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644E transmission suction screen.

fast_st ยท 2016-12-18 15:37

Well I think I found some bits of 4th gear, some gaskets, maybe a cricket or two and some other bits. there were very few metallic flakes, nothing magnetic that I could tell, some very hard black chips and some smaller not so hard ones, you could grind them into dust with finger pressure. There was a little glitter to the transmission fluid but not much at all. The screen had a fair bit of debris and there was some near the screen, that was a real bear to clean out, nothing would stick to the magnet so a finger followed by a paper towel wound around the end of a screwdriver, push and wiggle and turn to get more bits out, then added a half gallon and let it wash some more out the hole. The intake screen was cleaned and brushed and prodded and cleaned again, new filter and 4 gallons of fluid added. The report on the transmission fluid from Blackstone wasn't bad, but next to new fluid it sure looked dirty! Thankfully it doesn't take much fluid to change it and hopefully it'll last a good long time! Looks like fun to change a transmission! Park it over a big hole in the ground and undo all the bolts!

Replies4
  1. #1fast_st2016-12-20 06:01

    Well one improvement, it sounds like the trans is a lot more quiet when its cold, still seems to shift okay and has plenty of power going forward, it has to be happier with just having less junk in there and with that change, I'm done swapping out hydraulic fluids, that covers the main hyd, axles and now trans, all cleaned out and looking pretty, If I had my druthers to do the trans oil change again, I'd do it hot and tug the suction line out first and then spin a round nylon brush in the hole to coax everything to come out with the waste oil flow.

  2. #2Joe Walters2017-04-05 16:09

    If you ever need any help with this transmission we can help you out over at Centranz. www.centranz.com [email protected] 816-408-7100

  3. #3Bigbert2017-04-06 15:22

    Hello fast_st, looks like a suction screen of a ZF 4WG200 or so. The suction screen is able to keep back bigger debris from charge pump. Smaller parts will be collected in main filter. Fully right, debris looks like gasket material, some material from clutch discs and possibly thrust washers. As long there is no major metallic stuff on magnet there is litte risk of failing bearing or gears. Changing main filter is always a good idea. Noise: As cold oil is thicker it will dampen more tooth noise and transmission will run quieter. br

  4. #4fast_st2017-04-07 06:48

    Thanks for the reply, it is a ZF, ayep, before cleaning and fluid change I used to get a trans pressure light when shifting forward / reverse, that seems to have gone away. 4th gear doesn't grab super well but we're not roading it so 3rd works just dandy, pulls firmly in 1/2