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Discussion Starter #1 (Edited)
I have a 97 9000 CSE and drive it daily. Well, at least I used to. The ZF 4HP18 has around 150,000 miles on it. I replaced the gov seals about 30,000 miles ago.

I have had the following happen 3 times now. When moving from reverse to drive, the car wouldn't go into 1st gear. The engine would rev, with very little forward movement.

The first two times this happened (over a month apart), putting the car in park, turning if off and back on again, totally resolved the issue. After two months, it's happened a 3rd time. Except this time it has not resolved itself.

Between each incident, 1st gear has not slipped at all, so I have to think it isn't slipping clutches.

I've been draining the transmission fluid via the drain plug and filter and replacing four quarts of transmission fluid every time i change the oil, but decided to get a full flush after the second incident. Immediately after the flush, it started shifting pretty hard when going form 4th to 3rd under a load.

I've read forum 200366 many times. Chengny's post gives me hope that I may be able to fix easily. Could the accumulator spring referenced in that post solve this issue? Really hoping not to pull and rebuild the gearbox.
 

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You can try pulling the valve body and cleaning up the bores/valves and stretching the springs back out a bit. They specifically talk about the 3-4 and 4-3 traction valves sticking on occasion - which prevents the forward clutch from engaging:




Overall view of the VB with parts key:



In order to remove the cover (for the bank of valves where the 3-4 & 4-3 traction valves are located), this plate must be removed first:



And then, after you have removed the cover, some of the valves will not want to come out of their bores. If that's the case, this cover must be removed as well:



With that cover removed, you can get a pick down into the bore through one of the slots in the VB block. Using the pick you can then push the spool valve out - or at least get it close to the end of the bore. Then, if it's close enough, you can grab its stem with a pair of needle nose and withdraw it all the way.

I use a bottle brush and MEK/acetone to clean the bores. For the spools, I polish the OD's with 2000 grit emery. Lastly, I take pairs of pliers and grab the ends of each spring one by one and pull on them. This step is optional. I do it but I have no idea how long the springs are supposed to be. Doesn't really matter because they never seem to get much longer - if at all.

Just some random images from the first time I tried to rejuvenate a tired valve body using the methods above:



But, before you tear into the valve body, google a product called Lubegard Platinum - you might consider giving it a shot. You'll be hard pressed to find anyone say a bad word about it. And that is amazing when you consider the type of individual that frequents automotive forums. I have been using it for a couple of years now. It won't make a trashed transmission new again, but in my experience it definitely helps eliminate some minor slippage and harsh downshifts that these 4HP18's often exhibit.

BTW - I hope I haven't given you the impression that I am any kind of expert on transmissions. Far from it - I just try the possible remedies that I read about and hope for the best. Sometimes the suggested repairs work, and sometimes they don't. It might appear that I know what I am doing, but it isn't that way. Truth be told, many of the things I attempt are a waste of time, but no one will ever read about those - because I only share my procedures when they are successful.
 

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You can also purchase a complete rebuilt valve body for a few hundred dollars at Ericson’s. The shop is back East, and the guys there are total cool. If you like the car a lot, putting in a new tranny is not that hard, I have done it many times with just a floor jack; they slid out the driver wheel well. Ericson’s sells the trannys also. Chengny pictures are a big help also.
 

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Discussion Starter #4
I'll try these.

Thank you both.

Chengny, I've done several of your procedures over the years. You've helped me keep my favorite car ever on the road, and saved me a ton of money. Thanks. I'll give the Lubegard a shot.

SP53, I was on the phone with Eriksson's yesterday. You are right, they are really good. I hadn't considered purchasing a new/remanufactured valve body. That's a good idea.

I'll try these suggestions, in order. Thanks! With a little luck I'll get to stop at Lubegard. I'll let you know how it goes.

I've pretty much refurbished the car and the transmission is the only untouched area of the car. I've thought about just replacing it.

