Clutch "Chugging" - T/O Bearing, Adjustment issue, or Tranny Bearing?

[copper204]

My project 1972 with 1975 4 speed has exact sound and I have replaced everything in front of transmission forward during Hector's build. I did not know anything about transmission before i got it. And Mel Lowe who I got it from did not have a history on it either..

 

[RWBeringer4x4]

My project 1972 with 1975 4 speed has exact sound and I have replaced everything in front of transmission forward during Hector's build. I did not know anything about transmission before i got it. And Mel Lowe who I got it from did not have a history on it either..

This begs the question - will you be putting in new bearings to see if that shuts up the whining, or are you just going to run it?

 

[copper204]

On the down shifting issue. It could also be a seizing or galled pilot bearing or bushing.. Pretty much the way it happens with both a pilot bearing and input bearing is, as you push clutch in. It disengages the input shaft from engine rotation and or slow it somewhat and the transmission is then freewheeling with no direct force . This causes a slight or higher noise reduction due to rotational forces. Then after a short time the transmission allows you to slip into gear. This is just my expierence with working on these vehicles and about a dozen other brands.. LOL

 

[RWBeringer4x4]

On the down shifting issue. It could also be a seizing or galled pilot bearing or bushing.. Pretty much the way it happens with both a pilot bearing and input bearing is, as you push clutch in. It disengages the input shaft from engine rotation and or slow it somewhat and the transmission is then freewheeling with no direct force . This causes a slight or higher noise reduction due to rotational forces. Then after a short time the transmission allows you to slip into gear. This is just my expierence with working on these vehicles and about a dozen other brands.. LOL

Thanks for the input. If you get a second - go back to the first video I posted in this thread, you will hear the "chugging" that sent me down this rabbit hole in the first place. I sure hope it's my throw out bearing, and not my input shaft bearing. My concern is that the chugging goes away when I step on the clutch - which SHOULD be engaging the T/O Bearing and disengaging the input shaft (I think) which to me says it might be my input shaft bearing. But others here have heard similar noises and found it to be the T/O bearing. Quite the mystery. Dying to get the engine pulled and dig into it, but that won't be happening until summer.

 

[RWBeringer4x4]

My project 1972 with 1975 4 speed has exact sound and I have replaced everything in front of transmission forward during Hector's build. I did not know anything about transmission before i got it. And Mel Lowe who I got it from did not have a history on it either..

@copper204 - never heard back. The gear whine you're experiencing on your transmission, are you just going to run it, or is this something you're going to try and remedy with new bearings, etc?

 

[copper204]

I am going to run it. It is quieter than my 3 speed anyday.. Sorry got tired last night...

 

[Ian Macdonald]

My drivetrain is noisy - makes me crazy. I like quiet, so I suppose I should've bought a Lincoln, but no, I wanted a FJ40. I've been through the tranny and t-case, renewed bearings and shims, and checked gears. All good (according to my eye, anyway). Sometimes it just is what it is. I've never been able to decide what is normal for my rig.

PS - Sometimes in my job as a pump tech, it's nearly impossible to pinpoint a problem without a teardown. Just saying.

 

[roadstr6]

Copper, My FJ60 makes the same noise as yours except maybe worse. All stock. 2F/H42 (short version). The clutch was replaced by a PO. Throwout bearing is quiet and looks fine. Constant roar when in neutral and idling. The roar goes away when I press the clutch. My assumption is that it is a bad input bearing. I picked up another H42 to swap in if I end up needing it. I was hoping you would tear into yours to determine the problem. That would have put me on the correct path. Oh well.... If you do decide to go into it, let me know what fixes it. I'll probably pull my trans in the next couple of months to see what is going on.

 

[RWBeringer4x4]

My drivetrain is noisy - makes me crazy. I like quiet, so I suppose I should've bought a Lincoln, but no, I wanted a FJ40. I've been through the tranny and t-case, renewed bearings and shims, and checked gears. All good (according to my eye, anyway). Sometimes it just is what it is. I've never been able to decide what is normal for my rig.

PS - Sometimes in my job as a pump tech, it's nearly impossible to pinpoint a problem without a teardown. Just saying.

Ian - I've been in a few FJ40's and I'd say they all have a pretty significant amount of drivetrain noise. I also completely agree that to really know the source, it's going to need to be torn down - which is happening this summer. This thread is really helping me to gauge my expectations on what is "normal" vs. "a big problem" so that I know whether or not I need to source a new transmission (ideally before teardown). Helps with budgeting, and one of my biggest pet peeves - being unable to find a part you need, when you need it. Once I start a project, I like to finish it, I had sitting around waiting for parts so I try to avoid it at all costs!

Copper, My FJ60 makes the same noise as yours except maybe worse. All stock. 2F/H42 (short version). The clutch was replaced by a PO. Throwout bearing is quiet and looks fine. Constant roar when in neutral and idling. The roar goes away when I press the clutch. My assumption is that it is a bad input bearing. I picked up another H42 to swap in if I end up needing it. I was hoping you would tear into yours to determine the problem. That would have put me on the correct path. Oh well.... If you do decide to go into it, let me know what fixes it. I'll probably pull my trans in the next couple of months to see what is going on.

@roadstr6 - If you are referring to the videos at the beginning of the thread, that's my truck, not copper's. I'll be tearing mine down this spring/summer, hopefully - so if you can wait until May or June, you might get an answer.

 

[roadstr6]

Rick,

Sorry. Yes. Your truck, not Copper's! I have a long to-do list to get through before I tackle the trans issue so it may be spring before I get to it. Keep me posted and I will do the same for you.

