AX15 bolt pattern ?

[Ggg]

From what I have been told a Jeep AX15 bellhousing has the AMC BP. I am trying to mate it to a Chevy SB. So I bought an AMC BP to Chevy SB adapter. I get the adapter and only one of the AX15 bolt holes matches. I call the mfg. whom also said the AX15 is an AMC BP and explain the problem. They say send the adapter back, when they get it back they bolt it to a T176,T90 (AMC) bellhousing and all the bolt holes are fine. They even send me a picture of it.
So, are there some differences between AMC bellhousing BP and the Chrysler Jeep bellhousing BP? From what I am seeing they are not the same like I was told.

 

[Saddle Tramp]

In my mind, the AMC bolt pattern only refers to the bell housing to motor attachment. The transmissions were all different except autos which have the bell housing (so to speak) as part of the transmission case and the Iron Duke 2.5 used in CJs as it was a Chevy motor and bolt pattern. This will only apply from 1972 through 2006. From 1971 and back (to sometime in the 60s) Jeep bought motors from both Rambler (became AMC) and GM. In fact in the late 60s GM sold the tooling to Jeep for the V6 they were using only for GM to buy it back from Jeep when the oil shortage hit in the 70s. GM need a more economical V6 fast to compete so Jeep let it go. AMC bought Jeep from Kaiser in 1971 so it was natural for them to use their own motors, the AMC I6s & AMC V8s.


PS: Did I misunderstand your question? When you said bolt up the AX15 did you mean the bell housing or the transmission?

 

[Ggg]

Strictly dealing with the AX15 v/s AMC bellhousing to block bolt patterns, not Willys or Kaiser Frasier. From what I have seen the AX15 does not have the AMC BP like most people think it does.

 

[Ggg]

I found my answer.
I just got off the phone with an old friend who is a long time "authority" on AMC Jeeps and he said most certainly the Aisin Warner trannies are not AMC bolt pattern bellhousings, I would assume this goes for all DCX made Jeep trannies since that is when the engine was changed from a AMC made block.
Just a little fyi when doing an engine swap.

 

[carnuck]

Just a little something to think about. What motor was the "AX-15" bolted to? The 4 cyl has a Chev 60 degree pattern. The Dodge motors (V6 and V8) have a Mopar pattern. The 4.2L and 4.0L Jeep motors (inline 6, not V6!) have the same bolt pattern as the AMC V8s. Is that clear enough?

PS: This is from 30+ years as a tech.

PPS: AX-15 was built by Aisan Warner (a Toyota subsidiary) and outsourced, not built by Mopar DCX. Mopar trans are New Venture made.

 

[Ggg]

All I can say is with the upmost certainty the 98 4.0 AX15 does not have the AMC bolt pattern. I have compared my AX15 from my 98 TJ 4.0 to a AMC V8 and I6 258 bolt patterns and they are not the same.
carnuck I am not trying to argue at all, in fact I had always been told, read, and believed what you said about the DCX v/s AMC BP to be true until I started this engine swap ran into match up issues and physically compared the two patterns myself. Even the adapter companies thought the same was true, until I asked them to actually physically compare them. I then talked to the above mentioned friend and he told me the DCX engine BP is not the same as AMC BP. The Dodge and 4 cyl engines I can't comment on as like I said my info only pertains to the Jeep TJ 4/0 AX15 BP v/s AMC BP.

 

[Ggg]

Oh BTW carnuck I ran across this video I think you may appreciate.

 

[carnuck]

Cute video! When I get a chance I'll post the pic of my 304 with an AX-15 on it (and a 4.0L with T18A) using the stock bellhousings.

 

[Ggg]

Is your 4.0 and AX15 from a YJ or a TJ?

 

[Ggg]

Here is a pic of the first adapter with a AMC to GM BP. I marked which holes are "ok", which are "NFG", and where new holes are needed. This is of course AMC relative to a 98 TJ AX15 BP. The unmarked holes are either GM or dowel holes.

 

[gearheadmb]

So I'm confused, is the bolt pattern the same or different from a 258 to a 4.0 litre? I was considering doing a stroker for my 90 with a 258 in which case i will need a 4.0 block to bolt up in its place.

