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73-87 Chevy _ GMC Trucks => 4 Wheel Drives => Transfer Cases and Front Drivelines => Topic started by: frotosride on July 23, 2010, 10:41:01 pm
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I'm a little new to the 4x4 community as far as actually working on one of my own. Currently I have an '87 silver with 350tbi(soon to be laid to rest when i can walk again, and replaced with 383), 700r4, np208. I know that the np208 isn't the best case out there but I don't plan on rock crawling or anything outside of a few fields and mud holes..so, what are the down falls to this case and are there any upgrades that i can do when i rebuild it to make it last longer? Is there a kit out there that may replace the chain with a gear or maybe a stronger chain thats not hard to gt my hands on?
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No kit to replace the chain. The down fall of this case is in my experience bearings. I have had several that have had bearing failure. They don't like huge tires. The torque bar from the right side to the bell housing bolt adds longevity to them.
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upgrades two that i can think of i know theres more but one is a 205 and the other 203 lol i personally haven't used a 208 but i know with my 203 and 38s haven't broke it yet i doubt the 208 can hold up its like half the size of the 203. if you plan on doing any off road besides getting stuck on accident then go with a better transfer case
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The 208 isn't a bad t-case. If you are doing any serious 4 wheeling then do as Irish said and get a 205. I don't know of any way to beef up a 208, but if you don't beat it to death it can last for decades, like mine has.
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The one I have had fail not due to bearings was because of large tires, and hard wheeling. I have broken half a dozen in half. I have had them last for years in plow trucks though.
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Thanks guys, Grim I would like to say i wouldn't beat it but i treat all my toys like they are "red headed fords" and it would be a lie to say i won't. I think i will go with a 205 because i may run larger tires than 35 at some points and i like having the ability to do a doubler later on for climbing. but til it breaks i will just get a tougher chain and wait til it streaches too much or just breaks. What would be a good price to pay for a 205.
Irish you said there were two upgrades you can think of but you never said what they are. Mind sharing?
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It was a joke saying upgrade to a 203 or 205. IMO the 208 ain't good unless your staying stock
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If you are going 35's or bigger then go with a 205. I have seen them anywhere from $100 out of a parts truck to a grand for this beauty http://www.polyperformance.com/shop/Offroad-Design-Complete-NP205-Transfer-Case-p-19034.html
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I have 38s as I said and nothing on my 203 has failed yet. Broke front drive shafts and axle shafts but knock on wood nothing on the t case
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What would be a good price to pay for a 205.
I'd be more worried about that 700R4 tranny than your 208 transfer case.
Around here you can get a turbo 400/205 or a turbo 350/205 for around $500.
Thats for a complete set up with the tranny, transfer case, shifter, and crossmember.
Sometimes you can score a complete parts truck for cheap money if you look around.
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I'd be more worried about that 700R4 tranny than your 208 transfer case.
Around here you can get a turbo 400/205 or a turbo 350/205 for around $500.
Thats for a complete set up with the tranny, transfer case, shifter, and crossmember.
Sometimes you can score a complete parts truck for cheap money if you look around.
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The 700 should be fine. Monster in a box is amazing and with all the upgraded parts i've seen them take a lot of punishment.
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It was a joke saying upgrade to a 203 or 205. IMO the 208 ain't good unless your staying stock
Gotcha, after reading it again i got what you were saying. lil slow pain meds will do that to you but thank God i can walk now...
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frotosride, if you don't mind, what happened? In the Army I just happened to fall out of an airplane and broke my pelvis and sheared some tendons in my SI joints. Like you said, thank God, because I can also walk. I wish you a speedy recovery.
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Nothing wrong with a 208. The only problem with them is guys put 300,000 miles on them and then put in in their project truck and beat the crap out of them. Often times, the thing is ready to grenade as it is anyhow.
With fresh, tight internals you would have no problems running 38's with moderate to occasional severe use. They are light and have the awesome 2.61 low range. They were good enough to use with TH400's and diesel torque.
I have seen worn out 205's fail with weak 350's and 33's. If it was a 208 everyone would bag on it for being a weak chain driven case.
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Agreed with everything Josh454 said.
