Manual Tranny Upgrade for the 289 Ford

[Apebrains]

Hey guys.

Fairly new to the heavy drivetrain work (engines/transmissions), so I figured I'd come here to ask you gurus your thoughts. So as you can see on the left, I've got the CJ5 with a Ford Mustang 289 V8 bolted in there. It is, however, still running the original T-90 Transmission , rebuilt at this point, of course. When I get up to any reasonable speed, the tranny is obviously whirring pretty fast at the top of that 3rd gear, so I was wondering if any of you guys knew of any decent MANUAL tranny that I could bolt in behind that 289 with minimum hassle (minimum of course being relative) that would have 4 or 5 gears? I'd like to try to bump my fuel efficiency, and reduce my R's at middling to higher speeds by adding a few more gears to the line and bringin this old girl into the 21'st century...Kinda... Any thoughts on the matter?

I appreciate any feedback in advance! Thanks guys!

Oh yeah, and I certainly wouldn't mind if it was somewhat attainably priced...

 

[coldair]

Good luck its not going to be cheap. I would say go with a NV4500 if you want a Overdrive Transmission but your looking at $1500 or more depending on how much you can get one for and then you have the adapters.

 

[Apebrains]

WOOO yeah, you're not kidding, that bad boy isn't cheap. Would it be possible to bolt an AX15 up in there? Cheap isn't necessarily what I'm going for, just attainable, and I could see 1500 as doable, albeit some time in the future. Why did you suggest that one in particular?

 

[BusaDave9]

I put a Ford T-18 into a CJ. It easily mated up to my bellhousing.
You have a ford engine that is mated up to your jeep tranny.
I would think it should be easy to find a ford tranny to use. Broncos came with some good transmissions such as the T-18 and NP435. I think your T-90 has a 7 inch input shaft. I don't think you will have much problem there.

I think you will have more of an issue bolting the ford tranny to your TCase. Broncos also came with the Dana 20 TCase but the bolt pattern was different than the Jeep Dana 20 .

I think your best bet would be to get a ford tranny with the TCase. That would mean you would need to fabricate or modify your tranny mount and modify the lengths of the drive shafts.

 

[coldair]

Thats just a heavy duty 5 speed is why i said that. you could do a ax15 but you will be in it alot of money too $669.00 to adapt the Dana 20 then another $300 to adapt the motor to the Transmission .

 

[coldair]

I put a Ford T-18 into a CJ. It easily mated up to my bellhousing.
You have a ford engine that is mated up to your jeep tranny.
I would think it should be easy to find a ford tranny to use. Broncos came with some good transmissions such as the T-18 and NP435. I think your T-90 has a 7 inch input shaft. I don't think you will have much problem there.

I think you will have more of an issue bolting the ford tranny to your TCase. Broncos also came with the Dana 20 TCase but the bolt pattern was different than the Jeep Dana 20 .

I think your best bet would be to get a ford tranny with the TCase. That would mean you would need to fabricate or modify your tranny mount and modify the lengths of the drive shafts.

I think he is looking for a over drive you really wouldnt be changing anything by putting a T-18 in because you still end up with the same final ratio. Well besides getting a compound low.

 

[Saddle Tramp]

Find a Ford T-18 Transmission in 2 wheel drive. You may be able to get a bell housing that will bolt to both your engine and the T-18 at a bone yard for cheap. The only adaptor you will need is for the rear of the Transmission ($509 retail at Novak) which includes a new rear shaft and adaptor plate that can be used for a Jeep version Spicer 18 , Dana 20 , or a 1980 Scout Dana 300 Transfer Case and you’re good to go with a granny low and in your case by reusing the Spicer 18 the ability to add an Overdrive . Woo Hoo!

Try these:

http://www.novak-adapt.com/catalog/kit_188.htm

http://www.jeeptech.com/trans/t18.html

 

[coldair]

Find a Ford T-18 Transmission in 2 wheel drive. You may be able to get a bell housing that will bolt to both your engine and the T-18 at a bone yard for cheap. The only adaptor you will need is for the rear of the Transmission ($509 retail at Novak) which includes a new rear shaft and adaptor plate that can be used for a Jeep version Spicer 18 , Dana 20 , or a 1980 Scout Dana 300 Transfer Case and you’re good to go with a granny low and in your case by reusing the Spicer 18 the ability to add an Overdrive . Woo Hoo!

Try these:

http://www.novak-adapt.com/catalog/kit_188.htm

http://www.jeeptech.com/trans/t18.html

Good thinking you know i never even thought about it but all he would have to do is put a Overdrive in and would be good to go.

 

[Apebrains]

So all told, at the end of the day, this swap would cost me about 2,500 rocks, or something in that range? How difficult is it to install the Overdrive ?

