96 RMW Trans and converter in my 94 Fleetwood?

My limo trans took a crap. Will the 96 trans be a direct swap?

because '96 is obd2 vs your 94s obd1 your gonna run into some problems there

Swap tailshaft housings and you'll have to deal with disabling or bypassing the added TCC PWM solenoid. Don't just stake the valve in place like people have done for years - that valve regulates TCC lockup pressure to no more than 80psi; if the converter sees full line pressure (up to 200psi) it will balloon the converter and wear down your crankshaft's thrust bearing and possibly damage the converter itself. I would check the TransGo HD2C and Sonnax 4L60E-HP-01 kits and see if maybe they disable the valve that's controlled by the TCC PWM solenoid. Sonnax may also just make a valve that does this.

I'm sorry I'm not able to be more detailed at the moment but that's the best I can offer off the top of my head.

Ugh. That sucks. Is is possible to swap over solenoids and wiring to the 96 trans?

I don't know what happened to the Fleetwood trans. I was 250 miles from home. It made the trip out fine, though I noticed an odd shudder occasionally while cruising. The next morning, I loaded up 8 people to head to Mt. Snow. I pulled out onto the highway and made it about 75 feet when all forward motion ceased. Reverse still worked. I backed into the hotel parking lot and kicked everyone out. I put 3 quarts of fluid in it, which made it over filled. By revving it really high in D (or any forward gear - it didn't matter which) it would eventually engage. It wasn't slipping - it would engage hard and sometimes with a loud groan. Once it got to second it was fine - sort of. It had a vibration but stayed engaged and ran through all the gears.

After determining that a tow home far exceeded the car's value, I limped it toward home. The only dicey part is a long, steep mountain pass and a handful of stoplights. The majority of the trip is interstate highway. It made it home, I grabbed my Avalanche and went back out.

Now I'm exploring the most cost effective options. It the 96 trans is a nosebleed to make work, I can try to diagnose the 94. Any ideas?

It can't be this easy, can it?

http://www.700r4l60e.com/store/product.php?productid=315

No AAA?

I learned from that mistake, man. Worth every penny.

I hope that part is what you need. Your limo is badass.

Thanks! I'll get it sorted out.

I have AAA. It's a 500 mile roundtrip tow, which even with the optional 100 mile tow radius gets spendy, that is if you can find a tow company willing to tie up his driver for 8-10 hours. But, to be honest I didn't even call them. Once I realized I could get it moving with a little effort, I rolled the dice and headed home with it.

I could also swap over the complete 1996 drivetrain including the wiring harness and PCM from the wagon. It wouldn't be much more effort.

Wouldn't be the first time it underwent a motor swap... :p

What's with you and LT1s, Jimmy?

Stingroo wrote:

Wouldn't be the first time it underwent a motor swap... :p

What's with you and LT1s, Jimmy?

I dunno. Actually it was the '96 Limo that had the engine swap. The '94 engine is original and has 95k on it. The '96 RMW engine has 130k on it, so it would kind of be a backwards swap. Kind of dumb in retrospect. I know a guy who can rebuild the '94 trans on the side. I might go that route.

So....here's the 'ol insult to injury part of the story.

The reason I was in Vermont was to go snowboarding with my girlfriend and her son and a bunch of people we hang out with during the "snowboarding season". It's kind of our last weekend together before the season ends. I never did get to ride because swapping the limo for my Avalanche took all day Saturday and I didn't want to blow $85 on half a day of riding today.

Why did I take the limo and not the Avalanche in the first place, you might ask? Well the Avalanche had a subtle but obvious grinding noise occasionally from the left front wheel. I recently put new shocks in it and I boogered up the boot on the CV joint on that side in the process. All the grease came out and the CV joint was dry and exposed to the elements. Yeah, yeah - it's on the to-do list.

About 100 miles from home today the grinding got super loud. I had to slow down to like 50 for the rest of the trip while the grinding went from deafening to non-existent depending on road conditions and steering wheel position. But it made it. My girlfriend, however, is losing faith in my mechanical abilities. I'm wondering if she'll ever get in the limo again.

