Drive Train

[dlduscg]

1999 Q45 slight reduction in power at cold start up and while driving 40-45mph until 4 to 5 mins, then a clunk from beneath somewhere in drive train felt and car surges to normal power. Does not reoccur again until the next day when the car is cold and been sitting over night. No dash warning lights, or other symptoms from transmission or engine. Dave

[maxnix]

1999 Q45 slight reduction in power at cold start up

Dave, I think you need to become famliar with the concept of operating temperature.

Is the clunk the 2-3 upshift or the TC lock-up?

[Q45tech]

The software in TCU is designed to vary pressure based on temperature [ATF viscosity] unfortunate when the transmission gets worn, the cold to warm graph gets out of whack and the pressures get incorrect for smooth quiet shifts.

Assumming you want things to last a ATF flush and replacement is all you can do............usually smooths, quietens down shifts and increases AT life unless you have waited too long and severe wear and tear has occured.

[dlduscg]

The AT seems to shift properly thru 3rd gear. It feels smooth and normal from a cold start and any other time. It may very well be the torque converter, and it is definitely affected by temperature. When the symptom occurs, I am approximately 40-45 mph and it feels like something drops into place (clunk noise) then, as if shifting, the torque is released and it cruises freely. All of this happens momentarily, and then it does not happen again until the next time I leave the car cold, or overnight. I doubt if it is the differential, but I would like to try and nail it down somewhat before I put myself at the mercy of the transmission shop. I have reviewed the history of the vehicle, and the maintenance record and do not find that the transmission fluid or filter was changed, as least not back to 50K miles. The mileage is currently 154K. All transmission shops have told me not to flush, but I know infiniti owners disagree. Thanks for your input, it has been a great help.

[dlduscg]

My thanks go to Brian and Q45 tech I didn't get the name.

[maxnix]

The mileage is currently 154K. All transmission shops have told me not to flush, but I know infiniti owners disagree.

Dealers and transmission shops (don't want to confuse the gender uncertain among us) are in business to replace of rebuild, respectively. They are not interested in helping you maintain the tranmission for it longest life or at peak performance. Read the posts here on mechanical ATF exchanges and adding ATF auxiliary coolers.

Back to operating temperature, let the car fully warm to operating temperature tomorrow morning before driving, then report back on its operation in this same thread.

[jimbyjimb]

Flushing in the wrong hands, depending on the apparatus used, can be lethal to your transmission. Go to a good shop using a good machine. I.E., not air pressure powered. I personally prefer 3-4 drain/refills and a new bottle of lubeguard. Your diff wouldn't be the cause. If it's your TCC you'd notice the RPM drop on the tach as it engages, and when it engages acceleration is slower at lower speeds so it will often release under much load at lower speeds and RPM's, in which case you would see the rpm rapidly jump as it disengages. Does the car jerk or make any sort of quick movement when the clunk happens?

[dlduscg]

Ran as you suggested, and as you already know, there was no klunk, downshifting, or hesitation. Smooth as silk

[dlduscg]

I have read all the posts as suggested, and located a couple of BG service shops nearby. I will have to talk with them and go over their type of procedure before giving them the job. I think the BG universal synthetic ATF, with seal conditioner, and lube guard should do the job.

Unable to get a clear fluid level reading, even after following manual. Seems the fluid still runs up the stick even with carefull removal. The fluid is clean, pink and no burnt odor.

So, the main problem with the clunk and there is no noticible jerk motion, but it does seem to release or disengage.

[maxnix]

Read about what Q45tech recommends about dropping pan, inspecting, replacing striner and O ring, gasket and one time use bolts. Not all BG shops will do this.

Consider adding an external ATF cooler like a B&M 70268 or 70264 from summit racing. Read Skibane's excellent post on routing the hoses.

We tend to use M1 ATF with 6oz. of Lube Guard Red (not black). The best time to mechanically exchange your ATF is when you have the miles but it shows no sign of degadation via the white paper towel test.

[dlduscg]

Need help finding Skibanes post on ATF cooler

[maxnix]

Y33 ATF Cooler - Another mounting location?

And

BG Trans Flush Procedure?

My 70264 in front of driver's wheel.






Modified by maxnix at 1:22 PM 5/22/2009

[yodawill2000]

Nice placement Max ..Need to get one for my J before the 100+ days we enjoy so much hit !

