Cuty's 735 is needing help / advise

[Cutey]

Hello Kings of the road,

Please head me in the right direction.

 I have a 1992 BMW 735 IL ( 3.5L ) ( Automatic / Manual Transmission which I think is a ZF 4 HP 22 EH )

She has been doing wonderful, runs great handles well, shift good, etc...

Today, I was accelerating to merging into traffic and she seemed on top of her game, when instantly and smoothly the transmission seemed to just go into neutral.

No noise and no jerk. It was there and then it wasn't.

Tomorrow a friend is bringing a trailer to pick her up from the parking lot that she coasted into.

I was looking through the manual and saw that the brakes and the clutch hydraulic system used the same fluid tank and she was low on brake fluid, so I filled the brake fluid tank and tried again with no change. ( Is this mention of a clutch hydraulic system only on manual transmissions ? )

I came home and have been doing some research and I see mention of a flex disk in the drive shaft that one poster says should be checked first, he says that it can split or disconnect yet not be noticeable, however when I do a parts search the 1992 735iL does not seem to have one - I will be able to check tomorrow.

There is also a mention of a CV joint on the driveshaft - Could this shear smoothly with out jerking or noise?

I was scanning for items on the outside of the transmission that may be causing this disconnect response.

No burnt smells, fluid looks good, level in transmission has not changed, no leaking, etc….

Any suggestions on what it could be and how to check it ?

Any advise would be greatly appreciated,

Cutey
.

[Cutey]

I still have not been able to see under my Bimmer, but from what I gather from my research last night,
the 735 Automatic does not have a Flex Disk / Coupler / Guiber and the brake fluid reservoir that is
also used by the clutch hydraulic system is only referred to with the manual transmission, so neither
can be the reason for my disconnect to the transmission.

I have seen illustrations of a Driveshaft CV Joint on the 1992 735iL Automatic, I am thinking that could
be the issue.

Again the disconnect was just as smooth as pushing in the clutch on a manual shift.

Any other suggestions to look for and how to check them?

ALSO, even though my 735 has auto transmission and manual mode, it is still considered
an automatic and not a manual, CORRECT?

Any insight from the knowledgeable crowd would be much appreciated,


PS> For the last 3,000 miles when I would drive real slow for a long time. or sit at a long red light I would hear a thump as I started driving, it would get faster with the speed of the car, lessen when I turned to the left, thump harder when I turned to the right and would quit when I speed up to 45 mph or so.

I thought that it was the hydraulic line that ran from the steering reservoir to the self adjusting shocks that were removed and the line capped off in case I wanted to reinstall later. I was told that air might be getting trapped in the line making it flutter, I was going to have that capped at the steering unit when I had the tires rotated.

I guess it could have been a tranny issue instead.

[lincolnmaster80]

Ok, first of all: Is your transmission an automatic? Or Manual? You can't have both, and especially since you specifically mentioned the 4HP22EH (which is automatic).

Automatics have P-R-N-D-3-2-1 on the shifter lever. So, based on that, here is some info:

First, do a complete transmission fluid change including filter. I personally recommend taking it to a BMW shop or a shop that specializes with imports.

The transmission fluid is self contained (i.e.: not shared with any other system). Transmission fluid and brake fluid are completely different. If you poured brake fluid into the tranny, then yes, you need to do a transmission fluid flush and filter change immediately.

If you poured ATF (Automatic Transmission Fluid) into the brake chamber, then you have to flush the brakes out IMMEDIATELY along with a tranny flush.

That is the simplest thing first. Second you have all sorts of sensors. The next simplest thing is the gear selector sensor. This is located on the shifter lever inside the car underneath the center console. Clean the contacts. (You can find links in my signature)

Next you have the output shaft speed sensor. If that is goosed, then this might be your problem.

Next up is your torque converter has given up the ghost.

But don't let the last two scare you. Work on the fluid change and the gear selector sensor and report back.

[lincolnmaster80]

Originally Posted by Cutey

I have seen illustrations of a Driveshaft CV Joint on the 1992 735iL Automatic, I am thinking that could
be the issue.

The clunking noise you heard could be the CV joint. I'll have to do some research on that. But as for the CV joint shearing and causing this transmission neutral problem, that's not possible. You would have heard some clanging and grinding noises because the two driveshaft halves would be disconnected.

