Ford NH 6640 SLE transission problem

FrTed · Jul 25, 2016

Hi, first post on tractorbynet so Im hoping it appears where I want it!!

My 1995 blue roof 6640 SLE has lost gears 2,4,6 & 8 - works fine in 1,3,5,& 7. In the "even" gears just sits there, higher revs don't make her move. Would appreciate any advice as to where I would look first & how serious this problem could be.Thanks

FrTed · Jul 25, 2016

The lack of any response yet after 80ish views doesnt bode well!! Not having a clue where to start, I carried out the Clutch Spring Pressue Calibration procedure - the results were as follows:-

C2 & C3 went up to 240, then showed respective error codes U35 & U28 which both mean calibration is too high (should have stopped according to the manual between 120 & 180.)

C1 calibrated to value 128 while C4 calibrated to 164.

Does all this mean anything to anyone - Im struggling badly here!

FrTed · Jul 26, 2016

Bump!!

jimmysisson · Jul 26, 2016

Many of the folks on this forum own smaller, maybe simpler rigs than yours. There are several techs who come on but you may have to wait a bit. Good luck with it.
Jim

FrTed · Jul 26, 2016

Jim, I appreciate your words of wisdom!! Hopefully some of the techy guys will point me in the right direction.
Thanks again for taking the time.

FrTed · Aug 7, 2016

In case it helps anyone else

turned out that the soleniods are outside (relief). And better still, the problem was that one of them had lost a retaining nut and was hanging down. Pushed it back up into position and secured with cable tie - problem solved!! All I have to do is get a replacement nut from the dealers (its a very fine thread). So happy days - all working fine again.

Hard not to feel a little stupid when auto spark pointed it out but difficult when you just havent a clue where/what to look for. Disappointing though that the computer didnt throw up an error code.

Billio · Jan 16, 2025

Hello Fr Ted. Really interested in this as I'm looking at the same tractor, and it's working in the even gears, 2,4,6 &8 but not the others. Do you think this could be the same problem?
Where are the solenoids located?