1990 Q45 having tranny issues

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mattd1979
Posts: 707
Joined: Fri Oct 29, 2004 6:08 am
Car: 1990 Pearl White Q45 plain Jane with 266,000 miles. 2015 moonlight white metallic Q70L with 20” wheels, sport brakes and a 5.6L at 58,000 miles.
Location: Jacksonville

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Update....Since I last posted, the tranny lost 3rd gear and I decided to swap back in my other tranny that was in the car before I swapped engines. I swapped it in and went ahead and replaced the tranny cooler and bought another inline magnetic filter by Magnifine. I had the tranny flushed with bg products. They also added BG shutterguard to the tranny after the flush. This was all done prior to the inline filter going on. Right now the tranny seems to have a delay when shifting from 2nd to 3rd. Once it engages, it is firm but as it is shifting, the rpms slowly drop and then it falls into 3rd. It doesn't do this in any other gear.


maxnix
Posts: 22628
Joined: Mon Jul 22, 2002 8:11 pm
Car: 1995 Infiniti Q45
1995 Infiniti Q45t
2000 Infiniti Q45

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Varnished 2-3 shift solenoid?

Did you use the BG Quick Clean for AT as Q45tech instructed?

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mattd1979
Posts: 707
Joined: Fri Oct 29, 2004 6:08 am
Car: 1990 Pearl White Q45 plain Jane with 266,000 miles. 2015 moonlight white metallic Q70L with 20” wheels, sport brakes and a 5.6L at 58,000 miles.
Location: Jacksonville

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I don't know what the name was of the flush other then it is made by BG products. As far as the shifting goes, the more that it has been driven, I have noticed more about how it shifts. At part throttle from a stop, 1st and 2nd shift strong but it slides into 3rd. At WOT from stop, it stays in 1st until it hits the rev limiter which is at 7300 and slides into 2nd and shifts into 3rd strong. So at part throttle it feels like it is slipping into 3rd but at WOT it instead seems to slip into 2nd and then shifts firmly into 3rd. I have also noticed that with this transmission, when you are at 25mph and you go to WOT with it in drive, it will not down shift into 1st unless you manually do so.

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Haitian_King
Posts: 2868
Joined: Sat Jan 13, 2007 8:20 pm
Car: 1992 Black Infiniti Q45 /w TCS
1995 Black Infiniti Q45
Location: South NJ/PA/Canada

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Sounds like you used the right product. I don't know about the symptoms you're describing though. That's a new one for me.

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mattd1979
Posts: 707
Joined: Fri Oct 29, 2004 6:08 am
Car: 1990 Pearl White Q45 plain Jane with 266,000 miles. 2015 moonlight white metallic Q70L with 20” wheels, sport brakes and a 5.6L at 58,000 miles.
Location: Jacksonville

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After the flush was performed, I was told that the car needed to have around 200 miles put on it to allow for the additive to set in which is BG shudder Guard. I have around 186 miles I believe on it now since the flush.

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mattd1979
Posts: 707
Joined: Fri Oct 29, 2004 6:08 am
Car: 1990 Pearl White Q45 plain Jane with 266,000 miles. 2015 moonlight white metallic Q70L with 20” wheels, sport brakes and a 5.6L at 58,000 miles.
Location: Jacksonville

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Since this last post, the transmission would no longer shift into 2nd or 4th until it eventually wouldn't shift into 3rd. I believe that the solenoids eventually went bad. I had another transmission that had around 75,000 on it and I swapped it in. The car has been shifting better now then it ever did with the other 2 transmissions.

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Q451990
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Joined: Tue Jul 23, 2002 8:21 am
Car: 1990 Q45 - 118K, 2022 Toyota 4 Runner, 2004 Frontier M/T - 108K, 2012 Xterra (Mom's), 2023 Rogue (Inlaws)
Location: Columbia, SC
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Thanks for the update!

Heath


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