Transmission gear shift 1->2 problem

[hkchuen]

I have a problem with my 1994 J30. After I exit from a highway and stop in traffic for a little while, when I restart the transmission is often unable to shift from 1st gear to 2nd gear, even when the engine reaches 5000 rpm.

I observe the followings:

[1] This problem is alleviated after I change the transmission fluid. It still happens 3-4 times a week though.

[2] In normal running conditions, the transmission seems to be reaching 2nd gear somewhat "late", usually when the rpm is about 3500 (is this normal?)

I have talked to a mechanic briefly and he thinks that this indicates a failing transmission and he recommended me to junk the vehicle instead of fixing it, which he said will cost more than $1500. I really like my car and will feel bad if I have to leave it.

Thank you very much for your help!

Sam

[Skibane]

Assuming the fluid level is where it should be, it does indeed sound like your transmission may be on its deathbed.

You might try adding a pint of Trans-X to the fluid, as a way of keeping it running a little while longer. I've had good luck keeping several "almost dead" transmissions running indefinitely, using Trans-X every few thousand miles.

Regarding your mechanic's advice: Beware of the "cheaper to scrap it" trap - The trade-in value of the vehicle only matters if you decide to trade it in! As long as you keep the vehicle, the amount of money you spend on repairs should be based solely on how much you enjoy the vehicle - not on some imaginary number it might sell for on the used car market (or at the scrapyard).

If worse comes to worse, there are affordable repair options (i.e., installing a used JDM transmission, or rebuilding the original one). This doesn't have to be a death sentence for a car you really like.

[hkchuen]

Thank you very much for your reply! Since I am a newbie, there are a number of things I do not fully understand.

(1) What is Trans-X? How can I obtain it? When I add a pint of it to the tranmission fluid, would it affect the fluid level?

(2) I agree with your point that my decision should be based on how much I like the vehicle.

(3) Would you let me know approximately how much the repair options will cost? For instance, I have checked ebay and saw a used J30 transmssion going for 400-500. Would it cost a lot of labor time to replace it? Also, I would be very interested to know how much rebuilding will cost approximately.

Once again thank you so much for your help. I deeply appreciate it.

Sam

[Q451990]

You mentioned replacing the transmission fluid... tell us more about the process that you used. If you just had it drained and refilled you only got some of the fluid.

I would recommend a full flush with a BG flush machine (or similar), a pan drop and filter replacement, and then refill... assuming you hvaen't tried that. If changing the fluid helps - then there may be hope that multiple cleanings could bring it back for a while... especially if the filter hasn't been replaced.

Heath

[hkchuen]

Q451990:

Thank you so much for your useful reply!

I just went to jiffy lube to change my transmission fluid. They charged me $39.99 for the task, but I am no idea what "process" they used. I suspect that they did not perform the task (change filter, etc.) that you mentioned.

If I wish to do the "flush" you mentioned, where would be a good place to do so? Should I do it at jiffy lube / another car mechanic / at the dealer?

Thank you very much. You advice is much appreciated.

Sam

[driverdriver]

What's the condition of your transmission sensors? Is your vehicle throwing codes?

The rev sensor has been the root cause of rough or non transmission 1-2 shifting on a bunch of J's on this forum.

When you turn the car off and turn it on, does the problem disappear for a brief while and then come back?

A failing solenoid sensor will also cause a number of transmission issues.

[Q451990]

Ditto on DriverDriver's suggestions...

As far as the flush, I would check here for a shop in your area.

http://www.bgfindashop.com/locator/index.php

For $40 the best I would think you could have gotten was a pan drain and top off. That replaces maybe 25% of the fluid, since a lot of it is trapped in the torque convertor.

This flush method connects in-line with the transmission cooler in the radiator, capturing the old ATF as it comes out of the transmission, and pushes an equal amount of fresh fluid in to the transmission, so you get about 95% fresh fluid.

The "correct" process is:

1) add chemical flush to transmission through filler tube.

2) with the car up on a lift, drive the car at about 2500 RPM in each gear for about 5 minutes per gear

3) flush fluid with machine

4) remove pan and replace filter and o-ring

5) top off ATF (or even better, run second flush)

You should expect to pay about $200 for this service, plus you'll probably need to order or purchase a new transmission gasket and filter/o-ring from a dealer.

