Leaking D300
tireman74
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4.2L i6 258
T-176
Dana 300
AMC 20 rear and Dana 30 front
-
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Leaking D300
- Thread starter tireman74
- Start date Start date:
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HackFabrication
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Have you ck'd the bolts to see if they are 'tite'?
LG
LG
tireman74
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Yes they are tight
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Ck the oil level to be sure it isn't over filled.
Make sure the vent line isn't clogged or pinched.
LG
tireman74
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LG, what would you consider to be over full? I took plug out and quite a bit of fluid came out. It's in my garage which is pretty level. I let it drain for about 30 seconds until it was a weak stream coming out.
HackFabrication
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It's overfilled. There should be no stream of oil. Barely a drip. Oil should be even with the threads on the hole, or slightly below.
tireman74
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So pull the plug again and let it drain until nothing comes out?
HackFabrication
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Last edited:
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The oil level should be at the bottom of the fill plug.
Check the oil level in your tranny and your diffs to be sure they ain't overfilled.
LG
Check the oil level in your tranny and your diffs to be sure they ain't overfilled.
LG
Woolyworm
Old Time Jeeper
You may be getting transfer of oil from tranny to transfer. Check your tranny, is it low?
Wooly
Wooly
tireman74
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What do you mean by "clocked"?
Woolyworm
Old Time Jeeper
You can rotate the Transfer Case in relation to the tranny for ground clearance with a special adapter. Is your Transfer Case parallel with the bottom of the jeep or does is hang down on the passenger side at about a 30 deg angle to the bottom of the jeep. If it is clocked up, the fill level will be different because of it. Even if that were the case though, I'm not sure how more oil gets into the case than above the full hole except for a leak between the tranny and the transfer.
Wooly
Wooly
DHugg
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When I put together my Dana 300 after a rebuild, had a similar slow seep from that plate. Drained the case, then took the cover and steel shims out and cleaned them in denatured alcohol.
Before reassembly and tightening down, I coated every contact surface with PRIME SEAL aviation sealant. It goes on like honey but hardens to beeswax consistency. The value is that it never hardens beyond 'beeswax', allowing surfaces to be separated without mechanical prying. The rigorous engine overhaul and inspection schedule of aircraft engines demands easy tear-down, but it is a good sealant.
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- '85 CJ-7, 258/4.2L 6cyl. Bought new in 1985. Full cage, Warn 8274 winch, Ford 9" rear, front/rear Detroit Lockers w/4:88 R&P. T-5 tranny and 4:1 t'case. 33X12.50-15 BFG/AT, MSD ign, on board air---
D/300 is a stand alone t'case and any oil leakage from the tranny will drain out and not enter the t'case.
The D/20 t'case is notorious for this oil transfer deal from the tranny.
LG
tireman74
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4.2L i6 258
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Dana 300
AMC 20 rear and Dana 30 front
No mine is not clocked.
I will check the fluid level again tonight to make sure it i correct and then clean it all off to see if that fixed the problem.
Thanks for the info guys
I will check the fluid level again tonight to make sure it i correct and then clean it all off to see if that fixed the problem.
Thanks for the info guys
HackFabrication
Old Time Jeeper
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It's been a long time since I did my Dana 20 , but IIRC, I used a thin coat of hylomar on the bearing shims.
Thanks for the info on Prime Seal aviation sealant. I'll stash that back into the memory bank.
- Posts
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- Vehicle(s)
- '85 CJ-7, 258/4.2L 6cyl. Bought new in 1985. Full cage, Warn 8274 winch, Ford 9" rear, front/rear Detroit Lockers w/4:88 R&P. T-5 tranny and 4:1 t'case. 33X12.50-15 BFG/AT, MSD ign, on board air---
Aviation Form a Gasket works well also. 
Gasket Sealants : Permatex® Aviation Form-A-Gasket® No. 3 Sealant Liquid
LG
Gasket Sealants : Permatex® Aviation Form-A-Gasket® No. 3 Sealant Liquid
LG
Woolyworm
Old Time Jeeper
tireman74
Jeeper
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4.2L i6 258
T-176
Dana 300
AMC 20 rear and Dana 30 front
I'll check it again tonight, but no seeping when I check it last night. So hopefully it was just over filled.
Thanks for the info guys.
Thanks for the info guys.