trevorthetrekker

Hey y'all,

There is no service history for my L-50 transmission in my 1982 Trekker with over 280k miles, so it's completely possible this tx is original and has never been rebuilt. I do know that I installed a rebuilt 22R and just installed a brand new clutch last weekend trying to resolve this issue:

When she's in motion, being driven by the engine, everything sounds perfect. As soon as I let off the throttle, I get this horrible grinding sound. It seems most prominent in 1st and 2nd.

In 5th gear I get it almost constantly, but it's much quieter and doesn't sound nearly as bad.

4th gear is getting harder to shift into; I need to move the shift lever to the right extreme to get it to shift without grinding (I'm guessing synchro for that one)

Idling in neutral makes no sound whatsoever.

I have read tons of posts about grinding sounds, with diagnosises (diagnosis'? diagnosii?) ranging from:

-Bad output bearing on the 22R (impossible; it's brand new)
-Bad clutch (I just replaced it trying to fix this issue, so it's not the clutch)
-Bad drive shaft (no play; seems good to me)
-Something in the transmission or transfer case

I try my best to not let the sound happen. As soon as I let off the throttle, I immediately punch the clutch to stop the sound from happening.

So that's where I'm at. I'm hoping someone has had this problem before, or is better at searching than me and has seen this issue on a forum before.

Thanks for any help guys.

Have a great day and a happy Father's Day!

83

I know there's a "coast" and "accelerate" side of the transmission. Sounds like your coast gears are toast. When it's possibly an internal issue with the transmission...well, that's a big expensive job. So I won't diagnose over the internet and have you spend a bunch of time and money. You just don't know until you get in there. But it sure sounds like the tranny is bad. Take it to a tranny shop and see what they say. I don't know what kind of shops you've got near you, but I went to a shop, explained my problem, and they put it up on the lift and looked around.

They didn't charge me anything. They would have if they had taken it on a test drive, I guess, but just to put it on the lift and rule out driveshafts and other stuff, it was free. Can't be too expensive to have a specialty shop look at it and test drive it, though.

Depending on your money and skill...this might be a good time to upgrade to a newer model tranny, or at least an L52 5 speed. You might even just find a decent used one and throw it in.

kawazx636

iTrader: (3)

Mine (83 4WD shortbed) did a similar thing and still does to a certain extent. It wasn't "grinding" but has a really bad vibration (more like a shake) coming from the tranny when I got up around 45 MPH in any gear. It would vary depending on coasting and acceleration, but it was always there. It almost felt like an out of balance flywheel, but an out of balance flywheel wouldn't have a steady vibration with the clutch in at 45-65 MPH at 900 RPMS. I knew I needed a new clutch so I figured that I'd grab the wrenches and yank the tranny.

I had the flywheel checked and it was still balanced. Replaced the clutch, pressure plate, pilot bearing and throwout bearing. Went ahead and replaced the 30 year old u-joints (talk about a pain in the arse!) while I had the driveshafts out and replaced the rear seal while I was at it too.

In replacing everything, I noticed that the throwout bearing and pilot bearing were really loose and worn so I prayed that this was my problem. I bolted everything back up and took it for a test drive. The vibration was GREATLY reduced; however, I still had a slight rumble coming from the tranny while coasting (with or without the clutch in).

I'm certain that the tranny could use a rebuild, but this was a good bandaid to slap on until this fall when I plan to break down the entire truck to start my build. Perhaps this could buy you some time.

enigmaT120

I've had noise like that coming from the differential before, when my pinion nut had slackened off. Ruined the pinion and ring gears. If it's definitely coming from the transmission it probably should be rebuilt. You got your money's worth out of it, that's for sure.

83

Yes, it's a good idea to pull the driveshaft and make sure the pinion nuts are tight. Good call.