I found one off a low mile 9000, but a V6. I know the bell housing is different. Do either of you know if the gear ratios for each gear are the same? If push comes to shove, could I use that?
 

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IMO there's more art than anything in rebuilding these Zeppelin transmissions
(Yess Zeppelin Airships of Yore... IS ZF ;)
They are odd things.. Only a Honda Auto transmission has more odd complexity.
Erikssons is Great, their prices are v reasonable.. Big mistake IMO.. to not simply buy one of their rebuilds.. then never have to even think about the transbox .. again.
 

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Discussion Starter #6
Good call on the Lubegard Platinum

20 bucks for a bottle and not having to crack open the transmission was the perfect starting point.

It seems to have worked. After adding the Lubegard, the car went into drive, gave a hard shift between 3rd and 4th at first, but smoothed out very quickly. Now it is shifting.......perfectly.

Not sure just how long to count on this repair, so I'll add towing coverage to my insurance tomorrow and hope for the best.

The car has 228,000 miles now. I'll give an occasional update here as long as it's working, and certainly let you know if it fails.

Thanks again!
 

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It's my understanding that most transmission "miracle cures" contain additives which are specifically designed to induce softening and swelling of the internal soft parts (e.g. seals and gaskets). The theory being that if the thickness of these parts is increased, the various clearances will be returned to near factory condition. The expected end result: a reduction in leakage within - and between - the various internal hydraulic circuits and resumption of normal operation. But a negative side effect - that sometimes results from intentionally swelling the soft parts - is that they can get too big. When that happens things start to stick and bind. Basically, it's like "out of the frying pan and into the fire". You've just traded one problem for another.

On the other hand, from what I have read, it seems that the active ingredients in Lubegard essentially do the opposite - they increase the clearance between close tolerance moving parts by removing any built up deposits. I believe it is done with a blend of solvents and surfactants. The solvents loosen up any deposits on the moving parts and the surfactants break them free and flow them away from the part.

Maybe that's why the product seems to be especially successful when used in a 4HP-18 - there are hardly any internal soft parts, almost every sealed surface is metal to metal. So it's understandable that dissolving and flushing of any accumulated deposits from the surfaces of movable/metal parts, would result in cleaner quicker operation of the valves within the VB.

Funny you should mention this:

After adding the Lubegard, the car went into drive, gave a hard shift between 3rd and 4th at first, but smoothed out very quickly. Now it is shifting.......perfectly.

The first couple of times I used Lubegard, the same thing happened to me: things initially went from bad to worse. I had used it in an attempt to avoid pulling the VB because of some seriously high/harsh shift points that one of the kid's cars was experiencing. At first the shifts got more violent and I swore never to use an additive again. But then one day, about a month or so later, I had a chance to drive that car again - the one that had recently been dosed with LG. As I drove, I started to get the feeling that something wasn't normal. I paid attention and it only took a few full stops from cruising speed (at red lights)before I realized what the difference was. That kick in the a s s feeling - the one that comes with a harsh 4-3 downshift - was completely gone. That bump that occurs when slowing down had become so consistent that the transmission didn't feel right without it.

That was about 3 years ago and I haven't been into a valve body since.
 

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Discussion Starter #8
Sadly

While the car does shift nicely from 3-4 and 4-3, my issue of getting it to engage in first has resurfaced after a couple of drives.

i'm thinking it's time to replace or rebuild. Can I use one of these from a V6? Is the gear ratio the same and just a matter of changing the bell housing?
 

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Discussion Starter #10
Step 2. Valve Body

I did speak to Eriksson's about the V6 transmission. The have a smokin deal on a brand new one.

They tell me the bell housing is different. The gear ratios for each gear are the same, but the overall gear ratio is different. I'm guessing it has something to do with the differential or the gear that connects to it.

Changing the bell housing does expose the differential, so I may explore that.


