use a 8.5" ring and pinion. The Dana 44s with the two piece shafts are 19 spline or 27 spline and the versions with the once piece shafts are 30 spline.
The R&P ratio ranges supported by the carriers are 2.87-3.73 and 3.92-5.89. Not all ratios are available for all the variations of the Dana 44 .
CJ Dana 44
Before 1972 all CJ Dana 44s had an offset differential since the Dana 18 Transfer Case has the rear output shaft offset to the passenger side. Before mid 1970, they used a 19 spline or 27 spline, two piece axle shaft. After mid 1970, they used a superior 30 spline flanged axle shaft.
The Dana 44 was introduced in the CJ line on the CJ3a starting with serial number #37549 (late '50). Earlier CJ-2As and CJ3As did not use the Dana 44 .
Starting in 1972, the Dana 20 Transfer Case was used which has the rear output shaft centered, so the rear axle has the differential in the center. From 1972-1975 the Dana 44 was used with a 30 spline flanged axle shaft. This Dana 44 uses 11" drum brakes and the most common ratio is 3.73.
After '76, the AMC20 was the the only axle used in CJs with two exceptions. Some CJ-7s with the Borg-Warner Quadra-Trac Transfer Case came with a 30 spline, one piece shaft, offset, narrow track Dana 44 . The other exception is in 1986, when CJ production was coming to a close AMC 20s were in short supply, so they used wide track Dana 44s in some of the '86 models. Bolt on compatible with any '76-'86 CJ, but wider than earlier narrow tack AMC 20s. Use of the Dana 44 in 1986 began somewhere between serial numbers ending with 049379 and 054173. The axles were flanged and 30 spline. Common ratios were 2.73 and 3.31.
All CJ Dana 44s use a 5 on 5.5" wheel bolt pattern.

Model/Version ​

Spring Pads ​

Wheel to Wheel ​

Years​

Dana 44 /CJ Narrow Track​

28"
50.5"
'50-'75

Model/Version ​

Spring Pads ​

​

Wheel to Wheel ​

​

Years​

​

AMC20 /CJ Narrow Track ​

​

36"
50.5"
'76-'81​

I am not well versed on the dana 18 transfer.... you say it is offset on the rear axle and I believe you. The T-18 in my CJ7 with the Dana 20 transfer is centered on the rear axle. So not sure if you can use a offset axle. At first guess looks like yes.... but you mention offse.

This info will get you going.....

spring pads differ in mtd pads centerline
Your Dana 44 might be the flange verion..... The change happened 1/2 way in the 1970 production year..... they do not list part numbers.

Fred

 

[Saddle Tramp]

The Spicer 18 Transfer Case comes in 5 different versions. Version #5 is known as the “large hole” 18. Small hole 18s have an input hole that is about 3” in diameter while the large home comes in about 4”. In fact the large home 18 is the same case as the Spicer/Dana 20 Transfer Case and as such the large hole 18 will bolt to up to any Transmission that came with a 20 behind it, like a T-18 . All 18 & 20 input gears are 6 spline except for the ones behind the T-14 which is a 10 spline gear. The 18 uses a 29 tooth gear and the 20 uses a 26 tooth gear so you will need to match them up with the proper case.
The good news is if you have the original drive train you should have a large hole 18. The bad news is your bell housing will not work with the T-18 as the T-14 has a square bell housing bolt pattern (the T-18 does not) and your motor bolt pattern is GMC so an adaptor, which could be just a special bell housing (check Advanced Adaptor or Novak) is in the mix but if you go this route you can leave the offset axels. The added bonus with keeping the 18 Transfer Case is the ability to add a Warn/Saturn Overdrive to the Transfer Case . Couple that with the T-18 granny low gear and wow what a crawl ratio!

 

[cj5ben]

Hey guys thanks for the help...

Fred-i am looking to keep my offset rear axle because off all the time and money spent on it- 5.38gears(which i might change again), full float, warn hubs, detroit locker, stronger axle shafts, and disk brakes

So for conformation are all 20 transfer cases are centered so my only option is to keep the 18?

Any recommendations for locating a T-18 Transmission ?

thanks
-ben

 

[mylittlecj5]

I'd look on SearchTempest - The EASY way to search Craigslist in your area for a Transmission . You can search Craigslist in many different ways to find what you are looking for.