Originally Posted by Cutey

ALSO, even though my 735 has auto transmission and manual mode, it is still considered
an automatic and not a manual, CORRECT?

This is correct. The manual mode feature is used specificallyfor when you want to shift the car yourself. The reason for this mode is that the car, with all it's sensors, knows when to shift the car and electronically prepares for it so as to deliver the smoothest shift possible. In manual mode, it is prepared for that all the time. If you leave the gear lever in Drive (and not 3, 2, or 1) but have it in M-mode, this is called winter drive mode. It locks the transmission into 3rd gear so the power is derated when taking off from a stop, preventing wheel spin. Pretty neat, huh? Of course, winter isn't something you need to worry about in Florida.... :P

Originally Posted by Cutey

PS> For the last 3,000 miles when I would drive real slow for a long time. or sit at a long red light I would hear a thump as I started driving, it would get faster with the speed of the car, lessen when I turned to the left, thump harder when I turned to the right and would quit when I speed up to 45 mph or so.

Possibly related to CV shaft noise...again I will do more research on that.

[Cutey]

Thanks LincolnMaster80,

Your response gives me hope.

I am making arrangements for Cupcake ( My 735 ) to be picked up and delivered to have the fluid and filter changed. We do not have a BMW shop within 100 miles and the only import shop that I am aware of, seems to get off on sticker shock looks.

I am starting with a trusted mechanic for the basic items. I had considered having the trailered vehicle stopped at the Import shop for a diagnostic reading, I just do not have a trusting feeling about them.

First round as suggested will be change fluid and filter and I am going to search your signature links to find the info on cleaning the contacts for the gear selector sensor.

I would think that he could check the torque converter - I'll ask -

Does it require special equipment to check the output shaft speed sensor?


I went to see Cupcake earlier and we listen to the transmission as we shifted gears and could hear nothing and there is no resistance.

The instrument panel now says " Trans Program ", it did not say that yesterday.

I do not know if it is because of the " Trans Program " display, but the Letter that represents Auto or Manual next to the gear indicator now says nothing, just P,R,N,1,2,3,4 when shifting without "E" or "M" displayed.

Just a note from earlier I did not mix fluids - I was just referring to the owners manual stating that the brake and the clutch hydraulic system used the same reservoir, but I was also told that that only applied to Manual transmissions. Anyway, the fact that the reservoir was low on fluid does not seem to be a factor in my problem.

I am going to review the links in your signature - Thanks.

[Cutey]

Lincoln Master 80,

Is it proper to use any kind of cleaner on the internals after the transmission pan is dropped?

I understand that the torque converter will hold some fluids -

Other than draining by removing pan, changing the filter, replacing gasket and pan, and refilling with Dexron II are there any other flushing or parts to change while the pan is off?

[Cutey]

I was checking on transmission gaskets and filters at Advance Auto online and they speak of a ZF 3 HP 22 EH and says that it fits my 92 - 735IL which I understand to be a ZF 4.

Does their reference to ZF 3 sound right ?

Thanks

[lincolnmaster80]

No other parts that I can think of. Just filter and gaskets. It doesn't hurt to look at hoses and stuff while you're under there...y'know, check the condition. Also a good time to inspect driveshaft and other components.

I would have thought that there is a drain plug on your tranny pan??? There is one on my 1990. Maybe they changed it in later years. I know they went to a "sealed for life" transmission but I didn't think that happened until 1995. Anyhow, that's side points...

I'm not sure on the 3HP22 parts. As far as I know (and I have been known to be wrong at times), all E32 BMW's (7-series built between 88-94) have the 4HP22 or 4HP24 for automatic transmissions. You can get the proper part numbers by going to http://www.bmwfans.info, input the last seven digits of your VIN (I highly recommend you memorize those last seven digits or write them down for easy reference), and you can even cross reference part numbers by clicking the part number. I have found so many cheaper parts because some parts for my E32 750iL were also used for a E30 325i. Any how. That's a good link to favorite under a BMW folder.

As for cleaner, I believe there is a transmission flush agent you can add. This does require that you drive the car however. Most often, just changing the fluid is all that is required. The residual that is left behind from the old fluid is not enough to have an impact on the new stuff.