But first, I am going to pull the valve body and do what Chengny recommends with the shift valves. Per one of his other posts, I am going to replace the accumulator springs while I'm in there. I just noticed eEuroparts now stocks the springs and gaskets. For $20 dollars in parts and leaving the transmission in the car, that's worth a try. I'll let you know.
 

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This thread has a lot of good info! As it happens my '97 CSE suddenly developed automatic transmission problems. Prior to this the only thing it's needed was governor seals a few years ago.

What's happening is that there is no reverse gear. When driving forward the trans stays in 1st until you let up off the gas, then it suddenly slams into fourth - and then it loses drive. Pull over to the side of the road and it repeats. Lubegard additive did not help.

So using some articles at Townsend Imports as a guide I pulled out the valve body to check operation. One of the first things I did was check the springs in the upper valve body per the following tech bulletin:

http://townsendimports.com/Web/transmission_folder/9kvalvebody.htm

Problem is, though I tried to be careful, sure enough when I removed the last bolt a spring popped out. I was able to find it, but there was also an aluminum spacer next to it and I'm not certain if that came out of the valve body or just rolled off my messy workbench:



The diagram in the Townsend document doesn't show it:



However, the illustration of the valve body in this thread at item #20 does seem to show a spacer and a pin as well. This spacer does not really seem to fit though, and I don't see a pin anywhere. So am I missing some parts here? The springs etc otherwise seem to be OK in there.



I like the idea of cleaning up the spools with 2000 grit emery and making sure the springs are OK. Since the trans never slipped before it sure seems like this is a control issue rather than burned-out clutches.
 

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I called Eriksson today and they referred me to a PDF file on their zftranspart.com web site for the 4HP18Q transmission. It shows no spacer or other parts in that place, so it looks like it'll be safe to button up the upper valve body as is.
 

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Discussion Starter #13
Encouraging

I finally got around to working on the valve body today. I was hoping to find something that could explain the lack of any forward movement. I found a few issues that could be problematic.

I started with the accumulator springs. The plunger/piston for Accumulator A would not slide out without lots for help. Upon cleaning the cylinder and piston, the pieces are sliding like they are supposed to.

Unfortunately, I could not remove the plate allowing access to the traction valves, off without separating the various layers of the valve body, which I really did not want to do. Take a look a the little ridge that keeps the bolt from being removed.

Best I can tell, there were 4 plastic balls (2 green and 2 white) and 7 flow reducing disks. I believe worked out where all go except one of the white balls.

Aside from how I'm going to work out where that goes, the 4-3 traction valve was completely stuck, and the 3-4 traction valve was sticking. In addition to that, one of the springs on the Shift Sequencing Valve 1-2-3 was broken in two.

Thank you chengny for your guidance and images, as I would not have the vocabulary to articulate what I found. Finding these issues gives me a little hope that when I find a replacement spring and where that ball goes, the transmission might just work.

I've also included an image where I think most of the flow reducing disks and one of the green balls go, just in case one of you run into the same issue and are trying to figure out where to put them. It also seems to matter whether they are facing up or down. I think that shows on the picture okay.

I will keep you updated.
 

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Discussion Starter #14
Ball and Disk Locations

Thanks 1997CSE for the townsendimports.com link. In navigating back through their website from the homepage, I was able to find the ball and disk locations.

How did your project go? Do you have a working transmission yet?
 

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Thanks 1997CSE for the townsendimports.com link. In navigating back through their website from the homepage, I was able to find the ball and disk locations.

How did your project go? Do you have a working transmission yet?
I had the same broken spring that you did in your "broken.jpg" photo.



Could not find any other obvious problems, though I'm working blind as I don't really know what all these springs and valves do! I cleaned up the spools and bores with 2000-grit emery paper, though I only got to the ones you could reach by taking off the end plates. I know there are more inside.

I could not find the exact spring. Eriksson does not carry it, and no transmission parts supply house that I contacted could supply it either. Fastenal had one that was a close match so I installed that to see if it would make any difference. It didn't, still no reverse gear. (Now that I know that spring has nothing to do with Reverse it's no wonder!)