 

[MN CJ7]

Any recommendations for locating a T-18 Transmission ?

thanks
-ben

Ben,

Yes... I put a link in classifieds for a CJ version of T-18 in the post above. The purple is a link.. I am also in the twin cities not sure where your are in WI, might come into play also.

T-18 Transmission and Dana 20 Transfer Case …. Came out of a mid 70s CJ5 so its correct one
http://www.jeep-cj.com/forums/classifieds/viewad-230




Could resell the Dana 20 , and you may need the longer shafts for the Transfer Case operation?

I know the transfer shafts are important for the T-18 & Dana 20 and would expect / guess it to be of equal importance for the 18 Transfer Case ....

The longer shafts needed because the T-18 is big and with out the shaft the 4wd/2wd shifter location will not be in the correct spot. There is a video there you can see if it looks and get a brief Idea dimention whys.

Thanks for the thanks,

Fred

 

[cj5ben]

I have some another questions-

What are the differences between the T-18 and the t18a besides a steeper first gear?

-Is length the overall length different?

-Different bell housing?

-Different input shaft length?

-Would the conversion with a large hole 18 tcase be the same between the two transmissions?

Thanks

 

[MN CJ7]

I have some another questions-

What are the differences between the T-18 and the t18a besides a steeper first gear?

-Is length the overall length different?

-Different bell housing?

-Different input shaft length?

-Would the conversion with a large hole 18 tcase be the same between the two transmissions?

Thanks

Quest 1
Not sure on the delta on T-18 , T-18a, and T-181b. Could be the a & 1b are the lower gears but not sure and do not think so. I have two T-18 Jeep CJ Transmission , both are T-181b...... but one is the 6:1 and one is 4:1 granny gears. MY 78 CJ7 vin shows it was stock with T-18 and it has T-181b on the casting. The only way to know is to take cover off and count gears. The rev and first gears are different and the gear they interface is also different. To change/puchase the gears is also relaitive extwigve but the gears can still be purchased... is my understanding. I puch second one for spares and when counted gears its a diff ratio.

I have not seen much in print on T-18 -1b case casting numbers... it might be the short CJ input shaft. There is only 2-3 (?)years you could get a CJ T-18 and most that was optional. My Transmission has 36k miles and the spare has 50k per owner that took it out to put in auto Transmission for his fathers use. These are not easy to come by and even harder in good shape.

Question 2
T-18 cases are the same... the casting mark does change T-18 , T18a, T181b. More Numbers? There are a few differences on the top cover.... Jeep T-18 will have a square opening is one way to tell if Jeep. But... in ans to question most say the cases are same in use/dimension. Internals are interchangable and can also use T-90 internals too.

Question 3
Bell housing can be used from several CJ Jeeps years. Many are already drilled and taped. Some have the spots but not drilled and taped. There are a few Transmission types that will have the correct bell housing and would match... not sure off hand.. but research will tell you. The full size jeeps have a longer bell housing... too long and the T-18 Transmission will have longer input shafts that cannot be used on CJ

Question 4
T-18 input shaft. To use the T-18 in a CJ you need the short Input shaft and only CJ use this length input shaft. That is why the Jeep CJ T-18 is more valuable. Others will requirre a shorter input shaft change and 1-2 internal gear changes too. Expensive parts $400 or so and will also need a press is my impression.

Question 5
No Idea... think the poster above ans that question. Seemed to know the 18 Transfer Case could be used with T-18 discussed it & also mentioned a few advantages.. I think that is what I read the other day. Get older than the 70s CJ and I do know that stuff.




Just FYI... pretty mechanical.... but I do not see myself rebuiding transmisisons need press and measurement tools. Same for regear and lockers... need pinion deepth measuement tools, new bearings for each type of axle, 44, AMC20 , Dana 30 , that are honed out so they can taken on/off the carrier w/o damage, need mag base measurement tool, case expander, gear set marking stuff, and extra shims.

I understanding wanting to keep your 5.?? gears on the rear. I am changing my gears 3.73 or 4.09 and lockers ft/rear. Gonna cost me lots of money because I cannot do it.

 

[cj5ben]

Fred- what is the ratio of the T-18 -1b you have: close 4:1 or wide 6:1?

 

[MN CJ7]

Fred- what is the ratio of the T-18 -1b you have: close 4:1 or wide 6:1?

There is desc information and a nice video in the classifieds for the one I am selling. I have a T181b with a 4:1 granny gear for sale. Still a very good Transmission .

Take a look there, it will show the sq top and condition inside & out.

Fred