SM465 Chatters when I get on it.

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Big _Betsy_Red

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This is definitely the transmission chattering. I "recently" replacing the original 700R4 with my covid SM 465 transmission as a set with an NP 205 and adapter (but no power sleeve) that I got cheap from this kid who said he rebuilt it and it works well enough. I got a power sleeve from company XYZ that I ended up shattering in the adapter but thats another story. After some detent issues, I mated the SM465 to another NP205 that was rebuilt by midwest trans with the typical adapter and power sleeve by advanced adapters which was a very impressive part they machined in house. The truck never chattered like this before I installed this SM465 and after the second NP205 transfer case (and second power sleeve for that matter) it pretty much rules those out as the source. The tunnel still has no boot over the shifter so there is more noise getting into the cabin than normal but I doubt a properly rebuilt transmission would make such a distinct and loud chatter and only it only occurs when I get on it and try to ask her for some MPHs in a higher gear. It chatters when the truck is under load and the rpms are low and the torque is high. I would hate to give midwest transmission anymore money when this is porbably a known issue that I could fix myself for a lot less money - particularly when she does still run. I would be more apt to rip it out if I had a better idea of whats going on and what to expect but I think I may just have to go in head first with a blindfold on. It looks like NOVAK adapters has a descent schematic but I don't think they have all the different shifter forks and a couple of the other SM465 adapter schematics I have found online are call for info. Thoughts?
 

MarineOne

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What oil are you running in the transmission?
 

DoubleDingo

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Chatter is a clutch thing. Clatter is more of what your describing. Possible bearing noise?
 

SquareRoot

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Worn bearings. Remove, replace, carry on.
 

DoubleDingo

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Highly recommend 90w mineral oil, you can get it by the gallon at Napa.
 

DoubleDingo

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Not sure, but it's definitely what you need for the manual trans.
 

DoubleDingo

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If you want a good explanation on it, check out Stovebolt, the old boys over there explain it very well. If I tried to, I would just be paraphrasing and getting it wrong.
 

MarineOne

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What about the GL1?
Ive been using valvoline 80W90
Gl1 is okay if you put in additives as it has no anti foaming properties and very low extreme pressure resistance And dosent handle rpm well. Its for mostly very old transmissions and old tractors. If using gl1 currently I'd drain it and replace with gl4 lube. As your condition may be caused by the oil turning to foam

Also gl4 is good for transfercase aswell (gl1 not good)

Gl5 should be used in differentials as it has almost double the pressure resistance as gl4 type oil
 

geardaddy

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on the clustr shaft, 3rd gear is held in place by a snap ring, it is very common for the ring to break allowing the gear to move around. if you pull the pto cover on the side of the trans you should be able to tell if it moved or see witness marks. the fix was a simple piece of tube in between 3rd and 4th on the cluster
 

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