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T-300 Puking fluid out the vent

T-300 Puking fluid out the vent

Jimmy2x

Jeeper
Posts
10
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Location
Kingsley, MI
Vehicle(s)
1984 CJ7 with 350 SBC SM465 and D300.
1997 TJ (Gone with the birth of 2nd child)
2007 JK Rubicon (Gone with birth of 3rd child)
So, I got a free Jeep from a friend who decided that he didn't want to work on it. Overall the rig is not bad. It has a SBC, what I believe is either a SM420 or 465, and a T-300 Transfer Case . It also has 4.10 gears. I finally got the thing running good and am a little concerned about the setup because I'm already turning 2200 RPMs at only 45mph (still stock size tires). I was hot rodding a little bit the other day and got her up to almost 70mph. When I got back home I notice that the Transfer Case vent had bubbled over a bit and was dripping on the garage floor. Am I really building up that much heat with a 2 mile run at 70mph or do I just need to keep her around 45 to 50 MPH with this running gear? Thanks.
 
so, i got a free jeep from a friend who decided that he didn't want to work on it. Overall the rig is not bad. It has a sbc, what i believe is either a sm420 or 465, and a t-300 Transfer Case . It also has 4.10 gears. I finally got the thing running good and am a little concerned about the setup because i'm already turning 2200 rpms at only 45mph (still stock size tires). I was hot rodding a little bit the other day and got her up to almost 70mph. When i got back home i notice that the Transfer Case vent had bubbled over a bit and was dripping on the garage floor. Am i really building up that much heat with a 2 mile run at 70mph or do i just need to keep her around 45 to 50 mph with this running gear? Thanks.


t-300?
 
He meant to say Dana 300

Could the case have been overfilled?
 
The cruise RPM calculator on the Novak site shows 2137 RPM at 45mph with 4.10 gears, 1:1 top gear, and 29 inch tires. Your Transfer Case was probably overfilled.
 
Sorry about that, yes, I did mean Dana 300 . Fat fingers on the keyboard again. Anyway, I did check the fluid in the Transfer Case and some did run out when I pulled the fill plug but no more than I would expect. Just a few dribbles really. Not sure what is in there for fluid but it looked and smelled like a gear lube of some sort. I was just wondering if it was normal for the Transfer Case to spit a little when running at high rpms with this type of low geared drivetrain?
 
Thanks Bent. I'm going to take a closer look at the fluid levels this weekend. I should probably just change it anyway since I have no idea how long or what is even in there.
 
Is this 300 in it's stock position? As in not 'clocked' for ground clearance.
Any good 85W-90 gear oil is good.
How high up do you run the vent line?
LG
 
I'm pretty sure that it is in it's stock position. Doesn't look strange. The previous owner just ran the vent line up into the body support rail on the underside of the tub. You mentioned 85w-90 for a fluid choice. Is there any problem with running 75w-90? I would like to keep the same fluid as the tranny. Thanks for taking the time to reply.
 
I'm pretty sure that it is in it's stock position. Doesn't look strange. The previous owner just ran the vent line up into the body support rail on the underside of the tub. You mentioned 85w-90 for a fluid choice. Is there any problem with running 75w-90? I would like to keep the same fluid as the tranny. Thanks for taking the time to reply.

No issue at all-I run 75W-90 syn in my T-5 tranny.
Just think'n the heavyier oil might not 'climb' out the vent is all.
I do run the Syn 75W-90, in my 4:1-D/300 case with no issues.
LG
 
Thanks Lumpy. I'm gonna change the fluid and see what happens. I may just re-run the vent line to a more favorable spot.
 
IF that vent line is lay'n horazonal or tipped down any. It's acting like a syphon tube.
I just run my tube to where it's straight up and stops about 1" under the body.
LG
 

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