Hey everyone, this is my first post as I am fairly new to yotatech. Several months ago I purchased a 1981 4x4 longbed pickup with the 22r engine and the L50 five speed tranny. Recently the truck has been making an odd vibration in any gear at most any speed, but not while standing still, only while just applying very light throttle maintaining speed.This is not affecting driving as the truck runs and shifts fine. After changing the shocks, steering damper, tire rotation and balance, I decided to look a little deeper into the issue since while these dramatically helped ride quality, the vibration was still present. My first step was to change the gear oils. So, just the other day I unscrew the drain plug on the tranny and there was a ball bearing on the magnet... Bad news. So, I do believe I have narrowed the issue down. I don't think its an input shaft bearing since the truck isn't having this issue in neutral while not moving, but I certainly could be wrong. I'm just guessing some sort of output shaft bearing is fouling up but again, I am not very knowledgeable on detailed inner workings of these transmissions and could still be way off target. I do know that this particular model was notorious for some bearing issues and am considering a full rebuild for this guy since I'm sure there are more problems to come since its 30 years old and the fluid looked like it maybe had never been changed. I just thought getting some comments on the problem would help me sort out my options going forward. Thanks everyone!

Corey

 

Is there a difference in the vibration depending on what gear you're in (specifically, if 4th feels any different)? What if you have it rolling, in gear, clutch in; vibrating?

 

I should have mentioned earlier that I don't really get this vibration at low speeds. Its really 2nd gear and up but 4th and 5th gear going highway speed seems to be the worst.

 

With regards to the coasting with the clutch in at speed I'll have to take it for a quick spin tomorrow. I can't quite remember what happens in that situation. If my memory serves me right I believe the vibration goes away but I'll need to check.

 

Worse with vehicle speed? Sounds like an output shaft bearing lost a ball, and while it's somehow staying together and not grinding, there's now an imbalance in that bearing that causes a vibration, much like a wheel with one big chunk of crud in one place on the rim. Coasting may keep it quiet just because there's hardly any load on the trans internals. But either way, it seems pretty obvious that there's a rebuild or replacement that needs to happen, and you may as well do all the bearings while you're in there.

 

Yeah that's basically what I was thinking so we'll see once it gets opened up. Thanks for your comments! I do appreciate it. I'll keep the progress posted on the thread.

 

Okay so its been a good while since I got around to this issue but I ended up buying an L45 4 speed for cheap instead of going for the rebuild. The L45 transmission bolted right on but I am running into an issue with getting the slave cylinder back on. For starts, it seems like the piston inside has extended all of the way out. I suppose that I can take the pressure off by simply opening the bleed screw and then re-bleeding the whole system. Pushing the pin in by hand does nothing. Another issue is that the pin that moves the clutch release fork seems that its not going to line up just right. Does this mean something was installed incorrectly? This is my first transmission swap so I am not quite sure what all I am doing. I am pretty much just going by the Hayes manual. Thanks for any advice.

 

So after some tinkering all seems to be working. The truck has now been downgraded to a 4 speed but it is running fine. Hopefully I don't have to worry about transmission issues anytime soon!