 

[carnuck]

Is your 4.0 and AX15 from a YJ or a TJ?

I have two 4.0L motors. One from a '93 ZJ and one from a '99 TJ (building my stroker 4.6L from that one) and access to a 4.0L from an '02 WJ as well as 2.5L Jeep, 232, 258, 304, 360 AMC, 327 Nash, BG242 IH, 304 IH, 345 IH, 454 Chev, 327 Chev, 2.8 V6 Chev, 2.0L Chevota (86 Nova) and a couple others squirreled away in storage.

 

[Ggg]

So I'm confused, is the bolt pattern the same or different from a 258 to a 4.0 litre? I was considering doing a stroker for my 90 with a 258 in which case i will need a 4.0 block to bolt up in its place.

All I can say with certainty is a 1998 TJ 4.0/AX15 does not have an AMC bolt pattern, carnuck may say different. I am trying to tell if his 4.0 and AX15 he says have the AMC BP are YJ or TJ versions but he didn't answer the question. I am starting to think possibly the TJ AX15 has a different BP than the YJ but not sure yet.

 

[carnuck]

I said I have a 4.0L from a '93 ZJ (in my '84 J10), '99 TJ and access to an '02 WJ. TJ is a Wrangler and the other 2 are Grand Cherokees. (I also have a 4.2 from an '80 Eagle, '83 J10 and the AMC T5 bell I have from the '83 lines up to them all)

I even asked the Strokers board, where they mix and match all sorts of 4.0L stuff from up to '05 and down to '87. All say the pattern is the same. In '71 and earlier there was a different pattern for AMC 6 cyls that was different than the AMC V8s. (one year only 258 with the small pattern)

 

[Ggg]

the AMC T5 bell I have from the '83 lines up to them all)

This is the phrase that was not said in your first response that actually answered my question.

I don't know what else to say other than it seems there was more than one BP used.:???:

 

[carnuck]

Wait a sec! Maybe you have the NV3550 trans? That one has a different bell for some reason.

 

[volaredon]

I'm watching this thread because I have a different trans swap in mind on a different vehicle involving an AX 15 sourced from a 2WD Dakota this swap info may come in handy.

 

[gearheadmb]

Well that clears up everything!!!:scratch:

 

[Ggg]

Hmmm I can only assume my trans is an AX15 original to the 98 TJ. I am not the first owner, I know the previous owner well and he has never said the trans was replaced and he knows his previous owner as well.
Another thing is a friend of mine has an 02 TJ with the NSG 370 and bought the same adapter as I did and had the exact BP issues as I am, both of us are trying to get an adapter that works for our engine swap.
Here are some pics of my bellhousing, later I can take some of my trans, since it is still out.

 

[Ggg]

The more I look at this the more weird it gets.:roll: I believe my trans is an AX15 based on the throwout bearing retainer shape and the latteral bolt lug at the rear of the left side of the trans. I am using the pictures on Novak's site as reference.
I have a hunch what happened is a mistake on the adapters side of this which is a long story.
Here are some pictures of my trans, and a comparison between my FSJ T18 bell and the AX15. They are very close, in fact close enough to work with my new adapter. Which is why I believe a mistake was made by the adapter mfg. but they never said so. At least this is the only logical explanation I can think of right now. So I must say the two BP's are not exactly the same but close enough to work. I do not know what pattern the first adapter was but it was seriously jacked up and I have no idea exactly what bell they mounted the first adapter to in order to send me the pictures showing the first adapter was an AMC. That was when I started this thread thinking the AX was not an AMC BP. Now that I have all my parts back and in my hands for me to compare things are looking a bit different than I was led to think.
Pictures L-R, Top -Bottom;
#1- The T-18 is on the right. Three bolt holes from the T18 do not match (12;00, 2:00, 10:00) and neither do the two bottom on the AX.
#2- The AX15/GM adapter bolted to the T18 using all of the holes provided in the adapter except the two bottom holes that are in the AX bell.
#3- Right side AX15
#4- AX15 throwout bearing retainer with large mount unlike the NV3550 which has a small mount.
#5- Left side of AX15