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Dana 300 Gasket

Dana 300 Gasket

driver007

Senior Jeeper
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610
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Location
Canada
Vehicle(s)
1981 cj5 304 v8, 300 Dana,model 30 Dana and model 20 AMC rear end
In am pulling my Dana 300 out to do the clutch. It has low miles on it. The dana seems to operate fine covered in oil though. Do I do just a seal reseal kit on it and put it back in if I cannot see anything wrong. Or do you ripp it apart and go through it. Having not done a case before I would then have to go to a shop. Hate to pay for something I do not really need to do.
 
I would check gears condition while you have the cover off. If the gears look good and it drives fine as you say I would do just the seals and gasket and be done with it. Remember to replace the 2 small shift rail seals, you can removed them with a small flat head screwdriver just be careful you don’t nick the seal seat or rail.
 
I take it the rails are the linkage that goes into the Transfer Case from the shifter? If so yes the rails look like they could be a bad area for leaks. Learning as I go I find it good thearpy.I will post pics when I get it out thanks.
 
Got the tranny out can you tell me if it is a T-176 by looking at the pick. the tranny has a bit of play on the shaft is this normal?
 
Clean the tag up driver, it could be a T-176 or T177, the T177 has a lower first and second gear which is better for off road, both are good medium duty transmissions though.

A little play is fine, you can pull cover to get a look if you had concerns, since you have it out.
 
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The CJs only came from the factory with the T-176 . The T-177 came in the trucks.

The casting numbers on the cover in your pic (C-2604208) tells me its an original T-176.
 
Good eye posi on the numbers thanks!
 
I’ve never saw a T-177 case in a CJ not saying it can’t be, and I’m not doubting you, just don’t understand the reasoning. The T-177 case was designed to mate with a 208 Transfer Case so if used in a CJ the 300 wouldn’t be clocked correctly.

Is it possible what you had was a T-176 case and input shaft with the guts and top cover of a T-177? I’ve seen some unexplained things come out of the Jeep factory
 
Posi - Cj's did come from the factory with T-177.


5359389=T-177 3.82 first gear
5359890=T-176 3.52 first gear

Yep, that was why I asked for the tag to be cleaned. It should list one of these numbers. Top cover's were most likely interchangable, T-18 's used T-98 covers in the early years so it's possible those numbers won't tell everything.

*edit, although I will not pretend to be a pro on this tranny, I had researched as well. There are some other threads out there referencing long and short shaft (CJ5 's and 7's)T177's so it may have been as an option or leftovers like the Dana 44 in 86 CJ's? Just a guess.
 
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I cleaned the tag hope it is readable. Pulled the oil pan off started on the main seals. One part just seems to connect to another. Well I am down there might as well do the seals.
 
Sorry for the bad pic the tag reads 5359389 1649 rgk Appears to be a t177 . Are they as bad as they are made out to be?
 
They are considered the more desirable option by most. 1st and 2nd (very minimal) are geared lower and give you a better crawl ratio off road. Not a huge difference, but better. 1st is 3.82 vs 3.52 on a T-176 .

If you have 2.73 rear end and Dana 300 is 2.62 low. Then multiply x your tranny to get final crawl ratio.

2.73 x 2.62 x 3.52=25.177

2.73 x 2.62 x 3.82=27.23

Off road, good final ratio is about 75 manual Transmission and 50 auto. It keeps your foot off the clutch and less wheel hop that tears out u joints, twists drive shafts and breaks axles.

Although lower torque also means more ft lbs of pressure on parts but IMO well worth it. You don't have to work hard to get through obstacles and thats what usually breaks things. Although , then you will take it the next level as you can do more crazy stuff, so you still break stuff :D
 
I have a new twist I showed the the pilot bushing to the boys at work and they were afraid that the bushing was so beat up they sent me home with a dial on a mag base to check the crank for movement. They also want to take a peek at the tranny to see if the input shaft is done for. I have never seen a bushing so beat up. I dumped the 2.72 gears and I am putting in 3.73
 
The fruit of labour a cleaner tranny.Thought the writing on the tranny still intact was cool.
 
That is cool, what did you use to clean?
 
Tooth brush and elbow grease WD40. Funny thing I thought it was smokn clean tell YellowCJ85 showed me a pic of his cleaned up. Hopefully he will post a picture of it here.I keep my hunting dogs in the shop over night so I do not do solvent tanks because of the smells. I prefer they use their nose on birds. I know I would hate to sleep beside a tank of varsol .Maybe at work I will hit the tank and get it better.
 
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