PA-PAU Tranny Swap?

[Sarcazmo]

Good morning Everyone!

This is my first post to this forum, though I've been finding all sorts of handy tidbits of info here for years - hopefully at some point I can help someone as much as some of you have helped me!

My dad has a 92 PA, and a 94 PAU. The PAU was purchased to replace the PA that has served my folks well, and is ready for retirement (body shot). The PAU was picked up very cheap, knowing that the all three fuel lines and the rear brake lines were rotted through, so it was not driveable. I got all of that looked after, but now that we're able to drive it, it seems that the TCC clutch slips badly, so the tranny won't stay in OD for more than a few seconds - tranny swap in order. The question is, though, will the silky smooth tranny out of the 92 NA PA work in the 94 PAU? I've read that there was a change to a temp switch from the pressure switch in the guts of the tranny sometime in 94, but the PAU is a mid 93 build car that was sold as a 94. Of course, that may be a moot point, if there is some more fundamental reason why a tranny from a PA can't be swapped into a PAU.

Any help at all would be greatly appreciated!!
Cheers,
Andrew

[HotZ28]

Not trying to discourage you from this endeavor, however, there are many things to consider before you tear two cars apart with the hopes that the parts are compatible. First, I know of at least four different wiring configurations used to control the 4T60E between 1992 and 1994-95. In addition, the PA Ultra has the 4T60E-HD (heavy duty) and the final drive ratio is usually different than the NA cars. The drive axles are different part numbers and IIRC, the one on the right side is ½ in longer on the Ultra. The mounts should be in the same place on both transaxles. BTW, the “HD” has a beefier carrier assembly to handle the torque of the SC engine. Good Luck, if you plan to pursue this!

[Sarcazmo]

Hi HotZ,

I encourage the discouraging if it is warranted, and in this case I believe you've certainly given me cause for pause - I appreciate your thoughts.

We haven't laid wrenches to anything yet, and were trying to gain info/insight through forums like this, local dealers/tranny shops we know and trust, etc. We had determined the gear ratio difference, but hadn't looked at stuff like the CV shafts yet, so I'll check that out including the splines at the knuckles on both cars, etc. To be honest, the axle size doesn't concern me too much, but the final drive ratio might - is the ecm going to come to realize that 'hey, the engine is turning slower, and yet we're going down the highway faster!', and then decide to do something silly like light up the SES light, or worse?

As I mentioned, we're in an information gathering stage right now. We have located another (matched) tranny at our preferred wrecker to the tune of $650CDN, and if we have to we'll name that particular tune and we'll be back on the road without the unknowns.

Any further input is welcomed!
Cheers!
A

[kmax1]

Originally Posted by Sarcazmo

Hi HotZ,

I encourage the discouraging if it is warranted, and in this case I believe you've certainly given me cause for pause - I appreciate your thoughts.

We haven't laid wrenches to anything yet, and were trying to gain info/insight through forums like this, local dealers/tranny shops we know and trust, etc. We had determined the gear ratio difference, but hadn't looked at stuff like the CV shafts yet, so I'll check that out including the splines at the knuckles on both cars, etc. To be honest, the axle size doesn't concern me too much, but the final drive ratio might - is the ecm going to come to realize that 'hey, the engine is turning slower, and yet we're going down the highway faster!', and then decide to do something silly like light up the SES light, or worse?

As I mentioned, we're in an information gathering stage right now. We have located another (matched) tranny at our preferred wrecker to the tune of $650CDN, and if we have to we'll name that particular tune and we'll be back on the road without the unknowns.

Any further input is welcomed!
Cheers!
A

Since you'll have a tranny out of the vehicle, research the PCS. It will be cheap insurance to replace it now.

[Sarcazmo]

Good morning kmax1,

What exactly is the PCS? As a general update, we decided to purchase a warrantied tranny with 120,000km (75,000 miles) on it, to make sure we do it once, and do it right.

So, other than the PCS, are there other items that I should be checking out on the replacement tranny before we install it?

Cheers,
A

[kmax1]

Originally Posted by Sarcazmo

Good morning kmax1,

What exactly is the PCS? As a general update, we decided to purchase a warrantied tranny with 120,000km (75,000 miles) on it, to make sure we do it once, and do it right.

So, other than the PCS, are there other items that I should be checking out on the replacement tranny before we install it?

Cheers,
A

The PCS is the pressure control solenoid. The only way to get to it is by taking off the side of the case, which is darn near impossible while in the car. They tend to wear out. The results are harsh shifts when warm. SInce you got a reman they might have replaced it anyways.

[HotZ28]

Click Here for some good info on PCS failure. It sounds like you are purchasing a used trans from the "Automotive Parts Recycler", not a rebuilt unit. Be sure to replace the axle seals and change the fluid & filter. (No telling how long the unit has been sitting idle in the bone yard) In addition, if it were mine, I would install a new torque converter, or rebuilt unit and front pump seal, while they are easy to get to.

[Sarcazmo]

Hi Guys,

Thanks for all the info. HotZ, you're correct - the tranny is coming from a wrecker who warrants their parts for 4 months, and it has not been refurbed in any fashion. Generally, when we do tranny swaps (this is the 4th or 5th we've done over the years), we get the units from this yard, and we install an inline filter on the cooler lines, to make double sure we don't contaminate the new-to-us unit with crud from the old one. And of course, we also change the filter and fluid, and in general things like the axle seals.

I'll leave it up to my father, to see how deep he wants to dig into this thing (and his pocket book), but I greatly appreciate all of the tips and input - that's why I joined this forum!