Flushing without doing the pan drop/ filter replacement is strongly discouraged, because the filter can become partially clogged from the debris removed during the chemical flush. A clogged filter can cause starvation in the transmission and create even more problems.

If there's a dealership nearby with all of the equipment, that may be the easiest.

The important part is to ask the shop before you have the flush done to make sure they aren't skipping any steps. The most commonly skipped one is driving the car in each gear for the 5 minutes each... very time consuming...

Heath

[hkchuen]

What's the condition of your transmission sensors? Is your vehicle throwing codes?

The rev sensor has been the root cause of rough or non transmission 1-2 shifting on a bunch of J's on this forum.

When you turn the car off and turn it on, does the problem disappear for a brief while and then come back?

A failing solenoid sensor will also cause a number of transmission issues.

Driverdriver:

Thank you for your help! In response to your commentsL:

[1] I am not sure what the condition of the "transmission sensors" are (I am a newbie when it comes to car mechanics). I am not sure whether the vehicle is "throwing code". The engine light itself is not on. Is there a way for me to find out this important information?

[2] The problem only happens maybe once a day. Every time it happens, it is always when I slow down after reachnig a congestion on a highway. Usually, I have to slow down and then re-accelerate a number of times, and then the car will start shifting again.

[3] When the problem is less severe, I felt that the 1-2 gear shift is somewhat delayed because the engine has to go up to 3500-4000 before shifting.

I am from Bensalem, PA 19020. Would you recommend going to the infiniti dealer nearby to find out about the "transmission sensor" and the "code"? There is also a Cottman transmission nearby, and a number of car mechanics.

Thank you very much!

Sam

[hkchuen]

Q451990:

Thank you for your help. I have looked up the site you mentioned and the closest shops are listed in the link below (I am located at Bensalem, PA 19020)

http://www.bgfindashop.com/loc...ius=5

I saw from the website that they have "transmission service" available. Is this the procedure that you mentioned? Also, you mentioned that I need certain parts. I will go to their service centre, bring along your procedure list and ask them to follow it.

Thank you so much for all your prompt help. I will perform the transmission service and update you on how it goes.

P.S. Are there anything I should keep in mind of when visiting the store for transmission service?

Sam

[maxnix]

Call first as the website is not always correct. Some won't do the pan drop and clean and filter repalcement.

[Q451990]

"Transmission Service" is a pretty broad term... Like Brian said, call first. The parts you need are the transmission pan gasket, transmission filter (sometimes called filter screen) and o-ring for the transmission filter.

Heath

[driverdriver]

Just to be sure, I would get a consult from an Infiniti dealer to rule out a sensor. I took my car to an independent mechanic and a transmission shop, they both recommneded a transmission rebuild, when the cause of my transmission shifting and erratic transmission behaviour issues was a sensor replacement.

[hkchuen]

Thanks! I have just made an appointment to the dealer on 7/19. I will update you on what the dealer says at that point.

[DominickJ30]

Defenitely a good choice to see the dealer and get checked out.

Usually they have loaner cars, g35 sedans. Just for fun I would see if you can get one for the day, they usually dont have a problem with that.

[hkchuen]

I just got back from the dealer. They said that the transmission is fine.

They recommended _against_ doing a transmission flush because they say that the result is unpredictable. The mechanic believe that since the car is already very old, doing so may kill the transmission completely.

Also, they found an engine error code #34 : Knock Sensor. I looked up online and found that the part cost about $125. Is it easy to replace?

Thanks!

[Q45tech]

Dealers don't like to do total AT flushes because: if they have never been done the probablity is there may be problems [the sludge and dirt holding things together].

A complete system clean [and maybe a reclean in sequence] with a pan drop and filter change has the best success............they just don't want to hear " EVER SINCE YOU DID THAT IT IS WORSE....EVER SINCE - EVER SINCE- EVER SINCE"

Kind of like heart surgery............you could die on the table, lose your ability to walk or get better and live longer.

Why we have owners sign releases when things are old and abused from lack of maintenance [going to the gym, over weight, smoking etc].

You better get right with the car gods and get educated as it is likely you will have this situation come up repeatedly as most people drive until 80.

