mt pt tranny swap

moparneon00 · Post by **moparneon00** » Fri Dec 09, 2011 10:05 pm

Hey guys i bought a 2001 pt mt tranny for my 2.4 swap. I was wondering what tranny mount do i use. do i use a mt pt tranny mount or neon mt tranny mount? there both different, my car is a 2000 neon. please help

Post by **occasional demons** » Fri Dec 09, 2011 10:37 pm

I would imagine the neon mount, as the MTX is the same. What is different about the neon mount from yours? (Unless you have an ATX neon)

moparneon00 · Post by **moparneon00** » Fri Dec 09, 2011 10:45 pm

no i have mt mount. the pt tranny has two long mount bolts on the tranny it self. wasnt sure if neon mt tranny is the same

Post by **occasional demons** » Fri Dec 09, 2011 10:55 pm

That MTX should be the same as the one in the '01 to '04 RT/ACR neons.

You're going to have traction issues.

Edit: http://www.neons.org/forumdodge/trans.htm

moparneon00 · Post by **moparneon00** » Fri Dec 09, 2011 11:39 pm

so your saying its safe to use a neon mt mount for pt tranny because theres really no difference other than gearing.

Post by **occasional demons** » Sat Dec 10, 2011 10:34 am

Yes, they should be the same MTX, assuming the '01 PT you sourced it from was not PTGT swapped. In that case, you would be looking at a Getrag G288. I don't think they make a neon mount for that.

I haven't seen a PT to t350 mount set up, so I'm not sure about the two long mount bolts you mention. Hopefully someone who has done the PT MTX swap will chime in. When the time comes, I will opt for an N/A '02-'06 PT t350 if the car is still worth the effort.

chipdogg · Post by **chipdogg** » Sat Dec 10, 2011 10:54 am

The transmissions are the same externally. Use the Neon mount.

Only difference is the output shaft and ring gear.

moparneon00 · Post by **moparneon00** » Sat Dec 10, 2011 12:44 pm

thanks guys for info

a23dranger · Post by **a23dranger** » Sat Dec 10, 2011 9:43 pm

chipdogg wrote:The transmissions are the same externally. Use the Neon mount.

Only difference is the output shaft and ring gear.

Just wondering What are the differences on the output shaft n ring gear?

Post by **occasional demons** » Sun Dec 11, 2011 12:11 am

The number of teeth on the gears. If assuming he was thinking more of the 3.55 vs the 3.94, not the R/T vs the PT. That is what I took it as anyways.

chipdogg · Post by **chipdogg** » Sun Dec 11, 2011 12:22 am

Yes, tooth counts. Here's what they are:

3.55: 20 on output shaft (pinion), 71 on ring gear (FD = 3.55)
3.94: 18 on output shaft (pinion), 71 on ring gear (FD = 3.944444444444)
4.12: 17 on output shaft (pinion), 70 on ring gear (FD = 4.11764)

Counted by me on transmissions I have in garage.

There is a difference in material between 1st gen and 2nd gen/pt cruiser. Later transmissions are stonger, have more nickel in the gears. PT and 2nd gen ACR are basically the same.

a23dranger · Post by **a23dranger** » Sun Dec 11, 2011 10:56 am

ok yeah i knew that. Thought you meant something else chip. i dunno why. yeah the 1gn pinion and ring gear count is different then the 2gn/pt ring and pinion count.

and like you said material difference and syncro changes to between the 1gn and 2gn trans. or should we say hd vs non hd really.

OTHER thing is you have a 00 so you need to put a cable bell housing on the pt trans or convert your car to hydro clutch setup.

chipdogg · Post by **chipdogg** » Sun Dec 11, 2011 11:51 am

It's not different tooth count from 1st to 2nd gen. All 3.55's are same regardless of year, as are 3.94's.

Post by **occasional demons** » Sun Dec 11, 2011 1:11 pm

a23dranger wrote: OTHER thing is you have a 00 so you need to put a cable bell housing on the pt trans or convert your car to hydro clutch setup.

If you do swap bellhousings, be sure to have the turning torque checked on the differential. As the bearings may need re shimmed. Otherwise there is the potential to wipeout the output shaft and ring gear.

a23dranger · Post by **a23dranger** » Sun Dec 11, 2011 3:09 pm

chipdogg wrote:It's not different tooth count from 1st to 2nd gen. All 3.55's are same regardless of year, as are 3.94's.

On the 3.94 non hd 1gn trans there is a difference of teeth count on the differential ring gear and 1 tooth on the input gear compared to a 3.94 hd trans. i forget the order is but lets just say the the 3.94 non hd is 18/71 the hd is 17/67 you can't put an hd ring and diff in a non hd trans or vise versa with out swapping the input/pinion shaft

I don't know about the 3.55 but i can check as i have 1 3.55 non hd and 1 3.55 hd, plus 1 non hd 3.94 and 4 hd 3.94's.

http://forums.neons.org/viewtopic.php?f=89&t=352007

Drakito states it in the highlighted part Turbo: 2nd gen

And the diff turning torque you should have it checked when swapping bell housings. some get lucky,swap housing and never have issues but its good to do it. when i put my 3.94 hd from an 03r/t in my 98 coupe, the guy put new bearings and races in it. It measured out perfect but with the old half 1gn bellside/half 2gn trans side bearings the diff wouldn't turn

chipdogg · Post by **chipdogg** » Sun Dec 11, 2011 5:21 pm

a23dranger wrote:I don't know about the 3.55 but i can check as i have 1 3.55 non hd and 1 3.55 hd, plus 1 non hd 3.94 and 4 hd 3.94's.

Different tooth counts would make them different gear ratios. You can't mix the sets due to different material, the 1st gen stuff would wear out faster. I'm gonna run out and count right now a 1st gen and 2nd gen 3.94.

