Received with group purchase of pars. It has a Bolt on yoke . What is it for and what's it worth ? Do not see a tag on it.
So it might be a Chevrolet transmission ? Is there a good source for checking the bolt pattern other than checking a engine block ?
To use a standard yoke you either need to machine a counterbore on the inside of a standard yoke, or grind off the grooves that hold the Oring on the output shaft. The bolt on yoke uses a o ring to prevent oil from leaking from around the bolt. The standard yoke doesn’t need the o-ring, but will contact the oring bore before it bottoms out. Removing the o ring bore, or machining the yoke restores the full yoke travel needed for car application
Btw, that’s definitely a Chevy bolt pattern. http://www.ckperformance.com/Tech-B...nsmission-Case-Identification-and-Interchange
Show us a picture of the bolt pattern or simply look it up on Google. Not hard to ID. https://en.m.wikipedia.org/wiki/List_of_GM_bellhousing_patterns
That's a 400 out of a medium duty truck like a step van or something of the like. Probably has HD guts in it.
T Thanks Joe, Larry, Ben , and Matt sounds like it may be worth hanging on to for the internals or for a Truck project. Thanks! Tony
It's a simple as swap out the output shaft when your having it rebuild......nothing big or hard. But correct not with a non sliding yoke, but I assumed that was covered in the earlier post
Does it have a thick flange for a bolt on inspection cover? If so, it may have straight cut gears. Supposedly they are a little quicker on the track due to less thrust loading of the normal helical gearset. They are also much more noisy, like the rock crusher Muncie trans.
It would be interesting to see what heavy duty parts might be inside. Case molding, direct clutch plates, long yoke sleeve, deep pan, whatever. And is there a special overhaul kit for those? Bruce Roe
I wonder if it is a Turbo 475? From what I have read, it is a dead ringer for a 400. It does use the straight cut gears. Also known as the 3L80HD?
Some heavy duty applications ( motor homes, dump/tow trucks, etc) had a direct drum that used 6 frictions. If I remember correctly the only difference is the snap ring groove is cut higher. I have also found several of those drums in the fwd Toronado from the mid-late 60s. I’m guessing they probably used the smooth sprag style drum thru the entire TH425 production run, since you can’t flip the sprag for the reverse rotation of the front wheel drive. Other than needing an extra friction and steel, the overhaul kits are the same.
