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'91 1 ton 205 front output flange?

dyeager535

dyeager535

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\'91 1 ton 205 front output flange?

Hopefully this is an easy question. I'd rather not have to swap my front driveshaft when I convert to the '91 205. However, the '91 uses a flange instead of a yoke. Besides, the 4L80E shaft is too long.

Did the front output shaft splines change from say '74 to '91? I'm thinking they did, but I want to make sure.

If they didn't, I assume I could just swap the yoke for the flange, but if the spline count DID change, if possible (is it?) I would have to swap the whole output between the two cases.
 
Re: \'91 1 ton 205 front output flange?

Yes, they did.

Somewhere in the mid-70s, they switched from a 10 spline front output to 30. The 30 spline output is far more desirable.

No matter what, a 30 spline output is going to have a flange on it. If you want a yoke you can get one from Jesse @ High Angle. They make them in 1310, 1330, and 1350 for 30 spline outputs.
 
Re: \'91 1 ton 205 front output flange?

another example of chev being a PITA to swap parts on while a ford has a 32spline output and a 31spline input on all of em for easy swapping
 
Re: \'91 1 ton 205 front output flange?

Put in the 32 spline front output and at least you've got both outputs covered. /forums/images/graemlins/thumb.gif
 
Re: \'91 1 ton 205 front output flange?

[ QUOTE ]
No matter what, a 30 spline output is going to have a flange on it. If you want a yoke you can get one from Jesse @ High Angle. They make them in 1310, 1330, and 1350 for 30 spline outputs.

[/ QUOTE ]

So, without it being addressed as far as I can see, I can just pull the 10 spline output out of my older 205 case, and swap it into the new case, correct?

Before anyone gets all upset, a 10 spline will serve my purposes for the rest of my life, and if I can sell the newer output, will help make up having to replace the 205's 32 spline input. /forums/images/graemlins/frown.gif
 
Re: \'91 1 ton 205 front output flange?

I would say YES you could swap outputs but I wouldnt
there is probably a yoke for your output
 
Re: \'91 1 ton 205 front output flange?

Well, I'll think about it.

Already have an older 205 I can rob the output from, so cost isn't really a factor, but then again, time and hassle involved with changing the output shaft needs to be considered as well I guess.

I love how projects that should be simple and quick end up costing double what they should have. T-case should have cost me $200, now we're up to $300 perhaps, and thats not including the electronic speedometer stuff, which may require a speed density injection setup. /forums/images/graemlins/smile.gif
 
Re: \'91 1 ton 205 front output flange?

pony up and get the driveshaft that matches your TC
 
Re: \'91 1 ton 205 front output flange?

Already got $150 into this shaft (don't ask) and it seems a waste to go with the superior setup when I won't get any use out of it, and it just costs me more money. Shafts already the right length, mates to the axle with a standard u-joint, just has the wrong t-case end on it.

I can have the 4L80E shaft cut down, but thats another $75 or so, compared to buying a yoke that fits, which will hopefully be less than that. On top of that, then I'm into adapter u-joints again, when I don't need/want to be.

I think I'm failing to see the point here though...why are you pushing using the newer setup so much? My truck spends 95% of the time on the road in 2wd, (and that's as a secondary driver anyways) when I use 4wd, 95% of THAT time is on snowy logging roads, so about 1% of the time the truck sees anything that is even close to being "wheeling". And with 10 bolts front and rear with no lift, you know I'm not as hard on it as many on the board are.

Not being argumentative, I'm just wondering where you are coming from. Money isn't an issue, but I would rather go the cheapest route that will get it done, if that makes sense. I haven't checked prices yet, so perhaps you know better than I what another yoke will cost, compared to having the shaft cut down.
 
Re: \'91 1 ton 205 front output flange?

the 10 spline stuff is really old, detracts from the value, limits your options
seems backward to reshaft the case, to an obsolete design, to save a few bucks on a driveshaft modification.
 
