Does anyone know the differences from the original PTU and the 02-04 carvan PTU? I know the pacifica differences.
Does anyone know the differences from the original PTU and the 02-04 carvan PTU? I know the pacifica differences.
Following. I got those pictures for you. I am also curious on this as the Pacifica PTU raises the driveshaft output up quite a bit while the van one seems to lower it. I like the design of the Pacifica one better, but I'm unsure how well it will actually fit, though I do intend on trying it before I put my '90 back together since the K-frame is out and everything is easy access currently.
One thing that bugs me is how fast the driveshaft will be spinning at high speed. Both the van and the Pacifica have ~3.3 gear ratios (they are different, NOT interchangeable from what I know about these systems unless you don't care about frying the VC), so the shaft is spinning its @ss off. Other than that, they are both super stout units when compared to DSM and 3S stuff.
From what I gathered the older PTU is 3.4166 and the rear is 3.45. I have no info on the newer 02+ ratios if there any different. I plan to run a different rear diff any way, IRS 9" has a 3.40 option so the gear ratio will be a lot closer. I want the VC gone and the awd system to be locked.
I am far from an expert on this, but doesn't your change to the rear ratio effect the bias (front or rear) of the system? (ie make it rear biased?) Do you expect any issues with bind because of the removal of the VC?
Are you intending this to be a drag only setup?
Eliminating the VC and running the oem gear there will be a slight bind. Everyone I've talked to says it's not enough to cause any problems. But I rather get it as close as possible, so 3.40 with IRS 9" rear to 3.4166 isn't anything. All out drag setup, cant have front spinning and then rear grabbing.
The reason for the different gear ratios front to back is due to the VC. In order to ensure that the VC will act as quickly as possible, it must always be in a slight state of slip (a few %). The front is always overdriven compared to the rear for both stability and quick system activation.
I want to keep the VC due to my goals of road course activities, so I have been researching ways to rebuild it, modify it, etc. It *can* be done, but I'm unsure if the parts like seals can be obtained. I would figure with enough looking it should be possible. You can achieve up to ~98% lock with a VC (still not as efficient as a totally locked driveline, obviously).
Yea I wouldn’t recommend what I want to do for a street car that’s driven a lot.
So uhh, what are the pacifica differences?
Dont push the red button.You hear me?
The Pacifica PTU is a different design and places the output shaft above the centerline of the FD diff in the transmission. The van PTU places the output shaft lower than the centerline of the FD diff.
The Pacifica PTU goes though a transfer shaft to turn the output pinion whereas the van one drives it directly off of the PTU input shaft that goes into the FD diff.
The Pacifica PTU is basically flat on the "engine" side of the case and does not protrude any farther than the adapter plate, so there is no engine block interference. The van PTU has a big lump that sticks out because of the way the pinion is driven that can cause block and pan interference necessitating grinding of the block and or the PTU case.
The Pacifica unit is physically larger, and so are the gears in "meatiness" (both have drive ring gears that are ~6.5"). It *appears* stronger IMHO and certainly has a courser tooth pitch.
The van drive ring gear can be unbolted from the input shaft, so theoretically it would be *fairly* simple to make a custom gearset for it. The Pacifica one appears to be 1 piece and would require a lot more work to make a custom ratio simply because the transfer gear has to be included on the shaft.
If you want pictures I can send them to you. PM me.
Wayne H.
'91 Dodge Spirit ES 2.5L turbo 5spd
'05 PT GT 2.4T HO autostick (RIP)
'89 Plymouth Acclaim 2.5L turbo auto, "Slugmobile" yes, THE Slugmobile!
'89 Dodge Caravan SE 2.5L turbo auto, "Mean Mini" yes, Gus' Mean Mini! (Current best 11.699 @ 114.43 mph! - Oct 15th, 2022 Cecil County Dragway, MD)
MeanMini dragracing videos: https://www.youtube.com/playlist?lis...URZLB1RxGYF6vw
and other cars, trucks and motorcycles
https://www.youtube.com/user/SlugmobileMeanMini
Wayne H.
