More T18 Discussion...

Welding mount tabs onto either the case or the bellhousing is not a practical solution for me....I can barely weld sheet metal that will stick together.
Heard back from AA about the 'short' 23t input shaft on their site - this was my email - in hindsight I should have just kept it simple and asked about the OAL and the stickout length and stayed away from useless/confusing details:

INPUT SHAFT T98-T18 23 TOOTH 4:1 1ST GEAR RATIO
Product info:

• SKU: 716016-A
• Manufacturer part number:
• For product: https://www.advanceadapters.com/4622

From: James Orofino - jc_orofino@hotmail.com

Looking at:
INPUT SHAFT T98-T18 23 TOOTH
SKU: 716016-A

Details at the bottom say:
INPUT SHAFT T98-T18 23 TOOTH SPLINE IS 1-1/16" 9 1/8"OAL, 308N BRG, T19-14

Can someone confirm that the OAL length, and not the stickout, is 9 1/8". I have a jeep 4:1 T18 with the 12" OAL (9.5" stickout), 23 tooth input shaft, and wondering if this would be a replacement swap to it to a short 'ford' style 6.5" stickout. thanks!

I've received 3 responses so far - from Orren at noon:
Hi James,
The overall length is 9-1/8”
Best Regards Orren

from Alex at 1pm:
That shaft does not have the same stick out as the “Short” style Ford shaft

from Vic at 2pm:
That is correct

Yup...that cleared all that up....doesn't matter if I can't mate it to the bellhousing....Oh, I just figured the solution - swap to an AMC360 and find an early AMC OEM bellhousing from before they went to the ford butterfly.

 

would that make it an odd-fire 270 - sounds like a really cool engine actually.

 

What I used for both my T-18 conversions.

 

So revisiting this topic a bit....starting to narrow down the realistic options and price differences....as a starting point of reference, current T14 transmission length (including all adapters) between the bell and the D18 is 11.3". The somewhat standard ford T18 swap with the short input shaft and direct mount to the BOP bell (no adapters) and 1" or so D18 adapter is 12.87".
The jeep NR T18 I am looking to work with has 2 issues to be addressed (as mentioned earlier in this thread):
1) the slightly long input shaft with 9" stick out
2) the jeep bolt pattern and lack of additional mounting bosses make direct mounting to the BOP bell difficult/beyond my capabilities

So the reasonable solutions:
1) Use the Novak 1415 adapter (https://www.novak-adapt.com/catalog...ransmission/gm/jeep-t18-bh-adapters/kit-1415/) to mount the T18 with current long input shaft to the BOP bell.....this 1.75" adapter along with T18 and OEM D18 adapter yields 14.2" total length at cost of $274....thats about 1.5" longer than the 'standard' short T18 length, and not much additional cost.

2) Use a short 23tooth (NR) input shaft from AA (https://www.advanceadapters.com/4622) to mount directly to the BOP bell....BUT, given the Jeep t18 bolt pattern and no additional tabs, I would need to swap the OEM BOP bell for an AA GM/BOP bell (https://www.advanceadapters.com/5375) that accepts multiple transmission bolt patterns including jeep T18. This combination would yield a very short 12.5" total length at a cost of $588 for the input shaft and bell.....although I am still just a bit uncertain all of the details that might be required to swap the input shaft as Nick discussed above etc.

Just for fun, a ford NP435 popped up cheap locally, and the 10.7" case length caught my eye as its over an inch shorter than a T18. The ford bolt pattern can be made to work directly with the BOP bell, but it requires an expensive and long D18 adapter - whether from Novak or AA, its around 3.5" long for total length of 14.2" at $600 (plus the $100 purchase price of the NP435)....

And just for comparison, an sm420 swap would be similar to the np435 in that its a short case, but requires an expensive and long D18 adapter....total length of 15".

So basically, I kind of think the 14.25" length is reasonable (its in the same ballpark as the sm420 and np435 swap lengths), and the easiest, most cost effective solution is to use the current longer input shaft, adapter between the bell and jeep T18 to work with the bolt pattern and longer input.....For $400 additional plus some hassle with working out the short input shaft install, I can save the 1.75" in additional length. What do you all think is the better choice?

 

Fellas - please recognize that the T18 I have does not have that extra ford ear - thus requires welding a mounting tab on the BOP bellhousing or on the T18 case - or maybe some creative homebrewed solution. Neither are options for me......What I am really asking is how important is it to save the additional 1-1.5" in total length. With a replacement AA BOP bellhousing, then I can mount directly to the bell with the Jeep T18 (after going with a shorter input shaft), but I am not feeling its worth it. Using the OEM bell plus the adapter is simple, straightforward, cheap - but does come at the downside of a bit more length. Again, the question is how important is the 1.5"....or in comparison to Doug's mount, it'll only be an inch longer.

 

its not about the easiest route, or the best route for someone else or any of that.....its about a very specific question regarding length associated with a T18....so lets try again:

this is maybe more what I am asking, but instead of for some fancy double cardan etc, what about for a standard single u-joint drive shaft. At what point is too short.....