# 6400 MFWD with Power Quad



## lazyd (Oct 13, 2011)

I am rebuilding a 1994 JD 6400 with MFWD and the Power Quad transmission. Has anyone had experience repairing the range box on one of these ?? I have the PQ out on the floor but am puzzled about the range box. Thanks in advance.


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## jd110 (Nov 23, 2015)

The range box is typically very reliable. What needs to be repaired?


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## lazyd (Oct 13, 2011)

Previous owner was having trouble shifting it and forced it into gear. Broke the aluminum side cover where the shift rails are. I was wondering if this is common? Also, there is a tooth missing in the gear that the park pawl drops into. I'll try to post some pictures. It was a basket case so it is gonna be a real challenge. Alot of parts are in 5-gallon buckets. Are you familiar with the 6400 transmissions? Thanks


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## lazyd (Oct 13, 2011)

Here are some pictures of the 6400 project. Tried to show the broken cover, missing tooth, and I am pointing to the bearing race that is loose and turning...??? I wasn't expecting the case to come off like that. I thought the gears would come with it like a manual trans usually does. I have a few questions for you JD110. Sounds like you are the go to guy on these 6000 series Tractors...???


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## jd110 (Nov 23, 2015)

The area of shift cover that is broken has the interlock pin in it. It prevents both shift rails from shifting into a gear at the same time. There is a stepped pin that should be in the bore of that broken portion. I don't recall that bearing race being a floating race, but I will see what I can find out. (checked manual, bearing should be press fit)Been a while since I've had one apart. The broken tooth typically happens when someone put transmission in park while still moving.


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## lazyd (Oct 13, 2011)

What's the fix for the loose race ? new flange or center punch and Loctite...???


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## jd110 (Nov 23, 2015)

It depends on how loose it is. If there is not any clearance, but a slip fit, I wouldn't be afraid of using "Bearing Mount" loctite. Maybe called retaining compound now. If more than a thousandth or 2, I would replace it.


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## lazyd (Oct 13, 2011)

I am back at the 6400 project. I opened up the PowrQuad and found these cracks in the housing behind the pump. What would cause that? I am trying to lay out the parts so I can maybe put it back together...??? My main problem is, it was partially taken apart when I bought it. And me not being familiar with this transmission, it will be a puzzle putting together. I need a repair manual. Anybody got one they could copy a few pages out of ??


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## jd110 (Nov 23, 2015)

Hard to say for sure what cracked the housing. Possibly a broken driveshaft between engine and transmission could have stressed it or someone had it apart and when reassembling, didn't have something aligned properly and when bolted together could have cracked it. A manual is a must for proper assembly of transmission.


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## lazyd (Oct 13, 2011)

This transmission was partially apart before I got it. The previous owner decided not to fix it so the shop threw it back together and pushed it outside. But, the pump was in a bucket of other parts... What is a good manual to get? Right from JD or something else? looking for a recommendation.-------Thanks


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