Ala75Vette Vibration Trans. seal link

[81 MAKO]

Frank, I mistakenly sent my first reply back on "pm" msg to you and I wanted to reply on the forum so other 4-spd owners could have info. You mentioned your trans. shaft leaking lube, when replacing the rear oil seal, you may want to think about the extension Brass-Bushing that sits on the mainshaft in front of seal. When this bushing wear out, its will cause and produce some vibration to rear; when the bushing is worn out, it will keep destroying new seals and leakages will start. This Bushing is a sleeve type item which helps the mainshaft run true. A real transmission mechanic with the knowledge and tool for removing and installing should handle this project. Simple dropping front driveshaft and yoke to trans. and checking the play in rear of mainshaft might help. Make sure your manual trans. is full of gear lube; its got a lower drain plug and upper to refill, if its been that long since changed. As one vette owner said there are alot of moving parts that could add in a factor here...good luck on your mission and please let us know when you find it. LOBO out!!

 

[Ala75Vette]

Thanks for the insights into my tranny! I'm going to post an update to my original string, but to summarize, replacing the drive shaft u-joints helped a bit, but I've still got vibration at 2000-2100 rpm/50 mph which I suspect is transmission related. Still can't totally count out the exhaust, but when I (finally) get my sidepipes installed that'll sort of eliminate that as a potential source. Thanks for the words on the transmission.... my next "big" project will likely be getting it "rebuilt" (new bearings and seals), and while I'm at it sounds like I should also get the extension bushing replaced. I did replace the output seal & refill the trans with gear oil, so we'll see how long that holds. Again, thanks, and I'll always keep my vette friends posted on vehicle status on this forum!

Frank