The TRANS PROGRAM error can occur for any reason, but it isn't coincidence that you experience this problem and saw this error message. Sometimes it's a loss of pressure in the valve bodies and the transmission doesn't shift properly, doesn't shift at all, comes out of gear or gears don't engage. This message can appear to electrical problems and sensors. Cleaning the gear lever selector sensor can fix this and cleaning the A/M switch next to the gear lever (or S/E/M switch if so equipped). The output shaft sensor can cause this, down to a duff clutch pack in the torque converter. Hopefully it's a problem with the former as the torque converter can get fairly expensive if you don't have a trusted mechanic on hand.

Basically, the TRANS PROGRAM has put the car into what is known as LIMP MODE. If you sit and think about what LIMP MODE might mean, it's exactly what it implies. Your car is "injured" in a sense so it is limping. Your car will derate power and lock your tranny into high gear so as to reduce the risk of causing further complications. The TRANS PROGRAM is also why you are not seeing the E or the M next to the selected gear display. This was back in the 80's when BMW thought of this, almost 30 years ago...yeah, way ahead of it's time!!! Most of the technology that our cars had back then has only begun to be installed within the last 10 years on most "low end" cars.

As a final note, one web site I order parts from is http://www.autohausaz.com. They are based out of Arizona and are fairly cheap, even with shipping to Canada. Check there with the part numbers you have cross referenced from bmwfans.info.

[Cutey]

The issue that I am needing to overcome is that the transmission of my 1992 / 735IL does not
engage into any gear - It was great and then it was gone – No noise, no jerk, just seemed to
go into neutral –

I am starting at ground zero with knowledge about transmissions, but I am reading a lot and have
been given some great suggestions / information.

Any guidance would be appreciated -

( 1 ) My 735 IL was put up on jack stands and the transmission was drained.
( Fluid was not still reddish and did not smell like the new fluid, but I did not think that it smelled burnt )

The pan was dropped and a new filter installed, then reassembled.


Filled with Valvoline DEXRON III / MERCON Maxlife ATF Automatic Transmission Fluid

When the car was started the “ Trans Program “ warning was gone and the M and E displayed along with P,R,N,1,2,3,4.

HOWEVER, there still was no movement at all in the rear wheels when shifting from reverse to drive.

There is no sounds coming from the transmission and the tach does not change when shifting.


( 2 ) I was going to clean the shifter contacts next,
but if the dash display is working DOESN’T THAT MEAN the contacts are working?
SHOULD I CLEAN THEM ANY WAY?

In reviewing the instructions for accessing these contacts, I see mention of the release lever
In the shift handle being connected to a plunger – I NOTE that the release level has never
Worked since I have owned the car –


Would there be any advantage to resetting the computer at this time? I have instructions on
how to disconnect the battery cables and then shorting the cables to drain the capacitor in
the ECU/TCU.


( 3 ) I guess time to move onto other testing –

( A ) Any fuses that affect the transmission not going into gear

( B ) Which of the following are easy to check / test and what order should
they likely be checked?

*Output shaft speed sensor
*Input ( Turbine ) speed sensor

*Pressure regulating solenoids ( EDS )
*Magnetic Valve ( Shift ) Solenoids ( MV )
All magnetic valves (except THM R-1 to 12/95) are supplied power from an internal relay
located in the TCM. The magnetic valves are switched on and off by final stage transistors
in the TCM. During failsafe operation, power to all MV’s is switched off by the internal relay.


*Torque Converter Lock up Solenoid

*Band Brake Regulator

* Kick down Switch ( I am not sure I have one )

*Torque converter
4HP22/24 EH - These transmissions use an on/off control method to lock and unlock the torque converter.
The Torque Converter Clutch is either completely engaged or disengaged.


*Transmission Control Module

*Emergency Program
When a malfunction occurs within the transmission, the Emergency program (failsafe mode)
will be initiated. The Emergency Program will prevent unintended gear engagement and
ensure driver safety. The following will occur during Failsafe Operation:
• All shift solenoids are de-energized via TCM internal relay.
• The pressure regulation solenoid is de-energized resulting in maximum line pressure.
• The Torque Converter Clutch is de-activated. ( Interesting )
• The Reverse Lockout function is cancelled.
• Shift lock solenoid is de-energized.


*Valve Control Body (VCB) Switches gears



.

