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325-4L Transmission


Guest jensend

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Guest jensend

Hello Everyone,

I have a few questions about the 325-4L transmission. How dependable are these transmissions as far as general usability? Are there any warning signs to look out for as far as signs of condition deterioration? I'm in the process of restoring an '83 Buick Riviera and it's come down to whether or not the transmission needs to be rebuilt along with the engine. The last time the car was in a driving condition (if you would call it that) by all accounts the transmission appeared to be shifting and acting accordingly. I'm now approaching the end of the engine rebuild, which consisted of a complete rebuild with new pistons, lifters, rings, basically everything besides connecting rods, which I will be reusing. My question is, is it foolish to leave by all accounts a fully functional transmission alone and drop the engine back in the Riviera without cracking open that transmission? Should I go all out and have the piece of mind knowing that both the engine and transmission are sitting at equal mileage? Any advice is greatly appreciated, I've been searching around, and it appears that most transmission shops around my location are unfamiliar with the 325-4L transmission which leaves me even more apprehensive about trusting someone to rebuild it.

My question is, do I leave well enough alone, or rebuild a working 325-4L transmission?

Thank you,

Dane

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The only problem I've encountered with them is the TCC solenoid. It's not an every so often thing. Once it goes, it goes. The solenoid fails and leaves the torque converter locked. You try to stop with the car in gear and it's as if you're not pushing in the clutch on a manual transmission. Shifting into neutral will reset the torque converter. It's a cheap and easy fix by just dropping the pan.

Paul ??? (sorry the last name slips my mind) has done a couple of things to the same transmissions in his Olds Toronados. He installs a shift kit and an auxiliary transmission fluid cooler.

I used to never drove mine in OD unless I was driving over 55mph and on the highway; always D in town. One ROA member in southern Missouri put over 500K on his '84 and didn't rebuild the trans until 250K; rebuilt the engine at 375K.

Jayson or Nathaniel can probably tell you more. There's a big population of 79 - 85 owners over on Facebook. Lots of info about them there.

Ed

Edited by RivNut (see edit history)
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Guest wildcat465

Dane in the Twin Cities, we have have one of the smartest GM transmission guys I know. He is a ROA member (have you joined?). PM me and I will give you an e-mail address. Unless you joined the ROA, then you can find him in the tech advisor section of the Riview. You also have one of the largest chapters of the Buick Club that can be a resource (we have a lot of 79-85 Riv owners).

In my personal way of thinking, if I had an engine out of one of these cars, I wouldn't give it a second thought and grabbing the transmission when it is easy to get at and have it gone through. The extra dollars spent to do this would probably be less than just the labor part of removing that transmission if it fails in the future. Depends on what your plans are for the car.

As far as the durability goes, the TCC solenoid is common, but easily fixed. The V8 cars seem to have less problems than the turbos. That tells me that it is a bit fragile because the V8 cars do not stress it much.

Paul Floro is the guy I think Ed is talking about, I haven't seen him on here as much lately.

Jayson and Nathaniel are definitely the gurus on these cars overall.

Edited by wildcat465 (see edit history)
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I have had work done on 3 of my Riv's with that transmission (84/85's). Let me tell you, you better find a shop with someone older who's not a smart ass that thinks they know it all, because your 325 4L will never operate correctly.

Is it leaking fluid? Lots of gaskets can be changed without pulling the trans. Does it drain down after sitting for days? (There is suppose to be a check valve to keep the converter for draining back). Also if it slams when put in gear something still isn't correct.

I have had this trans-go-shift kit put in 3 of them. One operated flawlessly, one operated terribly and the final shop that fixed most all of them highly suggested to not put the trans-go-shift kit in it.

I would also suggest you drive around town with it in D without overdrive. I only use Overdrive cruising at highway speeds. Saves on the life of your existing trans and will keep you from getting bogged down while driving around town.

I would put your engine back in, you don't have to pull the engine again to drop the trans, then drive it around for a couple of days. IF it appears to shift normally to you then leave well enough alone unless you are having driveability problems.

Also please remember this trans was developed in mind for a personal luxury car, not a race car so don't expect high performance. Think of a nice smooth couch floating down the road.

Edited by sosuzguy (see edit history)
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Guest jensend

Thank you for the responses everyone.

Wildcat465, I have reached out the technical advisor you recommended, thank you for the tip!

As far the car and transmission goes, before pulling the engine, the car had barely over 115,000 miles, without ever being breached. While the engine sat before starting the rebuild of the engine, I didn't notice any leaks of any kind from the transmission. The engine was another story, but as the car sat for quite some time before without being started, deteriorated seals were to be expected. Upon cleaning the engine and transmission it was seen that some orange RTV could be seen on the seal closest to the driver side CV and sealing the black plastic chain cover. This leads me to believe that perhaps the tranny had been serviced, but it is hard to tell. I'm not sure what exactly It's even harder to decide whether or not I should trust the previous mechanic's work. I have included a link to an album which includes a few pictures of the 325-4L tranny, where the orange RTV can be seen: 325-4L - Imgur

I'm nearly at the point where I'd more or less convinced myself to go ahead and seek out a rebuild on this transmission, if I can track down a reputable mechanic. I have the funds to rebuild the transmission, but the urge to get this Riviera back on the road is almost too much to bear. I would hate to see myself having to potentially pull the motor again in a few thousand miles to rebuild this 325-4L however..