Re: \'91 1 ton 205 front output flange?

[ QUOTE ]
seems backward to reshaft the case, to an obsolete design, to save a few bucks on a driveshaft modification.

[/ QUOTE ]
Obsolete design vs. what? The one that's worked fine in the truck for 5 years? (plus the 15 years before that)

Only two reasons I'm swapping to the newer 205...32 spline input from the tranny, and the VSS on the tailshaft.

Other than that, truck is never going to be sold, and it will never see a Dana 60 up front.

Free input gear+time, vs. $75 front driveshaft mod. (or, yoke that will work with old driveline and new case) I'm of the opinion that my time will be worth more than swapping the input gears, even compared to the $75 driveshaft mod.

The newer flange design make it any easier to pull the shaft out?
 
Re: \'91 1 ton 205 front output flange?

10 spline output sucks.

Don't spend any money on it at all, or evne think about putting that junk in your case.

Just get a yoke. Let me know what size is on your driveshaft and I can price one for you, it's really not going to be that bad.
 
Re: \'91 1 ton 205 front output flange?

C'mon Tim, don't start that crap here, especially with me. I appreciate the offer, and may take you up on it, but the 10 spline has worked for 30 years in my case...I believe GM engineers understood my application far better than you are capable of understanding.

I understand the superiority of 32 spline versus 10 spline, you perhaps forget why I am going with a 32 spline 465, but if you can't comprehend my reasons, don't think that your answer is right for everyone.

I'm not going to explain my purpose again, if you refuse to read the previous posts, thats your problem.

I hope no one thinks that I disregard advice I don't like, rather, I dislike being told something that works perfectly fine (and has for as long as I've been alive) is worthless junk.

I don't get on you guys for cutting perfectly good sheet metal, or running huge tires, or anything else you do differently than I, so don't presume you know my application any better than I know yours.
 
Re: \'91 1 ton 205 front output flange?

i dont see what the big deal is...the 10 spline 205 came behind some 454, dana 60/14 bolt trucks. while it is a good idea to upgrade, if it will save you time and money, i would go for it. as long as they are interchangeable though...i would be pissd to find out they arent for some reason. good luck
 
Re: \'91 1 ton 205 front output flange?

[ QUOTE ]
I believe GM engineers understood my application far better than you are capable of understanding.

[/ QUOTE ]

If it worked, they wouldn't have changed it. You know it and I know it, GM changed things along the way to "better" their trucks, like the frame reinvorcement at the steering box in the early '80s, TBI, changing to a longer shackle on the 88-91 trucks, etc.

GM has always improved their trucks along the way. The 30 spline output is just another way that they have done it.

I never said you had to hack sheetmetal, run big tires, or beat on it. But the 30 spline output is superior, and it's a cheap/free upgrade for you right now.

I don't exactly agree with the use of a front shaft without a CV on your application either, but I didn't comment on that.
 
Re: \'91 1 ton 205 front output flange?

I was going to let this die as you seem all pissy for some reason but...

[ QUOTE ]
Obsolete design vs. what?

[/ QUOTE ]
look up the definition of the word "Obsolete"
1-[adj] no longer in use; "obsolete words"
2-[adj] old; no longer in use or valid or fashionable; "obsolete words"; "an obsolete locomotive"; "outdated equipment"; "superannuated laws"; "out-of-date ideas"

Pretty much sums up the 10 spline shaft.
No one truly gives a rats ass if you decide to run it, it is your ride, but you did ask for opinions and facts.
in my OPINION swapping a 10 spline mainshaft into a case that has the more desireable shaft is not good thinking and I would not recommend anyone go that course.
I have no idea where an adapter ujoint that you mentioned would go in a front shaft as chevy pretty much used the same small stuff in the front for decades and the yokes are everywhere.
so you want to run a beefy computer controlled auto OD but ancient front driveline.
seems a mismatch.
 
Re: \'91 1 ton 205 front output flange?