So, tonight's fun will be swapping out the CV axle on the Avalanche so I can get to work tomorrow. No rest for the wicked, I guess.

Sounds like possibly something with the forward piston has cracked or is leaking. Unfortunately this is a complete removal and disassembly.

That valve posted above would be great for this.

For the traveling you do, you may want to look into a Jasper or a AC Delco reman - they come with parts/labor warrantees that are good at any repair shop or GM dealer. I went this route with our wife's minivan that we travel with and it was good peace of mind.

sherlock9c1 wrote:

Sounds like possibly something with the forward piston has cracked or is leaking. Unfortunately this is a complete removal and disassembly.

That valve posted above would be great for this.

For the traveling you do, you may want to look into a Jasper or a AC Delco reman - they come with parts/labor warrantees that are good at any repair shop or GM dealer. I went this route with our wife's minivan that we travel with and it was good peace of mind.

Thanks - I'll check that out. In the short term, however, if I can get away with that valve and swapping the tail shaft I think I'll be golden.

If it's any more of a clue, it's been doing something odd that I didn't think was related but now I realize is related. When cruising along at a constant highway speeds, it would suddenly shudder noticeably. If I let off the gas or gave it more gas it would stop shuddering. I thought it was some sort of vibration from bad u-joints or the center bearing (2 driveshafts). But after this failure, I realize that the shuddering was actually the trans engaging and disengaging at a rapid pace. Like I said - it's not slipping but it's not "grabbing" when it should.

I talked to the guy that sells that valve. He said it should work. He said with that valve installed I'd have nomal on/off TCC functionality on the '96 trans. He said to swap over the 2-3 downshift solenoid from the '94 to the '96 because the impedence is different. He also suggested swapping over the '94 internal wiring harness and that the '96 PWM switch can just sit there unplugged without issue. Last, I need a new valve body gasket because I need to drill a hole in the '96 seperator plate to install the valve. He says he provides the bit and instructions.

If you talked to the guy at 700R4L60E, then yeah whatever he says. He knows what he's doing.

sherlock9c1 wrote:

If you talked to the guy at 700R4L60E, then yeah whatever he says. He knows what he's doing.

That's the guy. Really nice and seemed to enjoy the challenge of the question. He thought about it for a bit and then rattled off complete instructions. I immediately posted them here so I can refer to them later :-)

The new valve came in today. Looks pretty easy to swap over. I also ordered a set of valve body gaskets, a pan gasket and filter.

I was goofing around with it in the driveway today. It's weird because the MPH on the speedo will go up to about 4-7 MPH before it actually moves, but I have to rev it up really high before it will move. I ran it up against the brake to see if I could tell where the slippage was. Suddenly there was lots of smoke and reverse was gone. Reverse was the only gear that worked reliably.

I'm just about ready to yank the engine out of the '96 Roadmaster wagon. We'll see how the trans swap goes soon...

I finally got the bad trans out of the limo today. The fluid STINKS bad - it's all burned up and brown. I'll be doing the conversion on the '96 trans to make it work with the '94 this week. It seems to be pretty straightforward, but we'll see....

I found this little tidbit on the Impala SS forum. Now I'm worried about the 2-3 downshift solenoid. I had intended on swapping the '94 solenoid to the '96 valve body.

Will not interchange with '95 unless changing 3-2 solenoid, valvebody casting, and seperator plate. Has holes in plate marked in diagram. '94 or '95 computer will not accept the 20-31 OHM 3-2 solenoid and will throw an SES light and throw the transmission into limp mode. Some less knowledgeable builders will swap the solenoid so the computer will see the correct resistance, but the valve itself then causes downshift issues. If only the solenoid is changed, it will result in a 3-2 downshift cut loose. In other words...3-neutral-2 downshift.

I'm not sure whether the issue is putting a '96 solenoid in an older trans (which is NOT what I'm doing) or putting the older solenoid in a newer trans (which IS what I'm doing).

Anyone know more? I'd hate to have to do this job twice....

Some people have trouble with it, some don't. Worst-case it causes occasional strange behavior on the 3-2 downshift when the 3-4 clutchpack releases but the 2-4 band doesn't apply fast enough, so you end up in first for a split second.