Not only was there no reverse after reinstalling the valve body there is in fact there is a slight forward rotation when Reverse is selected while the front wheels are off the ground. Drive still engages, but I did not road test to see if shifting in the forward gears was any better.

I did also remove and take apart the governor. Everything looks OK there as far as I can see. The seals are all good and the valves aren't sticking. So I put it back together and reinstalled it.

As far as I've been able to determine the "mystery part" spacer that I found just happened to be on the floor where the spring and screw landed when I took the upper valve body apart.

I've been offered the valve body from a failed transmission on a 1998 CSE by a gentlemen on Saabnet. He replaced his trans with a good used one and still has the original. His problem was that reverse worked but no forward gears. I'm thinking I might be able to make one good valve body out of the two of them. This all assumes the problem with mine really is a control issue and not some deeper mechanical failure like burned clutches. (There was no prior slippage though and the fluid was not burned so I'm holding out some hope.)

Would love to just install a rebuilt Eriksson transmission but unfortunately the condition of the car just does not merit the expense, especially since I'd have to pay a shop to install it. (The car has over 330,000 miles on it and is quite rusty.) Eriksson did offer me a great deal on one and if the car were overall in better shape I'd definitely go that route.

So that's where I'm at right now. When I get the valve body from the '98 I might just bolt that one on as-is if there's no obvious damage to see if reverse gear works.
 

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Heck yes bolt it in and see what happens. The times I have worked on my automatic transmissions was enjoyable. They were and still are to some extant a mystery that stretched my skills and help build confidence.
 

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OK, I installed the used valve body and there is no change. Still no reverse gear. (The valve body came out of a transmission where reverse gear was known to work.)

I'm not sure if the band is used for reverse, but I figured I'd try adjusting it. I found that it was necessary to screw the adjuster in so far before reaching the specified 7.5 ft-lb torque that even after backing off two turns per the instructions there are not enough threads exposed to install the locknut. So it seems likely the band is worn out or broken. If this is the case then it looks like I have a parts car on my hands. :cry:

http://townsendimports.com/Web/transmission_folder/9kautobandadj.htm

(I found that the adjusting screw was T40 torx rather than the 6mm hex in the above document, probably it was changed in the later year transmissions.)
 

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If this is the case then it looks like I have a parts car on my hands. :cry:

http://townsendimports.com/Web/transmission_folder/9kautobandadj.htm

(I found that the adjusting screw was T40 torx rather than the 6mm hex in the above document, probably it was changed in the later year transmissions.)
Sorry for the woes. Unless the car is pretty much bodged otherwise, just get a used transmission and replace it. The Zep auto boxes are good boxes and a good replacement should give you plenty of years' use.
 

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Sorry for the woes. Unless the car is pretty much bodged otherwise, just get a used transmission and replace it. The Zep auto boxes are good boxes and a good replacement should give you plenty of years' use.
Unfortunately this car has some pretty bad rust problems after exposure to 20 years worth of winter road salt. Also I really can't swap out the transmission myself.

If not for the rust I'd have an Eriksson rebuilt transmission installed which would probably outlast me! But the cost with labor by the time it was done would be somewhere between $2500 and $3000 US and the car's condition just doesn't merit that kind of expense. I do have another 9000, so looks like I'll have plenty of spare parts for it.
 

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Unfortunately this car has some pretty bad rust problems after exposure to 20 years worth of winter road salt. Also I really can't swap out the transmission myself.

If not for the rust I'd have an Eriksson rebuilt transmission installed which would probably outlast me! But the cost with labor by the time it was done would be somewhere between $2500 and $3000 US and the car's condition just doesn't merit that kind of expense. I do have another 9000, so looks like I'll have plenty of spare parts for it.
Well that being the case, sounds like a cadaver for your other one is the best option. Good luck with it!
 
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