'91 Dodge Spirit ES 2.5L turbo 5spd
'05 PT GT 2.4T HO autostick (RIP)
'89 Plymouth Acclaim 2.5L turbo auto, "Slugmobile" yes, THE Slugmobile!
'89 Dodge Caravan SE 2.5L turbo auto, "Mean Mini" yes, Gus' Mean Mini! (Current best 11.699 @ 114.43 mph! - Oct 15th, 2022 Cecil County Dragway, MD)
MeanMini dragracing videos: https://www.youtube.com/playlist?lis...URZLB1RxGYF6vw
and other cars, trucks and motorcycles
https://www.youtube.com/user/SlugmobileMeanMini
Sorry, I forgot to post these from Chris.
Van PTU
Sent from my ONEPLUS A6000 using Tapatalk
Wayne H.
'91 Dodge Spirit ES 2.5L turbo 5spd
'05 PT GT 2.4T HO autostick (RIP)
'89 Plymouth Acclaim 2.5L turbo auto, "Slugmobile" yes, THE Slugmobile!
'89 Dodge Caravan SE 2.5L turbo auto, "Mean Mini" yes, Gus' Mean Mini! (Current best 11.699 @ 114.43 mph! - Oct 15th, 2022 Cecil County Dragway, MD)
MeanMini dragracing videos: https://www.youtube.com/playlist?lis...URZLB1RxGYF6vw
and other cars, trucks and motorcycles
https://www.youtube.com/user/SlugmobileMeanMini
Pacifica PTU
Sent from my ONEPLUS A6000 using Tapatalk
Wayne H.
'91 Dodge Spirit ES 2.5L turbo 5spd
'05 PT GT 2.4T HO autostick (RIP)
'89 Plymouth Acclaim 2.5L turbo auto, "Slugmobile" yes, THE Slugmobile!
'89 Dodge Caravan SE 2.5L turbo auto, "Mean Mini" yes, Gus' Mean Mini! (Current best 11.699 @ 114.43 mph! - Oct 15th, 2022 Cecil County Dragway, MD)
MeanMini dragracing videos: https://www.youtube.com/playlist?lis...URZLB1RxGYF6vw
and other cars, trucks and motorcycles
https://www.youtube.com/user/SlugmobileMeanMini
Thanks for posting those, Wayne!
Wayne H.
'91 Dodge Spirit ES 2.5L turbo 5spd
'05 PT GT 2.4T HO autostick (RIP)
'89 Plymouth Acclaim 2.5L turbo auto, "Slugmobile" yes, THE Slugmobile!
'89 Dodge Caravan SE 2.5L turbo auto, "Mean Mini" yes, Gus' Mean Mini! (Current best 11.699 @ 114.43 mph! - Oct 15th, 2022 Cecil County Dragway, MD)
MeanMini dragracing videos: https://www.youtube.com/playlist?lis...URZLB1RxGYF6vw
and other cars, trucks and motorcycles
https://www.youtube.com/user/SlugmobileMeanMini
Caravan PTU would be my choice
For what reasons? Just curious. I know there's certain aspects to it that are desirable, but that case interference thing is very close to a deal-breaker.
An interesting note is that years ago I found that there was replacement gears available for the van PTU. Dunno if they are still around.
Well as anything, I always think ahead of me breaking it. The caravan PTU design is a lot simpler, and making a billet bevel gear will be easier. Also making another case is option. What clearance issues are you talking about?
Because of the position of the ring gear being on the input shaft, the case protrudes past the adapter plate/bearing carrier of the transmission. This causes interference with the oil pan rail on the engine and part of the block if it's a 2.2/2.5 or a 3.0 V6. Grinding can clearance things, but I'm not too big of a fan of that solution as I'm unsure about the compromise to any strength of the parts by doing this. I'm sure for low power stuff and soft launches it'll be fine, but start abusing things...well...who knows? For this reason, that is why I like the Pacifica unit. I just recently found out that the newer Jeep Cherokee PTU is designed in a similar way, but it includes electronically controlled hi/low ranges. According to this video it's 2.92:1 instead of the 3.xx:1 of the van and Pacifica https://www.offroadxtreme.com/featur...e-14-cherokee/