If it was me, I'd put it in and see what it does. Your other option is to find another '94 or '95 transmission. You could swap valvebodies but then you'd have to swap the pump too, and at that point, you may be moving problems from the '94 to the '96 transmission.

New solenoids are only about $10 each. Just buy the new ones is a VERY easy swap if you have the pan off.

Thanks guys.

I think I'll just roll the dice and pop it in. I've already made the investment (albeit a small one) in the other stuff (TCC valve, TCC plate gaskets, etc.). There's a local guy with a '94 that had it for sale, but now wants to keep it. He insists the '94 and '96 are the same - so I offered to trade him my '96 for his '94.

EDIT: I also noticed that my '94 valve body has the casting for a PWM solenoid, though none is installed. Maybe my trans has already been messed with? Or do the early ones have the casting but not use the PWM solenoid?

Good eyes. All '94 valvebodies had the provision for the TCC PWM solenoid. It's possible that GM hadn't finished development on that particular aspect of the transmission before production deadlines hit and so they just left the solenoid out, built an interim valve setup, and maxed all the tables in the PCM.

sherlock9c1 wrote:

Good eyes. All '94 valvebodies had the provision for the TCC PWM solenoid. It's possible that GM hadn't finished development on that particular aspect of the transmission before production deadlines hit and so they just left the solenoid out, built an interim valve setup, and maxed all the tables in the PCM.

Ah. Makes sense.

I can use the '96 torque converter, right? My understanding is that the converters are the same and that the PWM magic takes place as the result of a modified front pump? The '94 converter is polluted with burned fluid and metal shavings. The '96 converter is brand new.

turbojimmy wrote:

I can use the '96 torque converter, right?

yes,.

Nick

The transmission surgery is done. I swapped over the wiring harness, 3-2 downshift solenoid and tailshaft housing from the '94 transmission. In the '96 transmission, I installed the TransGo TCC valve and drilled a hole in the separator plate.

The biggest challenge was getting the 2-piece, stock TCC valve out. The big piece and the spring fell out easily, but the smaller piece wouldn't fall out of the bore. After prying at it, tapping on it, picking at it with long wooden skewers I finally had an epiphany. Compressed air. I put 100 PSI behind it and that valve shot out of it like a cannon. Thankfully the new valve fit okay. There were additional instructions as to how to deal with it if it were too sticky in the bore. It fit perfectly.

The valve body gasket set I got came with 4 gaskets. I only need 2. My amazing powers of deduction led me to choose the 2 gaskets from the kit that had the same markings as my originals.

Now I have to find time to install it in the Caddy.

Pics:

The '94 guts. It's not just the lighting - it's dirty inside. There was a lot of ground up stuff in the oil. I hesitated to use anything from it in the '96, but I cleaned the stuff I did use well:


The '96 guts are much cleaner. We did work on it recently, but just to replace the torque converter, front seal and bushing. The previous owner of the car did mention that he had transmission work done in the past but I'm not sure how long ago or what was done.



To install the TransGo TCC valve, you drill an existing .073" hole in the separator plate to .094". Who thinks of this stuff?

Wow, the difference between those two shots is amazing.

jayoldschool wrote:

Wow, the difference between those two shots is amazing.

Yeah - particularly the color of the oil sitting in the valleys on the valve body. It was all black like used motor oil on the '94. Whatever happened to it happened in a big way.

Now would be an excellent time to put in a Sonnax pinless 1-2 accumulator piston if you haven't already bolted it in. Bottom left of the picture, three 10mm bolts. Be careful not to rip the paper gaskets when you take it off. I'd also look hard at the Sonnax boost valve (goes into the bottom of the pump). Not trying to add scope (well, yeah I am) but those are great things to do when the trans is out.

I might do that. I need to take the pan off again because I don't remember plugging the pressure motor back in. I had to remove it to install the wiring harness (I forgot to put the harness in while the valve body was out).

All done. The trans works great. TCC lockup and 3-2 downshift are fine. I took it up to highway speeds and back down. Left it in 3rd and nailed it and it downshifted like it should. It takes off from a stop very strong - better than it has since I've owned it (a year-and-a-half). This '94 always seemed a bit down on power versus my '96. I think it was the transmission all along.

