ALright i will try to keep this short and sweet


MY t-18 tranny in my 79 f-250 is acting up:mad: , while in 3rd gear it makes a strange grinding (hard to desrcribe) grinding type noise. IT has also began to pop out of gear when under a decent amount of power also. It does not do this in granny, 2nd or 4th.
what could be wrong??????

All i know is this.....my truck sat upside down for 10-15 mins after i rolled it and almost all the tranny oil ran out the top. Towed it home and after a few weeks i had ti fixed and drained what was left of the old oiul and put in fresh 80-90 gear oil. that was about 2 months ago...it just started acting up this week. That was the first time the oil was changed in the tranny also. IT has never ever given me any problems before.

Now heres the catch, i have two friends, one with a 76 f-250, and another with a 79 f-150. Both w/ a np435, they started doing the EXACT same thing as my tranny a few weeks after they changed their tranny oil too. The one with the 79 has been running his for awhile now and sometimes it will hardly go into 3rd gear....it just grinds. Im not too familiar with the insides of a tranny, could it be the syncros?(sp?) Help me out here guys

I dunno about the 435, but the SM465 in my dumptruck (chev) does the same thing. I just hold it in gear, and its all good. Not reallys sure what causes it, i might pull the top cover off sometime and check. Another 465 in a friend's wrcker had the same thing happen, whe we took it apart, the 3rd syncro was junk, but the shift forks were bent too. This one didn't just jump out of gear, though, it attacked you. If you tried to hold it in, it WOULD break your arm. I know this doen't help much, but its all I kno about the subject

i was thinking syncros too, and its progressively getting worse. I wonder if these old iron trannys are like an old auto wihtout ever changing the fluid? when you put fresh fluid in it breaks a bunch of crap loose and screws everything up. Anybody else got ideaS?

could be bad thrust washers too, Either way it needs a rebuild.

As for changing the fluid, If you tranny was trashed to start with, then the fulid probally had junk in it, that was keeping the tranny together.

ill bet that the fluid was original....and when it sat upside down, all the metal got up in the bearings and shit. then i had to drive about a mile back to some land to get towed home.

Oh well obviosly something is wrong, i guess ill pull it out and have it rebuilt. Hopefully my gears and such are ok :beer:

I don't know that I would pay for a rebuild. Those are such common tranny's. I find them all the time used for $100. But you just want to be done with it, then rebuild away $$ I hear they are fairly simple for the do it yourselfer.

My NP435 made all kinds of noise when I first put it in. FearMe said would go probably go away.....guess what... It did! However, if yours is poping out of gear then its' probably done.

yea man that sucks

SM465s jump out of third b/c:

"third and fourth are held on the countershaft with snap rings. Under load, Third wants to walk forward and fourth wants to walk back. After time, the snap rings flex enough to allow the tranny to jump out of gear."

4WOR, Aug. 2002, p. 113

They list a cluster spacer p/n 14020811 from Anaheim Gear that replaces the snap rings. Heavier springs on the shift rails and diamond cut synchros finish it off.

Looking at some photos of the T-18, there are a series of synchros between the 3rd and 4th gears on the mainshaft. It's possible you're hearing those synchros. There's a brass ring and a spring in there... could be worn out.

Hope that helps.... I've never rebuilt either one, but I have a lot of stuff laying around that talks about it. :D

THanks guys, i think me and john deere are going to attempt a rebuild:smokin: :rasta: