Transmission Blues

Hello again,

My new 74 runs great and shifts "OK" for the most part. My only problem arises after the tranny is in 3rd. I'm crising along... as happily as can be then, I need to take my foot off the gas and... :twisted: <<REALLY LOUD GRINDING SOUND>>, I give it more gas and it goes away. If I push in the clutch it give me the same lovely sound. Now if I'm in 2nd or 1st and ease off the gas or push the clutch... Nothing. It's quiet. Any thoughts? Do I need a new clutch or is the tranny going bad?

 

U-joint?

Is it only in third? Can you get it to do it in 1st or 2nd?

 

Just 3rd.

 

Put the transfer case in neutral and run through the gears, up to driving speed.

If you push in the clutch in 3rd gear (ie rolling along with the wheels driving the transmission) the noise is gone?

 

Forgive my ignorance... I need to take the 4x4 shifter (transfer case control) place it in neutral, then try to drive it? Or are you saying to let it sit in place (which I assume it will) and run through the gears. Whats the schmatic for that shifter? I don't have an owner's manual, my buddy tried it out and told me it worked (hubs and everything) but I don't know the order myself.

If I'm cruising in 3rd and push the clutch in it makes the grinding sound, when I release the clutch and give it a little gas it stops.

 

Yes. All the way forward - 4WD high. One notch back, 2WD high. Back some more, neutral. All the way back, almost touching the floor, 4WD low.

I would expect you to hear the noise all the time in 3rd, since there's no load on the transmission.

My guess is that the front main bearing on your transmission is noisy. When you are coasting in 3rd, the transmission input shaft is supported by the pilot bushing and the transmission main shaft, so the slop in the bearing can be heard. When you apply a little gas, the torque on the input shaft pushes against the bearing, making it quiet. Just a theory.

have you checked the gear oil level in the trans and transfer case?

 

No I haven't, how do I? :? Sorry... it's going to be a long learning process for me. Thanks for all the help, hopefully I can return some in the future.

 

There's a fill plug on the side of the transmission and on the side of the transfer case. Remove the plug and stick your finger in the hole to feel the level of the oil. It should be filled right up to the level of the hole.

 

Cold Engine I assume! LOL Will it spill out when I take them off, or will I be able to take it off even full and feel it?

 

Engine heat won't matter. A manual transmission doesn't get very hot.

If it spills out, it's overfilled. The TC might spill a little, since some oil goes from the transmission through the bearings to the TC - no problem. The oil is reeeaaaallly thick, so if oil comes out, just quickly put the plug back in and wipe up the spill. You won't lose much.

<edit> Sometimes service stations overfill gear oil - the oil is thick enough that you can pump it in and put the plug in before it drains out. Doesn't make much difference - most of the time you can stick your pinky in the hole and feel the surface of the oil. You might want to top it off if it's more than a half-inch down or so.

 

Is there a spot under the hood to top it off or do I need some weird funnel to get it in down there? Thanks again.

 

Heh. Nope, nothing under the hood.

Various contraptions are available, like squeeze bottles, pumps, suction guns. Local garage will fill them for you, shouldn't cost much. They can drain and fill - but check their work with your pinky afterwards.

 

LOL Sounds like fun. Hope about a good ole "suck and spit". LOL

 

Don't be surprissed if you find a 2WD Low twixt neutral & 4WD Low. They put them in many of the cast iron trannies, even marked the transfer case knobs, but the majority of transfer cases jumped out of 2WD Low, so they just changed the transfer case knobs.
I had a 3 spd. that would hold 2WD Low consistently, sorry i traded it.
Somebody sells a retro part for 2WD Low now.
Get yourself a pint container of gear lube & cut the tip to fit inside a piece of vacuum hose about 5' long, clamp or tape it & squeeze away or run gravity.
Some transfer cases step down from the tranny w/a dam at the mating surface, so fill each unit to it's own level.

gj

ps: try an old fashioned squeeze oiler and carefully squirt some oil on your throwout bearing, clutch in & noise coulda be that.