Nice work! Always good to put spare parts to use.

sherlock9c1 wrote:

Nice work! Always good to put spare parts to use.

Thanks! It's particularly good when the budget is tight. If we hadn't kept that wagon around I'd have been totally hosed.

Must be a Fleetwood thing, I put a 94 in my 96 and had to swap some stuff to make it work. Too bad ours didn't die at the same time, could have traded transmissions and been done with it

95BRMW wrote:

Must be a Fleetwood thing, I put a 94 in my 96 and had to swap some stuff to make it work. Too bad ours didn't die at the same time, could have traded transmissions and been done with it

I had to swap some stuff, too. But I kept the '96 valve body and pump - that was the big question mark because of the revised 3-2 downshift valve.

I had tried to negotiate a swap of my '96 transmission for a '94 a guy had on Craigslist. He had it for sale but then decided he wanted to keep it for another project. He insisted they were identical and said I was "misinformed". He couldn't understand why I wanted to trade. I explained the whole PWM TCC strategy, 3-2 downshift valve differences, etc. I think his head exploded with that information because I never heard back from him.

Now the question is do I keep the '94 transmission around just in case something gets funky with this tweaked '96.

Also, I neglected to publicly thank sherlock9C1 for the advice and maintaining those very valuable stickies on the subject. Couldn't have done it otherwise.

Just noticed that I didn't install that vent tube on top of the trans. I'm not even sure I can install it at this point. Does it matter?

I think Dave "95BRMW" may weigh in on that.

Tom

Glad you were able to be successful. I just wanted folks to avoid all the trouble I've been through while I've learned about this stuff.

Yes, install that tube. The 4L60E needs to breathe (a lot, like every time you step on the gas), and it needs NOT to suck up crap from under the car. The idea is that any dirt or water that the end of the tube sucks in will fall out of the air and roll back out well before it gets to the trans. With a 3" long pipe, you don't get any of that junk in the trans.

Is it possible to install that tube with the trans in place? I haven't looked at it and am not looking forward to getting back under that thing.

I don't know about the venting part, but I do know that if the tranny gets overfilled, that's where it comes out rather than blowing a seal.

Tom C.

So I took the car to work today. The trip is a good mix of stop and go traffic, highway speeds and road rage incidents requiring WOT application. The car performed flawlessly except for a vibration between 55 ad 65. I didn't have that problem before. I probably should have marked the orientation of the flange on the driveshaft at the rear and also where the two driveshafts connect. Shifts are firm, if not a bit harsh.

I'm installing a new ac compressor this weekend so I'll see if I can get that vent tube installed while I'm under there.

As said above (thanks for the little reminder Tom ) install the tube. In a case where you over fill it the fluid comes out of it as well. I think you may have to remove the cross member and lower it a bit to get up there.

If I have to remove the crossmember, I'll just leave the tube off. The rear HVAC unit is behind the passenger seat (recall that it's a Fleetwood limousine). The heating and cooling lines (4 big hoses) run up over the crossmember. I had to use a sledgehammer to persuade the crossmember past the lines both removing and installing it. I'm not sure how much more the lines can take without rupturing.

So that vibration? It's not good. It's to the point now where it's screwing things up. Now it sounds like the driveshaft is hitting something. I think it's actually rubbing on the rear seal as it wobbles. I put it on jackstands and put it in gear. In first you can see the driveshaft wobble directly behind the trans. When it shifts to second and up it makes some noises. You can feel the vibration in all gears. I think, but I haven't gotten under it far enough to see, that there are metal shavings at the rear seal. It may wobble that much.

It's either the tailshaft in the trans or the driveshaft. I didn't have any trouble with either one before the swap (the donor wagon worked fine; the limo worked fine). The only mod to the trans was the tailshaft housing, which is really just cosmetic, right? Or is it???? Could it have the driveshaft positioned incorrectly?

I guess I'll yank the driveshaft, but it's a pain in the butt because there are 2 driveshafts.

