T90 To T18

Hey all, new to the forum. I recently purchased my second CJ5. It’s a bit of a Frankenstein. The frames is a ‘52 and the tub is a ‘73. It has a Chevy 350 motor that was mated to a T90 and a Dana 20 t-case.

My first CJ5 is a ‘77 with a straight 6 mated to a T18 with a Dana 20 t-case.

I want to replace the t-90 with the t-18. My problem is the input shaft length. The jeep has an adapter plate for the t-90 but I don’t know if it will work with the t-18. Also will I need to replace the clutch and flywheel? The spline count is the exact same. Any help is much appreciated.

 

No T90 front pattern is way different than any of the IH, Ford or Jeep T18 patterns.
Som what make of Borg Warner T18 do you have anyway ?
Regardless you must either use a bellhousing adapter or modify your transmission face to fit onto the GM pattern.

Click onto Novak Transmission research: Novak Conversions Transmission Knowledge Gateway

 

It might be easier to use the SM465 with that 350 V-8.

 

Just a friendly comment ... this topic has been covered again and again in earlier threads. Search the old posts using some appropriate key words and one of the online search engines like Google or Bing. For example site:earlycj5.com T-18 transmission swap - Bing

First Post! Welcome from Boston!

 

I did read Through a lot of the older posts. None of them covered exactly what I was doing. Hence the new post. Thanks for looking out though

 

You’re probably right but I don’t have access to one and the T18 kit is only $200

 

The front pattern looks identical but I’ll do some measuring tonight when I get home.

 

Novak sells a bellhousing to put a 77-78 Jeep T-18 behind a Chevy motor.

 

Yeah I saw that. I was just hoping it would slap right in without spending any money.

 

T18 1 B

 

Now that's funny right there.....
I wonder how many times that comment has been made about Jeeps and conversions?

 

Pretty much every time I would expect.

 

I didn't want to be the one that typed it

 

I'm in the middle of a similar swap, yeah, it's more than a drop in deal, but it's doable. Spend some time getting your head around what you have and what you need and how available the parts are.

 

It really is about the easiest thing you can do for a bolt-in swap.lots of people have spent 3xs that on the same swap sourcing parts from worse suited donors.

 

The Chevrolet 350 and the Buick v6 have the same bolt pattern on the back of the bell housing (but not the same from bell housing to engine). They also use the same clutch splines.
Might help you in doing your research.

 

Tag number says 1977 CJ5 or CJ-7 with a 4-speed manual transmission (a wide ratio T-18).

 

Thing is the bolt pattern between the two transmissions are nearly identical. The shaft is about half an inch shorter on the T18 and the spline count is exactly the same. I was really hoping that I don’t have to replace the clutch, pressure plate, throw out, and flywheel.

 

It came out of a 77 CJ 5

 

In many cases, all that needs to be swapped is the clutch disc only to get the correct spline count and shaft diameter, where all the rest can remain the same. In your case, the T-90 has the truck/wagon (longer) input shaft to work with the adapter. I'm not aware of alternate input shafts for your T-18 that may be suitable for your swap. You may be better off looking at an aftermarket bellhousing to mate your components.
-Donny