[lincolnmaster80]

Krickey! You've certainly done your research. Good job. What you are doing is troubleshooting, aka eliminating possible causes.

Before I get into details with replying to your thread, and I just thought of this as I was reading your latest post, I'm going to ask one simple question: To move the car, do you have to take it out of park?

If no, then I highly recommend you checking the gear selector shifter cable. It may have come loose. In some cases, it may be nessessary to replace the cable.

If yes, then it may not be the gear selector shifter cable, BUT it is worth checking as those have been known to go slack and cause problems similiar to what you are having. I can't provide any explanation as to why it went suddenly as usually it's something that progresses, i.e.: gears not engaging unless you shift all the way into 2 or 1, or engaging sometimes but not all the time.

I don't know enough to say whether or not a loose/slack selector cable would cause the TRANS PROGRAM error...I would say not but at least you are eliminating that possibility.

If the cable is fine...then it was worth a look because that would have been so dead easy and simple...and likely free.

Anyhow, on with the rest of your post.

1), at least you got it changed. It sounded like it was at that stage when it wasn't bad, but probably shouldn't have gone on much longer.

2) Yes, it's a good idea to clean. It's simple and easy to do and it will be one less thing to wonder about if that may be the cause.

Resetting the computer could very well be the magical fix to this all, some have dubbed it "The Magic Reset" because it will solve the most mystifying problems. One thing to mention is that these cars are very, VERY, VERY sensitive to voltage. The slightest increase or decrease in voltage flow (aka resistance) can wreak havoc in some cases, and you're left scratching your head wondering what is going on and seeing nothing but dollar signs being thrown at your car. This can be caused by an old battery to something harder to find like a broken wire. (Speaking of broken wire, do some research on "fusible link." Even upon inspection it may look fine, it might have microfractures...)

I can't give you any info on anything in 3.B except that I do believe your car should have the kick down switch. I say that because there may have been models that weren't fitted, but I don't recall any info saying that. To find out for sure, press the throttle pedal all the way to the floor until it stops (car should not be running for this). When it stops, push it just a little bit harder and you should feel like something gave way. Or if you want a visual, look underneath the throttle pedal and you should see a large round button looking thing and give it a push. If it doesn't push, try pulling on it slightly to see if maybe it is stuck in. Like I say, you should have it...

A good forum to check out (and that is responded to other than myself) is bimmerboard.com. There is this 7-series guru handled "shogun" and he will most definately help you out, along with the other guys on there.

[Cutey]

LincolnMaster80,

Thanks for the thoughtful reply, my research has been greatly influenced by you wonderful guys and yes including Shogun too -

It is this feedback that gives that feeling of anything is possible -

It really helps to get pointed in the right direction -

You mentioned "Park" and I am thinking, how did I not think to verify that Park was or was not working - I have been putting it in Park, because that is a habit -

I will check on Wednesday -

I will look into the gear selector cable - I thought the contacts on the shifter sent an electrical message to the transmission instead of using a cable -

I poured some of the old ATF into a plastic water bottle, so that I could see if it had any metal shavings in it - I say no, others say they see some real fine metal dust - Maybe!

I will reset the computer next - I have the " Magic Reset Instructions" and I think that I found them on one of the links in your signature -

I found some info on checking solenoids, etc... with a volt / ohm meter -
I do not have any experience here either, but I will in a couple of days -

Any other info on trouble shooting / testing would be appreciated -

I went to Advantage Auto Parts to rent a computer code reader, but they said their unit would not fit the 92 BMW - He thought the earliest was 97 -

If I were to call around, what type of reader would I be looking for?

Thanks again for taking the time to share your knowledge,

[lincolnmaster80]

There is only one code reader that I know of for our early OBD cars.
They aren't cheap if you buy directly from them. Its made by a company called CarSoft, you can google them. I got my carsoft from a website called dealextreme.com. You will need a computer (preferably a laptop) with a serial port for this software to work. If you don't have one, your money just might be better spent hauling your car to someone who can run a scan. Its unfortunate that you live so far away from a BMW dealership as they have the most comprehensive scanners available. But for the money you spend now can possibly save you a bunch of headache down the road when attempting to troubleshoot future problems.

