Clutch Question

1941 - 1945, MB, GPW Technical questions and discussions, regarding anything related to the WWII jeep.
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Re: Clutch Question

Post by Joe Gopan » Mon Mar 19, 2018 2:10 pm

The JEEP Clutch Pilot Bushing is Graphite Impregnated Bronze which is self lubricating. The WWII TM for the G-503 specifies that the Pilot bushing is "Graphite Bronze". No need to soak them in oil either, install them right out of the box. No where is there a Jeep Service Factory Manual or an Army TM for the MB thru M-38A1 that instructs to soak the Pilot Bushing in oil.
Have yet to see an aftermarket Pilot Bushing that is other than Graphite Bronze.
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Re: Clutch Question

Post by twinflyer17 » Tue Mar 20, 2018 3:17 am

Thanks for all the input, gentleman. Since this clutch has been having issues since early fall, it sounds like it makes the most sense just to pull the tranny/engine and replace or check that everything is where it should be and is working as it should be. I’m going to touch base with the owner to get his thoughts, the will be sure to post what we (or he) end(s) up doing to hopefully solve this problem once and for all.
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Re: Clutch Question

Post by Chuck Lutz » Tue Mar 20, 2018 8:24 am

One more thing to consider....the main gear has the front bearing pressed onto it, right? That bearing should be a snug fit in the front bearing retainer and not allowed to wobble. Wobble will certainly cause the tip of the main gear to oscillate and wear out the flywheel bushing. Don't reassemble the T-84 with those gasket sets meant for a T-90. The front bearing retainer gasket is WAY too thick. In addition, if you were lucky enough to find a GPW marked front bearing retainer, it is properly cut so that the snap ring on the bearing is compressed by the retainer and immobilizing the bearing and the main gear. Lastly, modern front bearings seem to have the snap ring groove in the right place, but they used a thinner snap ring which also allows for the possibility of more movement by the bearing and main gear. With any alignment issues compounding these issues, the flywheel bushing can bind the main gear.

You can relieve the face of the front bearing retainer to get it to capture the snap ring/bearing.

When you do take it apart, check for axial play on the main gear (should have only the movement the ball-bearings in the bearing require) and try to see if it has any side-to-side play by moving the tip of the main gear.

What company made the front bearing? Did you replace the THIN snap ring on it with old one from the original Federal or other period-correct bearings?
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Re: Clutch Question

Post by twinflyer17 » Wed Mar 21, 2018 7:46 am

We didn't touch the T-84 at all when we did the clutch. The old engine was pulled and a new rebuilt engine, with a new clutch kit, was installed. From what I remember, there was minimal play in the movement of the input shaft, and seeing as everything worked fine prior to removal (due to a cracked block) of the old engine, I'm thinking that's not a factor in the current issue. If we pull the engine again, though, I'll be looking into that as the potential culprit.
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Re: Clutch Question

Post by Joe Gopan » Wed Mar 21, 2018 7:58 am

It would be a good idea to inspect the clutch linkage for wear, and if you have installed a replacement clutch rod to compare the length with an original. The replacement Clutch parts do not always duplicate the originals which is not a new problem.
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Re: Clutch Question

Post by twinflyer17 » Thu Mar 22, 2018 5:04 am

I agree that it would be beneficial to inspect the clutch linkage, but none of that was replaced or touched during the replacement. The previous clutch kit/setup had thousands of miles on it without issue.
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Re: Clutch Question

Post by artificer » Thu Mar 22, 2018 7:38 am

After a clutch job if the transmission was removed [not the engine] one should check the clutch pedal shaft has not been reversed when re-assembling.
This reversing is done purposely by some & will produce a lighter pedal feel but in some cases good adjustment will not be fully achievable.
This incorrect adjustment can cause the clutch to not dis-engage properly & clashing when selecting gears.
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Re: Clutch Question

Post by Joe Gopan » Thu Mar 22, 2018 9:18 am

Best to inspect the Lever and Tube (Cross shaft) and the rod for wear. What is the length of the clutch rod?
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Re: Clutch Question

Post by twinflyer17 » Thu May 03, 2018 5:10 am

Update on the status of this. I spoke with my friend several weekends ago and he was able to make some progress. He opened the inspection cover on the bell housing and was able to fit a wrench through the hole and slightly tighten the pressure plate bolts (the ones that mount the plate to the flywheel). He also added a few sprays of PB Blaster to the end of the input shaft and voila, everything seems to be working okay again. The question will be whether this is a short term or long term fix...only time will tell I guess. It makes me think it was a pressure plate torque problem, though. If the problem arises again and we end up actually pulling things apart, I'll of course post an update again with what the fix ends up being. Fingers crossed this is a long terms fix.
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Re: Clutch Question

Post by OldPappy » Thu May 03, 2018 10:54 am

If PB blaster "fixed" the problem it sure seems to point to what others have said about the pilot bushing binding, for whatever reason, and while a squirt of PB Blaster may have cleared the issue, it will not last very long.

I also am not sure you can properly torque the pressure plate bolts with a wrench through the inspection port, and if he was able to tighten them, they weren't properly torqued during install. You sure do not want a pressure plate to come loose.

Were it mine, I would pull the engine, replace the pilot bearing, dab some grease on the pilot, check the pressure plate bolts, and since the fork needed replacement I would also check the pivot ball for wear and replace it if needed.

Pulling the engine isn't that hard, and it is the only way to get to the bottom of the issue.

I once had a Jeep that made a loud whining noise every time the clutch was disengaged. When I finally did pull the engine I found that whoever had put the clutch in had botched the pilot bearing, evidently trying to remove it, and that was binding on the shaft. I haven't worked on these in many years, but I remember having some trouble removing that banged up pilot bearing.

Here is a trick I used to remove that stuck pilot bearing. I had an old input shaft, which of course was a tight fit into the pilot bearing. I packed the bearing with heavy grease, inserted the shaft, and a few taps with a hammer created enough hydraulics to push the bearing out. This doesn't always work, but it worked that time.
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Re: Clutch Question

Post by twinflyer17 » Thu May 03, 2018 11:05 am

Thanks, Pappy. All good points.
Sean

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Re: Clutch Question

Post by Joe Gopan » Mon Nov 19, 2018 6:59 am

Just a reminder.
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Re: Clutch Question

Post by twinflyer17 » Tue Nov 20, 2018 4:25 am

What are you reminding us about, Joel?
Sean

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Re: Clutch Question

Post by Joe Gopan » Tue Nov 20, 2018 4:57 am

There some Jeep Owners who come aboard who may benifit from this reminder.
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Re: Clutch Question

Post by twinflyer17 » Tue Nov 20, 2018 5:35 am

Fair enough :D
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