I am trying to replace the seal in the output shaft, and I am having problems getting the old one out. I believe it is the original seal; it had a felt seal instead of rubber and it is a little different than the one I bought (the new one does fit the yoke, so I believe it is the correct one). I have tried prying it out and attempted bending it in on the side to loosen it up and get something under it, but so far it has not budged nor have I been able to bend it. So far all I have accomplished is bending the thin metal on the top. I can remove the tail shaft if anybody thinks that would help; that is my next step if I can’t get this thing out. Maybe having more room to swing a hammer will help!
Bend the lip of the seal out far enough to grab it with a small pair of vise grips- - - -- -then pry on the vise grips. I've also replaced the tension screw on a vise grip with a long piece of all thread rod and used a big socket as a slide hammer over the rod. Jerry
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt! There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway Love your enemies and drive 'em nuts!
I have tried grabbing the part that I could bend up with vise grips and then tapped on the grips with a hammer. All it did was eventually slide off the lip I was clamped on. I’ll keep trying though.
Those original seals had several layers of steel, rubber, and felt. Just keep working it. Don't even think about removing the tail housing, it is connected to the main shaft and will hang up and provide you with a giant mess. Fred
1956 3100 Pickup/Red/350/3sp OD/PS/Disc Brakes 1957 Bel Air Sport Coupe/Red/355/TH350/PS/Disc Brakes 2017 Silverado LT Single Cab SB/Black/5.3/6 Speed Trans 1947 Willys CJ2A w/F-Head engine
Well, I screwed up. I didn’t see Fred’s reply before I took off the tail piece. And yes, now there are loose needle bearings that I have to put back in place. I said several swear words when I saw it. Oh, well, at least I got the seal out. So now, does anybody have or know where I can find a more detailed overhaul manual that can show me how to get to them? I have the chevy shop manual, but it is not much on details. I don’t know if it would be possible to place the bearings back in position with a long screw driver and some assembly grease to hold them in place? I guess now I go drop the rest of the transmission.
Thanks Kevin, I forgot about the old car manual website, lots of good information there. I have rebuilt one transmission in my life (also a 3 speed) and I recall using some kind of grease to hold the needle bearings in place before assembly. If I pull the rest of the transmission out and stand it on its nose, I think I can place all the bearings in and then carefully slide the main shaft back in. Not sure if that would be easier than taking the side cover and maybe the nose too to get at those bearings. I’ll figure it out. Hopefully!
does anybody have or know where I can find a more detailed overhaul manual that can show me how to get to them?
Look in your email inbox. I just emailed you a .PDF copy of a GMC SM318 overhaul manual in .PDF form that is 19 pages long. May help.
Last edited by Bill Hanlon; 04/10/20263:25 AM. Reason: new info
'57 GMC 102, Original 347 V8, HydraMatic, 3.08 rear gear, added A/C, disk front brakes, HEI, AFB carb, '98 Honda Black Currant paint. T-boned and totaled 10/12 '52 GMC 152 Stake Bed, Original 228, SM420, added A/C, HEI, disk front brakes, '67 Chev 3.55 rear gear. Gets used as a real truck.
Got it; thank you Bill. It looks like the book way to install the needle bearings is to do so with the front drive shaft removed. Not sure I can do that without a special tool to remove the bearing from the case. I’ll see if there is a work around to using the tool.
Remove the transmission from the truck, remove the side cover and the front bearing retainer. The clutch gear will pull out with the front bearing. Reinstall the needle bearings and rings. It's probably a good time to replace the rear bushing, bearings, worn shift forks, gaskets, and any other worn components. You now have a rebuild in progress. Fred
1956 3100 Pickup/Red/350/3sp OD/PS/Disc Brakes 1957 Bel Air Sport Coupe/Red/355/TH350/PS/Disc Brakes 2017 Silverado LT Single Cab SB/Black/5.3/6 Speed Trans 1947 Willys CJ2A w/F-Head engine
I probably could have removed it in place with some more work. I was worried about damaging the output shaft and it was hard working around it. After I got the housing out, I removed the main shaft so I could see better what needed to come out and I could really pound on it. Basically deformed it into the space that the output shaft occupied and then I was able to pull it out.
A small addition: the seal I had to remove was the original style seal as is displayed in the shop manual. It has a lot more to it than the replacements available today. I would think that the newer style would be a lot easier to remove without having to take off the tail piece so as to get the output shaft out of the way.
It was not easy, but I was successful in getting the main shaft back in the transmission with all the needle bearings in place. Could not locate a puller to remove the clutch bearing so I stood the front part of the transmission on its nose, carefully installed the needle bearings using sticky grease and a long common screwdriver, then slowly lowered the tail piece/main shaft into place. It took a few tries to get it all lined up, but it finally did and the test went well. Not something I would recommend though. Thanks to everyone for your advice and information!
