What’s Wrong with my Transmission...and Other Stuff

Stakebed said:
On most engines that I've worked on, crankshaft endplay is only a few thousands of an inch. If you can literally see the flywheel and crank moving fore and aft, that might be your problem. Just guessing but perhaps the thrust flange on one of your main bearings is worn. Hopefully Carter, one of the members that has rebuilt your engine family will chime in.
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yikes .....end play should be minimal ! a few thousanth's ....like maybe 3-5 ? If you are starting the engine with your foot on the clutch - you should stop doing that. It puts pressure on the Thrust bearing with no pressurized oil around it. That seems like an issue that needs to be addressed soon. How much movement ? And good luck !
 
Stakebed said:
How miserable that must be. Bench pressing a transfer case and a transmission.

Personally Carter, I think you've found the causes of both of your problems in two different areas.
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I actually have a transmission jack, so it shouldn’t be too bad.
 
You’re crankshaft play should fall within.003-.006, which is set by the rear main bearing flange, how much movement do you see at the flywheel? If you’re bearings are worn but the crankshaft undamaged you can slip a new set in without pulling the engine. Good luck!
 
bobthebuilder said:
yikes .....end play should be minimal ! a few thousanth's ....like maybe 3-5 ? If you are starting the engine with your foot on the clutch - you should stop doing that. It puts pressure on the Thrust bearing with no pressurized oil around it. That seems like an issue that needs to be addressed soon. How much movement ? And good luck !
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I use the clutch pretty sparingly, so I’m not really sure of the cause. I haven’t measured it, but I have watched it from underneath with the engine running and was a bit shocked at how noticeable the movement is. While I have the transmission out, I’m going to drop the pan and see what’s what. I may take the cap off that rear main seal, and loosen the others a hair and see if I can sneak a new rear main bearing in there.
 
Sorry to hear about your revelations. At least you know what needs attention and are not without some potential cures.
 
Rustynuts said:
I used a harbor freight motorcycle jack to remove the trans, t case and cross member as a unit. It actually went smoothly, I never used the jack on an actual motorcycle but the 10 inch bars built into it worked perfectly.
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I usually separate the trans and transfer in the vehicle. Then lift by hand. It's not that bad. But if it's too heavy I as well use a motorcycle "stand" They don't call them "jack" anymore for liability reasons. I build a wood plate to fit whatever trans I am removing. and I've done some big ones.
diggerG
 
Yesterday I got the trans ready to pull and fabricated a brace that goes between the frame rails to support the engine at the back of the bell housing when the transmission crossbar support is removed.

In the past, I’d supported the engine with a tower of blocks from the floor, but I found that this got in the way of the transmission jack and made it harder to access the clutch and t/o bearing.

While the drivelines were out, I figured it was a good time to pull the differential yokes to deal with their leaks.

Further work was suspended for a Father’s Day picnic.
 
Lookout Ranch said:
Yesterday I got the trans ready to pull and fabricated a brace that goes between the frame rails to support the engine at the back of the bell housing when the transmission crossbar support is removed.

In the past, I’d supported the engine with a tower of blocks from the floor, but I found that this got in the way of the transmission jack and made it harder to access the clutch and t/o bearing.

While the drivelines were out, I figured it was a good time to pull the differential yokes to deal with their leaks.

Further work was suspended for a Father’s Day picnic.
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Really looking forward to this thread now.
 
If you do re-install the trans and transfer case separately, just be careful to not allow the mainshaft and rear bearing to slip to the rear. If it goes far enough the roller bearings between the main and input shaft will fall out and you'll have to go back in and re-install them. DAMHIK.
 
Seabee said:
If you do re-install the trans and transfer case separately, just be careful to not allow the mainshaft and rear bearing to slip to the rear. If it goes far enough the roller bearings between the main and input shaft will fall out and you'll have to go back in and re-install them. DAMHIK.
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that's what separates the men from the boys !!! Lol
 
Ahhh the old stop leak strip out! I was 85% good on my rip out rebuild no leak attempt. The transmission still spits but the transfer case and engine are high and tight.. I'll take what I can get! Good luck!
 
Dropped the oil pan this evening after work and removed the rear filler block and found that it has been updated to a neoprene seal. According to Walck’s, these were stock in 1958 and later; mine is an early 1957.

It was a shame to open it up, whoever put it together had it sealed up pretty well. It never really leaked from the rear main seal

51F2172D-4DB0-4158-8AAE-ECE33548E307.jpeg

Had hoped to get the cap off the rear main bearing to see the grind, to order a replacement, but I was going slow and careful and ran out of time.
 
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Just a question as I have never torn in to one of these engines, can you get just one main bearing? Seems all the other engines I have worked on I always had to get a full set.
 
Late response. But have you checked the thruster bearing? Been there done that before. Get hot and will engage. Cool down and will release again till it gets hot again.
 
My FC-170 parts book shows 5 part numbers for the rear main:
912796 STD
914318 .002 under
914320 .010 under
914322 .012 under
914323 .020 under
 
Snowillys said:
Late response. But have you checked the thruster bearing? Been there done that before. Get hot and will engage. Cool down and will release again till it gets hot again.
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Are you referring to the throwout bearing? If so, mine is just a couple of years old and is operating normally and quietly. I can see it spinning when engaged and not spinning when disengaged.
 
The crank is ground 10 under STD and the rear main I removed is worn 15 thousandths narrower than another visibly worn bearing from another engine.

Before removing the bearing cap, I was able to gently pry the crank back and forth With a screwdriver and observe the “slop.”

The bearing face looks great - not worn at all.
FF7B6F1F-DE2C-48D6-845A-6EA66B559DF7.jpeg

Got distracted dealing with this critter after our puppy found it hiding under an old Willys truck gas tank and started barking at it.
E49F63F7-9C62-4F99-814C-E5DB567EEEC2.jpeg
 
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Lookout Ranch said:
The crank is ground 10 under STD and the rear main I removed is worn 15 thousandths narrower than another visibly worn bearing from another engine.

Before removing the bearing cap, I was able to gently pry the crank back and forth With a screwdriver and observe the “slop.”

The bearing face looks great - not worn at all.
View attachment 77502

Got distracted dealing with this critter after our puppy found it hiding under an old Willys truck Gas tank and started barking at it.
View attachment 77504
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Well I think you know the clutch release issue.

That rattler looks unhappy. Your puppy earned it's keep today. That coulda been a nasty surprise.
 
Did you try to measure the "slop?" Will .015" take care of it? From your previous observations it seems like you have a lot more than that to deal with. I can't help but wonder if the machine shop that ground the crank the last time didn't over grind the thrust faces, thus producing your excessive movement of the crank.
 
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