Both Paul and sosuzguy have mentioned the Trans-Go shift kit, each with their own opinions regarding them. Is this similar to a stage shift kit?

-Dane

Edited by jensend (see edit history)
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Paul what do you suggest might be wrong with a 325-4L that slams when put into Drive after a cold start with a higher than normal (warm) idle? I've had one that needed the valve body changed and it never used to slam but slid into gear during a higher idle now after the valve body replacement it slams into gear if idling a little high. The shop suggested it was idling too high but it didn't do that before hand.

Ohh and I have an 84 Turbo Riv that I think Dave put a high performance shift kit in, it was a very high output engine lots of upgrades and yes it snapped your neck when it shifted. I'll have to dig around to see which one he used.

Edited by sosuzguy (see edit history)
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One thing that really gave the T-Type transmissions some snap was the 3.36 final drive instead of the 2.78 found in all of the others. Is it possible that Buick put a different valve body in the T-Type transmission like they did in the '65 Grans Sport transmission?

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Okay it wasn't a shift kit but a 2800 rpm stall torque converter, a new drive chain, clutch packs, maybe a new pump. That thing is the first E-body that would smoke a Mustang! This was in my 85 T-type Riviera Blackhawk Super-modified.

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Some great advice here already and I'll chime in with my experience.

My 1st 85 Riv I bought in 1990 with 25k miles on it. The 325-4 lasted until 167k when the TCC was going bad. I was servicing the trans every 25k (once a year) and figured I was on borrowed time and had it rebuilt. It lasted until 196k, when I put it in reverse and it did not go anywhere. I won't even go into all the issues I had with that shop and I brought it to a friend and had him inspect it. It turns out that the reverse band gave out, which is all the way in the back of the trans so everything had to come out to replace it. The other shop did a cheap rebuild and did not replace all the wear items.

My current 85 Riv has 160k on it and I just replaced the TV Cable. It was shifting very late and going into overdrive at over 60mph. No adjustment was left on it as they stretch out over time. Makes sure yours is adjusted properly as per the GM Factory Service Manual so it provides smooth shifting and protects transmission life.

Whatever shop you go to, make sure they are familiar with your unit and all the correct adjustments and settings. If they are a good shop, they should also provide you with a great warranty.

Hope that helps.

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Jayson, There is something wrong with that replacement valve body. I suspect that the line pressure is too high. Somewhere on the 325-4L's case there is a line pressure tap with a plug in it. In Park or Neutral, I believe it should be about 50 - 60 psi at normal idle. It will slowly increase as engine speed increases. There is a line pressure regulator valve in the valve body with springs and perhaps check balls in it's bore. One or more of those springs are changed when a shift kit is installed. If the line pressure is too high at idle or jumps up quickly at high idle, a harsh 'engagement' into Drive or Reverse will occur.

Does it slam into Reverse too? I suspect it would...

Is the TV cable properly adjusted? Do the shift points occur early & are they harsh?

A transmission mechanic who knows his way around a 200-R4 should be able to understand the valve body & power flow of a 325-4L. The 200-R4 is very similar hydraulically (but not mechanically) to the 325-4L.

Paul

Yes slams some in reverse but not as bad as drive. I will have to ask them about the TV cable adjustment but they knew about that up front. What would make the line pressure too high, malfunctioning line pressure reg valve or wrong missing springs/balls? I'm about to take this car back to the shop so the fun will start there. It's always difficult to take something back after someones worked on it when they think there isn't anything wrong with it...

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  • 4 years later...

Hello I am new here as of last 5 minutes. Hope this is correct way to handle. 

I have a 1985 riv project that just had an issue. The car is drivable for moving purposes. Mostly stripped apart. I was just driving back into the shop the other day and put it into Park. Now the front axle seems to be locked it does nothing when I put it into reverse I put it in drive and then put it back into Park it sounds like something spinning and trying to go back together. Any wisdom from someone would be great. I will eventually rebuild the transmission but right now I just wanted to get it so I can move in and out of the shop. Thank you very much for any help you may have for me

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You say the front axle is locked.  Are you saying that because you can't move the car even by pushing it. or locked because it won't go forward?  I know this may sound really simple, but the first thing I'd suggest is to check the fluid level.   Your spinning the torque converter, but there's no fluid in it.  ???????

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  • 1 year later...

1982 Oldsmobile Toronado with the TH325-4l. Computer deleted. Installing a vacuum switch to operate the lock up solnoid since the previous owner did not. The fluid was clean with no metal shavings or much friction material. Problem. It drives fine in first, second, and reverse. Slips in 3rd, and 4th. Won't engage or go anywhere in 3rd or 4th. Is this a torque converter problem because of the lock up? Could the clutch in the converter be toast from being constantly locked up and abused by the previous owner. Just bought the car and sorting things out. I understand there is no band adjustment possible on these so if it's a band then I'm gonna have to rebuild. Should I try the vacuum switch first and hope for the best? 3 wires on the square plug which one do I put the 12v switched power to? I will be rebuilding the transmission in the near future as it's not beyond my skill level. I'd just like to  keep it going until I have time for a full rebuild. Also what is a good torque converter for replacement? Thank you. 

Edited by agoodoldsoul (see edit history)
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