 

[Sasquach]

You should have a dana/Spicer 18 Transfer Case and not a 20 as implied, there is an Overdrive available and a bolt in affair afaik.
Check with Herm's Herm The Overdrive Guy

 

[Apebrains]

Good god, this just continues to crank closer and closer toward that 3 grand mark, if it isn't already past it. Is there no way to do this more affordably? I'm just a lowly worker bee... Perhaps I'll just have to make do with the three speed for now? I think 2k would be the most I could ever really put into this project, at least for this particular purpose. The T-90 is just so relatively inexpensive, I figured there would be something out there that could replace it a close to it's cost. Guess there's just too many incompatibility issues... Thoughts?

 

[BusaDave9]

You should have a dana/Spicer 18 Transfer Case and not a 20 as implied, there is an Overdrive available and a bolt in affair afaik.
Check with Herm's Herm The Overdrive Guy

Yes, you have a Dana 18 TCase. I misled you.

You can get a Ford manual Transmission and TCase for a lot less than $2500. You have a 7 inch input shaft. That's what you want to look for. I am no Ford expert but I do know they are more standardized and much more common. A ford site might help you more but there are so many Ford 4x4's that it should be easy to find something that will bolt up to your Ford V8. Use the Ford TCase too. No adapters nessisary. You won't have to replace tcase or tranny shafts.

 

[Apebrains]

So essentially I'd end up with pretty much a total Ford powertrain, with a Jeep body and frame? Lol, something about that chills my spine, but I guess it's the price I pay for having the fun of all that power under the hood. Alright, sounds like I have some pricing to do. Gotta do some scrapyard searches. Thanks for all the tips guys. I really appreciate it.

So what do you think, an old school Bronco drivetrain with the T-18 , than just yank it's Transfer Case as well?

 

[Sasquach]

Transmission change is not gona alter his 1 to 1 ratio in high gear and OP suggests lowering engine RPM as the goal.
An Overdrive will though and Herm's has them for $950, not sure if that gets all needed goodies to make a complete system.
I have ridden around in an old Willy's with the OD and they are pretty cool.

 

[Apebrains]

So wait a seccy....what you're saying is that this Herm gent will allow me to put an Overdrive on my existing T-90 , giving me an effective 4th gear, and thus reducing my R's at cruising speed?

 

[BusaDave9]

Yes, Listen to Sasquach. I assumed you needed a replacement tranny anyway. The Overdrive will mount on the back of your Dana 18. Like this. It's the silver part:

You can't shift on the fly so it's not quite like haveing a 4 speed. When you are on the street you use the Overdrive for 3 tall gears.
When off-road disengage the Overdrive .

 

[Apebrains]

No no, the tranny's in good shape, sorry if I miscommunicated that. I'd just like to be able to reduce my R's at speed. The damn thing drinks so fast, my wallet can hardly keep up with it, but more than that, I just don't want to stress the tranny any more than I need to. Now of course there's always the option of just driving slower, but what fun is that?

So this sounds to me like I'd be sacrificing acceleration for lower RPMs, while still maintaining the same 3 gear setup, am I correct? It would essentially be like another Transfer Case that I would shift while at a stop so as to change the overall ratio of all three gears? Is this kinda like what Honda had in their old CB900's (sorry for the bike reference, but it's the only thing similar that I could think of at the time...)? I appologize for my ignorance, but hey, gotta learn somewhere!

 

[Saddle Tramp]

So all told, at the end of the day, this swap would cost me about 2,500 rocks, or something in that range? How difficult is it to install the Overdrive ?

My guess is-

-Bone Yard Bell Housing = $50 +/-
-Bone Yard Ford T-18 = $AMC 150
-Rear Adaptor (T-18 ) - $500
-Saturn Overdrive (new) $1,000

Total = $1,700 +/-

You may get lucky and find a Warn of Saturn Overdrive used and save a few bucks. Install is not that bad. Follow this:

http://www.jpmagazine.com/howto/23638/index.html


PS: The T-90 is about 9” long and the Ford T-18 is about 11-3/4” long so with the adaptor plate of about 1” at the back of the Transmission the Transfer Case will move about 3-3/4” to the rear. Better add another $300 to your costs to have the drivelines reworked, for a total of $2,000+/-.

 

[Saddle Tramp]

With an Overdrive in a Spicer 18 you can use it through all of the Transmission gears which can be quite handy. So, the way I see it is if all you want to do is spend around a $1,000 today you could add about 25% to your top gear ratio or as you called it a 4th gear. The best of all worlds still would be to have the T-18 bolted to a Spicer 18 with an Overdrive and I still think you could get it done for under $2K if you do the work yourself, except the drive lines. With new drive lines, not reworked it could cost you over the $2.5K

 

[Apebrains]

Still trying to make sure that I understand what I'll be getting though. If I put the Overdrive on the T-90 as is, I'll be achieving what I put in my last post? Then if I decide to down the road, I can install the new tranny, etc? And I'm not sure that I completely understand the operation of the OD. Does that put another lever next to my shifter that I use to drop it into Tall gears and back down to the shorts (when stopped of course)?