Dave

 

[JAFO2014]

The throw out bearing should only contact the pressure plate when you press on the clutch pedal. Its sole purpose is to allow you to release the clutch disc from being squeezed by the pressure plate. When correctly adjusted, when you let off the clutch pedal there should be a gap between the pressure plate and throw out bearing so that the bearing is not turning. A incorrectly adjusted clutch, allowing the throw out bearing to touch the pressure plate while driving will shorten the TO bearing life expectancy greatly. A really poorly adjusted clutch could actually allow the clutch disc to slip and burn up the clutch disc. The throw out bearing is meant to only turn while the engine is idling. I was taught that when I came up to the light to throw the transmission into neutral and let out the clutch pedal to give that throw out bearing even less use. Then pop it back in gear when ready to go.

So, really you should hear a bad throw out bearing when you depress the clutch and it starts turning. It should not make a sound when the clutch pedal is out.

 

[RWBeringer4x4]

The throw out bearing should only contact the pressure plate when you press on the clutch pedal. Its sole purpose is to allow you to release the clutch disc from being squeezed by the pressure plate. When correctly adjusted, when you let off the clutch pedal there should be a gap between the pressure plate and throw out bearing so that the bearing is not turning. A incorrectly adjusted clutch, allowing the throw out bearing to touch the pressure plate while driving will shorten the TO bearing life expectancy greatly. A really poorly adjusted clutch could actually allow the clutch disc to slip and burn up the clutch disc. The throw out bearing is meant to only turn while the engine is idling. I was taught that when I came up to the light to throw the transmission into neutral and let out the clutch pedal to give that throw out bearing even less use. Then pop it back in gear when ready to go.

Thanks @JAFO2014 - I understand how the T/O bearing works, what I DON'T know is how poorly adjusted my clutch is. I'm really trying to determine whether the sound I'm hearing is coming from a badly adjusted throw out bearing riding on the pressure plate while the clutch is released, or if it's the input bearing on the transmission, since I believe the transmission input shaft spins, if the truck is in Neutral and the clutch is released.

 

[roadstr6]

My TOB is adjusted properly. I have confirmed this by dropping the inspection plate and watching it in action. No contact with pressure plate. Still the noise persists. My noise is NOT the TOB. Your results may vary, Rick.

 

[RWBeringer4x4]

My TOB is adjusted properly. I have confirmed this by dropping the inspection plate and watching it in action. No contact with pressure plate. Still the noise persists. My noise is NOT the TOB. Your results may vary, Rick.

Yeah, unfortunately no inspection cover on my truck. It uses a one piece, lakewood scattershield bellhousing as part of its V8 conversion. I won't know until I'm in there.

 

[JAFO2014]

OK, sorry for the basic post. Then of course it is a feel thing. You remove the spring from the clutch lever and then move it manually. Should be able to tell when the TOB is touching the pressure plate.

 

[RWBeringer4x4]

OK, sorry for the basic post. Then of course it is a feel thing. You remove the spring from the clutch lever and then move it manually. Should be able to tell when the TOB is touching the pressure plate.

No spring on my clutch. It didn't have one when I got it, and when I tried to install it, it wound up making the slave/fork almost impossible to adjust. In fact, the only place the truck even functions is where the clutch is now. I've tried spring/no spring, adjusting the slave in and out, regardless of what I do, I get a situation where the truck won't go into gear.

My only thought is that there really is 0 clearance in the whole assembly - which makes me lean toward a throw out bearing, BUT if it was, I would think the sound would get worse, or continue, when I pressed the clutch in. When I press in the clutch, it goes quiet, which makes me think input shaft bearing.

 

[JAFO2014]

That is weird. You would expect that you could remove a spring, adjust the linkage for the correct clearance, then install the spring so that it holds the fork back from the pressure plate. Both my FJ40 and my 1973 Bronco have a spring and works as expected. But I have stock stuff in both. The FJ40 having the 2F and the Bronco having the 302 with mechanical clutch linkage from the pedal.

If you remove everything from the clutch fork, so you are moving it with your hand, can you feel the correct movement and play? With every clutch fork I have dealt with, you can move it forward and back feeling the throw out bearing as it comes in contact with the pressure plate. You could get an idea if things are working (moving) as expected, get a feel for where the fork is positioned and then connect back the linkage.

I guess when you get in there you are going to find that possibly someone installed the wrong parts and something is in a bind.

Years ago, in my twenties I was trying to help out a friend and we installed a new transmission into their cluster jeep. Jeep had a V6 from some Chevy as I remember and some I think three speed or maybe four speed trans. Engine had blown and they got another from the junk yard. We installed the engine and trans and it was real tight going up to the engine. Actually, seemed it would not slide right in. I remember we just used the bolts to draw it up tight to the engine. Did not think anything of it. But then after some miles of driving it was noticed the front pulley was moving in and out as the clutch was pushed. The final outcome was, the engine was from an automatic transmission car. Then crankshaft was not drilled out deep and even though the pilot bearing went into the end of the crank, the hole was not deep and the transmission shaft was actually hitting the crank. When we bolted the trans to the engine, it was putting pressure on the crank. It wore the center main bearing. The part that keeps the crank centered. We had to drop the pan and install a new crank kit. And we removed the trans mission and for good measure ground 1'4" off the end of the shaft. Was a learning experience 28 years ago. Don't force anything. If something does not slide together, investigate.

 

[mmw68]

Any updates?

 

[RWBeringer4x4]

Nope, plans to pull the engine this summer got canceled when my garage renovation ended up taking 6 months - the new plan is to get back to the truck in November/Decemeber timeframe when my welder buddy is free.