View Full Version : NP208 question. Hey Andrew!
05-05-2003, 07:18 AM
I know that the Jeep NP208 is really durable and has 32 spline outputs so that you can change the yokes to Heavy Duty units. What about the GM 3/4 ton NP208? Is this unit just as strong? Would it be easy to swap out the slip yoke on it for a fixed yoke? I know that Dobosh you romp hard on yours, so I figure that if I can get this one cheap and change the rear to fixed yoke, I'd be set.
05-05-2003, 08:49 AM
Yea, as far as I know the GM unit is just as beefy but you're going to pay out the @ss for a SYE kit. I think they range somewhere around 400-500 bux but you may what to check me on that. But you are correct, with the 32 spline outputs I was able to upgrade to a 1410 yoke in the front (massive) and a 1350 in the rear (equally as massive). The only trick is finding the right seals to fit the t-case and around those yokes but I already got that covered so if you go that route I can hook you up with part numbers cuz the replacement 208 seals will no longer fit. If you can find a 208 out of a CUCV chevy or something real cheap then the SYE may be worth it. I know I've seen em on ebay for next to nothing, the chevy 208 that is. Check junkyards too.
[ May 05, 2003, 02:50 PM: Message edited by: rockjeep44 ]
05-05-2003, 09:08 AM
Thanks Andrew for the info. Yeah, I was wondering how bad that SYE kit would be. I was hoping that I could get a fixed yoke NP208 and swap out parts that way because the NP208 I'm looking at is on Ebay for around $50 at the moment, but will no doubt go for more. Thanks for the info though.
05-05-2003, 09:19 AM
Oh yeah, any idea where I might find the slip yoke eliminator kits?
05-05-2003, 09:26 AM
Someone told me the the NP208 case half from the Jeep can be put on the GM... I dunno how true... but worth a look into.... easiest SYE you can get if it works!!!!
FSJeeper may know....
05-05-2003, 01:48 PM
I have a 31 spline input, drivers side drop NP208 case (Ford model?). It is identical to my Jeep NP208, just the input shaft is 31 splines instead of 23. There were a couple in the yard the last time I was there, so you might want to check into that if you are thinking of possibly swapping parts to make it work. Oh yea...its a fixed yoke. Or ya could just get a Jeep NP208...
05-05-2003, 02:13 PM
FYR WOOD, I've got a Dodge Dana 60 front axle so I need something that's passanger side drop and TH400/NP205s are expensive combos, so that's what got me thinking about the 208.
05-05-2003, 04:20 PM
gotcha...I should prolly read sigs first!
05-05-2003, 10:13 PM
Well here's the good news and the bad news. Chevy NP208s have the 32 spline outputs and I've heard some even have 32 spline inputs which is huge. Not sure if this is true. So far, no company out there is making fixed yoke conversions for the GM model. But, what I've been hearing is that mid 80s dodge 208s can be taken apart and by using the rear half of that case you can make your GM a fixed yoke. There are also fixed yoke mid 80s Ford 208s and even though they are drivers side drop you might want to look into them as possible fixed yoke donors as well as the Jeep case. Between the Jeep, Dodge, and Ford fixed yoke 208s I don't see how it can't be done. I will be working on my Jeep today with a friend of mine that will definitely know the answer to this question for sure so I'll post back later.
05-06-2003, 02:36 AM
Andrew, I looked around for a SYE kit for the 208, but couldn't come up with anything, so that's what got me wondering. I would think that if I mixed and matched enough parts that I could eliminate the slip yoke some how. Also, to the best of my knowledge, I think the 3/4 ton GM versions had 32 spline inputs. I'll be interested to see what you find out though.
208's from behind T-400's are 32 spline input and both outputs are 32 spline.the 208 from a 700-R is 27 spline if i remember corectly. i have one from each.what tranny is this going behind?there is a sye kit for the 208 but it doesn't shorten the rear output any and it is a cut drill and tape type. you can do a search an coloradok5.com find the garage section and search for 208 sye and you should find the kit i'm talking about
05-06-2003, 05:00 AM
I think I know what KRUM is talking about... I read somewhere about drilling a hole in the yoke center and tapping the output and screwing the yoke down to the shaft.... is that what you are referrring to?
yeah thats the idea,but the kit comes with a flat flanged yoke for like a cv driveshaft and if i remember correctly you have to saw a little bit off of your rear output shaft and then drill an tap your rear output shaft.
try this and see what ya get.personally i think it's pretty butch i have one the 208's from a J-10
and one from my t-400 32 spline i'm going to take both of theses apart and i'll tell ya what i find out later.
05-06-2003, 04:15 PM
Well I talked to my friend about the conversion. We were both a little dumbfounded. He seemed to think it may be possible but he had never heard of anyone successfully doing it. So, if it's gonna happen it's gonna take a lot of trial and error.
05-07-2003, 02:46 AM
too bad we can't find a few cases and try to work this out.... sounds like a winner... just need the cases to mix-match the parts....
Between the GM, Dodge, Jeep and ford.... SOMETHING should be able to be put together...
Do all the NP208's have the same 2.6:1 reduction?
05-07-2003, 06:01 AM
05-07-2003, 06:04 AM
Interesting. Well I might have to give it a go if I can find all the parts. Otherwise I'll just have to save up a lot of money for an TH400/NP205.
05-07-2003, 06:06 AM
Thanks for the info though Andrew. I'll let you know what ends up happening.
ok guys i've put my np 208 from my J-10 and the 32spline unit from my blazer apart and the only part that is not going to work is the rear output housing because the little oil gallie is cast upside down because the one is a pass drop and the other is a driver drop.I'm going to do some junkyardin here in the next few days and see if i can find one from a dodge!
05-14-2003, 08:27 AM
Krum, sounds good to me. Let me know what you end up finding out. It could prove to be my solution.
05-15-2003, 09:34 AM
my 208 came from an '86 grand with the 258 and tf727. it has fixed rear output from the factory. driver side drop. james
05-15-2003, 12:50 PM
We're trying to make a fixed yoke passenger drop
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