QT Sun gear/ shaft assembly

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Holland Waggy
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Re: QT Sun gear/ shaft assembly

Post by Holland Waggy »

Got both drive- shafts off this morning and did the torque bias test. It slipped between 90 and 95 ft/lb, that doesn't seem that bad to me, right? Put a new front output shaft seal in, couldn't see any damage to the old one but it was the obvious culprit. Could a high oil-level in the QT do any harm? It has been leaking for sure, but level still was OK. Perhaps some overfill from the low range unit seeped into the main drive..
Gilbert Doggen

1978 Wagoneer, AMC360, TH400, Quadratrac, HEI Ignition, Headlight LED conversion,
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fulsizjeep
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Re: QT Sun gear/ shaft assembly

Post by fulsizjeep »

That is on the low end of acceptable but should get you around. If the fluid gets too high, you could get it up in the vent and burbling out. At this point, I think I would try some extra additive. Drain a little off to compensate for what you put in. When I fill one up, I fill the main case with 2 quarts and then add half quart to low range. The fluid does splash back and forth between main case and low range unit.
Flint Boardman
88 GW, 401/727/208, 5" lift, D44s/4.10s/locked up, 35s
https://jubileejeeps.org/quadratrac
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Holland Waggy
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Re: QT Sun gear/ shaft assembly

Post by Holland Waggy »

Thanks for your reply Flint,

I have filled both units to the fill plug level, might have been a little too much... I will get my friction modifier additive today so I'll keep you posted. Now the second front output seal is leaking, but I think I might not have pushed in it in far enough. It's hard to find any drawings or pictures with the right mounting depth but it's now square with the case an I think that's causing the problem. Am I somewhat thinking in the right direction??
Gilbert Doggen

1978 Wagoneer, AMC360, TH400, Quadratrac, HEI Ignition, Headlight LED conversion,
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fulsizjeep
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Re: QT Sun gear/ shaft assembly

Post by fulsizjeep »

I push the output shaft seals until they are flush with the case. I have seen them pushed inside a ways and wondered if they leaked. Did you look real good at the yoke seal surface? It could be scored and need a speedy sleeve.
Flint Boardman
88 GW, 401/727/208, 5" lift, D44s/4.10s/locked up, 35s
https://jubileejeeps.org/quadratrac
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Holland Waggy
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Re: QT Sun gear/ shaft assembly

Post by Holland Waggy »

https://i.imgur.com/449Q479.png

The yoke looked ok, Some slight discoloration but no scoring. I looked at the pic on your site wich shows the output seal. IT looks like if that seal is pushes in about a quarter of an inch.
Gilbert Doggen

1978 Wagoneer, AMC360, TH400, Quadratrac, HEI Ignition, Headlight LED conversion,
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fulsizjeep
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Re: QT Sun gear/ shaft assembly

Post by fulsizjeep »

Hi. I should have looked at the AMJ-73 tool kit before my last reply.

I have a factory tool kit here that I have only recently started using. One tool is for seating the output shaft seals. It pushes seal in .25 inches, so yes - you are correct. When I do them by hand, I set them flush with the case because I would mess the seal up by pushing any further with a really big socket.

Image


This lists the tools in the kit. The W-365 is not part of the AMJ-73.

Image
Flint Boardman
88 GW, 401/727/208, 5" lift, D44s/4.10s/locked up, 35s
https://jubileejeeps.org/quadratrac
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Holland Waggy
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Re: QT Sun gear/ shaft assembly

Post by Holland Waggy »

It's been a while, but today i put in another new seal for the front output, lots of thanks to Flint for the pic of the mounting tool. I've managed to fabricate a similar device on a lathe at work. So, finally got to it! Pulled the old one, put in the new one and drove it in 0.25". When measuring the lenght of the yoke shaft is was dead on in the middle of the smooth surface, so no chance of leaking over the chamfered edge. Topped up the QT and went for a testdrive.


…. And again there's a pool of QT fluid at exact the same spot... This is starting to get really annoying.


So far adding friction modifier still didn't help very much on the stick/slip condition. Perhaps I need to ad some more, since a 4 oz. bottle is ment for a diff which contains a little less fluid..


We'll keep trying//
Gilbert Doggen

1978 Wagoneer, AMC360, TH400, Quadratrac, HEI Ignition, Headlight LED conversion,
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Holland Waggy
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Re: QT Sun gear/ shaft assembly

Post by Holland Waggy »

Finally able to solve this case; there appeared to be bad thread in the lower bolt of the reduction unit which opened up after warming up and spill QT-fluid all over the place. So that's replaced with a threaded bush. And for the stick/slip; the friction modifier took a while to run in, but it has a positive effect and slip-stick is gone now. I've done a ton of work over the past time, but I'll save that for another thread..
Gilbert Doggen

1978 Wagoneer, AMC360, TH400, Quadratrac, HEI Ignition, Headlight LED conversion,
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fulsizjeep
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Re: QT Sun gear/ shaft assembly

Post by fulsizjeep »

Holland Waggy wrote:Finally able to solve this case; there appeared to be bad thread in the lower bolt of the reduction unit which opened up after warming up and spill QT-fluid all over the place. So that's replaced with a threaded bush. And for the stick/slip; the friction modifier took a while to run in, but it has a positive effect and slip-stick is gone now. I've done a ton of work over the past time, but I'll save that for another thread..
This is good news! QTs have all kinds of leak opportunities. :-bd Congrats!
Flint Boardman
88 GW, 401/727/208, 5" lift, D44s/4.10s/locked up, 35s
https://jubileejeeps.org/quadratrac
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