The military trucks came with them and I've had great luck with them. They are light and dependable. They are easy to R&R&R and the best part is they are a dime a dozen. You blow yours up, you can find another one for $75 bucks. Run ATF in it too not 10w or gear oil. The chain is pretty dang strong too. Chains have a little more give whereas gears are more likely to cause a catastrophic event when they go.
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Also the 203 is chain driven and you dont hear anything well that much bad about its chain
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My 88 Jimmy had a 350/700R4/208 with a 4" lift and 33"s.
In 3 years I owned it (1991-1994)The damage done was:
Blew up 3 700R4's (finally switched to a turbo 350)
Bent the front 10 bolt (I liked to get airborn in it)
Blew up the rear 10 bolt 2 times (shredded the spider gears doing burnouts/donuts)
Cracked the rear frame at the shock mount (had the crack welded to fix it)
Ripped the shock mount off of the replacement 10 bolt front axle (another job for the welder)
Thats allot of damage done to the truck but that 208 worked perfectly throughout the abuse.
A 241 from a 89/90 blazer/suburban is a direct bolt in replacement for your 208. It's basically the same transfer case with a better oiling systen inside.
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Interesting reading. I just got my transmission and transfer case out today and figured out that mine is an np208 as well. It's behind a th400. Both will get inspected and repaired as needed before they get installed. Not looking to beat on mine much, just maybe get it a little dirty now and then.
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frotosride, if you don't mind, what happened? In the Army I just happened to fall out of an airplane and broke my pelvis and sheared some tendons in my SI joints. Like you said, thank God, because I can also walk. I wish you a speedy recovery.
Don't mind at all..for all who like two wheels as well as four here's a story for you...On my was to work in march on the bike and a young man looked @ me and the wrecker in front of me. when i went to turn left in front of him is when i realized he never saw me because he pulled out. Thought it was over after bout 20 sec.(which seemed like a life time) but he was towing a trailer and thought it was what was slowing him down. little did he know it was me and my bike that begged his silverado for more of the skinny pedal. he pushed back into the lane i came from and thank God for the people getting out of their cars b/c thats the only reason he thought somethings wrong and actually stopped. That was my first time flying in the air (life flight) as opposed to under the water(submariner "pride runs deep".
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Little late on the draw, but using Fitz's post as a example the 208 is one of the last weak leaks in the chain. The tranny, and axles are going to be a problem before the case will be. The 700R4 just has its limitations, and 1/2-ton axles will bite back at you if you are running hard enough to make the transfer case your concern. No real upgrades really. At least nothing worth investing in.
For what you described the 208 is plenty strong enough. A 203, or 205 is just over kill, and I think you'll like the deeper reduction of the 208 low-range. It'll make all the difference.
If you decide to upgrade later, I'd keep a couple things in mind. First is the NP203 is a full-time case. You can do part-time conversions though. Second both cases came in a few spline patterns. 10, 27, and 32. Your 700 has a 27 so you need to get a case that will match this. Although when you are getting into the range of needing a larger transfer case, I would go ahead and swap a Turbo 400 into it. This will use a 32 spline case. I also suggest building brackets to support these heavy pieces of iron. Also, if you want more reduction a 203/205 doubler is a option. Or a 241/205 doubler. But I'm rambling now.
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Thanks to all. i think i'm just going to slap it all together and do as most fix/upgrade as i brake it. I like the thought of doing a doubler later but i don't see me being stationed anywhere that will have any trails worth the time and money.
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Just ran into this on Pirate. Good info!
Ratings for those are hard to find. Somebody emailed NV quite some time back, and asked what the specs were for the 205. The reply was that the original input spec was 1100lb-ft, later uprated to 1500lb-ft. Those are continuous ratings, no max was given. For comparison, the NP241 was rated 1028lb-ft continuous, 5555lb-ft max, which is a ratio of 5.4:1. If we apply that same ratio to the 205 (with the uprated specs), then the max input would be 8100lb-ft, which is higher than even the 271 and 273 cases used in the late Dodge Cummins.
The 203 range box can handle at least as much as the 205, but the chain is the weak link. 208's are probably somewhere in between the231's 730/1885 rating (continuous/max) and the 241's 1028/5555 rating.
I wouldn't get too hung up on this though. With the possible exception of the chain in a chain drive case, the weak link on any 32 spline input t-case is usually the output shafts.