So whats the final word on Q45 transmission maintenance?
Some folks say do a flush, but that seems to result in possible transmission failure. Apparently there's crud lodged in there that needs to stay where it is? I'm worried about causing damage to already old equipment.
Fluid is pink, Mobil 1 ATF. Shifting is smooth, except when its cold during the first minute of driving there can be a brief delay. Has a transmission cooler, installed after I bought the car about 9 months ago. It has had Mobil 1 and annual fluid changes at least since 2000.
I'm due for service, but I'm not sure what to do. At 181k on a 92Q, 140k on the current transmission, would the safest route be to just let the fluid drain, refill, and change the filter at the same time?
I'm also confused with terminology. What is a fluid drain compared to a flush or an exchange?
Thanks,-Jesda
Final Word On Transmission Maintenance
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Jeff Williams
- Posts: 3394
- Joined: Fri Aug 02, 2002 4:17 am
- Car: 1994 Infiniti Q45t
2000 Infiniti I30t
2004 Infiniti M45
71, 72, 73, 82 & 2000 Corvettes - Contact:
I am no expert.
Fluid drain means to me, "gravity drain from plug, or remove pan, if you don't have a plug"
Fluid exchange or flush means to me, "Take it somewhere, and have an external pump attached, to replace all the fluid in the transmission & converter, while using a cleaning agent, to remove all varnshes and deposits"
I have done fluid drains all my life, with no adverse effects.
I just did my first fluid exchange in this Q, and now woner if I should have.
The bottom line is, IF you have regularly done fluid drains, and the fluid is clean & pink, the fluid exchange should not harm the transmission. IF you have darker fluid, and have NOT done regular drains, it's a crap shoot, whether the trany will be adversely affected.
My case, was a 60K rebuild, with no fluid drains (my fault). I did the flush, it ran fine for 5,000 miles, now it "hunts" while at low RPM's (1200 to 1700) in "4". Not a big problem, really.
Fluid drain means to me, "gravity drain from plug, or remove pan, if you don't have a plug"
Fluid exchange or flush means to me, "Take it somewhere, and have an external pump attached, to replace all the fluid in the transmission & converter, while using a cleaning agent, to remove all varnshes and deposits"
I have done fluid drains all my life, with no adverse effects.
I just did my first fluid exchange in this Q, and now woner if I should have.
The bottom line is, IF you have regularly done fluid drains, and the fluid is clean & pink, the fluid exchange should not harm the transmission. IF you have darker fluid, and have NOT done regular drains, it's a crap shoot, whether the trany will be adversely affected.
My case, was a 60K rebuild, with no fluid drains (my fault). I did the flush, it ran fine for 5,000 miles, now it "hunts" while at low RPM's (1200 to 1700) in "4". Not a big problem, really.
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Q45tech
- Moderator
- Posts: 14296
- Joined: Tue Apr 30, 2002 3:19 am
- Car: 1990 Q45 342,400 miles 22 years ownership with original engine
1995 G20t 5 speed 334,000 miles 16" 2002 wheels - 205/50/16 Sr20ve vvl
Never seen pink ATF! Bright crispy/sparkley red is the color of new ATF [Dexron, Mobil 1, Nissamatic].
If a white paper towel rubbed from the dip stick doesn't look exactly like a similar drop of brand new, you know you need to change it till it looks identical.
Simple.
Flush is more than just exchanging all the fluids, as the heat induced varnish will not be removed. Chemical solvents not found in ATF are needed, yet these solvent are too active to stay in the system LONG..........they are circulated for no more than 30 minutes [say 20 minutes at full operating temperature]. Then the ATF internal pump exchanges 85-90-95% of the solvent and old ATF.
Many times a single cycle leaves the ATF NOT at brand new color, a 2nd exchange may be necessary, either while the exchange machine is connected or a week later.......cheaper while connected].......negotiate.
We have seen 94Q trannies last over 200,000 miles with 6 exchanges and chemical flushes.We have seen 90Q [replacement new trannies 1993 version] last 200k with Mobil1 and 6 flushes. [with 1st gear start and external cooler added from day one
All of these long lived units were serviced at roughly 30k, 60k,90k,120,150k, 180k.
On my current factory remanned [been in my Q for 16 months for 23k], I flush and exchange every 15k [after the install flush] since the unit was used in another car [without 1st gear start for 1 year maybe 15k]. =38- 40k current mileage on unit.
All one can do is flush and exchange, clean and refilter frequently. And keep the ATF at or under 190F.
The ATF going into the cooler is totally from the TC which is last in the circuit.......ATF in the sump pan is from the rear planetary output.
If a white paper towel rubbed from the dip stick doesn't look exactly like a similar drop of brand new, you know you need to change it till it looks identical.
Simple.
Flush is more than just exchanging all the fluids, as the heat induced varnish will not be removed. Chemical solvents not found in ATF are needed, yet these solvent are too active to stay in the system LONG..........they are circulated for no more than 30 minutes [say 20 minutes at full operating temperature]. Then the ATF internal pump exchanges 85-90-95% of the solvent and old ATF.
Many times a single cycle leaves the ATF NOT at brand new color, a 2nd exchange may be necessary, either while the exchange machine is connected or a week later.......cheaper while connected].......negotiate.
We have seen 94Q trannies last over 200,000 miles with 6 exchanges and chemical flushes.We have seen 90Q [replacement new trannies 1993 version] last 200k with Mobil1 and 6 flushes. [with 1st gear start and external cooler added from day one
All of these long lived units were serviced at roughly 30k, 60k,90k,120,150k, 180k.
On my current factory remanned [been in my Q for 16 months for 23k], I flush and exchange every 15k [after the install flush] since the unit was used in another car [without 1st gear start for 1 year maybe 15k]. =38- 40k current mileage on unit.
All one can do is flush and exchange, clean and refilter frequently. And keep the ATF at or under 190F.
The ATF going into the cooler is totally from the TC which is last in the circuit.......ATF in the sump pan is from the rear planetary output.
Well, the fluid looks like a faded red on a napkin. Red + white napkin = pink to me I guess.
So the service I should request at the dealer is a chemical transmission flush? Two cycles? $300 for such a service is chump change compared to a new transmission. At least thats the maximum price I assume.
My only concern was dislodging something that could adversely affect my transmission. However, with anually flushed, clean Mobil 1 fluid, I think I'll be fine.
Thanks Dennis!!!
-Jesda
So the service I should request at the dealer is a chemical transmission flush? Two cycles? $300 for such a service is chump change compared to a new transmission. At least thats the maximum price I assume.
My only concern was dislodging something that could adversely affect my transmission. However, with anually flushed, clean Mobil 1 fluid, I think I'll be fine.
Thanks Dennis!!!
-Jesda
The coldness affects your transmission if you have an external cooler. What that does is bypass the stock exchange which is used to warm up the ATF in colder weather. So, if you have bypassed the stock heat exchange then you need to allow your car extra time to warm up in cold weather before you put her into gear.
Nick
Nick