Granny low 4 speed

Since the rebirth of the Jeep, Ive realized the rig is way to long legged. After much contemplation on gearing options considering gears and total tranny/tc length I think Ive decided to run a sm465 since advance adapters now offers the 7/8" thick adapter for it. What Im wondering is if anyone has used this 465/d20 combo with that adapter? Whats the total length difference between it and the t14/d20? Does anyone have a said adapter laying in the garage looking like it wants to be shipped to Washington?R)

 

I'm working on one of these now. Looks like it will be about 1.5-2" longer than my T-15/D20 combo. not to mention easily 100lbs heavier. IMHO, I'd go the ford t-18 route before the SM465. Lighter and easier to work on. The only reason I'm gettin the 465 was that I got a screaming deal on the trans, adapter, and rebuild kit.

 

I like the SM-465. It's a great heavy duty transmission with a slightly lower first gear. Having said that I'd also recommend the T-18. A little more compact, lighter, and MUCH easier for the guy at home to work on/convert to a Jeep transfer case. Dealing with the mainshaft bushings is a pita even for people like me that have the right tools. I recently had one that my 20 ton home press and heat wouldn't budge one of the bushings. I had to take it to work and use the big press.

 

Now you tell me--------

 

I'll attest to the ease of the T18. I rebuilt mine and installed an AA adapter to the D20 at home with basic hand tools and absolutely no transmission rebuilding experience. I was really surprised at how easy it was.

Good luck with which ever one you choose.

 

Howdy, I did the AA T18 to Dana 20, it was easy to rebuild the T18 and it is more managable size wise and weight wise. I am happy with it, so good luck!!!

 

None of these transmissions are really "manageable" by any stretch of the imagination. They are all big heavy monsters by comparison to the T14 you are removing. Make sure you have a helper when it comes time for the install.

 

Different beast but I have a SM465 and D18. I used the Novak adapter and really like their products, great customer service as well. http://www.novak-adapt.com/catalog/kit_462.htm

 

Thanks for the input folks! So my thought is the adapter for the t18 is 3+ inces, right? It seems to me they will all be "fun" to adapt in there, and they are all of somewhat similar in size-huge compared to the t15 and all have great compound low 1st gears. I know, Im generalizing a bit, but bear with me. So that means the only distinct advantage one will have over the rest of the granny 4 speeds will be the depth of the adapter. My understanding of the research says with any of the other all the tranny/tc//adapter will add 3.5-5" to total length over stock. So, with the advance adapters sm465-d20 kit, the adapter plate is only 7/8" thick. http://www.advanceadapters.com/products/pn-50-4703/

It makes sense to me. Has anyone used this particular adapter before? I would prefer novak but they dont offer the size advantage this one does.

The main concern is with the height and flex of the Jeep, I wont have a 11" 45 degree driveshaft. If I cant keep the combo short and gear it down considerably, then its back to the drawing board.

 

I don't know the over all length difference between the t15/d20 vs t18/d20 combo, but the adapter plate itself is only 1 inch think. The tranny is longer but the bell housing is shorter, so there really isn't much over length gain. In fact I was able to put the stock drive shaft back in to drive the jeep to the drive shaft shop. I wouldn't drive very far or wheel it that way but it did go back in. With that said, it couldn't have shortened the rear shaft more than a couple of inches.

If you have an AMC engine it may be easier to swap in the T18 as you can use many off-the-shelf jeep parts. Same could be said about a GM engine and and SM420/465 tranny,

 

All the stock and aftermarket adapter's I've seen and used for the T-18 to model 20/18 transfer case were 1" thick. The ones for the Jeep 300 t/c are longer. If you have a T-15 now the path of least resistance is to find a Ford T-18, a '76 and newer CJ bellhousing, and use either a Jeep, Scout 2, or purchase an adapter kit for the 20. That will give you the shortest combination possible. There's more to it but it's pretty easy to do.

Give me a call in the next couple of days and I can tell you what you need to know. I've built/converted well over 100-150 T-18's for Jeeps in the last 15 years....
I know you have my phone #...

 

Alright, that clears that up pretty well. Ill give you a ring soon Nick. I think we are due to knock the dust off of your Jeep anyway and make a run!

 

The Novak is only 1" thick. I have it in my 71' and the rear driveshaft is around 17" long.

 

Yanno, but all those great big honkin gears in the case are pretty dang good for not breaking things. They might be big and heavy, but they just don't quit....

 

i pulled the t15 dana 20 and went with a t18 scout dana 300. with the adition of the 2.5 inch lift I installed the origional drive shaft fit perfect. i was tickled pink to not have to go and buy a new shaft. still need to get a new front shaft cause of my shackle reversal.

 

Great find roadhog304! That would be the perfect swap with the lower geared 300. I have been eyeballing that one also. My transfer case needs a rebuild anyway.

It would be nice to not have to lengthen my brand new drive shafts since the brand new front one already needed to be lengthened costing nearly the price of buying another new one.

 

i really like the combo but it was not cheap. i picked up both the tranny and transfer case separately off ebay. the tranny price was reasonable as it was completely rebuilt but the scout dana 300's are getting hard to come by so i thought the price was high but i wanted it so i got it. i did find another scout dana 300 on craigslist but called to late on it. was on there forever and he ended up selling it for $125 bucks. i missed out but that is just how it goes some time. i twin sticked the t case and it works really well.

 

x2

 

Sorry for my ignorance, but how does the Jeep dana 300 differ from the Scout 300? I have a CJ-7 dana 300 sitting in my shed waiting for a project to put it in, and I would like to put a T-18 in my '67 project (it has a T-86 with T-90 gears). Also, is that a Ford or Jeep T-18?