If you buy from dealextreme, the carsoft 6.5 will work with our early OBD computers. I hear the brand new ones off Carsoft web site are best and a bit more comprehensive than 6.5. The dealextreme came with all the cables including ones for your car and for newer OBD II BMW's and including the software. I recommend a laptop with Windows XP as I had trouble getting carsoft software to work on my Vista laptop.

But the guy you talked to is right. The earliest the code scanners at the stores can read is late 97 BMW's.

[Cutey]

I am going to reset the computer today.

I have a couple sheets that refer to ohm testing different components,
that sounds easy enough if the correct test points can be located.

Anyone have any additional literature that may have illustrations or good descriptions to find the correct contact points to apply the ohm meter?

[Cutey]

NOTE: I could not load pictures from my hard drive, please refer to post link below for photos of sockets.

http://forum.roadfly.com/threads/131...1#post13198420



Today I cleaned the Shifter selector and the A & M switch contacts, they were not bad looking.

I did a reset of the onboard computer - Disconnected the cables from the battery and "Shorted them for 20 minutes".

Please supply the " Magic Reset" instructions - Where the doors are locked and then unlocked, etc... I apparently failed to print them out.

I checked the shifter cable - Looked Ok -

I identified the transmission as a 4 HP - 22 ZF -

I checked fuses 1,15, 17, & 20.

I confirmed that I do have Kickdown switch under the gas peddle.
( It did not appear to compress under pressure, should it ? )

I did confirm that Park does engage, while it does appear to be the only gear.


I have located an OHM meter and ready to dig deeper.

I located two electrical sockets under the hood -
* The diagnostic socket - 10 points - not numbered
* A numbered 25 point connector just behind the Diagnostic socket.

I am looking for test that can be ran on these two sockets with an OHM meter.

( Picture at mentioned link mentioned )


Neither socket look like the 7 point and the 8 point shown below.

Are the 7 & 8 point sockets located somewhere else?


( Picture of sockets at link mentioned )


Where are the connectors mentioned below located?
Any picture of the above connectors?

http://twrite.org/shogunnew/topmenu.html Suggested tests of:
Transmission Control Unit Connector,
Motronic Control Unit Connector,
Program Selector Switch Connector,
Transmission Range Display Connector,



Other tests that need instructions:

*How is the torque converter tested? Says that the convertor is either engaged or not / on or off/ This test is important.
*Output shaft sensor
*Transmission oil pump test
*Transmission pressure regulator test
*Band brake regulator





The next two sound serious - Must


*Magnetic Valve ( Shift ) Solenoids ( MV )
All magnetic valves (except THM R-1 to 12/95) are supplied power from an internal relay
located in the TCM. The magnetic valves are switched on and off by final stage transistors
in the TCM. During failsafe operation, power to all MV’s is switched off by the internal relay.




*Emergency Program
When a malfunction occurs within the transmission, the Emergency program (failsafe mode)
will be initiated. The Emergency Program will prevent unintended gear engagement and
ensure driver safety. The following will occur during Failsafe Operation:
• All shift solenoids are de-energized via TCM internal relay.
• The pressure regulation solenoid is de-energized resulting in maximum line pressure.
• The Torque Converter Clutch is de-activated. ( Interesting )
• The Reverse Lockout function is cancelled.
• Shift lock solenoid is de-energized.


Any test instructions or component locations would be greatly appreciated -


I should be able to come to final conclusion soon -

Thanks to everyone -

[lincolnmaster80]

Originally Posted by Cutey

I did a reset of the onboard computer - Disconnected the cables from the battery and "Shorted them for 20 minutes".

Please supply the " Magic Reset" instructions - Where the doors are locked and then unlocked, etc... I apparently failed to print them out.

If you've done the battery disconnect and short, then you've done a magic reset.

Originally Posted by Cutey

I confirmed that I do have Kickdown switch under the gas peddle.
( It did not appear to compress under pressure, should it ? )

Yes it should. If you pushed with with your hand, it may need more pressure than what your hand might supply, i.e.: use your foot. If you did use your foot, then it maybe you just can't feel it or the button "click" feel might be too subtle to notice (it's definately noticeable on my car). While I don't think this would be the cause of your problem, it functions by downshifting to the lowest possible gear when you've got the throttle floored. You'll definately notice the difference when this button is activated...

On second thought, maybe ask 'shogun' if this might be the cause of your problem if kickdown switch is activated all the time even when not driving with the pedal to the floor. I'm curious to know...