Edit.

Learned something new today. Tooth counts:

1st gen output shaft: 18 teeth Ring gear : 71 teeth

2nd gen output shaft: 17 teeth Ring gear: 67 teeth

Both are 3.94xxxx ratios. Weird. Must have missed that when talking to Ed.

Don't have any HD 3.55's except the one in our '04 and that one is staying there.

Post by **occasional demons** » Sun Dec 11, 2011 7:57 pm

Wonder why they changed to the 67:17 on the HD. Generally you lose strength with a lower tooth count pinion.

chipdogg · Post by **chipdogg** » Sun Dec 11, 2011 8:08 pm

Only thing I can think of is the 4.12 is already made of the stronger material and is 17 teeth. Has a difference in tooth pitch but otherwise looks to be the same. Save money in casting? Not sure how they make the stuff, obviously machining is involved at the end but I'm sure they start from a cast piece?

moparneon00 · Post by **moparneon00** » Sun Dec 11, 2011 8:17 pm

hey guys i have no choice but to go hydro because i used srt4 pedals for my 2000 dodge neon. I also found out that my stock hole in the firewall for a cable clutch is set to high for hydro clutch. so now i have to redrill a new hole in firewall.

chipdogg · Post by **chipdogg** » Sun Dec 11, 2011 8:22 pm

Have fun with that, hope you don't have ABS. I parted out a 2001 R/T with ABS and I have no clue how anybody is supposed to get anywhere near the clutch master cylinder with that clusterfuck in the way.

a23dranger · Post by **a23dranger** » Sun Dec 11, 2011 8:40 pm

occasional demons wrote:

Wonder why they changed to the 67:17 on the HD. Generally you lose strength with a lower tooth count pinion.

The overall size of the pinion gear between the hd 17 tooth and the non hd 18 tooth it isn't really any smaller or bigger. Iirc they knock off one tooth so the other teeth can be thicker making it stronger. Get what i mean

This week i will split apart all the trans i have (3.55hd, 3.55non hd, 3.94hd, 3.94 non hd) I will do a teeth count and take pictures so we have the info and can see the differences or chip if you wanna do the 3.94s and ill do the 3.55's don't matter to me.

chipdogg · Post by **chipdogg** » Sun Dec 11, 2011 10:09 pm

I can do both 3.94's, non HD 3.55, and 4.12 tomorrow. Have all in garage. Gotta tear apart the rest of mine anyways so I can put together the 4.12 and 2 2nd gen 3.94's with brand new internals I got from Ed.

a23dranger · Post by **a23dranger** » Sun Dec 11, 2011 10:44 pm

Sounds good chip. I can do the 3.55 hd tomorrow to as that trans is sitting at my house and not over at my garage.

a23dranger · Post by **a23dranger** » Mon Dec 12, 2011 6:00 pm

hey chip i pulled apart the 3.55 hd tonight code 04668697AC
and the gear set is 20 on output(pinion) and 71 on ring gear. So no difference there. also i had a 3.94 1gn ring gear set laying here which is 71 and it dropped right in no difference in pitch of the teeth.

So comes down to the 3.94hd is different then the non hd. 18/71 non hd to the 17/63 hd. Now also seems like getting the 4.12 70 tooth ring gear and throwing it in a 2gn hd 3.94 would be the ticket to make a 4.12 export pt spec trans. right down to the correct gearing. Might not be new news to some but is to me.. lol

If this is new news then chip can you confirm by putting your 4.12 ring gear in an 3.94 hd trans and see if it fits, gears meshes correctly and works?

chipdogg · Post by **chipdogg** » Mon Dec 12, 2011 7:53 pm

There is a slight difference on pitch for the 3.94 vs 3.55 ring gear. Likely not noticable until you drive the car, may whine.

I'm talking pitch of each individual tooth if you look at it from the side like a pyramid.

If you look on the top of the "peaks" you can see little notches.

No notch = 3.55
1 notch = 1st gen 3.94
2 notches = 4.12
3 notches = 3.94 HD

a23dranger · Post by **a23dranger** » Mon Dec 12, 2011 7:59 pm

yeah i figured it wouldn't be that easy and that there might be a difference in the pitch of the gears.

just throwing it out there but those notches could they just be a way of quickly identifying what ring gear it is and not the pitch.

chipdogg · Post by **chipdogg** » Mon Dec 12, 2011 8:49 pm

The notches are on the pinion/output shaft AND the ring gear. Quick way of identifying them, yes. That's the reason for them.

They are different though since there are more teeth wedged into the same space, same height. They'd be skinnier so the angle would be steeper on the ones with more teeth. Not much but it's gotta be right as it's a precise fit.

If they were exactly the same, there would be no need for a different set of marks. IE 4.12 and 3.94 HD pinion, both 17 teeth but different marks.

a23dranger · Post by **a23dranger** » Mon Dec 12, 2011 9:00 pm

chipdogg wrote:
If they were exactly the same, there would be no need for a different set of marks. IE 4.12 and 3.94 HD ring gear.

Don't you mean Input gear having same marks since they are both 17 tooth.. not ring gear.

chipdogg · Post by **chipdogg** » Mon Dec 12, 2011 9:03 pm

4.12 output shaft/pinion has 2 marks on it, 3.94 HD has 3 marks on it. Both have 17 teeth and are made of same material. For some reason they are different.

Same goes for 3.94 non-HD and 3.55 ring gears. Both have 71 teeth, made of same material, and have different marks. None on 3.55 and 1 on 3.94 non-HD.

a23dranger · Post by **a23dranger** » Mon Dec 12, 2011 9:10 pm

I think I miss read ya there. Lol