[qship96]

It made it 170,000 miles and 15 years already without it.........why the rush now????

[yodawill2000]

To get another 170 K out of it

[dlduscg]

Skibanes Flex-A-Lite is neat but is it as efficient as your B&M 70264? Both seem to have advantages/disadvantages. Air flow, in my opinion, is most important. The Flex blocks airflow to AC & radiator, which probably degrades the efficiency of those systems, and also impedes some air flow to the cooler, and there is more heat radiating in that confined area between the rad and cond. Your B&M cooler is also neat and much easier to install, but airflow is also a problem, especially looking at my 99 Q, and where the ariflow will be coming from. Which is better in lowering the temp, the Flex says 20 degrees, but do not find anything on the B&M?

[maxnix]

Stacked plate is the most efficient design.

In TX, I didn't want to load the radiator with more heat. Also I like it protected since ATF is not instrumented, and the louvers in the wheel liner give it a good flow in motion.

[maxnix]

To get another 170 K out of it

Exactly! Why ATF cooler and synthetic ATF will help modulate the temperature spikes of the ATF which is how all the damage is done.

[maxnix]

Your B&M cooler is also neat and much easier to install, but airflow is also a problem, especially looking at my 99 Q, and where the ariflow will be coming from.

1999 and 2000 are identical in front of hte A pillar.

[dlduscg]

I've heard pros and cons concerning whether to install external cooler lines before or after the radiator, and in series with the rad, or to bypass the rad entirely. What do you think is the best method?

[maxnix]

Skibane is the only one who has genrated the data.

In TX, I don't want to add additional thermal load to the radiator.

[oldmako]

I bypassed the rad on mine. I figure that the engine rad just preheats the ATF and keeps it hot. While stuck in traffic on a hot summer day I like knowing that my ATF isn't cooking at whatever temp is in the radiator. Perhaps it's just as hot, I don't know. But at least it's getting decent airflow in front of the radiator.

Installed mine at last year at 125K and now have 150 so not much empirical data yet. I have no idea how it was treated before my purchase and I hope to get at least another 50-75K out of it...because I don't plan on dropping 4K into a new trans...the car just won't be worth that investment by then.

[paranoidjack]

oops double
Modified by paranoidjack at 12:26 PM 5/26/2009

[paranoidjack]

Quote »[/quote]That fire extinguisher looks a bit tired Brian...routine inspection and recharging is necessary to maintain as-new performance.




Modified by paranoidjack at 5:45 PM 5/29/2009

[maxnix]

...because I don't plan on dropping 4K into a new trans...the car just won't be worth that investment by then.

Which begs the question, "Which other car would you rather drive for a $4K investment?"

[jimbyjimb]

Depends on the ride and personal beliefs of the user. Some would say that in-radiator units impede transmission cooling as coolant is hot and some transfer must occur. I ran my cooler and eliminated the radiator cooler from flow, but I'd say I've seen it (in general, not just Q's) about a 50/50 split to go in series or isolated cooler. Also consider adding a redundant filter on the transmission return line. with two filters, a cooler and lube guard your trans should stand a better chance against Father Time. Not, by any means, a cheap fix if your transmission goes bad. I think a new trans from a dealer is 4k. Used, 100-1000 bucks I've seen. Rebuild kits, aye, not sure. I know there is a kevlar clutch kit, however. Also may help.

[dlduscg]

Thanks. I guess it's all about how long you want to run the car and avoid the major costs. Still beats car payments on some over rated piece of recycled junk.

[jimbyjimb]

I suppose that's so. Im interested in cost of ownership G50 vs later Q. Maybe the power trade off is worth it? Later models must be smoother and quieter as well. So far the 92 has been a spine transplant. Much rather would have my 2.3L Accord back. Or better yet, my 64 Daytona. May have been squeeky but it put smiles on faces. I do love my Q in a sick, demented, self abusing EMO sadistic way.

[maxnix]

Later models must be smoother and quieter as well.

Time to get after the suspension.

Later G50 Q45 are quieter, but not by that much. WA uses a really coarse grade of asphalt.

FGY33 is the least expensive to maintain, also the slowest, maybe the quietest.

[jimbyjimb]

It is a natural progession for things to improve, if they don't something got F*d up somewhere, hence my assumption that later Q SHOULD have been improved from older. Whether or not that is true I cannot answer as I have never been in or driven any Q other than my 92 G50.