Trade before transmission failure, spend money and expertise maintaining transmission, or just wait until they fail at a really really bad time in the rain with a dead cell area or battery.

[Skibane]

I just got back from the dealer. They said that the transmission is fine.

How could a transmission that fails to shift from 1-2 be "fine"?

Did they say that a bad knock sensor is causing your transmission problems?

[hkchuen]

They said that the transmission is fine before "it still shifts" and tell me that it is better to "just drive the car until the transmission fall out"...

They said that the knock sensor has nothing to do with the transmission problem, but it is just an engine code that comes up.

[elwesso]

Personally what I would do is drain the fluid and refill yourself before going and having a flush done... Sort of to gte the trans "ready" for a fluid exchange... You will want to be sure to drop the pan and do all that fun stuff!!

FORTUNATELY, the J uses the same transmission as the N/A 300ZX, so you can get them really cheap.....

[maxnix]

1.) They said that the transmission is fine before "it still shifts" and tell me that it is better to "just drive the car until the transmission fall out"...

2.) They said that the knock sensor has nothing to do with the transmission problem, but it is just an engine code that comes up.

1.) To a hammer, all problems look like a nail. Dealers are geared to replace broken/abused/malfunctioning items rather than maintain or repair them. I mean, if the car survives the manufacturer's warranty, who cares what it costs after that becasue the cost falls to the owner, right?

2.) And why, pray tell, does the dealer think the code is being generated? Here is a news flash for them: THE FREAKING O2 SENSOR HAS PROBABLY FAILED!

Ditch this dealer and find another, or a specialty Z shop.

For the transmission, use http://www.bgfindashop.com and call to be sure they will do hte service the way you want including the pan drop and filter replacement. Consider also performing a PS fluid exchange if it has never been done in the last 30K miles.

No mention of you how the ATF does in the white papaer towel test.

[Q451990]

I would do some reading on knock sensors... anything Q45Tech has mentioned about them regarding the Q45 will apply to your J. You should notice an increase in power after replacing it. I have no idea how difficult it is to replace on the J.

There are definately two theories on transmission flushes. I think you see where we fall on that...

You may have mentioned it earlier, but how many miles are on your transmission and car? Do you have any service history regarding the transmission?

Good luck!

Heath

[hkchuen]

Thanks for your commments.

There is about 131k on the transmission and on the car.

Since I purchase the car when it is around 90k, I do not have any information regarding the service history of the transmission. I will check harder to see whether I can see any clues from the stack of incomplete service records the previous owner has.

Another quick question: if I wish to replace the spark plugs, how many do I need to buy? Where can I order them? I have check http://www.infiniti-parts.com and cannot find any there. The dealer has them but wants to charge $15 a piece, which seems quite expensive.

Thanks !

[maxnix]

Call IOS, and look at http://www.sparkplugs.com . If you call the latter, tell Natasha you are a NICO member, and get a nice discount. Be sure to get the NGK as recommended in the manuals.

Get the dealer performed service history by submitting the VIN to your friendly service writer.

[hkchuen]

This must be a stupid question... who is the "friendly service writer" that you referred to ? How do I contact him / here?

[maxnix]

This must be a stupid question... who is the "friendly service writer" that you referred to ? How do I contact him / here?

He or she is your contact at your local preferred dealer that you have cultivated. Read Q45tech's posts on tiipping your technician and social engineering.

[hkchuen]

My mechanic quotes me $300 for a used transmission (50-60k miles) and $550 labor to put it in = a total of $850.

Is that a reasonable amount? Is there a place where I can do it more cheaply? Thanks in advance.

Sam

[sudcricket]

I am new to this website but face the similar issue on my hyundai elantra 1997. I read through one of the forums here for 90 240x convertible, gear shift problem, and the solution they found was "to unplug the revolution sensor, and the vehicle will fall on to backup sensor which is the speedometer, and will work fine, if you dont see the problems, that means the connection to revolution sensor is bad or revolution sensor itself. Also, when you disconnect the revolution sensor you will see the od light on, which is ok",

Just passing on the information from the previous threads.....

[driverdriver]

My mechanic quotes me $300 for a used transmission (50-60k miles) and $550 labor to put it in = a total of $850.

Is that a reasonable amount? Is there a place where I can do it more cheaply? Thanks in advance.

Sam

That's not to bad a price.