[ QUOTE ]
2-[adj] old; no longer in use or valid or fashionable

[/ QUOTE ]

I guess if I really want to get into it, this appears to be some folks definition of 30 spline stuff. "Fashionable" seems to be a perfect definition for something like 16 chromed shocks on a mall runner, or spending money on a driveshaft to go with 32 spline strength when it isn't needed, compared to spending $55 for a part that will solve the entire problem.

[ QUOTE ]

I was going to let this die as you seem all pissy for some reason but.

[/ QUOTE ]

You know, I was going to write up a long explanation of why I'm not "pissy", but apparently you too are made of gold, and throwing money at something is the ultimate solution, even when it isn't necessary. Reason doesn't apparently enter your vocabulary.

[ QUOTE ]
No one truly gives a rats ass if you decide to run it, it is your ride, but you did ask for opinions and facts.

[/ QUOTE ]

So where are the "facts"? We know 30 splines are stronger. Continue on as to what "facts" are relevant to my usage as compared to opinions that have worked on other vehicles.

I'd like either of you two champions of ultimate strength to explain why a 30 spline is a necessity in all applications. Go ahead and cite everyone with my driving habits that has destroyed a 10 spline 205 front output shaft.

Obviously, a $55 yoke keeping the newer output shaft is a better idea than swapping in the older 10 spline output.

[ QUOTE ]
so you want to run a beefy computer controlled auto OD but ancient front driveline.
seems a mismatch.

[/ QUOTE ]

I guess I *could* have the right to be pissy, as nowhere in my post did I mention I'm running a 4L80E, yet you ASSUMED I was, just like you ASSUMED I'm pissy.

My driveline will be crushed to know it is ancient, and therefore "obsolete". We might want to make a news bulletin for all the people running older 205's in their rigs, those obsolete 10 spline fronts and their driveshafts are no longer fashionable nor should they be in service.

It's rather humourous that both of you suggest the same idea, and I'm poised to use the suggestion, yet you both persist in the pursuit to crucify the 10 spline stuff for whatever reason.

Tim, I challenge you to find a service bulletin or recall that indicates it was such a large problem, as opposed to a potential problem due to any variety of factors outside of GM's control.
 
Re: \'91 1 ton 205 front output flange?

Ok, put in the 10 spline stuff. It rocks. /forums/images/graemlins/thumb.gif
 
Re: \'91 1 ton 205 front output flange?

If I may interrupt the little argument here...

I'm assuming the following is correct:
1) You have a '91 NP205 T-case with a 30 spline front input 4-bolt flange style yoke.

2) This transfer case is getting swapped into a '74, of which you have the old U-joint style front 10-spline yoke.

3) You have your front driveline all setup for the older style U-joint 10spline front yoke.

4) What tranny do you have (or are you running/will you be running) Ok, so this is a question, not an assumption.

If I'm correct in gathering that (and tell me if I'm not)... I believe I have pulled off 30 spline front yokes that were the U-joint style and not the 4-bolt flange style.

On 205's, the last year for 10 splines on the front output was 1976 I believe, and in '77 and newer rigs, they used the 30 spline.

The 30 spline front yokes I've pulled off and swapped around onto 205's before were off of 203 T-cases. I'm not 100% positive, but it seems like I do remember swapping a u-joint style front yoke off a 203 onto a 30 spline 205 a few years ago.

If this is the case, thats the yoke that you need that would simplify life... a mid 70's 203 front u-joint style yoke with 30 splines. Now, if I made one incorrect assumption, then pretty much all I said was worthless, which it may be anyway.
 
Re: \'91 1 ton 205 front output flange?

[ QUOTE ]
just like you ASSUMED I'm pissy

[/ QUOTE ]

that is not an assumption.
what did you post the thread in the form of a question for if you had already decided the course of action?
just do it and tell us how cool it is later.

did you need a flathead motor to go with that? heard they are the latest thing?
 
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