# Cleaning Trany Filter



## characterboat (Jun 1, 2008)

Hi, I just joined ad apologize if this is in the wrong section but this one makes the most sense i guess. I have a 90 D21 and am replacing the auto tranny on it. For whatever reason i've ordered a few tranny filters and the wrong one always comes in. Is there a way to clean the old one out and just use it? The tranny from the junk yard specificaly called for a new filter but maybe thats just a general recommendation cause it looked alright to me. I'd rather just get a new one but its proving difficult. Thanks.


-Steve, 90 D21


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## rogoman (Dec 16, 2004)

If you're going to reuse the old filter, use some lacquer thinner to clean the screen as long as it's not excessively dirty. It's the metal particles that have to be cleaned from the filter; if they get into the valve body, problems could occur. Also make sure the O-ring is in good condition.


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## smj999smj (Jan 1, 2006)

It probably doesn't have a "filter," rather a metal screen which typically doesn't get replaced. Nissan's thinking is that if there is enough debris in the fluid to clog the screen, then there is something breaking down to the point where more than just a simple service will correct. If you want, drop the pan and spray it clean with some brake cleaner and clean out the inside of the pan and wipe off the metal shavings off of the magnet. I would recommend a new genuine Nissan gasket (P/N: 31377-41X25 ) and bolt set (P/N: 31397-41X04 ). Nissan recommends replacing the bolts as they are coated with a sealant. Part numbers apply to both 2WD and 4WD trannies for 1990. 

If you still want to replace the filter, the part #'s are as follows:

2WD:
88-89: 31728-X8600
90-97: 31728-48X01 (4 cyl. engine)
90-95: 31728-80X03 (V6 engine)

4WD:
88-95: 31728-41X03
96-97: 31728-48X01


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## characterboat (Jun 1, 2008)

I did manage to find a new filter before i got the reply to this thread and the truck is all up and running. FYI for anyone that needs to find a new filter, for some reason the 90 filter for the 4cyl 2wd D21 is very slightly different, have one ready before you take the old one out. The 'new' transmission i bought from the wreckers said specifically to change the filter and gasket and i wasn't going to take any chances.


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