G50: New Member HELP!! 91 Q45 transmission

[Fiesty91]

Hello everyone....I have a 1991 Q45 that I've owned for 7 yrs and used very little but it has never failed me and everything other than the cassette works great. A couple of weeks ago I was driving it and for no reason I lost my transmission gears. I pulled over, put it in neutral and let it sit for a bit then tried it in D and it worked for another couple of miles then started acting up again. I got it home then took it to a transmission shop and they did an electric diagnostic and said the TCM was gone and something is wrong with the idle control. They said everything would be very expensive to fix but I question this whole repair as the car has been great for so long. Any ideas (I've been taken in the past and there doesn't seem to be any reputable repair shops that can work on this car around here) The Nissan dealer ripped me off. HELP!!

[qship96]

original transmission? how many miles on it? what does fluid look like? service history of fluid exchanges?

[maxnix]

I question this whole repair as the car has been great for so long. Any ideas?

I think we'll need a history also of all the maintenance you have done to keep the transmission in such good shape over the last 7 years.

Auxiliary ATF cooler?

[Fiesty91]

Sorry, forgot about the details...168k miles, I've put 25k on it since I bought it and it had a thorough check before I purchased it. Oil has been changed every 5k miles and trans fluid every 10k miles. Original trans as far as I know, car is American but brought to Canada. No extra trans cooler that I can see. Fluid and level is fine and no burnt smell.

[qship96]

168,000 is excellent life{if original} for a 1991-a known bad year for q transmission-most died and replaced before 70,000 miles.

[maxnix]

Sounds like this car may not have receieved the silent factory update as a miniscule cooler was part of it.

How does the white paper towel test look?

Which ATF did you use when it was flushed (change = mechanical fluid exchange?)? BG or Sun machine? How did the old fluid appear?

[Fiesty91]

Sorry, didn't get the last reply by email. What is the white paper towel test? We don't have the TF that was mentioned up here but Dextron III was used. The rad was replaced with a OEM rad 5K ago.

I would appreciate any advice on my Q's problem. Do you think it is the transmission or just the TCM? Where should I start? Who would I get either from in the States if I have to order them from there?

I know there are tons of questions etc. from newbies, but I really need help from people who know and understand these cars, please!

Modified by Fiesty91 at 12:10 PM 1/19/2007
Modified by Fiesty91 at 12:18 PM 1/19/2007

[maxnix]

So, total mechanical fluid exhcanges, or just drain and fill? Pan drop and filter replacements?

[Fiesty91]

Geez, I feel like a dummy sometimes....since I've owned it no pan drop or filter changes, only trans flush and refill. Thanks for replying!! The old fluid was the same color as the new pretty much.

[elwesso]

Now, we will get on to some diagnosis of the problem, not a lesson about deferred transmission maintenance...... Unfortunately it may not matter how well the trans was taken care of now...

I would wager my Q plus my current bank account balance (which is not outstanding) that your TCM is not bad.... Unless of course something was fried electricaly but from the sounds of it doesnt sound like thats the case.. Never seen or heard of TCMs failing.

Since the fluid is newish (still red) and full, then we're golden in that regard IMO.. If the fluid was changed on a semi regular basis then that doesnt concern me so much... It does seem weird that one day without warning it would just slip out of gear.

Im going to go ahead and think that the trans is probably toast... What Id like to see is if your trans has been replaced with the updated one... Look under the car, and look at the pan of the transmission... If there is a drain plug on the drivers side corner, then the transmission has been replaced under warranty at some point in time... If theres no drain plug you can rest assured it was original.. Most Qs got replacement transmissions from 90-92 MY's for whatever reason....

Anyway, do you ever see "TRANSMISSION MALFUNCTION" on the display? If you have that means you have an electrical problem and that doesnt concern us as much as an internal problem.

[Fiesty91]

I will check the things you've mentioned as well as some others that also have been pointed out and get back to all of you as soon as possible....thanks for replying

[maxnix]

Now, we will get on to some diagnosis of the problem, not a lesson about deferred transmission maintenance......

Sounds strange coming from the guy who said transmission filter change was not necessary until he actually did it.

A clogged filter could well be the culprit. Hate to think what is has trapped in 168K+ miles. Readers of the early posts will recall that Jerry Tucker once thought the filter change was unnecessary until a member's transmission would not operate afte a mechanical fluid exchange.

Just like Wes now professes, Jerry does the pan drop and filter replacement with every ATF exchange.

Education, not blind ego, is what this board is about for most members here. Reading the previous posts can educate you and save money and increase pleasure immensely.

You could measure your ATF pressures before and after doing the maintenance correctly and report back. Planetary gears may be damaged, but maybe it will recover. Might save you installing a remanufactured one for a little while.