The tail housing contains a bushing (plain bearing) that supports and centers the driveshaft yoke. If the bushing is shot and/or the yoke is worn this could account for the issue. Hard to believe the rear oil seal on the tail housing wouldn't be leaking though if things got this bad.

Olds Weighty Eight wrote:

The tail housing contains a bushing (plain bearing) that supports and centers the driveshaft yoke. If the bushing is shot and/or the yoke is worn this could account for the issue. Hard to believe the rear oil seal on the tail housing wouldn't be leaking though if things got this bad.

I remember that when I swapped them over. It doesn't look like the rear seal is leaking. The only logical explanation is that bearing - I had forgotten about that.

Thanks - I'll check that out.

Twas a u-joint on the yoke on the 2nd driveshaft where it meets the first driveshaft. It wasn't obvious where the 2 driveshafts meet, but it was really obvious at the transmission because the wobble had the entire length of the first driveshaft to travel.

Best possible outcome. Whew!

So the U-joint is a Spicer unit and it's not the stock type. Rather than mess with it, I took it to a local "professional" trans shop. Conversation went like this:

"I'll have it done tomorrow."

"Great, how much?"

"Well, an hour labor plus the part: $100-$125"

I'm thinking, at today's labor rates $100 is fair, so I said "Sounds good!". Apparently I accepted too quickly. He shot back with:

"Well maybe $200-225 if it takes me a couple of hours."

I stopped him there. I told him if it takes him 2 hours then he needs to find another line of work. He tried to feed me some BS about special tools, torch, etc. I told him I had a torch and a C-clamp at home. Autozone had the part for $9 and could do it in 15 minutes, but I don't have the actual U-joint and don't want to drive all around town trying to match it up. I told him if he had the part I'd give him $100 for the job, otherwise I'll take it somewhere else.

He said "Cash?"

I said "Of course"

Deal.

We'll see what happens later today when I try to pick it up for $100. This is exactly why I do my own work. I rubbed his nose in it a bit more by telling him that this was the last step in a transmission swap. He didn't react other than to say "you should have brought it here." I laughed. Probably should have waited until I had the driveshaft back, but I couldn't resist.

Guy was true to his word: $100 cash out the door. He complained it was a "2 mechanic job", tied them up for an hour, yadda yadda yadda.

So that U-joint must have been bad for a while. Now that it's fixed, the car has never been so smooth since I've owned it.

Stupid me went out and spent big bucks of an aftermarket driveshaft to cure a nasty vibration after my 3.73 install... and as I was putting the new shaft in, I discovered that the front u-joint had somehow walked inside the yoke and was causing all the runout in the stock shaft. Probably could have gotten away with just replacing the U-joint. Doh.

FWIW, I send ANYBODY locally with u-joint or driveshaft work to the local Fleet Pride. Those guys rock. There are multiple stores across the country.

sherlock9c1 wrote:

Stupid me went out and spent big bucks of an aftermarket driveshaft to cure a nasty vibration after my 3.73 install... and as I was putting the new shaft in, I discovered that the front u-joint had somehow walked inside the yoke and was causing all the runout in the stock shaft. Probably could have gotten away with just replacing the U-joint. Doh.

FWIW, I send ANYBODY locally with u-joint or driveshaft work to the local Fleet Pride. Those guys rock. There are multiple stores across the country.

I'll have to look them up next time.

That u-joint was probably like that since I got it. The driveshaft would make a binding sound and I would occasionally get a horrible vibration at highway speeds that would stop if I let of the gas or gave it some more. I guess it would free up when I did that. When I took it out, that must have been the last straw and it bound up in such a way that it wouldn't recover. I'm wondering now if that bad u-joint took out the first transmission. After watching the wobble at the tail shaft, I can't imagine it being good for the transmission.

Anyway, all that's left is a very subtle vibration that the car has always had. I even hesitate to call it a vibration, more of like a low growl between 40 and 50. I think it's the rear since it "sings" at certain speeds, too. One day I'd like to put a posi differential in it, but that's a lot farther down the to-do list. I just wanted to make the car road-worthy for our annual trip to Hershey PA in a few weeks. In that vein, the next jobs are sealing up the leaky trans cooler lines and getting the A/C back in working order (long story).